Better Survival 3 Years After TAVR for Patients With Mixed Aortic Valve Disease

Patients who have both aortic stenosis and some degree of aortic regurgitation, so-called mixed aortic valve disease (MAVD), appear to have better survival after TAVR than those with pure aortic stenosis, new research suggests.

Despite increasing rates of TAVR over the last decade, many of the pivotal trials in patients at high or intermediate surgical risk did not include those with MAVD, leaving clinicians uncertain about how to extrapolate outcomes of patients with severe aortic stenosis alone to those who also have some preexisting aortic regurgitation, said senior author Samir R. Kapadia, MD (Cleveland Clinic, OH).

“I think what we can say from our study is that a heart that is exposed to aortic regurgitation is able to tolerate mild aortic regurgitation at the end of the procedure better, and maybe that is the reason why people do better with mixed valve disease,” he told TCTMD.

David Hildick-Smith, MD (Royal Sussex County Hospital, Brighton, England), in an accompanying editorial, concludes that the results come as “a relief” and give clinicians “a little bit of latitude” in terms of post-TAVR aortic regurgitation in patients with preexisting regurgitation. 

“This can be helpful when, for example, trying to decide whether the additional risk associated with further postdilatation is warranted in any given individual,” he writes. “Nothing comes for free, and postdilatation carries risks of annular rupture, valve embolization, stroke, or coronary occlusion. These risks may be small, but most operators remember a case where they undertook postdilatation and then wished they hadn’t.”

Survival Advantage

For the study, published online October 30, 2019, ahead of print in JACC: Cardiovascular Interventions, investigators, led by Johnny Chahine, MD (Cleveland Clinic), compared outcomes for 688 patients with MAVD and 445 patients with pure aortic stenosis who underwent TAVR at their institution from 2014 through 2017. Compared with the aortic-stenosis group, those with MAVD had slightly lower body mass index, were less likely to have diabetes or A-fib, and were more likely to have a history of stroke or TIA.

At a median follow-up of 3 years, the MAVD group had a lower mortality rate than those with pure aortic stenosis (15.3% vs 20.4%; P = 0.02). Post-TAVR aortic regurgitation was more common in the MAVD group than the pure-stenosis group (22.1% vs 14.4%; P = 0.001), but when it was present, Kaplan-Meier analysis showed better overall survival for the MAVD group compared with the stenosis group (3- year mortality 13.2% vs 25.0%; P = 0.03). The advantage for the MAVD group was sustained in both propensity-score matching and multivariable logistic regression.

Mortality rates for both groups were similar when post-TAVR aortic regurgitation did not develop (15.9% vs 19.7%; P = 0.13). Secondary endpoints, including bleeding and vascular complications, stroke, kidney injury, valve dysfunction, and composite endpoints of early safety and clinical efficacy, also were similar between both groups.

Chahine and colleagues say large randomized trials are needed to confirm the findings, noting the data are derived from a single-center, retrospective, observational analysis. Additionally, they point out that  the mortality data may have been underestimated because they relied on electronic medical records and a commercial obituary service. It also remains unknown if the mortality benefits extend to surgical aortic valve replacement and/or aortic valve repair.

Additional Considerations

“We all know how important it is to leave the patient with no aortic regurgitation if possible,” Hildick-Smith writes. “Symptom relief among patients with residual aortic regurgitation is poor, and longevity is restricted. But sometimes it is not possible to leave the patient with an optimal result and in these cases one of many factors to take into consideration can now be the degree of preexisting aortic regurgitation.”

To TCTMD, Kapadia said he is not convinced though that that is the case, or that better tolerance of aortic regurgitation is the sole driver of improved survival.

“It is possible that these patients with mixed valve disease present a little bit earlier for TAVR and that’s why their outcomes are better,” he noted. “Obviously there are no data to support that, but it is hypothesis-generating and something we have to study in the future to understand a little bit more.” Kapadia added that performing TAVR early in patients with MAVD may be a future consideration if the findings are borne out. The ongoing EARLY-TAVR study, he observed, may provide some additional insight about the degree of biologic change that occurs after intervention in patients presenting earlier in the course of aortic stenosis.

As for leaving patients with a little aortic regurgitation, though, Kapadia said he does not advocate that based on the study findings.

“This is a slippery slope. We should eradicate aortic regurgitation, or we should try by whatever means possible to eliminate it. Of course, if the risk is too high, and there is preexisting [aortic regurgitation] you should not push too much,” he said. “But we don’t have a cause and effect relationship. We found an association, it’s a questionable association, and we should strive for the best result.”