Cardiac MRI vs Echocardiography for Post-TAVR Aortic Regurgitation

Worse aortic regurgitation quantified by cardiac magnetic resonance (CMR) was associated with increased mortality and poorer clinical outcomes after transcatheter aortic valve replacement (TAVR), according to research published in the Journal of the American College of Cardiology.

Henrique B. Ribeiro, MD, PhD, of the Quebec Heart & Lung Institute at Laval University in Canada, and colleagues evaluated the effect of aortic regurgitation as assessed by CMR on post-TAVR clinical outcomes. They explained, “Although Doppler echocardiography has been the most common method used for AR [aortic regurgitation] assessment following TAVR, its accurate quantification is challenging, as the AR jets are often multiple and eccentric.”

“Furthermore acoustic shadowing from the annulus and left ventricular outflow tract calcifications and Doppler attenuation from the prosthetic valve stent may also interfere with the accurate quantification of regurgitant jets.”

The study included 135 patients from 3 centers. The researchers  found moderate-severe aortic regurgitation occurred in 17.1% of patients as measured by echocardiography vs 12.8% of patients as measured by CMR.

Higher regurgitant fraction after TAVR was associated with increased mortality (hazard ratio [HR]: 1.18 for each 5% increase; 95% confidence interval [CI]: 1.08-1.30; P<.001), as well as the combined end point of mortality and rehospitalization for heart failure (HR: 1.19 for each 5% increase; 95% CI: 1.15-1.23; P<.001).

CMR that was performed a median of 40 days after TAVR had a greater association with post-TAVR clinical events compared with early echocardiography (P<.01).

“TAVR technology has evolved significantly in recent years; however, transcatheter heart valves are still associated with a much higher rate of residual R, chiefly paravalvular regurgitation, as compared with surgical aortic valve replacement,” Dr Ribeiro and colleagues pointed out. “Although the incidence of residual post-TAVR AR may approach 70%, it is moderate-to-severe in ~12% of the time, also affecting the device success rates.”

They also noted that the device success rates have been lower when using Valve Academic Research Consortium-2 criteria, which is consistent with the current findings.

Further studies are necessary to determine CMR’s exact role in treatment for patients who undergo TAVR and experience post-procedure aortic regurgitation, the researchers concluded.

Reference

Ribeiro HB, Orwat S, Hayek SS, et al. Cardiovascular magnetic resonance to evaluate aortic regurgitation after transcatheter aortic valve replacement. J Am Coll Cardiol. 2016;68(6):577-585. doi: 10.1016/j.jacc.2016.05.059.