Use of Temporary Mechanical Circulatory Support for Management of Cardiogenic Shock Before and After the United Network for Organ Sharing Donor Heart Allocation System Changes

Anubodh S Varshney; David D Berg; Jason N Katz; Vivian M Baird-Zars; Erin A Bohula; Anthony P Carnicelli; Sunit-Preet Chaudhry; Jianping Guo; Patrick R Lawler; Jose Nativi-Nicolau; Shashank S Sinha; Jeffrey J Teuteberg; Sean van Diepen; David A Morrow

doi:10.1001/jamacardio.2020.0692

. 2020 Apr 15;5(6):1–6. doi: 10.1001/jamacardio.2020.0692

Use of Temporary Mechanical Circulatory Support for Management of Cardiogenic Shock Before and After the United Network for Organ Sharing Donor Heart Allocation System Changes

Anubodh S Varshney ¹, David D Berg ¹, Jason N Katz ^2,^3,⁴, Vivian M Baird-Zars ¹, Erin A Bohula ¹, Anthony P Carnicelli ⁴, Sunit-Preet Chaudhry ⁵, Jianping Guo ¹, Patrick R Lawler ^6,⁷, Jose Nativi-Nicolau ⁸, Shashank S Sinha ⁹, Jeffrey J Teuteberg ¹⁰, Sean van Diepen ^11,¹², David A Morrow ^1,^✉, for the Critical Care Cardiology Trials Network Investigators

¹Levine Cardiac Intensive Care Unit, Thrombolysis in Myocardial Infarction (TIMI) Study Group, Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts

²Division of Cardiology, Center for Heart and Vascular Care, University of North Carolina, Chapel Hill

³Division of Pulmonary and Critical Care Medicine, Center for Heart and Vascular Care, University of North Carolina, Chapel Hill

⁴Duke Clinical Research Institute, Duke University School of Medicine, Durham, North Carolina

⁵Department of Cardiology, St. Vincent Hospital, Indianapolis, Indiana

⁶Division of Cardiology, Peter Munk Cardiac Centre, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada

⁷Interdepartmental Division of Critical Care Medicine, Peter Munk Cardiac Centre, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada

⁸Division of Cardiovascular Medicine, University of Utah School of Medicine, Salt Lake City

⁹Inova Heart and Vascular Institute, Inova Fairfax Medical Center, Falls Church, Virginia

¹⁰Department of Medicine, Stanford University School of Medicine, Stanford, California

¹¹Department of Critical Care, University of Alberta, Edmonton, Alberta, Canada

¹²Division of Cardiology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada

Group Information: The Critical Care Cardiology Trials Network investigators are listed at the end of this article.

Accepted for Publication: February 22, 2020.

^✉

Corresponding Author: David A. Morrow, MD, MPH, Levine Cardiac Intensive Care Unit, Thrombolysis in Myocardial Infarction (TIMI) Study Group, Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, 60 Fenwood Rd, Ste 7022, Boston, MA 02115 (dmorrow@bwh.harvard.edu).

Published Online: April 15, 2020. doi:10.1001/jamacardio.2020.0692

Author Contributions: Drs Varshney and Berg contributed equally to this work. Drs Varshney and Morrow had full access to all the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: Varshney, Berg, Katz, Bohula, Nativi-Nicolau, van Diepen, Morrow.

Acquisition, analysis, or interpretation of data: All authors.

Drafting of the manuscript: Varshney, Berg, Katz, Baird-Zars, Sinha, Morrow.

Critical revision of the manuscript for important intellectual content: Varshney, Berg, Katz, Bohula, Carnicelli, Chaudhry, Guo, Lawler, Nativi-Nicolau, Sinha, Teuteberg, van Diepen, Morrow.

Statistical analysis: Varshney, Berg, Baird-Zars, Carnicelli, Guo.

Obtained funding: van Diepen.

Administrative, technical, or material support: Varshney, Berg, Baird-Zars, Carnicelli, Nativi-Nicolau, van Diepen.

Supervision: Katz, Bohula, Lawler, Morrow.

Conflict of Interest Disclosures: Dr Katz reported receiving research support from Abbott Corporation outside the submitted work. Dr Carnicelli reported receiving grants from the National Institutes of Health during the conduct of the study. Dr Berg, Dr Bohula, Ms Baird-Zars, Dr Guo, and Dr Morrow reported serving as a member of the TIMI Study Group, which has received institutional research grant support through Brigham and Women's from Abbott Laboratories, Amgen, AstraZeneca, Critical Diagnostics, Daiichi-Sankyo, Eisai, Genzyme, Gilead, GlaxoSmithKline, Intarcia, Janssen Research and Development, Medicines Company, MedImmune, Merck, Novartis, Pfizer, Poxel, Roche Diagnostics, and Takeda. Dr Nativi-Nicolau’s institution received funding for clinical trials for Pfizer, Akcea, and Eidos and educational grants from Pfizer. Dr Nativi-Nicolau has been a consultant for Pfizer, Eidos, Akcea, and Alnylam. Dr Sinha reported receiving personal fees from Abiomed outside the submitted work. Dr Teuteberg reported receiving personal fees from Abiomed, Medtronic, Abbott, CareDx, and EcoR1 outside the submitted work. No other disclosures were reported.

Group Information: CCCTN Executive Committee: David A. Morrow, MD, MPH, Jason N. Katz, MD, MHS, Sean van Diepen, MD, MSc. CCCTN Steering Committee: Gregory W. Barsness, MD, Christopher B. Granger, MD, Steven M. Hollenberg, MD, James D. Horowitz, MD, Venu Menon, MD, Robert O. Roswell, MD, Michael A. Solomon, MD. CCCTN Data Coordinating Center (TIMI Study Group): Marc S. Sabatine, MD, MPH (TIMI Study Group chairman), David A. Morrow, MD MPH (TIMI principal investigator), Erin A Bohula, MD, DPhil (coinvestigator), David D. Berg, MD (coinvestigator), Vivian Baird-Zars, MPH (project manager/data manager), Sabina A. Murphy, MPH (director of statistics), Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts. Collaborating Centers: Brigham and Women’s Hospital, Boston, Massachusetts: E. Bohula, MD, DPhil (principal investigator), D. Morrow, MD, MPH (coinvestigator), D. Silva, RN, BSN, MPH (research coordinator). Duke University, Durham, North Carolina: C. Granger, MD (principal investigator), K. Newby, MD (coprincipal investigator), K. Brown, RN, A. Carnicelli, MD, T. Granger, R. Harrison, MD, J. Katz, MD, P. Kendersky, MD (subinvestigators). Cleveland Clinic Foundation, Cleveland, Ohio: V. Menon, MD (principal investigator), M. Kaur, MD (subinvestigator), P. Cremer, MD (investigator), K. Rutkowski, RN (nurse coordinator). Cooper University Hospital, Camden, New Jersey: S. Hollenberg, MD (principal investigator), A. Bakhshi, MD, MPH, E. Caruso, MD, J. Cruz, DO, D. Ricketti, MD, J. Weinstock, MD (subinvestigators). INOVA Fairfax Hospital/INOVA Heart and Vascular Institute, Falls Church, Virginia: S. Sinha, MD (principal investigator), A. Raja, BS, A. Vyas, MBBS (research coordinators). Johns Hopkins Hospital, Baltimore, Maryland: T. Metkus, MD (principal investigator), S. Schulman, MD (co–principal investigator), D. Ambinder, MD, E. Dugan, MD (research fellows). Lehigh Valley Health Network, Allentown, Pennsylvania: J. Burke, MD (principal investigator), R. Biggs, MD, S. Vadhar, MD (subinvestigators), K. Cornell, RN, BSN (research coordinator). Mayo Clinic, Rochester, Minnesota: G. Barsness, MD (principal investigator), J. Gladden, MD, J. Jentzer, MD (subinvestigators). Medstar Washington Hospital Center, Washington, DC: C. Barnett, MD, MPH (principal investigator), A. Brown, PA-C, B. Kenigsberg, MD, A. Papolos, MD (subinvestigators). National Institutes of Health, Bethesda, Maryland: M. Solomon, MD (principal investigator), S. Brusca, MD, N. Rassekh, MD (subinvestigators). New York University Langone Health, New York, New York: N. Keller, MD (principal investigator), C. Alviar, MD (coinvestigator), B. Li, MD (subinvestigator), D. Petit Del, PA-C, K. Selig, PA-C (research coordinators). Northwell Health, Lenox Hill, New York, New York: R. Roswell, MD (principal investigator), J. Alzate, A. Delicce, A. Prince, J. Toole, DO (subinvestigators), K. Coleman, S. Karkal, MPH (research coordinators). Rush University Medical Center, Chicago, Illinois: J. Snell, MD (principal investigator), I. Atallah, MD, S. Devanesan, N. Jahan, MBBS, S. Majid, MBBS (research coordinators). Stanford Hospital & Clinics, Stanford, California: J. Teuteberg, MD (principal investigator), D. Gerber, MD (co–principal investigator). St. Vincent Indianapolis/St. Vincent Heart Center of Indiana, Indianapolis: S. P. Chaudhry, MD (principal investigator), A. Patel, MD (subinvestigator), B. Wendling, RN, BSN (research coordinator). Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada: P. Lawler, MD, MPH (principal investigator), M. Mahanta, MBBS, A. Rungta, MBBS (research coordinators). University of Alberta, Edmonton, Alberta, Canada: S. van Diepen, MD, MSc (principal investigator), W. Tymchak, MD (co–principal investigator), N. Hogg, RN (research coordinator). University of Florida, Gainesville: E. Keeley, MD (principal investigator), G. Bhattal, MD, N. Gargus, MD, D. Leach, DNP, ARNP-C, C. Nallapati, MD, M. Saifee, DO (subinvestigators), S. Long, RN, BSN (primary coordinator), J. Bostick, M. Mohammed (research coordinators). University of California San Diego, La Jolla: L. Daniels, MD, MAS (principal investigator), N. Phreaner, MD (subinvestigator), P. Anzenberg, C. Belza, D. Coskey, T. Getz, J. Gonzalez, V. Lizak, J. Panian, R. Sedighi, L. Smith, G. Stewart, A. Toomu, BS, S. Toomu (research coordinators). University of Louisville, Louisville, Kentucky: A.P. DeFilippis, MD, MSc (principal investigator), N. Barry, MD, N. Singam, MD (research fellows), S. Vincent, RN, MSN (study nurse). University of North Carolina, Chapel Hill: J. Katz, MD (past principal investigator), C. Dangerfield, RN, MSN, CNL, CCRN-K, R. Orgel, MD (subinvestigator), Z. Ozen, RN, E. Prosser, RN (investigators), T. Wade (research coordinator). University of Utah Health, Salt Lake City: J. Nativi-Nicolau, MD (principal investigator), J. Fang, MD (subinvestigator), J. Hong, A. Siu, J. Chaney (research coordinators). Virginia Commonwealth University, Richmond: M. Kontos, MD (principal investigator), S. Dow, MD, C. Vo, MD (subinvestigator), D. Spillman (research coordinator). Yale University, New Haven, Connecticut: J. Brennan, MD (principal investigator), E. Miller, MD (subinvestigator).

Meeting Presentation: This study was presented at the ACC 2020: American College of Cardiology 69th Scientific Session and Expo; March 29, 2020 (online).

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Corresponding author.

PMCID: PMC7160750 PMID: 32293644

This cohort study examines the association of revisions to the United Network for Organ Sharing donor heart allocation system with use of temporary mechanical circulatory support and whether temporary mechanical circulatory support use differed between US transplant centers and US nontransplant centers and Canadian centers.

Key Points

Question

Was implementation of the new United Network for Organ Sharing (UNOS) donor heart allocation system associated with changes in the use of temporary mechanical circulatory support for the management of cardiogenic shock in tertiary cardiac intensive care units, and did use differ between US transplant centers and US nontransplant centers and Canadian centers?

Findings

In this cohort study from 14 centers in North America, among 384 patients admitted with acute, decompensated, heart failure–related cardiogenic shock, the use of temporary mechanical circulatory support increased significantly in US transplant centers but not in other cardiac intensive care units and not for other forms of cardiogenic shock in the year after the UNOS donor heart allocation system revisions.

Meaning

Changes in the UNOS donor heart allocation system may have been associated with changes in practitioners’ management strategies for patients with acute, decompensated, heart failure–related cardiogenic shock at US transplant centers.

Abstract

Importance

The new United Network for Organ Sharing (UNOS) donor heart allocation system gives priority to patients supported with nondischargeable mechanical circulatory support (MCS) devices while awaiting heart transplant. Whether there has been a change in temporary MCS use in cardiac intensive care units (CICUs) since the implementation of this policy is unknown.

Objectives

To examine whether the UNOS donor heart allocation system revision in October 2018 was associated with changes in temporary MCS use in CICUs and whether temporary MCS use differed between US transplant centers and US nontransplant centers and Canadian centers.

Design, Setting, and Participants

In this cohort study, 14 centers from the Critical Care Cardiology Trials Network (CCCTN), a multicenter network of tertiary CICUs in North America, contributed 2-month snapshots of consecutive medical CICU admissions between September 1, 2017, and September 1, 2018 (prerevision period), and October 1, 2018, and September 1, 2019 (postrevision period). CICUs were classified as US transplant centers (n = 7) or other CICUs (US nontransplant centers or Canadian centers; n = 7).

Exposure

Revision to the UNOS donor heart allocation system.

Main Outcomes and Measures

Treatment with temporary MCS (intra-aortic balloon pump, microaxial intracardiac ventricular assist device, percutaneous centrifugal ventricular assist device, venoarterial extracorporeal membrane oxygenation, or surgically implanted, nondischargeable MCS device) during hospital admission.

Results

A total of 384 admissions for acute, decompensated, heart failure–related cardiogenic shock (ADHF-CS) were included, among which 248 (64.6%) were to US transplant centers; 126 admissions (51%) were in the prerevision period and 122 (49%) were in the postrevision period. The mean (SD) patient age was 61.2 (14.6) years; 246 patients (64.1%) were male. The proportion of admissions with ADHF-CS managed with temporary MCS at US transplant centers significantly increased from 25.4% (32 of 126 admissions) before to 42.6% (52 of 122 admissions) after the UNOS allocation system changes (P = .004). In other CICUs, the proportion did not significantly change (24.5% [13 of 53 admissions] to 24.1% [20 of 83 admissions]; P = .95). After multivariable adjustment, patients admitted to US transplant centers in the postrevision period were more likely to receive temporary MCS compared with those admitted in the prerevision period (adjusted odds ratio, 2.19; 95% CI, 1.13-4.24; P = .02).

Conclusions and Relevance

In the year after implementation of the new UNOS donor heart allocation system, temporary MCS use in patients admitted with ADHF-CS increased in US transplant centers but not in other CICUs. Whether this shift in practice will affect outcomes of patients with ADHF-CS or organ distribution should be evaluated.

Introduction

In October 2018, the United Network for Organ Sharing (UNOS) changed its donor heart allocation system in an effort to reduce mortality among patients on a waiting list.¹ Patients treated with temporary, nondischargeable mechanical circulatory support (MCS) had the highest waitlist mortality and thus received the highest priority under the new system. Specifically, UNOS status 1 now includes patients supported with venoarterial extracorporeal membrane oxygenation (VA-ECMO) or surgically implanted, nondischargeable MCS devices, and UNOS status 2 includes support with intra-aortic balloon pump (IABP) or percutaneous MCS devices (eg, microaxial intracardiac ventricular assist device). Patients supported only with inotropes are assigned a lower status (eTable 1 in the Supplement).

Although the new allocation system addresses limitations of the prior system, prioritization of patients treated with temporary MCS may incentivize transplant centers to use these devices as a bridge to transplant. In an analysis from the UNOS registry, patients undergoing orthotopic heart transplant (OHT) after the revision were more likely to have received temporary MCS before OHT.² However, because that study² was limited to OHT recipients, whether greater temporary MCS use after the revision reflected the prioritization of these patients in the new system or whether there was a shift in the treatment of patients with cardiogenic shock (CS) more broadly was unknown.

Whereas decision-making regarding MCS device implantation in patients with acute myocardial infarction (AMI)–related CS is most often obligated before evaluation for advanced heart failure therapies, MCS decision-making in patients with acute, decompensated, heart failure (ADHF)–related CS is more likely to take into account OHT candidacy. Thus, the treatment strategy of patients with ADHF-CS may have changed after the UNOS system revision. Using data from the Critical Care Cardiology Trials Network (CCCTN) Registry, we assessed whether patients with ADHF-CS admitted to US transplant centers after the 2018 UNOS heart allocation system changes were more likely to receive temporary MCS compared with before the change.

Methods

This cohort study used data from the CCCTN, an investigator-initiated, collaborative research network coordinated by the Thrombolysis in Myocardial Infarction (TIMI) Study Group of American Heart Association Level I cardiac intensive care units (CICUs)³ in North America. The CCCTN Registry design is described elsewhere.⁴ A total of 14 centers contributed data on all consecutive medical CICU admissions during a 2-month period between September 1, 2017, and September 1, 2018, and another 2-month period between October 1, 2018, and September 1, 2019. The protocol and waiver of informed consent were approved by each center’s institutional review board. Consent was waived by the institutional review boards because of the minimal risk associated with inclusion in the registry, and all data were deidentified.

Patients with CS in the CCCTN Registry were characterized based on having primary ventricular failure (ischemic or nonischemic) or an alternative cause (eg, incessant arrhythmia or severe valvular disease). Ischemic ventricular dysfunction was further stratified as AMI or not.⁵ Because we anticipated a priori that the care of patients with ADHF-CS would more likely be associated with the UNOS system changes, the present analysis focused on this cohort, defined as CS due to ventricular failure excluding AMI or postcardiotomy CS. Patients with AMI-CS and mixed shock were analyzed separately (eMethods in the Supplement). Patients were classified as being in the pre-UNOS allocation system revision period (September 1, 2017, to September 1, 2018) or postrevision period (October 1, 2018, to September 1, 2019). Centers were classified as US transplant centers (n = 7) or other CICUs (US nontransplant centers or Canadian centers; n = 7). Even though Canadian centers in the CCCTN perform OHT, these centers were classified as other CICUs because donor heart allocation in Canada is dictated by a system developed by the Canadian Cardiac Transplant Network.⁶ Temporary MCS devices included IABP, microaxial intracardiac ventricular assist device (Impella [2.5, CP, 5.0, or RP types]), percutaneous centrifugal ventricular assist device (TandemHeart), VA-ECMO, and surgically implanted, nondischargeable MCS device (eg, CentriMag).

Statistical Analysis

Admissions documented as receiving a temporary MCS device during the prerevision and postrevision periods were compared and stratified by transplant center status. A logistic regression model was used to adjust for potential confounders. Among patients who received treatment with multiple devices, a hierarchical classification scheme was used with the following order: (1) a surgically implanted, biventricular MCS device, (2) VA-ECMO, (3) microaxial pump or percutaneous centrifugal ventricular assist device, and (4) IABP. All analyses were performed with SAS software, version 9.4 (SAS Institute Inc). A 2-sided P ≤ .05 was considered to be statistically significant.

Results

A total of 384 admissions for ADHF-CS were included, among which 248 (64.6%) were to US transplant centers; 126 admissions (51%) were in the prerevision periods and 122 (49%) were in the postrevision period. The mean (SD) patient age was 61.2 (14.6) years, and 246 (64.1%) were male. Patient characteristics stratified by timing relative to the UNOS changes and transplant center status were generally similar (Table 1). Pulmonary artery (PA) catheter use increased in US transplant centers in the year after the UNOS changes. After multivariable adjustment, admissions documented as receiving temporary MCS were more likely to have PA catheters (adjusted odds ratio, 4.58; 95% CI, 2.61-8.04; P < .001).

Table 1. Characteristics of Acute, Decompensated, Heart Failure–Related Cardiogenic Shock Admissions Before and After United Network for Organ Sharing Heart Donor Allocation System Changes by Transplant Center Status^a.

Characteristic	US transplant centers			Other CICUs
Characteristic	Before revision (n = 126)	After revision (n = 122)	P value	Before revision (n = 53)	After revision (n = 83)	P value
Demographics
Age, median (IQR), y	63 (54-73)	61 (53-68)	.09	65 (58-72)	63 (53-74)	.78
Female	48 (38.1)	39 (32.0)	.31	20 (37.7)	31 (37.3)	.96
Nonwhite race	47 (37.3)	59 (48.4)	.13	15 (28.3)	20 (24.1)	.78
BMI, median (IQR)	27.6 (23.1-32.1)	28.0 (23.8-31.1)	.77	29.8 (26.2-32.9)	27.5 (23.5-31.5)	.05
Comorbidities
Current smoker	17 (13.5)	12 (9.8)	.57	7 (13.2)	13 (15.7)	.05
Diabetes mellitus	41 (32.5)	37 (30.3)	.71	21 (39.6)	30 (36.1)	.68
Coronary artery disease	52 (41.3)	51 (41.8)	.93	25 (47.2)	30 (36.1)	.20
Cerebrovascular disease	9 (7.1)	8 (6.6)	.86	3 (5.7)	6 (7.2)	>.99
Peripheral artery disease	12 (9.5)	6 (4.9)	.16	7 (13.2)	12 (14.5)	.84
Prior heart failure	86 (68.3)	99 (81.1)	.02	38 (71.7)	65 (78.3)	.38
Severe valvular disease	10 (7.9)	25 (20.5)	.01	10 (18.9)	19 (22.9)	.58
Chronic kidney disease	45 (35.7)	43 (35.2)	.94	26 (49.1)	30 (36.1)	.14
Significant pulmonary disease	24 (19.0)	26 (21.3)	.66	10 (18.9)	19 (22.9)	.58
Significant liver disease	6 (4.8)	5 (4.1)	>.99	2 (3.8)	5 (6.0)	.71
Active cancer	14 (11.1)	7 (5.7)	.13	4 (7.5)	5 (6.0)	.74
Illness severity
SOFA score, median (IQR)	7 (5-10)	7.5 (5-11)	.21	8 (6-11)	6 (4-10)	.02
Preceding cardiac arrest	21 (16.7)	23 (18.9)	.65	10 (18.9)	12 (14.5)	.50
Maximum No. of inotropes and vasopressors^b
0	6 (4.8)	5 (4.1)	.99	1 (1.9)	8 (9.6)	.27
1	50 (39.7)	50 (41.0)		26 (49.1)	43 (51.8)
≥2	69 (54.8)	67 (54.9)		26 (49.1)	32 (38.6)
Mechanical ventilatory support	52 (41.3)	48 (39.3)	.76	20 (37.7)	23 (27.7)	.22
Short-term kidney replacement therapy	21 (16.7)	23 (18.9)	.65	7 (13.2)	15 (18.1)	.45
Pulmonary artery catheter	34 (27.0)	69 (56.6)	<.001	23 (43.4)	43 (51.8)	.34
Serum lactate level, median (IQR), mg/dL	30.63 (16.22-58.56)	26.13 (15.32-48.65)	.27	24.32 (26.13-62.16)	32.43 (30.63-50.45)	.52
Serum creatinine level, median (IQR), mg/dL	1.7 (1.4-3.1)	2.1 (1.4-3.1)	.40	2.1 (1.6-3.2)	2.2 (1.6-3.4)	.55

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Abbreviations: BMI, body mass index (calculated as weight in kilograms divided by height in meters squared); CICU, cardiac intensive care unit; IQR, interquartile range; SOFA, Sequential Organ Failure Assessment.

SI conversion factors: To convert lactate to millimoles per liter, multiply by 0.111; creatinine to micromoles per liter, multiply by 88.4.

^{^a}

Data are presented as number (percentage) of patients unless otherwise indicated. Categorical variables were compared with χ² test or Fisher exact test, and continuous variables were compared with the Wilcoxon rank sum test.

^{^b}

One patient in the US transplant centers prerevision group had an unknown value for maximum number of inotropes and vasopressors.

The proportion of admissions of patients with ADHF-CS who received temporary MCS at US transplant centers increased after the UNOS changes (25.4% [32 of 126 admissions] in the prerevision period vs 42.6% [52 of 122 admissions] in the postrevision period; P = .004) (Figure, A). In other CICUs, the proportion did not significantly change (24.5% [13 of 53 admissions] in the prerevision period vs 24.1% [20 of 83 admissions] in the postrevision period; P = .95). When we excluded the only site that contributed data from October 1 to October 17, 2018, the results were similar (eTable 2 in the Supplement). After adjusting for age, prior heart failure, severe valvular disease, Sequential Organ Failure Assessment score, lactate level, preceding cardiac arrest, maximum number of inotropes and vasopressors, mechanical ventilatory support, short-term kidney replacement therapy, current smoking, and active cancer, admissions of patients in the postrevision period at US transplant centers were more likely to receive temporary MCS compared with admissions in the prerevision period (adjusted odds ratio, 2.28; 95% CI, 1.17-4.47; P = .02). In US transplant centers, use of each of the temporary MCS devices increased with the exception of VA-ECMO (Table 2 and Figure, B).

Figure. — A, Temporary MCS use before and after United Network for Organ Sharing (UNOS) donor heart allocation system changes. B, Device use by type at US transplant centers before and after UNOS donor heart allocation system changes. IABP indicates intra-aortic balloon pump; PVAD, percutaneous centrifugal ventricular assist device; and VA-ECMO, venoarterial extracorporeal membrane oxygenation.

Table 2. Temporary MCS Use Before and After United Network for Organ Sharing Donor Heart Allocation System Changes Among Acute, Decompensated, Heart Failure–Related Cardiogenic Shock Admissions to US Transplant Centers.

MCS use	Admissions, No. (%)
MCS use	Prerevision group (n = 126)	Postrevision group (n = 122)
Any temporary MCS use	32 (25.4)	52 (42.6)
IABP	25 (19.8)	31 (25.4)
Percutaneous centrifugal ventricular assist device	0	5 (4.1)
Microaxial intracardiac ventricular assist device	3 (2.4)	9 (7.4)
VA-ECMO	4 (3.2)	5 (4.1)
Surgically implanted, nondischargeable MCS device	0	2 (1.6)

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Abbreviations: IABP, intra-aortic balloon pump; MCS, mechanical circulatory support; VA-ECMO, venoarterial extracorporeal membrane oxygenation.

In patients admitted to US transplant centers with AMI-CS (n = 117) or mixed shock (n = 126), temporary MCS use did not change (eTable 3 in the Supplement). Temporary MCS use was numerically higher in the postrevision period among admissions with AMI-CS treated in other CICUs compared with admissions with AMI-CS in the prerevision period in the same CICUs; this difference was not statistically significant when tested in the primary logistic regression model (69.8% vs 49.0%; P = .06). In ADHF-CS admissions to US transplant centers, the falsification end points of mechanical ventilatory support and kidney replacement therapy use did not differ in patients admitted in the postrevision period vs prerevision period (eTable 4 in the Supplement).

Discussion

In this analysis from the CCCTN Registry, we found a significant increase in temporary MCS use among patients with ADHF-CS in US transplant centers but not in other CICUs and not for other forms of CS in the year after the UNOS allocation system changes. The increase in US transplant centers occurred despite similar patient characteristics during the study period. This finding suggests that the prioritization of temporary MCS devices in the new UNOS heart allocation system may have a causal influence on the management strategy for patients with ADHF-CS at US transplant centers. As we anticipated, use of temporary MCS did not change for patients with AMI-CS at US transplant centers, likely owing to the timing of decision-making before an evaluation for advanced heart failure therapies.⁷ Similar to prior studies,^8,9 IABP was the most commonly used temporary MCS device despite a lack of supporting data from randomized clinical trials.¹⁰ PA catheter use also increased significantly in US transplant centers in the year after the UNOS revision. By providing quantitative metrics of cardiac performance, PA catheter use may have been associated with decisions to use MCS. Conversely, PA catheter use may have increased because of higher MCS use or to facilitate transplant wait-listing by defining hemodynamic status.

Our findings add to an analysis² of post-UNOS change outcomes in OHT recipients, among whom pretransplant temporary MCS use increased from 10% to 41%. Of importance, our study complements prior data among OHT recipients and found that since the UNOS system changes patients with ADHF-CS at US transplant centers have been increasingly receiving treatment with temporary MCS. Because temporary MCS device use is resource intensive and associated with risks, the effect of increasing use on clinical outcomes will be important to delineate. Other researchers^11,12 have reported possible increased costs, adverse events, and mortality associated with advanced temporary MCS in patients with AMI-CS. Our finding of increased MCS use in the absence of new supporting data suggests the need for additional evidence to guide management strategies for ADHF-CS.

Limitations

Our study should be interpreted in the context of several limitations. First, the sample size of 384 ADHF-CS admissions is limited, affecting the confidence limits around our estimates. Second, patients treated exclusively in cardiac surgical ICUs are not captured in the registry, which may affect estimates of temporary MCS use, especially use of VA-ECMO and surgical devices. Nevertheless, this limitation applies to both study periods and thus would not be expected to have a differential effect in the postrevision period. Third, the UNOS changes were implemented on October 18, 2018, whereas the postrevision group includes admissions from October 1, 2018 onward. However, the results were similar when the only site that contributed data from October 1 to October 17, 2018 was excluded. Fourth, the data set did not capture transplant listing status, which could have further clarified whether the observed change in temporary MCS use was present among all patients with ADHF-CS or restricted to those listed for transplant only. Fifth, although we examined 2 consecutive years and did not observe a change in temporary MCS use in nontransplant centers or for forms of CS other than ADHF-CS in US transplant centers, we are unable to completely exclude an influence of secular temporal trends in MCS use. However, several falsification analyses supported the robustness of our primary finding.

Conclusions

In patients admitted to CICUs with ADHF-CS, temporary MCS use increased in US transplant centers but not in other CICUs in the year after the UNOS donor heart allocation system changes. The effect of this shift on outcomes and organ distribution in patients with ADHF-CS should be evaluated.

Supplement.

eTable 1. Revised UNOS Donor Heart Allocation System Statuses and Criteria

eTable 2. Rate of Temporary Mechanical Circulatory Support Use in ADHF-CS Admissions Before and After UNOS Heart Transplantation Allocation System Changes Excluding One Site That Contributed Data From October 1, 2018 – October 17, 2018

eTable 3. Temporary Mechanical Circulatory Support Use (%) Before and After UNOS Heart Transplantation Allocation System Changes in Various Patient Cohorts by Transplant Center Status

eTable 4. Adjusted Odds of Mechanical Ventilation and Acute Renal Replacement Therapy in Use in ADHF-CS Patients Admitted to US Transplant Centers Admissions After Versus Before UNOS Heart Transplantation Allocation System Changes

eMethods. Shock Definitions

Click here for additional data file.^{(166.5KB, pdf)}

References

1.US Department of Health and Human Services, Organ Procurement and Transplantation Network Adult heart allocation. June 15, 2019. Accessed December 1, 2019. https://optn.transplant.hrsa.gov/learn/professional-education/adult-heart-allocation/
2.Cogswell R, John R, Estep JD, et al. An early investigation of outcomes with the new 2018 donor heart allocation system in the United States. J Heart Lung Transplant. 2020;39(1):1-4. doi: 10.1016/j.healun.2019.11.002 [DOI] [PubMed] [Google Scholar]
3.Morrow DA, Fang JC, Fintel DJ, et al. ; American Heart Association Council on Cardiopulmonary, Critical Care, Perioperative and Resuscitation, Council on Clinical Cardiology, Council on Cardiovascular Nursing, and Council on Quality of Care and Outcomes Research . Evolution of critical care cardiology: transformation of the cardiovascular intensive care unit and the emerging need for new medical staffing and training models: a scientific statement from the American Heart Association. Circulation. 2012;126(11):1408-1428. doi: 10.1161/CIR.0b013e31826890b0 [DOI] [PubMed] [Google Scholar]
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6.Canadian Cardiac Transplant Network. February 11, 2020. Accessed February 16, 2020. https://www.ccs.ca/en/affiliate-societies/cctn-home
7.Malick W, Fried JA, Masoumi A, et al. Comparison of the hemodynamic response to intra-aortic balloon counterpulsation in patients with cardiogenic shock resulting from acute myocardial infarction versus acute decompensated heart failure. Am J Cardiol. 2019;124(12):1947-1953. doi: 10.1016/j.amjcard.2019.09.016 [DOI] [PMC free article] [PubMed] [Google Scholar]
8.Berg DD, Barnett CF, Kenigsberg BB, et al. Clinical practice patterns in temporary mechanical circulatory support for shock in the Critical Care Cardiology Trials Network (CCCTN) Registry. Circ Heart Fail. 2019;12(11):e006635. doi: 10.1161/CIRCHEARTFAILURE.119.006635 [DOI] [PMC free article] [PubMed] [Google Scholar]
9.Strom JB, Zhao Y, Shen C, et al. Hospital variation in the utilization of short-term nondurable mechanical circulatory support in myocardial infarction complicated by cardiogenic shock. Circ Cardiovasc Interv. 2019;12(1):e007270. doi: 10.1161/CIRCINTERVENTIONS.118.007270 [DOI] [PMC free article] [PubMed] [Google Scholar]
10.Thiele H, Zeymer U, Neumann F-J, et al. ; IABP-SHOCK II Trial Investigators . Intraaortic balloon support for myocardial infarction with cardiogenic shock. N Engl J Med. 2012;367(14):1287-1296. doi: 10.1056/NEJMoa1208410 [DOI] [PubMed] [Google Scholar]
11.Amin AP, Spertus JA, Curtis JP, et al. The evolving landscape of Impella® use in the United States among patients undergoing percutaneous coronary intervention with mechanical circulatory support. Circulation. 2020;141(4):273-284. doi: 10.1161/CIRCULATIONAHA.119.044007 [DOI] [PubMed] [Google Scholar]
12.Dhruva SS, Ross JS, Mortazavi BJ, et al. Association of use of an intravascular microaxial left ventricular assist device vs intra-aortic balloon pump with in-hospital mortality and major bleeding among patients with acute myocardial infarction complicated by cardiogenic shock. JAMA. Published online February 10, 2020. doi: 10.1001/jama.2020.0254 [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Supplement.

eTable 1. Revised UNOS Donor Heart Allocation System Statuses and Criteria

eTable 3. Temporary Mechanical Circulatory Support Use (%) Before and After UNOS Heart Transplantation Allocation System Changes in Various Patient Cohorts by Transplant Center Status

eMethods. Shock Definitions

Click here for additional data file.^{(166.5KB, pdf)}

[hbr200001r1] 1.US Department of Health and Human Services, Organ Procurement and Transplantation Network Adult heart allocation. June 15, 2019. Accessed December 1, 2019. https://optn.transplant.hrsa.gov/learn/professional-education/adult-heart-allocation/

[hbr200001r2] 2.Cogswell R, John R, Estep JD, et al. An early investigation of outcomes with the new 2018 donor heart allocation system in the United States. J Heart Lung Transplant. 2020;39(1):1-4. doi: 10.1016/j.healun.2019.11.002 [DOI] [PubMed] [Google Scholar]

[hbr200001r3] 3.Morrow DA, Fang JC, Fintel DJ, et al. ; American Heart Association Council on Cardiopulmonary, Critical Care, Perioperative and Resuscitation, Council on Clinical Cardiology, Council on Cardiovascular Nursing, and Council on Quality of Care and Outcomes Research . Evolution of critical care cardiology: transformation of the cardiovascular intensive care unit and the emerging need for new medical staffing and training models: a scientific statement from the American Heart Association. Circulation. 2012;126(11):1408-1428. doi: 10.1161/CIR.0b013e31826890b0 [DOI] [PubMed] [Google Scholar]

[hbr200001r4] 4.Bohula EA, Katz JN, van Diepen S, et al. ; Critical Care Cardiology Trials Network . Demographics, care patterns, and outcomes of patients admitted to cardiac intensive care units: the Critical Care Cardiology Trials Network prospective North American multicenter registry of cardiac critical illness. JAMA Cardiol. 2019;4(9):928-935. doi: 10.1001/jamacardio.2019.2467 [DOI] [PMC free article] [PubMed] [Google Scholar]

[hbr200001r5] 5.Berg DD, Bohula EA, van Diepen S, et al. Epidemiology of shock in contemporary cardiac intensive care units. Circ Cardiovasc Qual Outcomes. 2019;12(3):e005618. doi: 10.1161/CIRCOUTCOMES.119.005618 [DOI] [PMC free article] [PubMed] [Google Scholar]

[hbr200001r6] 6.Canadian Cardiac Transplant Network. February 11, 2020. Accessed February 16, 2020. https://www.ccs.ca/en/affiliate-societies/cctn-home

[hbr200001r7] 7.Malick W, Fried JA, Masoumi A, et al. Comparison of the hemodynamic response to intra-aortic balloon counterpulsation in patients with cardiogenic shock resulting from acute myocardial infarction versus acute decompensated heart failure. Am J Cardiol. 2019;124(12):1947-1953. doi: 10.1016/j.amjcard.2019.09.016 [DOI] [PMC free article] [PubMed] [Google Scholar]

[hbr200001r8] 8.Berg DD, Barnett CF, Kenigsberg BB, et al. Clinical practice patterns in temporary mechanical circulatory support for shock in the Critical Care Cardiology Trials Network (CCCTN) Registry. Circ Heart Fail. 2019;12(11):e006635. doi: 10.1161/CIRCHEARTFAILURE.119.006635 [DOI] [PMC free article] [PubMed] [Google Scholar]

[hbr200001r9] 9.Strom JB, Zhao Y, Shen C, et al. Hospital variation in the utilization of short-term nondurable mechanical circulatory support in myocardial infarction complicated by cardiogenic shock. Circ Cardiovasc Interv. 2019;12(1):e007270. doi: 10.1161/CIRCINTERVENTIONS.118.007270 [DOI] [PMC free article] [PubMed] [Google Scholar]

[hbr200001r10] 10.Thiele H, Zeymer U, Neumann F-J, et al. ; IABP-SHOCK II Trial Investigators . Intraaortic balloon support for myocardial infarction with cardiogenic shock. N Engl J Med. 2012;367(14):1287-1296. doi: 10.1056/NEJMoa1208410 [DOI] [PubMed] [Google Scholar]

[hbr200001r11] 11.Amin AP, Spertus JA, Curtis JP, et al. The evolving landscape of Impella® use in the United States among patients undergoing percutaneous coronary intervention with mechanical circulatory support. Circulation. 2020;141(4):273-284. doi: 10.1161/CIRCULATIONAHA.119.044007 [DOI] [PubMed] [Google Scholar]

[hbr200001r12] 12.Dhruva SS, Ross JS, Mortazavi BJ, et al. Association of use of an intravascular microaxial left ventricular assist device vs intra-aortic balloon pump with in-hospital mortality and major bleeding among patients with acute myocardial infarction complicated by cardiogenic shock. JAMA. Published online February 10, 2020. doi: 10.1001/jama.2020.0254 [DOI] [PMC free article] [PubMed] [Google Scholar]

PERMALINK

Use of Temporary Mechanical Circulatory Support for Management of Cardiogenic Shock Before and After the United Network for Organ Sharing Donor Heart Allocation System Changes

Anubodh S Varshney, MD

David D Berg, MD

Jason N Katz, MD, MHS

Vivian M Baird-Zars, MPH

Erin A Bohula, MD, DPhil

Anthony P Carnicelli, MD

Sunit-Preet Chaudhry, MD

Jianping Guo, MAS

Patrick R Lawler, MD, MPH

Jose Nativi-Nicolau, MD

Shashank S Sinha, MD, MSc

Jeffrey J Teuteberg, MD

Sean van Diepen, MD, MSc

David A Morrow, MD, MPH

Key Points

Question

Findings

Meaning

Abstract

Importance

Objectives

Design, Setting, and Participants

Exposure

Main Outcomes and Measures

Results

Conclusions and Relevance

Introduction

Methods

Statistical Analysis

Results

Table 1. Characteristics of Acute, Decompensated, Heart Failure–Related Cardiogenic Shock Admissions Before and After United Network for Organ Sharing Heart Donor Allocation System Changes by Transplant Center Statusa.

Figure. Temporary Mechanical Circulatory Support (MCS) Use in US Transplant Centers and Other Cardiac Intensive Care Units (CICUs).

Table 2. Temporary MCS Use Before and After United Network for Organ Sharing Donor Heart Allocation System Changes Among Acute, Decompensated, Heart Failure–Related Cardiogenic Shock Admissions to US Transplant Centers.

Discussion

Limitations

Conclusions

References

Associated Data

Supplementary Materials

ACTIONS

PERMALINK

RESOURCES

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Links to NCBI Databases

Table 1. Characteristics of Acute, Decompensated, Heart Failure–Related Cardiogenic Shock Admissions Before and After United Network for Organ Sharing Heart Donor Allocation System Changes by Transplant Center Status^a.