Transcatheter aortic valve replacement (TAVR), as opposed to surgical aortic valve replacement (SAVR), could be a viable and durable treatment option for patients with rheumatic aortic stenosis (AS), according to a new U.S. study.
The findings by lead author Amgad Mentias, MD, MSc, of the Cleveland Clinic Foundation, together with colleagues, were published online Monday and appear in the April 13 issue of the Journal of the American College of Cardiology.
The study was launched in a bid to fill the knowledge gap on TAVR in patients with rheumatic etiology for their AS, who were excluded from the pivotal randomized controlled trials on the procedure.
Together with low prevalence of rheumatic AS in developed countries, it means understanding of the role of TAVR in these patients has remained limited, despite increasing popularity of the procedure as an alternative to SAVR in other AS groups, including severely calcific patients, the researchers noted.
Although prevalence is low in developed countries, stagnant progress in the field of valve replacements due to the advanced age of patients generally receiving valves is “devastating” for the vast number of patients requiring valve replacement in low- to middle-income countries where rheumatic heart disease continues to rise, an accompanying editorial notes.
The current study set out to examine TAVR vs. SAVR outcomes in patients with rheumatic AS and compare with TAVR in nonrheumatic patients.
Medicare beneficiaries who underwent TAVR or SAVR from October 2015 through December 2017 were found, before identifying patients with rheumatic AS using prior validated International Classification of Diseases, Tenth Revision codes. The final cohort included 1,159 patients with rheumatic AS who underwent aortic valve replacement (554 with SAVR and 605 with TAVR), and 88,554 with nonrheumatic disease who underwent TAVR.
SAVR patients tended to be younger (mean age 73.4 ± 7.2 years vs. 79.4 ± 8.1 years) and had lower prevalence of most comorbidities, including hypertension, diabetes, heart failure, lung disease, kidney disease, peripheral arterial disease, stroke, coronary artery disease, atrial fibrillation, anemia and pulmonary hypertension, in comparison with the TAVR group. Frailty scores were also lower for the SAVR group at a median of 5.3 vs. 11.3 in TAVR patients, with 9.4% vs. 39% respectively having high frailty scores.
Overlap propensity-score-weighting analysis adjustment was applied, after which both groups were balanced on all baseline characteristics.
At median follow-up of 19 months (interquartile range [IQR]: 13 to 26 months), no significant difference in the primary outcome measure of all-cause mortality was found between TAVR and SAVR groups for rheumatic AS (11.2 vs. 7.0 per 100 person-years; adjusted hazard ratio [HR]: 1.53; 95% confidence interval [CI]: 0.84 to 2.79; p = 0.2).
No difference was observed for in-hospital and 30-day mortality between the same groups (TAVR at 2.4% vs. SAVR at 3.5%, p = 0.6, and 3.6% vs. 3.2%, p = 0.9, respectively), as was the case for 30-day stroke (2.4% vs. 2.8%, p = 0.8).
There was also no difference in heart-failure admissions between TAVR and SAVR (14.8 vs. 19.4 events per 100 person-years; sub-distribution HR: 0.71; 95% CI: 0.41 to 1.23; p = 0.2).
Compared with TAVR in nonrheumatic AS after a median follow-up of 17 months (IQR: 11 to 24 months), TAVR for rheumatic AS was associated with similar mortality (15.2 vs. 17.7 deaths per 100 person-years; adjusted HR: 0.87; 95% confidence interval: 0.68 to 1.09; p = 0.2).
None of the rheumatic TAVR patients, less than 11 SAVR patients and 242 nonrheumatic TAVR patients underwent repeat aortic valve replacement at follow-up.
“TAVR can be accomplished with midterm outcomes comparable to surgical replacement in patients with rheumatic AS,” the researchers said.
They called for randomized trials comparing the safety and long-term efficacy of TAVR versus SAVR in these patients.
Incentive to develop ‘for the many’
In an accompanying editorial, Peter Zilla, MD, PhD, of the University of Cape Town and Groote Schuur Hospital, South Africa, and colleagues called the study a “major step” in raising awareness for the feasibility of TAVR in rheumatic heart disease patients.
They noted that the rising prevalence of rheumatic heart disease in lower-income countries has remained the major cause of surgical valve disease, with affected patients largely from disadvantaged socioeconomic backgrounds.
The current study will “hopefully act as a catalyst of higher awareness for the ‘many’ and, crucially, for industry to see in the huge underserved population of emerging economies an incentive to develop heart valve prostheses that also cater to these patients,” the editorialists wrote.
“Recent developments that saw decellularization, as a fundamental step toward bioprosthetic longevity, find its way into tissue treatment; cost-effective, nondegrading polymer valves being clinically pioneered; and the emergence of TAVR designs that cater to pure AR [aortic regurgitation] are encouraging.”
Mentias A, Saad M, Desai MY. Transcatheter Versus Surgical Aortic Valve Replacement in Patients With Rheumatic Aortic Stenosis. J Am Coll Cardiol 2021;77:1703–13.
Zilla P, Williams DF, Bezuidenhout D. TAVR for Patients With Rheumatic Heart Disease: Opening the Door for the Many? J Am Coll Cardiol 2021;77:1714–6.