Days at Home after Transcatheter versus Surgical Aortic Valve Replacement in Low-Risk Patients

Abstract

Background:

Days at Home (DAH) represents an important patient-oriented outcome that quantifies time spent at home after a medical event; however, this outcome has not been fully evaluated for low surgical-risk patients undergoing transcatheter aortic valve replacement (TAVR). We sought to compare 1- and 2-year DAH (DAH_365, DAH₇₃₀) among low-risk patients participating in a randomized trial of TAVR with a self-expanding bioprosthesis versus surgical aortic valve replacement (SAVR).

Methods:

Using Medicare-linked data from the Evolut Low Risk Trial we identified 619 patients; 606 (322 TAVR/284 SAVR) and 593 (312 TAVR/281 SAVR) were analyzed at 1- and 2-years, respectively. DAH was calculated as days alive and spent outside a hospital, inpatient rehabilitation, skilled nursing facility, long-term acute care hospital, emergency department, or observation stay. Mean DAH was compared using the t-test.

Results:

Mean (SD) age and female sex were 74.7 (5.1) and 74.3 (4.9) years and 34.6% (115/332) and 30.3% (87/287) in TAVR and SAVR, respectively. Post-procedural discharge to rehabilitation occurred in ≤3.0% (≤10/332) in TAVR and 4.5% (13/287) in SAVR. Mean DAH₃₆₅ was comparable in TAVR vs. SAVR (352.2±45.4 vs. 347.8±39.0, difference-in-days 4.5 [95% CI −2.3, 11.2], p=0.20). DAH₇₃₀ was also comparable in TAVR vs. SAVR (701.6±106.0 vs. 699.6±94.5; difference-in-days 2.0 [-14.1, 18.2], p=0.81). Secondary outcomes DAH₃₀ and DAH₉₀ were higher in TAVR (DAH_30:26.0±3.6 vs. 20.7±6.4, difference-in-days 5.3 [4.5, 6.2], p<0.001; DAH₉₀:85.1±8.3 vs. 78.7±13.6, difference-in-days 6.4 [4.6, 8.2], p<0.001).

Conclusions:

In the Evolut Trial linked to Medicare, low-risk patients undergoing TAVR spend a similar number of days at home at 1- and 2-years compared with SAVR. Days spent at home at 30 and 90 days were higher in TAVR. In contrast to higher-risk patients studied in prior work, there is no clear advantage of TAVR vs. SAVR for DAH in the first 2 years after AVR in low surgical-risk patients.

Introduction

In patients with severe, symptomatic aortic stenosis at low surgical risk, transcatheter aortic valve replacement (TAVR) with a self-expanding valve is non-inferior to surgical aortic valve replacement (SAVR) for the outcome of combined stroke and death.¹ While TAVR is a viable alternative to surgery in this population, other outcomes such as valve durability, permanent pacemaker use, and functional status may be crucial for shared decision-making in these relatively young and healthy patients. Days at home (DAH), defined as the time a patient spends alive and out of a healthcare facility, is an important patient-centered outcome associated with postoperative complications² and quality of life.³ DAH is also associated with functional outcomes, particularly in post-stroke patients where it has been found to strongly correlate with formal measures of function including the modified Rankin Scale.^4–6 This emerging outcome may be important to individuals with severe aortic stenosis seeking to maximize post-procedural functional status and independence, and thus could potentially aid in the decision-making for the mode of aortic valve replacement. We previously examined DAH in high-⁷ and intermediate-risk⁸ patients using the U.S. CoreValve High Risk Trial and the Surgical or Transcatheter Aortic-Valve Replacement in Intermediate-Risk Patients (SURTAVI) trial linked with Medicare claims and found that in the first year after the procedure, high-risk patients undergoing TAVR had approximately 27 additional DAH compared with SAVR and that intermediate-risk patients had approximately 15 more DAH compared with the surgical group. These differences were primarily due to longer post-procedural lengths of stay, excess mortality days, and more facility days after initial discharge including time in skilled nursing facilities (SNFs). However, little is known about the impact of AVR in low-risk patients on DAH. To address this gap in knowledge, we linked the Evolut Low Risk trial to Medicare claims to compare DAH at 1- and 2-years (DAH₃₆₅, DAH₇₃₀) among low-risk patients with symptomatic, severe aortic stenosis randomized to receive TAVR versus SAVR.

Methods

This post-hoc analysis was supported by an investigator-initiated research grant from Medtronic and was approved by the Institutional Review Board at Beth Israel Deaconess Medical Center. The authors are solely responsible for the design and conduct of this study, all study analyses, the drafting and editing of the paper and its final contents. The data that support the findings of this study will not be made available. The methods used will be made available on reasonable request.

Our study cohort was derived from patients undergoing TAVR or SAVR from the Evolut Low Risk trial.¹ The Evolut Low Risk trial was a randomized clinical trial of self-expanding TAVR vs. SAVR in low-risk patients. This trial occurred from March 28, 2016 to November 27, 2018 and involved 86 centers in the United States, Canada, France, the Netherlands, Japan, Australia, and New Zealand. The Evolut Low Risk Trial dataset was linked to the Centers for Medicare and Medicaid Services (CMS) Medicare Provider Analysis and Review (MedPAR) files, which capture 100% of inpatient discharge (Part A) claims for Medicare fee-for-service beneficiaries. Patients were linked with indirect identifiers using deterministic matching algorithms based on age, sex, procedure date and type, discharge date, and hospital identifiers as previously described.^9–11 We excluded patients who could not be linked to MedPAR files, which included those patients younger than 65 years of age and those who underwent the index procedure at a hospital outside the United States. Medicare Advantage beneficiaries, who are included in MedPAR files but have incomplete capture of healthcare claims,¹² were also excluded from the analysis.

Demographic and comorbidity data were available from the Evolut Low Risk Trial, which included age, sex, body mass index (BMI), New York Heart Association class, Society of Thoracic Surgeons Predicted Risk of Mortality (STS-PROM) score, diabetes mellitus, serum creatinine, hypertension, peripheral arterial disease, previous coronary artery bypass graft (CABG) or percutaneous coronary intervention, preexisting pacemaker/defibrillator, myocardial infarction, and atrial fibrillation/flutter.

The primary outcomes were DAH₃₆₅ and DAH₇₃₀.¹³ We determined the number of inpatient (index hospitalization and readmission), inpatient rehabilitation, SNF, and long-term acute care hospital (LTAC) days using MedPAR files, which contain claims with associated institutional admission and discharge dates, for 2016–2020. Missing discharge dates for SNF stays occurred in 8.5% [11/129] of the cohort. These missing dates suggest CMS benefit exhaustion (CMS covers 100 SNF days per benefit period after which the beneficiary pays for care; a new benefit period begins after 60 consecutive days without inpatient or SNF care) and in these instances, the CMS-covered length of stay, which is calculated using the last day on the billing statement covering services rendered to the beneficiary, was used to calculate SNF days. Emergency department (ED) and observation stays were identified using CMS Outpatient files. Mortality was determined by the presence of a death date in Master Beneficiary Summary files. As a data source distinct from trial data, these administrative claims files capture the healthcare utilization of all linked trial participants including those lost to follow up or who withdrew from the study.

DAH₃₆₅ was calculated using mortality and healthcare facility data from the date of the index procedure (day 0) to 365 days after the procedure.^7,8 We calculated DAH₃₆₅ for each patient in the following manner:¹³ DAH₃₆₅ = 365 – (Mortality days + Inpatient days + Rehabilitation days + SNF days + LTAC days + ED days + Observation days). “Mortality days,” representing the number of days lost to mortality by each patient, were defined as the number of days remaining in the calendar year following the date of death. For example, for DAH₃₆₅, a patient who was alive 1 year after the procedure would have zero mortality days while a patient who died 100 days after the procedure would have 265 mortality days. Inpatient, rehabilitation, SNF, and LTAC days were defined as the total number of days during the first post-procedural year that the patient spent in these respective settings. ED or observations days overlapping with a readmission were counted as inpatient days and ED visits overlapping with observation claims were counted as observation days in order to count the most severe of the overlapping events; this method is similar to that used by CMS to count Publicly Reported Condition-Specific Excess Days in Acute Care.¹⁴ Each isolated ED visit was counted as 1 day.¹³ Each observation claim was counted as 1 day. DAH₇₃₀ was calculated in a similar manner.

Secondary outcomes of interest included 30- and 90-day DAH (DAH₃₀, DAH₉₀). Subgroup analyses were performed for age, sex, BMI, diabetes, coronary artery disease (including prior CABG, percutaneous intervention, and myocardial infarction), peripheral vascular disease, and prior atrial fibrillation at outcomes for 1 year. To illustrate the different post-procedural courses, we computed the proportion of patients with 1) discharge to home- and non-home locations after the index hospitalization, 2) no additional facility days after discharge alive from the index hospitalization, and 3) zero DAH, which represents patients who died after the procedure without any home days either during the index hospitalization or in the post-acute care setting. Rates of facility use by patients were analyzed by calculating the numbers of patients from each group who experienced any time in a particular healthcare facility.

Cell counts ≤ 10 were redacted as per the data use agreement with the Centers for Medicare and Medicaid Services.¹⁵ Baseline patient characteristics were reported as percentages for categorical data and mean±standard deviation (SD) for continuous variables. The distributions of DAH were summarized using mean, SD, median, and interquartile range (IQR), and range. Differences between groups were tested by the 2-sample t-test for continuous variables and Chi-squared or Fisher’s exact test for categorical variables. The rate of accumulation of mean DAH was plotted over 1 year with a close up of 0–30 days and a landmark analysis at 31–90 days analyzing survivors at 30 days and their days at home to 90 days; the rate of accumulation of mean DAH was also plotted over 2 years. Differences between treatment groups among subgroups were reported as mean±standard error (SE). All analyses were conducted in SAS version 9.4 (Cary, North Carolina) using a 2-tailed p-value < 0.05 to define significance.

Results

One thousand four hundred and fourteen participants in the Evolut Low Risk trial were initially considered for inclusion and 274 patients were excluded (age < 65 years, procedure at hospital outside of United States; TAVR: 141/727 [19.4%] SAVR: 133/686 [19.4%]) (Figure S1). Of the remaining 1139 patients (TAVR: 586, SAVR: 553), 252 were unable to be linked to CMS (TAVR: 95/586 [16.2%], SAVR: 157/553 (28.4%]) resulting in 887 patients successfully linked to MedPAR (TAVR: 491, SAVR: 396) Individuals whose trial records could be linked to Medicare claims were similar to individuals whose records were unable to be linked (Table S1).

Table 1.

Baseline Characteristics of Evolut Low Risk Trial Participants Linked to Medicare Claims

Characteristic	TAVR (N =332)	SAVR (N =287)	p-value
Age, years – mean (SD)	74.7±5.1	74.3±4.9	0.35
Female sex – no. (%)	115 (34.6)	87 (30.3)	0.27
Body mass index (kg/m2) – mean (SD)	30.8±5.9	30.7±5.3	0.88
NYHA class – no. (%)			0.01
Class I	44 (13.3)	23 (8.0)
Class II	211 (63.6)	170 (59.2)
Class III	77 (23.2)	92 (32.1)
Class IV	≤10 (≤3.0)*	≤10 (≤3.5)
STS-PROM score - mean % (SD)	2.0±0.6	1.9±0.6	0.10
Diabetes mellitus – no. (%)	99 (29.8)	76 (26.5)	0.37
Insulin dependent	12 (3.6)	≤10 (≤3.5)	0.83
Serum creatinine (mg/dl) – mean (SD)	1.2±4.5	1.0±0.2	0.31
Hypertension – no. (%)	276 (83.4)	230 (80.4)	0.35
Peripheral arterial disease – no. (%)	31 (3.0)	20 (7.0)	0.31
Cardiac risk factors – no. (%)
Prior CABG	≤10 (≤3.0)	≤10 (≤3.5)	0.43
Prior PCI	50 (15.1)	31 (10.8)	0.12
Preexisting pacemaker/defibrillator	12 (3.6)	11 (3.8)	1.00
Prior myocardial infarction	17 (5.1)	13 (4.5)	0.85
Prior atrial fibrillation or flutter	55 (16.6)	42 (14.7)	0.58

CABG, coronary artery bypass graft; NYHA, New York Heart Association; PCI, percutaneous coronary intervention; SAVR, surgical aortic valve replacement; STS-PROM, Society of Thoracic Surgeons Predicted Risk of Mortality; TAVR, transcatheter aortic valve replacement. Data on hypertension were available for 331 patients in the TAVR group and 286 patients in the SAVR group; peripheral arterial disease, 328 and 287, respectively; prior atrial fibrillation or flutter, 331 and 286, respectively.

^*Cell counts ≤ 10 have been redacted as per the data use agreement with the Centers for Medicare and Medicaid Services.

Two hundred sixty-eight Medicare Advantage records (TAVR: 32.4% [159/491], SAVR: 27.5% [109/396]) were excluded resulting in the availability of 619 fee-for-service records (43.8%; 619/1414). Of these 619 patients, 332 patients were randomized to TAVR and 287 patients were randomized to SAVR. The cohorts available for analysis of days at home at 1-year and 2-years after the procedure (patients who had fee-for-service coverage during the entire follow-up time or up to time of death) were 606 and 593, respectively.

Baseline characteristics of the TAVR and SAVR groups were similar (Table 1). The mean age in the TAVR and SAVR groups were 74.7±5.1 and 74.3±4.9 years, respectively. The mean STS-PROM scores were 2.0±0.6 and 1.9±0.6 in the TAVR and SAVR groups. Patients undergoing TAVR had a shorter index length of stay (LOS) compared with SAVR (3.4±1.9 vs. 7.0±2.9 days, difference in days −3.7, [95% CI −4.1, −3.3], p<0.001). The proportion of in-hospital death was <1% across the entire cohort. Discharge to home occurred in 96.7% (321/332) of TAVR (77.7% home, 19.0% home with health services) and in 84.0% (241/287) of SAVR patients (32.4% home, 51.6% home with health services). Discharge to inpatient rehabilitation occurred in ≤3.0% (≤10/332) of patients undergoing TAVR and 4.5% (13/287) patients undergoing SAVR. Discharge to a SNF occurred in ≤3.0% (≤10/332) in TAVR and 9.4% (27/287) in SAVR. Discharges to an LTAC were ≤3.0% (≤10/332) in TAVR and ≤3.5% (≤10/287) in SAVR.

Mean DAH₃₀ was significantly higher in patients who underwent TAVR compared with SAVR (26.0±3.6 vs. 20.7±6.4, difference in days 5.3 [95% CI 4.5, 6.2], p<0.001)(Table S2). DAH₉₀ was also significantly higher in patients who underwent TAVR compared with SAVR (85.1±8.3 vs. 78.7±13.6, difference in days 6.4 [95% CI 4.6, 8.2], p<0.001)(Table S3).

Table 2.

Number of Days Spent Home and in Facilities in the First Year after TAVR or SAVR in Low Surgical-Risk Patients

DAH365 and Components	TAVR (N =322)	SAVR (N =284)	Difference (95% CI)	p-value
DAH365
Mean±SD	352.2±45.4	347.8±39.0	4.5 [−2.3, 11.2]	0.20
Median (IQR)	361(359,362)	357(352,359)
Range (min,max)	(0,363)	(0,362)
Mortality days
Mean±SD	6.3±43.2	4.8±35.9	1.5 [−4.8, 7.8]	0.63
Median (IQR)	0 (0,0)	0 (0,0)
Range (min,max)	(0,363)	(0,360)
Index LOS
Mean±SD	3.4±1.9	7.0±2.9	−3.7 [−4.1, −3.3]	<0.001
Median (IQR)	3 (2,4)	6 (5,8)
Range (min,max)	(2,18)	(3,31)
Total Facility Days After Discharge from the Index Hospitalization
Mean±SD	3.1±10.5	5.4±13.5	−2.3 [−4.3, −0.4]	0.02
Median (IQR)	0 (0,2)	0 (0,4)
Range (min,max)	(0,109)	(0,99)
Readmission Days
Mean±SD	1.7±5.7	2.2±6.3	−0.5 [−1.5, 0.5]	0.31
Median (IQR)	0 (0,0)	0 (0,0)
Range (min,max)	(0,75)	(0,48)
Rehabilitation Days
Mean±SD	0.1±0.9	0.3±1.7	−0.2 [−0.4, 0.0]	0.12
Median (IQR)	0 (0,0)	0 (0,0)
Range (min,max)	(0,13)	(0,19)
LTAC Days
Mean±SD	0.0±0.0	0.1±1.5	−0.1 [−0.3, 0.1]	0.32
Median (IQR)	0 (0,0)	0 (0,0)
Range (min,max)	(0,0)	(0,26)
SNF Days
Mean±SD	0.8±5.9	2.4±8.9	−1.6 [−2.8, −0.3]	0.01
Median (IQR)	0 (0,0)	0 (0,0)
Range (min,max)	(0,72)	(0,70)
ED Days
Mean±SD	0.4±0.8	0.4±0.8	0 [−0.1, 0.2]	0.50
Median (IQR)	0 (0,1)	0 (0,0)
Range (min,max)	(0,6)	(0,8)
Observation Days
Mean±SD	0.1±0.5	0.2±0.6	0 [−0.1, 0.1]	0.46
Median (IQR)	0 (0,0)	0 (0,0)
Range (min,max)	(0,6)	(0,5)

DAH₃₆₅, Days at Home at 1 year; ED, emergency department; LOS, length of stay; LTAC, long-term acute care hospital; SAVR, surgical aortic valve replacement; SNF, skilled nursing facility; TAVR, transcatheter aortic valve replacement.

Table 3:

Number of Days Spent Home and in Facilities in the First Two Years after TAVR or SAVR in Low Surgical-Risk Patients

DAH730 and Components	TAVR (N =312)	SAVR (N =281)	Difference (95% CI)	p-value
DAH730
Mean±SD	701.6±106.0	699.6±94.5	2.0 [−14.1, 18.2]	0.81
Median (IQR)	725.(722,727)	722.(714,724)
Range (min,max)	(0,728.0)	(0,727)
Mortality days
Mean±SD	18.8±102.4	15.7±91.6	3.2 [−12.4, 18.8]	0.69
Median (IQR)	0 (0,0)	0 (0,0)
Range (min,max)	(0,728)	(0,725)
Index LOS
Mean±SD	3.4±1.9	7.1±2.9	−3.7 [−4.1, −3.3]	<0.001
Median (IQR)	3 (2,4)	6 (5,8)
Range (min,max)	(2,18)	(3,31)
Total Facility Days After Discharge from the Index Hospitalization
Mean±SD	6.2±17.2	7.7±18.5	−1.5 [−4.4, 1.4]	0.30
Median (IQR)	1 (0,5)	1 (0,7)
Range (min,max)	(0,185)	(0,191)
Readmission Days
Mean±SD	3.2±8.1 (312)	3.5±9.2	−0.3 [−1.7, 1.1]	0.67
Median (IQR)	0 (0,3)	0 (0,3)
Range (min,max)	(0,87)	(0,85)
Rehabilitation Days
Mean±SD	0.3±2.7	0.3±1.8	0 [−0.4, 0.3]	0.88
Median (IQR)	0 (0,0)	0 (0,0)
Range (min,max)	(0,44)	(0,19)
LTAC Days
Mean±SD	0.1±1.8	0.1±1.6	0 [−0.3, 0.3]	0.96
Median (IQR)	0 (0,0)	0 (0,0)
Range (min,max)	(0,31)	(0,26)
SNF Days
Mean±SD	1.6±9.8	2.9±11.4	−1.3 [−3.0, 0.4]	0.14
Median (IQR)	0 (0,0)	0 (0,0)
Range (min,max)	(0,125)	(0,120)
ED Days
Mean±SD	0.7±1.3	0.6±1.2	0.1 [−0.1, 0.3]	0.25
Median (IQR)	0 (0,1)	0 (0,1)
Range (min,max)	(0,10)	(0,12)
Observation Days
Mean±SD	0.2±0.8	0.2±0.7	0 [−0.1, 0.1]	0.69
Median (IQR)	0 (0,0)	0 (0,0)
Range (min,max)	(0,7)	(0,5)

DAH₇₃₀, Days at Home at 2 years; ED, emergency department; LOS, length of stay; LTAC, long-term acute care hospital; SAVR, surgical aortic valve replacement; SNF, skilled nursing facility; TAVR, transcatheter aortic valve replacement.

The distribution of DAH₃₆₅ in the 2 treatment groups was left skewed with 1 major peak near 365 days (Figure 1a, b, c, d). DAH₃₆₅ was comparable in patients who underwent TAVR compared with SAVR (352.2±45.4 vs. 347.8±39.0, difference in days 4.5 [95% CI −2.3, 11.2], p=0.20)(Table 2). The largest contributions to time spent away from home at 1 year were post-procedural index LOS (TAVR: 3.4±1.9 vs. SAVR: 7.0±2.9 days, difference in days −3.7, [95% CI −4.1, −3.3], p<0.001) and total facility days after discharge from the index hospitalization (inclusive of all rehospitalization, inpatient rehabilitation, SNF, LTAC, ER, and observation days after initial discharge; TAVR: 3.1±10.5 vs. SAVR: 5.4±13.5, difference in days −2.3 [95% CI −4.3, −0.4], p<0.02). One-year mortality was <4% in both groups. Among patients discharged alive from the index hospitalization, the proportion of patients alive and without any additional facility days at 1 year was similar in TAVR and SAVR (TAVR: 55.2% [174/315], SAVR: 51.1% [142/278], p=0.32). The highest rates of facility use by patients at 1 year occurred with readmissions (TAVR and SAVR: 23.4% (142/606)) and ED visits (TAVR and SAVR: 26.7% (162/606) (Table S4). The rate of accumulation of mean DAH₃₆₅ was initially slower in SAVR compared with TAVR diverging early in the post-procedural course, but recovered by 1 year (Figure 2a, 2c, 2d). Subgroup analysis did not reveal any significant interactions at 1 year (Figure 3).

Figure 1: Distribution of Days at Home in Evolut Low Risk Trial Participants Linked to Medicare Claims.

Distribution of Days at Home at 365 days in TAVR (A) and SAVR (B) patients with closeups at 300–365 days (C, D). Distribution of Days at Home at 730 days in TAVR (E) and SAVR (F) patients with closeups at 600–730 days (G, H). SAVR, surgical aortic valve replacement; TAVR, transcatheter aortic valve replacement.

Table 4:

Comparison of Days at Home with Components and Other Outcomes Among TAVR and SAVR Patients in 3 Surgical Risk Groups

	High Risk7	Intermediate Risk8	Low Risk
DAH365 and Largest Contributions to Decreased DAH	Difference in Days (TAVR-SAVR) 95% CI, p-value
DAH365	27.2 (6.0, 48.5), p=0.01	14.7 (5.1, 24.2), p=0.003	4.5 (−2.3, 11.2), p=0.2
LOS	−5.1 (−6.5, −3.8), p<0.001	−3.7 (−4.3, −3.2), p<0.001	−3.7 (−4.1, −3.3), p<0.001
Mortality days	−13.3 (−32.1, 5.5), p=0.17	−4.1 (−12.5, 4.3), p=0.34	1.5 (−4.8, 7.8), p=0.63
Total facility days*	−8.8 (−17.8, 0.1), p=0.05	−6.8 (−10.4, −3.2), p<0.001	−2.3 (−4.3, −0.4), p=0.02
Other Outcomes
After discharge, patients alive at 1 year without additional facility days	TAVR: 20.3% (46/227)	TAVR: 40.2% (134/333)	TAVR: 55.2% (174/315)
	SAVR: 14.8% (31/210) p=0.13	SAVR: 29.9% (106/354) p=0.005	SAVR: 51.1% (142/278) p=0.32
Zero DAH365	TAVR and SAVR: 6.2% (28/450)	TAVR and SAVR: Cell count ≤10/687†	TAVR and SAVR: Cell count ≤10/606

DAH₃₆₅, Days at Home at 1 year. Reference 7: Chung M, Butala NM, Faridi KF, Almarzooq ZI, Liu D, Xu J, Song Y, Baron SJ, Shen C, Kazi DS, Yeh RW. Days at Home after Transcatheter or Surgical Aortic Valve Replacement in High-Risk Patients. Am Heart J. 2022. Reference 8: Chung M, Faridi KF, Kazi DS, Almarzooq ZI, Song Y, Baron SJ, Yeh RW. Days at Home After Transcatheter vs Surgical Aortic Valve Replacement in Intermediate-Risk Patients. JAMA Cardiol. 2022;7:110–112.

^*After discharge alive from the index hospitalization

^†Unpublished data.

Figure 2: Mean Days at Home Accrued in Evolut Low Risk Trial Participants Linked to Medicare Claims.

Rate of accumulation of mean Days at Home over (A) 1 year and (B) 2 years after TAVR and SAVR. (C) Close up of 0–30 days and (D) landmark plot of days 31–90. Vertical lines indicate 95% confidence intervals. SAVR, surgical aortic valve replacement; TAVR, transcatheter aortic valve replacement.

Figure 3: Subgroup Analysis for Days at Home at 1 Year in Evolut Low Risk Trial Participants Linked to Medicare Claims.

Days at Home at 1 year across 7 clinical subgroups. Horizontal lines indicate 95% confidence intervals. AF, atrial fibrillation; BMI, body mass index; CAD, coronary artery disease; DAH, Days at Home; PVD, peripheral vascular disease; SAVR, surgical aortic valve replacement; TAVR, transcatheter aortic valve replacement.

The distribution of DAH₇₃₀ in the 2 treatment groups was also left skewed with 1 major peak near 730 days (Figure 1e, f, g, h). DAH₇₃₀ was similar in TAVR and SAVR (701.6±106.0 vs. 699.6±94.5, respectively; difference in days 2.0 [95% CI −14.1, 18.2], p=0.81)(Table 3). The largest contribution to time spent away from home at 2 years was post-procedural index LOS. 2-year mortality rates were <4% in both groups. After discharge alive from the index hospitalization, the proportion of patients alive without any additional facility days at 2 years was similar in both groups (TAVR:38.7% (116/300), SAVR: 39.3% (107/272), p=0.93). The highest rates of facility use by patients at 2 years occurred with readmissions (TAVR and SAVR: 35.7% (209/593)) and ED visits (TAVR and SAVR: 38.6% (229/593)). The rate of accumulation of mean DAH₇₃₀ was similar in SAVR compared with TAVR (Figure 2b).

Fewer than 10 patients (≤ 4%) had zero DAH₃₆₅ or DAH₇₃₀ after TAVR or SAVR.

Discussion:

In the Evolut Low Risk trial linked to Medicare claims, low-risk patients with severe, symptomatic aortic stenosis undergoing TAVR with a self-expanding bioprosthesis spent more days at home in the first 30 and 90 days as those undergoing SAVR, but the number of days spent at home was similar between the groups at the end of the first year after the procedure. At the end of the first year, DAH continued to be numerically higher in the TAVR group compared with the SAVR group (due to a shorter LOS and fewer facility days after discharge), but the difference was no longer statistically significant. Similarly, DAH at 2 years was comparable between TAVR and SAVR. As would be expected in a low-surgical risk group, rates of discharge to home were high in both groups (>80% in both groups), but after discharge from the index hospitalization, the rate of patients alive and without any additional facility days at 1 year was ~50% in the 2 groups and ~40% at 2 years. These results give insight into the expected post-procedure burden in time spent in facilities and suggest no clear advantage to DAH in low surgical-risk patients undergoing SAVR or TAVR for severe, symptomatic aortic stenosis in the first 2 years after the procedure.

Our results, in conjunction with prior work, help identify the relationships between key patient factors and days at home after TAVR and SAVR. One factor is patient health status, in which early improvements mirror the early functional advantage of TAVR over SAVR. The mean Kansas City Cardiomyopathy Questionnaire (KCCQ) score change from baseline to 30 days was superior in TAVR vs. SAVR (11-point higher difference in TAVR); similarly, DAH₃₀ (~5 additional DAH) and DAH₉₀ (~6 additional DAH) were both significantly higher in TAVR compared with SAVR. While these initial differences attenuated by 1 year in both metrics, nonetheless, these early DAH endpoints may be informative where early functional recovery is a priority, such as for individuals still active in work.

In contrast to the low-risk cohort, higher surgical risk cohorts show a divergence between 1-year KCCQ and 1-year DAH.⁸ In high-risk TAVR and SAVR, 1-year KCCQ scores were similarly increased in the two groups (change from baseline TAVR: 23.2±25.6, SAVR: 21.9±26.6) while patients undergoing TAVR experienced nearly one more month of time at home compared with SAVR. In intermediate risk patients, 1-year KCCQ scores were also comparably increased in the two groups (change from baseline TAVR: 20.9±22.2, SAVR: 20.6±22.2) while DAH was higher by ~2 weeks in TAVR. As such, DAH, overall, appears to highlight a facet of patient functionality distinct from the KCCQ. These two patient-centered outcomes illuminate different aspects of a therapy and should be used together to provide a more global understanding of the impact of treatment options for more informed decision-making.

Surgical risk, in fact, is a key driver of the magnitude of benefit in DAH in TAVR compared with SAVR. (Table 4). The high- and intermediate-risk cohorts experience more DAH in TAVR compared with SAVR (~27 DAH₃₆₅⁷ and ~15 DAH₃₆₅⁸, respectively) while those in the low-risk cohort experience similar DAH₃₆₅. Mortality days and facility days after discharge follow the same pattern. Together, these trends suggest that older, sicker patients, as compared with younger, healthier groups, are impacted more profoundly by the minimally invasive nature of TAVR with greater benefit for this endpoint in higher STS risk patients.

Surgical risk also correlates with freedom from facility days after discharge (high-risk: ~15–20%, intermediate-risk: ~30–40%, low-risk: ~50–55%). While it would be expected that patients with more comorbidities would require greater post-procedural facility support, experience higher readmission rates, and have a greater ED and observation time burden compared with healthier counterparts, it is remarkable that nearly half of low-risk patients still go on to experience at least 1 facility day after discharge home. This result may be reflective of the fact that, despite low-risk status, these patients are still older individuals in their 70’s with significant comorbidities including hypertension, diabetes, and prior atrial fibrillation. While the overall burden of facility use timewise over 1 year is low (readmission time ~2 days, ED time ~0.4 days), the number of low-risk patients impacted is substantial (~25% experiencing any readmission days, ~25% experiencing any ED time) and represents an area for further investigation and improvement.

DAH captures the ability to live independently in the community and hence is reflective of good patient functionality superseding the need for health facility support. However, while DAH is an indicator of health status, it does not take into account how well a patient feels while at home and should supplement other quality-of-life outcomes such as the KCCQ, which directly assess the impact of disease on enjoyment of life. For some, the DAH₃₀ and DAH₉₀ differences may be meaningful. DAH₃₆₅ itself, despite similar results between the two groups, may be informative in that it contextualizes the impact of a diverse set of adverse events in TAVR and SAVR. However, for other patients and clinicians, the choice between SAVR and TAVR may be more strongly guided by other considerations such as anatomy (e.g. bicuspid aortic valve), comorbid conditions (e.g. coronary artery disease, aortic aneurysm, valvulopathies), or the need for additional procedures such as pacemaker placement or that related to valve durability. These anatomic factors and comorbidities are particularly important to consider given their use as exclusion criteria in the Evolut Low Risk trial. Furthermore, characteristics not included in the STS score, such as frailty and porcelain aorta, may warrant strong consideration, as well.

Our study has several limitations. The loss of statistical significance of our primary outcomes may be a Type 2 false negative error from insufficient power, which may be due to a relatively small study cohort, expected small differences between the groups, and higher variances at one and two years. The outcomes involving component facility days have not been adjusted for multiple testing and should be considered exploratory. Our results may not be generalizable to patients receiving balloon-expandable prostheses and patients aged < 65 years; in addition, our results may not generalize to the real-world due to loss of a randomized controlled trial setting and possible differences in comorbidity burden between trial and real-world patients. Hospice days and non-skilled custodial nursing home days – days that may also be considered away from home but are not included in the MedPAR, Outpatient, or Master Beneficiary files – were not counted. Given the limited coverage of SNF days by CMS, these may be underestimated if paid for out-of-pocket by patients themselves or via a non-Medicare insurance. Finally, DAH does not capture whether a day outside of a facility is spent living with family, in an assisted-living facility, or undomiciled.

Conclusions:

In the Evolut Low Risk trial linked to Medicare claims, low surgical risk patients with severe, symptomatic aortic stenosis undergoing TAVR with a self-expanding bioprosthesis spent more days at home within the first 3 months compared with SAVR. However, these differences were no longer significant after the first year. DAH, a patient-centered outcome, provides insight into the post-procedural course after aortic valve replacement. In a low-risk population, time spent at home may be a less important outcome impacting the decision to pursue TAVR vs. SAVR compared with higher risk patients.

What is Known

• Patients undergoing TAVR for severe, symptomatic aortic stenosis who are at high or intermediate surgical risk spend more time at home at one year compared with similar risk patients undergoing SAVR (~27 days and ~15 days, respectively).

• Among patients at low surgical risk, TAVR is non-inferior to SAVR for stroke and death; however, little is known about the days that low-risk patients spend at home after TAVR vs. SAVR in the first year after AVR.

What the Study Adds:

• Low surgical-risk patients undergoing TAVR spend more days at home in the first 30 and 90 days compared with SAVR, but the number of days spent at home was similar between the groups at one year.

• Approximately ~50% of patients were free from facility days after discharge from TAVR or SAVR at 1-year; conversely, ~50% of patients experienced at least 1 facility day after discharge in this period despite low-risk status.

• In low-risk patients, there is no clear advantage of TAVR vs. SAVR for days spent at home in the first year after AVR.

Non-standard Abbreviations and Acronyms:

DAH

days at home

TAVR

transcatheter aortic valve replacement

SAVR

surgical aortic valve replacement