There were no cases of structural valve deterioration observed up to 8 years after transcatheter aortic valve replacement (TAVR) with CoreValve, a single-center study found.
When 152 consecutive patients were followed for a median of 6.3 years, severe valve deterioration — defined as severe intra-prosthetic aortic regurgitation or a trans-prosthetic mean pressure gradient reaching 40 mmHg or a 20 mmHg rise from baseline — was notably absent, reported Mohamed Abdel-Wahab, MD, of Segeberger Kliniken’s Heart Center in Germany, and colleagues.
“While a durability of at least 5 years, as suggested by previous studies, is acceptable for an elderly high-risk population,” Abdel-Wahab’s group wrote in a newly accepted paper in EuroIntervention, “evidence of longer-term durability is mandatory before replacing surgery with [TAVR] in younger, lower-risk patients.”
The rate of bioprosthetic valve failure — the primary study endpoint — occurred in less than 8% of patients by year 8. These failures could be from either severe structural valve deterioration or bioprosthetic valve dysfunction leading to death or re-intervention, but in the study they were mainly due to re-intervention for paravalvular regurgitation.
Recipients of the self-expanding transcatheter heart valve were a median 81 years old upon TAVR. Patients were followed up in the clinic and with echocardiography at 30 days and 6 months, and then at 1, 2 and 5 years.
All-cause mortality in this group was 14% at 1 year and 50% at 5 years, reaching 73% by 8 years. Median survival following TAVR was 3.4 years.
Among the 68 survivors beyond 5 years, effective orifice area was 1.60 cm2 and mean transvalvular pressure gradient was 6.7 mmHg. Due to paravalvular leakage, 3.3% of these patients needed re-intervention (from 0.6 to 5.2 years after the initial procedure).
Ultimately, the investigators estimated bioprosthetic valve failure at 8 years to be 7.9% with Kaplan-Meier — or 4.5% with cumulative incidence analysis.
While their study “cannot conclude” the extent of transcatheter heart valve durability, it contributes to a growing body of evidence, the authors said, adding that the results point to a “favorable performance” of CoreValve.
“Despite a very close follow-up, the study is derived from a high-risk population with exceedingly high mortality rates and is therefore limited by the relatively low number of patients with a truly long-term follow-up,” they cautioned. “It is important to underline that assessment of long-term transcatheter heart valve performance by echocardiography was only performed through a snapshot examination in a ‘surviving cohort’ and therefore the competing risk of death in this particularly high-risk population may have biased the results.”
Patients included in the study got TAVR with CoreValve at Segeberger Kliniken’s Heart Center from 2007 to 2011. Echocardiographic follow-up beyond 5 years was completed in 88% of patients (60 of 68); the last sonograms were taken mostly at years 6 (n=23) and 7 (n=23) — less so in years 8 (n=6) and 9 (n=4).
An independent core laboratory in Switzerland provided echocardiographic analysis.
Abdel-Wahab disclosed receiving institutional research grants from St. Jude Medical, Biotronik, and Medtronic; lecture fees from Edwards Lifesciences and Boston Scientific; and proctoring for Boston Scientific.