Mitral, Aortic Regurgitation Increase Mortality After Transcatheter Valve Replacement

SAN FRANCISCO, CALIF.—Moderate or severe mitral regurgitation present before transcatheter aortic valve replacement (TAVR) and moderate to severe paravalvular aortic regurgitation after the procedure are both associated with increased mortality risk, according to a pair of studies that investigated the complications.

However, roughly half of the cases of moderate to severe mitral regurgitation improve after TAVR and even in those with baseline moderate to severe problems, no impact on mortality is seen beyond 30 days.

Stefan Toggweiler, MD, of St. Paul’s Hospital in Vancouver, British Columbia, Canada and colleagues looked at 535 consecutive patients who underwent TAVR with a balloon-expandable valve, comparing outcomes for the 28% who presented with concomitant moderate or severe mitral regurgitation with those of the 72% who had mild, trivial or no regurgitation.

In the former group, consisting of higher-risk patients who were older, regurgitation had improved to mild or disappeared by discharge in more than half (53%). Among patients who had no or mild baseline regurgitation, the condition worsened to moderate or severe in 4%.

Survival rates for patients with moderate or severe mitral regurgitation at baseline were 85% at 30 days, 72.3% at 1 year and 53.4% at 3 years compared with 93.4%, 79.2% and 51.8% for the respective periods among those with mild or no baseline regurgitation (log rank P=.038).

Moderate or severe mitral regurgitation proved to be an independent risk factor for mortality during the first 30 days (adjusted HR=2.25, 95% CI 1.25-4.05, P<.01), but not thereafter (P=.90).

“Mitral regurgitation is present in most patients with severe aortic stenosis and is typically left untreated during TAVR. Our questions were, ‘What happens to mitral regurgitation?’ and ‘What is its impact on outcome after TAVR?’” Toggweiler told TCT Daily.

“Patients with concomitant moderate or severe mitral regurgitation require careful hemodynamic monitoring and optimized medical therapy after TAVR,” he observed. “Patients with functional mitral regurgitation may improve more often than patients with primary mitral regurgitation, and thus could be better candidates [for the procedure]. Patients with severe aortic stenosis and concomitant moderate or severe mitral regurgitation will need to be carefully considered as TAVR begins to be applied to lower-risk surgical patients.”

Assessment of residual aortic regurgitation key to post-TAVR management

In the second study, 167 consecutive patients underwent TAVR with either a CoreValve (Medtronic, n=88) or Edwards Sapien bioprosthesis (Edwards Lifesciences, n=79).

Implantation was successful in all patients, with mortality rates of 9% at 30 days, 13% at 6 months and 20% at 1 year. Paravalvular aortic regurgitation was seen in 67% of patients, and was predominantly mild (78.8%). Compared with patients with no or mild aortic regurgitation, those in whom the condition was moderate (18.6%) or severe (2.7%) experienced higher CV mortality at 30 days (50% vs. 4.5%), 6 months (61% vs. 5.1%) and 1 year (71% vs. 6.9%, P<.05 for each comparison).

Analysis of intra-procedural hemodynamics suggested that a difference between diastolic aortic pressure and left ventricular end-diastolic pressure of 18 mm Hg could serve as a good predictor of mortality.

“Because of the possible crucial impact of paravalvular aortic regurgitation after TAVR, we have used this [intra-procedural pressure] gradient as an additional parameter to measure aortic regurgitation,” investigator P.C. Patsalis, MD, of Essen University Hospital in Essen, Germany, told TCT Daily. “[Since it] has predictive value, it could [help decide] whether countermeasures [such as post-dilatation or valve-in-valve implantation] should be taken.”