Paravalvular Regurgitation After Transcatheter Aortic Valve Replacement With the Edwards Sapien Valve in the PARTNER Trial: Characterizing Patients and Impact on Outcomes
What is the clinical significance of paravalvular aortic regurgitation (PAR) following transcatheter aortic valve replacement (TAVR)?
This study examined 2,434 patients treated with a balloon-expandable TAVR as part of a randomized trial or continued-access registries. Outcomes and changes in left ventricular size and function were compared between groups with different degrees of PAR.
Post-procedural PAR was none/trace in 52.9%, mild in 38.0%, and moderate/severe in 9.1% of patients. There were significant differences between groups in clinical characteristics, baseline echocardiography findings, and procedural details. In comparison to patients with moderate/severe PAR, those with mild (p < 0.01) or no/trace PAR (p < 0.001) were more likely to have an increase of >1 New York Heart Association symptom class. Between baseline and 1 year, left ventricular ejection fraction improved in all groups without between-group differences, end-systolic left ventricular diameter decreased in patients with no/trace PAR (p = 0.03), with no differences in the other groups; no groups had a significant change in end-diastolic diameter. Comparing patients with none/trace, mild, and moderate/severe PAR after TAVR, there were significant differences at 1 year in the rate of all-cause mortality (15.9% vs. 22.2% vs. 35.1%, p < 0.001), cardiac death (6.1% vs. 7.4% vs. 16.3%, p < 0.001), and repeat hospitalization (14.4% vs. 23.0% vs. 31.3%, p < 0.001). In comparison to no/trace PAR and after multivariable adjustment, mild PAR (hazard ratio, 1.35; 95% confidence interval, 1.07-1.72; p = 0.01) and moderate/severe PAR (hazard ratio, 2.20; 95% confidence interval, 1.60-3.03; p < 0.001) were associated with an increased risk of mortality at 1 year.
The authors concluded that both mild and moderate/severe PAR are associated with increased all-cause mortality.
While moderate/severe PAR has been demonstrated to result in increased adverse events including mortality, the risk of mild PAR has been less certain, and variable findings have been reported. The results of this study suggest that even mild PAR is associated with increased mortality at 1 year. There are several potential explanations for these discordant findings. First, grading PAR is challenging and there is likely wide variation in how it is interpreted, particularly outside of core labs. Further, it is easy to underestimate, as traditional echo views may miss or incompletely capture PAR, as these jets tend to be highly eccentric and often require extra effort to ‘hunt’ for them. It is also difficult to determine whether there is a true cause and effect between PAR and adverse events, as there were many significant baseline differences between groups, and the same features that may cause PAR may also be related to risk of adverse events (e.g., severity of valvular calcification). Nevertheless, the presence of PAR (particularly moderate/severe) appears to be a marker for increased risk, and it is hoped that improvements in device design and implantation techniques should reduce its prevalence.
Keywords: Heart Valve Prosthesis, Aortic Valve, Ventricular Function, Left, Stroke Volume, Confidence Intervals, Hospitalization, Equipment Design, Echocardiography
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