Abstract
Background
The Ringer perfusion catheter (Teleflex) features a novel design with a spiral-shaped inflatable balloon that approximates a hollow cylinder when inflated to manage hemorrhage associated with coronary artery perforation (CAP) during percutaneous coronary intervention while enabling distal perfusion.
Methods
In a multicenter, prospective, single-arm study, the safety and efficacy of using the Ringer device in the treatment of CAP were assessed. The primary efficacy end point included successful Ringer delivery across the perforation site, angiographic confirmation of no extravasation with balloon inflation, and demonstration of antegrade coronary flow. The primary safety end point was freedom from device-related thrombosis and coronary dissection. Clinical and angiographic outcomes were independently adjudicated.
Results
Among 30 patients with CAP, lesion characteristics included: chronic total occlusion, 50%; severe calcification, 63.3%; lesion length 34.1 ± 23.4 mm. Ellis type II and III perforations occurred in 50% and 30% of patients, respectively. For all patients, the primary efficacy end point was 73.3% by intention to treat analysis. However, among the 26 patients with successful Ringer delivery across the perforation site, the primary end point was 84.6%. In this latter group, acute resolution of contrast extravasation was 84.6%, and maintenance of thrombolysis in myocardial infarction 2/3 antegrade flow during device inflation was 100%. No device-related safety events were observed.
Conclusions
Treatment of CAP with a novel perfusion balloon catheter achieved favorable rates of deliverability and reduction in hemorrhage while maintaining antegrade flow. These results demonstrate that the Ringer perfusion catheter is a safe and effective method to manage CAP until definitive treatment is decided.
Keywords: balloon angioplasty, complications, coronary perforation
Introduction
Coronary artery perforation (CAP) is an uncommon but life-threatening complication of percutaneous coronary intervention (PCI) procedures that requires immediate treatment.1, 2, 3 Contemporary studies report an incidence of CAP between 0.34% and 0.71% among all PCI procedures,4, 5, 6, 7, 8 yet its occurrence is associated with considerable morbidity and mortality. Aside from the development of tamponade that requires pericardiocentesis,9, 10, 11 rates of mortality and/or need for emergency surgery may exceed 30%.12,13
Urgent treatment of CAP is essential, beginning with rapid and effective control of hemorrhage and thus the avoidance of pericardial tamponade and hemodynamic collapse. Current management of CAP ranges from prolonged balloon inflation, covered stent placement, therapeutic embolization, and reversal of anticoagulation after intracoronary equipment is removed. However, existing treatments are not reliably successful due in part to complex anatomy that both predisposes to CAP and interferes with the delivery of specific CAP therapies, in addition to a lack of readily available solutions.12 Despite being the most common and readily available maneuver, prolonged balloon inflation compromises myocardial perfusion distal to the perforation site, introducing ischemic injury and shortening tolerable inflation times.
Originally designed as a catheter that would permit prolonged balloon inflations without inducing ischemia, the Ringer perfusion balloon catheter (Teleflex) is a novel design rapid-exchange catheter with a spiral-shaped inflatable balloon that approximates a hollow cylinder when inflated. Specific to CAP, the catheter is designed to provide a physical barrier to seal perforated or ruptured coronary arteries and manage hemorrhage while enabling distal coronary perfusion. Because of the design characteristics with cylindrical balloon expansion, the device also permits the delivery of guide wires and catheters through its lumen if needed. No other devices exist that both manage CAP hemorrhage and provide distal coronary perfusion. To evaluate the safety and efficacy of this novel technology, a prospective, multicenter study was performed at centers according to exception from informed consent (EFIC) regulations for emergency research.
Methods
Device description
The Ringer perfusion balloon catheter is a 0.014-inch guidewire compatible, rapid-exchange catheter with a maximal crossing profile ranging from 0.050 to 0.062 inches. A Pebax balloon tube is configured in a helix that when inflated approximates a hollow cylinder that apposes the vessel wall but allows distal perfusion through the coil lumen (Figure 1). Radiopaque markers at the proximal and distal end of the balloon facilitate visualization and intravascular placement of the catheter prior to inflation. The device size matrix ranges from 2.0 mm to 5.0 mm stent diameters and lengths of 20 mm and 30 mm. Nominal and rated burst pressures are 6 atm and 8 atm, respectively.
Figure 1.
The Ringer coronary perfusion balloon catheter. The Ringer perfusion balloon catheter is a rapid-exchange catheter with a helical-shaped inflatable balloon on the distal end and a wire lumen for delivery over a ≤0.014-inch guidewire. The inflated spiral balloon approximates a hollow cylinder apposing the vessel wall, permitting antegrade coronary flow.
Study design and patient population
The Ringer study is a single-arm, prospective, multicenter investigational device exemption study (Clinicaltrials.gov; NCT04849169) performed with U.S. Food and Drug Administration oversight. Because CAP is an uncommon yet life-threatening event that requires emergency treatment, prospective identification of eligible patients and obtaining informed consent is not feasible. The study was therefore conducted in accordance with the EFIC regulations codified in 21 CFR 50.24 for emergency research and included preenrollment site-based community consultation and disclosure activities.14 The study protocol was approved by the institutional review board at each enrolling center, and the study was conducted in accordance with the Declaration of Helsinki.
Clinical and angiographic enrollment criteria were intentionally limited to include a broad survey of patients with CAP. Inclusion criteria were patients at least 18 years of age with angiographic confirmation of CAP as a complication of PCI. The only exclusion criterion was perforation location that might knowingly preclude complete balloon expansion or catheter placement. Patients experiencing CAP as a complication of PCI were treated with at least 1 Ringer perfusion balloon catheter and device sizing was selected according to the treating physician’s preference. The use of additional therapies to treat CAP (eg, covered stent placement, embolization, etc) was according to operator discretion.
Study objectives and end point definitions
The intent of the Ringer device was to cease hemorrhage at the perforation site while permitting antegrade coronary flow until a more definitive treatment was determined. The primary efficacy end point included the following: (1) successful Ringer delivery across the perforation site, (2) angiographic confirmation of no extravasation with balloon inflation (defined as residual Ellis grade 0 or 1 perforation), and (3) demonstration of Thrombolysis in Myocardial Infarction (TIMI) grade ≥2 antegrade coronary flow. The primary safety end point was the occurrence of device-related thrombosis and new or worsening coronary dissection related to Ringer device use.
Secondary end points included the development of cardiac tamponade and the need for pericardiocentesis, the performance of emergency surgery, and in-hospital occurrence of major adverse cardiac events (MACE; composite of all-cause death, myocardial infarction [MI] and clinically indicated target lesion revascularization by PCI or bypass surgery) and individual component end points. Procedural-related MI was defined according to the Society of Coronary Angiography and Interventions criteria.15
All data were submitted to a central data coordinating facility. An independent clinical events committee adjudicated all adverse events, and study conduct was supervised by an independent data safety monitoring committee. Coronary angiograms performed at baseline and follow-up, if clinically indicated, were reviewed by an independent angiographic core laboratory.
Statistical analyses
The primary analysis included all available data for all enrolled subjects and was conducted according to the principle of intention to treat. Given the absence of historical controls for devices intended for the temporary management of CAP, it is not possible to estimate a sample size for comparison with a performance goal or specific control group; therefore, a study population size of 30 patients was selected to represent a reasonable determination of safety and effectiveness considering the established performance of prolonged balloon angioplasty inflation, preclinical study and the well-understood technology of the device. Assessment of patient characteristics, procedural outcomes, and clinical events were prespecified and are reported as descriptive measures. No formal hypothesis testing was prespecified. Continuous variables are reported as mean ± SD and categorical variables as frequency, percentage, and 2-sided exact 95% CI. All analyses were performed with SAS version 9.4 or higher (SAS Institute).
The authors had full access and take full responsibility for the integrity of the data. The principal investigator and author (D.E.K.) had access to review and confirm all data and analyses and was responsible for drafting the manuscript.
Results
From July 2022 to December 2023, 30 patients experiencing CAP as a complication of PCI were enrolled at 4 participating centers. Baseline angiographic and clinical characteristics are summarized in Table 1, and selected individual clinical, angiographic, and procedural characteristics are listed in Supplemental Table S1. Overall, the prevalence of diabetes was 43.3%; prior MI was documented in 43.3% of patients; and more than half of patients underwent previous coronary revascularization (prior coronary artery bypass surgery, 26.7%; prior PCI, 46.7%). Perforations involving the left anterior descending artery were most common, and 50.0% and 63.3% of treated lesions involved a chronic total occlusion and severe calcification, respectively.
Table 1.
Baseline patient clinical and angiographic characteristics.
| Characteristics | N = 30 |
|---|---|
| Clinical characteristics | |
| Age, y | 73.5 ± 7.3 |
| Male sex | 80.0% (24) |
| Diabetes mellitus | 43.3% (13) |
| Hypertension | 86.7% (26) |
| History of smoking | 36.7% (11) |
| Hyperlipidemia | 93.3% (28) |
| Prior myocardial infarction | 43.3% (13) |
| Angina class III/IV | 53.3% (16) |
| Heart failure class III/IV | 13.3% (4) |
| Prior percutaneous revascularization | 46.7% (14) |
| Prior coronary bypass surgery | 26.7% (8) |
| Angiographic characteristics | |
| Target vessel | |
| Left main | 0 (0) |
| Left anterior descending artery | 43.3% (13) |
| Right coronary artery | 30.0% (9) |
| Left circumflex artery | 26.7% (8) |
| Reference vessel diameter, mm | 3.2 ± 0.4 |
| Severe calcification | 63.3% (19) |
| Severe tortuosity | 23.2% (7) |
| Chronic total occlusion | 50.0% (15) |
| Long lesions (>20 mm) | 56.7% (17) |
| Lesion length, mm | 34.1 ± 23.4 |
Values are mean ± SD or % (n). Angina and heart failure severity according to the Canadian Cardiovascular Society and New York Heart Association classification, respectively.
Perforation characteristics and management are detailed in Table 2. The Ellis classification of contrast extravasation for the population was assessed as type I (20.0%), type II (50.0%), and type III (30.0%). Mechanisms of perforation included balloon angioplasty (36.7%), stent placement (33.3%), guide wire (20.0%), and atherectomy (3.3%). In half of the cases, Ringer deployment was the initial method to manage hemorrhage followed by prolonged balloon inflation using a conventional angioplasty balloon. Following management of the perforation using the Ringer device, no further treatment was performed in nearly half of cases, and 40.0% of cases involved covered stent placement. Among 24 cases with Ellis grade 2/3 perforations, 10 patients (41.7%; type 3, n = 2 and type 2, n = 8) did not require additional therapy (eg, covered stent or other) to manage extravasation after prolonged inflation of the Ringer catheter (Figure 2). An additional 4 patients with type 1 perforation similarly required no further intervention following Ringer treatment. Pericardiocentesis was performed in 7 (23.3%) procedures at varying time points relative to Ringer use.
Table 2.
Perforation characteristics and management.
| Characteristics | N = 30 |
|---|---|
| Ellis perforation classification | |
| Type 1 | 20.0% (6) |
| Type 2 | 50.0% (15) |
| Type 3 | 30.0% (9) |
| Perforation mechanism | |
| Conventional angioplasty balloon | 36.7% (11) |
| Stent | 33.3% (10) |
| Guide wire | 20.0% (6) |
| Atherectomy | 3.3% (1) |
| Microcatheter | 3.3% (1) |
| Other/unknown | 6.7% (2) |
| Procedures to manage perforation prior to Ringer device | |
| None | 50.0% (15) |
| Conventional balloon inflation | 40.0% (12) |
| Reversal of anticoagulation | 3.3% (1) |
| Othera | 10.0% (3) |
| Procedures to manage perforation after Ringer device | |
| None | 46.7% (14) |
| Covered stent placement | 40.0% (12) |
| Conventional balloon inflation | 20.0% (6) |
| Reversal of anticoagulation | 20.0% (6) |
| Pericardiocentesis | 23.3% (7) |
Values expressed as percent (N) or mean ± SD.
Other treatments prior to Ringer include 2 subjects receiving stents and 1 subject treated with intentional vessel dissection.
Figure 2.
Management of perforation hemorrhage with the Ringer catheter. Baseline angiography demonstrating attempted guide wire crossing of right coronary artery chronic total occlusion (A). Coronary perforation identified (arrows) in the midsegment of the artery following successful guide wire crossing (B). The Ringer balloon inflated with the sealing of the perforation while maintaining thrombolysis in myocardial infarction 3 antegrade flow (C). Final angiogram following successful resolution of perforation with the Ringer catheter and requiring no additional treatment (D).
At least 2 Ringer perfusion balloon catheters were used in 5 cases (16.7%), and for all patients, the mean inflation time was 20.3 ± 12.9 minutes, with the longest inflation duration of 60 minutes. By intention to treat analysis for the entire study cohort, the primary efficacy end point occurred in 73.3% of patients (Table 3). Individual component end points included the following: successful Ringer delivery across the perforation site, 86.7%; angiographic confirmation of extravasation sealing, 73.3%; and TIMI grade 2/3 antegrade flow during Ringer inflation, 86.7% (Central Illustration). In the 4 instances of failed Ringer delivery, lesion characteristics included severe calcification (n = 3) and excessive tortuosity (n = 1). Among the 26 procedures with successful Ringer catheter delivery across the perforation site, the primary efficacy end point was 84.6%. Confirmation of extravasation sealing and TIMI 2/3 flow during inflation increased to 84.6% and 100.0%, respectively. No device-related safety events were observed.
Table 3.
Procedural outcomes associated with the Ringer perfusion balloon catheter.
| Outcomes | N = 30 |
|---|---|
| ≥2 Ringer devices used | 16.7% (5/30) |
| Maximum balloon pressure, atm | 9.1 ± 3.3 (30) |
| Total inflation time, min | 20.3 ± 12.9 (30) |
| Primary efficacy end point, intent to treat (N = 30) | 73.3% (22) |
| Successful Ringer delivery across perforation site | 86.7% (26) |
| Angiographic confirmation of extravasation sealing | 73.3% (22) |
| TIMI grade 2/3 antegrade flow during Ringer inflation | 86.7% (26) |
| Primary efficacy end point, assessable subjects | 84.6% (22/26) |
| Successful Ringer delivery across perforation site | 100% (26/26) |
| Angiographic confirmation of extravasation sealing | 84.6% (22/26) |
| TIMI grade 2/3 antegrade flow during Ringer inflation | 100.0% (26/26) |
| Ringer device-related thrombosis | 0 (0/30) |
| New or worsening Ringer device-related coronary dissection | 0 (0/30) |
Values expressed as % (n/N) or mean ± SD (n).
atm, atmospheres; TIMI, Thrombolysis in Myocardial Infarction.
Central Illustration.
Primary end point results of the Ringer perfusion balloon catheter coronary perforation study. RCA, right coronary artery; TIMI, thrombolysis in myocardial infarction.
Among these 30 CAP events, overall MACE occurred in 3 (10.0%) patients (Table 4). In-hospital mortality was 10.0%, and emergency cardiac surgery was infrequent (1 patient, 3.3%) related to right ventricular perforation during the performance of pericardiocentesis. Causes of death were attributed to cardiogenic shock and/or arrest secondary to the following: (1) a second coronary perforation during the index procedure not treated with the Ringer device, (2) MI, and (3) iatrogenic right ventricular perforation.
Table 4.
In-hospital clinical outcomes.
| Outcomes | N = 30 |
|---|---|
| Major adverse cardiac events | 10.0% (3) |
| Death | 10.0% (3) |
| Myocardial infarction | 3.3% (1) |
| Clinically-driven target lesion revascularization | 0 (0) |
| Emergency surgery | 3.3% (1) |
Values expressed as % (n).
Discussion
In a multicenter, prospective study of patients treated for CAP in the setting of real-world practice, the use of the Ringer perfusion balloon catheter was associated with favorable delivery and successful sealing of the perforation site while maintaining antegrade coronary flow during prolonged durations of inflation. Specifically, among procedures with successful catheter delivery across the perforation site, cessation of contrast extravasation was 84.6%, and maintenance of TIMI 2/3 flow was 100%. These findings support the use of the Ringer perfusion catheter as a safe and effective method to manage CAP until definitive treatment is determined.
As a rare but potentially fatal complication of PCI, CAP necessitates immediate control of hemorrhage at the perforation site, yet methods to achieve hemostasis and avoid hemodynamic collapse are often challenged by deliverability across the site of bleeding in often complex anatomy, limited effectiveness of existing maneuvers, and lack of readiness with available technologies. Accordingly, the use of conventional balloon angioplasty catheters to cover the perforation site remains a mainstay of initial management, yet prolonged balloon inflation often leads to ischemia and patient discomfort with subsequent hemodynamic instability and ischemic myocardial injury. In a complicated rescue setting where many simultaneous actions are taken, protracted ischemia may be so significant that mechanical circulatory support is required. A balloon catheter that permits sealing of the perforation while maintaining coronary flow may therefore simplify workflow and avoid secondary complications.
Although an infrequent event, the incidence of coronary perforation has not declined over time, a finding that may reflect the increasing patient and lesion complexity with contemporary PCI.3,5 At present, no approved devices exist with the indication to manage hemorrhage associated with CAP while providing distal coronary perfusion. As a solution to address this unmet need, the Ringer perfusion balloon catheter is a novel design catheter with a helical-shaped inflatable balloon that approximates a hollow cylinder when inflated. The catheter is designed to provide a physical barrier to seal perforated or ruptured coronary arteries and mitigate hemorrhage while enabling distal coronary perfusion. The low-profile design may not only enable passage through tortuous or calcified anatomy but also permit compatibility with the contemporary use of small-caliber guiding catheters and guide catheter extensions. Uniquely, the cylindrical design of the catheter also permits simultaneous advancement of additional guide wires or catheters (eg, covered stent delivery to the perforation site while continuously maintaining hemostasis). Although not evaluated in this study, 2 Ringer catheters could also be deployed in tandem to seal an extensive tear in an artery or bypass graft. Notably, as a device intended to cease bleeding at the perforation site until a more definitive treatment is decided, no further intervention was required in nearly half of the cases following prolonged inflation of the Ringer perfusion catheter.
Some unique aspects of this study merit further comment regarding conduct and design that challenge new device technology evaluation. Because the study involved the use of a device without prior usage in humans, the study was performed with FDA oversight. However, because CAP is an unpredictable, rare, and yet life-threatening event that requires emergency treatment, prospective identification of eligible patients and obtaining informed consent is not feasible. Such challenges have been previously described in non-US–based trials involving acute MI and shock.16,17 Therefore, the study was performed in accordance with the EFIC regulations codified in 21 CFR 50.24 for emergency research and included preenrollment site-based community consultation and disclosure activities that are unfamiliar to most coronary device trials.
As a single-arm, observational study, this analysis has important limitations, in part related to the limited sample size that precludes any definitive conclusions of safety and efficacy. Comparisons with alternative device therapies were also not available nor were the intent of the study; whether the Ringer perfusion catheter reduces the need for pericardiocentesis and improves outcome is unstudied, although rates of in-hospital mortality are consistent with other observational studies.5,9,18 Further, follow-up beyond the index hospitalization was not intended for this study to assess Ringer's performance as a management strategy during the procedure.
Conclusion
Among patients experiencing CAP as a complication of PCI, the use of the Ringer perfusion catheter is an effective intervention associated with favorable delivery to the perforation site, cessation of extravasation, and maintenance of coronary flow during device inflation. These results endorse the addition of this technology to existing methods to treat coronary perforation with the potential to reduce the high morbidity and mortality associated with this event.
Acknowledgments
The authors are grateful to Sherry Lane, an employee of Teleflex, Inc, and Hannah Bearinger, an employee of Bright Research, for their assistance with data management and trial conduct.
Peer review statement
Editor-in-Chief Alexandra J. Lansky had no involvement in the peer review of this article and has no access to information regarding its peer review. Full responsibility for the editorial process for this article was delegated to Associate Editor Cindy L. Grines.
Declaration of competing interest
David E. Kandzari has received institutional research and grant support from Biotronik, Boston Scientific, Medtronic, Orbus Neich, and Teleflex; and has received personal consulting honoraria from Medtronic and Boston Scientific. Mohammad Alqarqaz and William J. Nicholson report no relevant disclosures. Kathleen E. Kearney has received consulting honoraria from Abiomed, Abbott, Boston Scientific, Medtronic, and Teleflex. Christopher E. Buller is an employee of Teleflex, Inc. Ecaterina Cristea and Alexandra Lansky receive institutional research support from Teleflex.
Funding sources
This work was supported by Teleflex, Inc.
Ethics statement and patient consent
The study was conducted in accordance with the exception from informed consent (EFIC) regulations codified in 21 CFR 50.24 for emergency research and included preenrollment site-based community consultation and disclosure activities.
Footnotes
To access the supplementary material accompanying this article, visit the online version of the Journal of the Society for Cardiovascular Angiography & Interventions at 10.1016/j.jscai.2025.103575.
Supplementary material
References
- 1.Hendry C., Fraser D., Eichhofer J., et al. Coronary perforation in the drug-eluting stent era: incidence, risk factors, management and outcome: the UK experience. EuroIntervention. 2012;8(1):79–86. doi: 10.4244/EIJV8I1A13. [DOI] [PubMed] [Google Scholar]
- 2.Lansky A.J., Yang Y.M., Khan Y., et al. Treatment of coronary artery perforations complicating percutaneous coronary intervention with a polytetrafluoroethylene-covered stent graft. Am J Cardiol. 2006;98(3):370–374. doi: 10.1016/j.amjcard.2006.02.041. [DOI] [PubMed] [Google Scholar]
- 3.Eeckhout E., De Palma R. Coronary perforation: an inconvenient complication. JACC Cardiovasc Interv. 2011;4(1):96–97. doi: 10.1016/j.jcin.2010.09.021. [DOI] [PubMed] [Google Scholar]
- 4.Parsh J., Seth M., Green J., et al. Coronary artery perforations after contemporary percutaneous coronary interventions: evaluation of incidence, risk factors, outcomes, and predictors of mortality. Catheter Cardiovasc Interv. 2017;89(6):966–973. doi: 10.1002/ccd.26917. [DOI] [PubMed] [Google Scholar]
- 5.Harnek J., James S., Lagerqvist B. Coronary artery perforation and tamponade ― incidence, risk factors, predictors and outcomes from 12 years' data of the SCAAR Registry. Circ J. 2019;84(1):43–53. doi: 10.1253/circj.CJ-19-0757. [DOI] [PubMed] [Google Scholar]
- 6.Lemmert M.E., van Bommel R.J., Diletti R., et al. Clinical characteristics and management of coronary artery perforations: a single-center 11-year experience and practical overview. J Am Heart Assoc. 2017;6(9) doi: 10.1161/JAHA.117.007049. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Guttmann O.P., Jones D.A., Gulati A., et al. Prevalence and outcomes of coronary artery perforation during percutaneous coronary intervention. EuroIntervention. 2017;13(5):e595–e601. doi: 10.4244/EIJ-D-16-01038. [DOI] [PubMed] [Google Scholar]
- 8.Shaukat A., Tajti P., Sandoval Y., et al. Incidence, predictors, management and outcomes of coronary perforations. Catheter Cardiovasc Interv. 2019;93(1):48–56. doi: 10.1002/ccd.27706. [DOI] [PubMed] [Google Scholar]
- 9.Al-Lamee R., Ielasi A., Latib A., et al. Incidence, predictors, management, immediate and long-term outcomes following grade III coronary perforation. JACC Cardiovasc Interv. 2011;4(1):87–95. doi: 10.1016/j.jcin.2010.08.026. [DOI] [PubMed] [Google Scholar]
- 10.Fasseas P., Orford J.L., Panetta C.J., et al. Incidence, correlates, management, and clinical outcome of coronary perforation: analysis of 16,298 procedures. Am Heart J. 2004;147(1):140–145. doi: 10.1016/s0002-8703(03)00505-2. [DOI] [PubMed] [Google Scholar]
- 11.Cerrato E., Pavani M., Barbero U., et al. Incidence, management, immediate and long-term outcome of guidewire and device related grade III coronary perforation (from G3CAP - Cardiogroup VI Registry) Am J Cardiol. 2021;143:37–45. doi: 10.1016/j.amjcard.2020.12.041. [DOI] [PubMed] [Google Scholar]
- 12.Briguori C., Nishida T., Anzuini A., Di Mario C., Grube E., Colombo A. Emergency polytetrafluoroethylene-covered stent implantation to treat coronary ruptures. Circulation. 2000;102(25):3028–3031. doi: 10.1161/01.cir.102.25.3028. [DOI] [PubMed] [Google Scholar]
- 13.Javaid A., Buch A.N., Satler L.F., et al. Management and outcomes of coronary artery perforation during percutaneous coronary intervention. Am J Cardiol. 2006;98(7):911–914. doi: 10.1016/j.amjcard.2006.04.032. [DOI] [PubMed] [Google Scholar]
- 14.U.S. Food and Drug Administration Exception from informed consent requirements for emergency research. Guidance for institutional review boards, clinical investigators, and sponsors. 2013. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/exception-informed-consent-requirements-emergency-research
- 15.Moussa I.D., Klein L.W., Shah B., et al. Consideration of a new definition of clinically relevant myocardial infarction after coronary revascularization: an expert consensus document from the Society for Cardiovascular Angiography and Interventions (SCAI) J Am Coll Cardiol. 2013;62(17):1563–1570. doi: 10.1016/j.jacc.2013.08.720. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Shahzad A., Kemp I., Mars C., et al. Unfractionated heparin versus bivalirudin in primary percutaneous coronary intervention (HEAT-PPCI): an open-label, single centre, randomised controlled trial. Lancet. 2014;384(9957):1849–1858. doi: 10.1016/S0140-6736(14)60924-7. [DOI] [PubMed] [Google Scholar]
- 17.Møller J.E., Engstrøm T., Jensen L.O., et al. Microaxial flow pump or standard care in infarct-related cardiogenic shock. N Engl J Med. 2024;390(15):1382–1393. doi: 10.1056/NEJMoa2312572. [DOI] [PubMed] [Google Scholar]
- 18.Kandzari D.E., Sarao R.C., Waksman R. Clinical experience of the PK Papyrus covered stent in patients with coronary artery perforations: Results from a multi-center humanitarian device exemption survey. Cardiovasc Revasc Med. 2022;43:97–101. doi: 10.1016/j.carrev.2022.04.009. [DOI] [PubMed] [Google Scholar]
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