Evaluation of myocardial contraction fraction in transcatheter aortic valve replacement

Abstract

Objective: Myocardial contraction fraction (MCF), a costless, easy-to-perform echocardiographic measure, which estimates cardiac function through the volumetric measurement of myocardial shortening, may be a useful prognostic indicator in patients undergoing transcatheter aortic valve replacement (TAVR). This study aimed to evaluate MCF in patients who underwent TAVR at a public hospital in Rio de Janeiro, Brazil. Methods: This was a retrospective cohort study. Clinical and echocardiographic data were obtained from medical records. MCF was calculated as FDV in mL/FSV in mL x100, where FDV= final diastolic volume and FSV= final systolic volume. These were derived from the dimensions of the left ventricle. The FDV was estimated as 4.5 x (final diastolic diameter of the left ventricle) and the FSV was estimated as 3.72 x (final systolic diameter of the left ventricle). Patients were followed for 66 months, and all-cause mortality was registered. Results: Overall, 78 patients were studied. Median age was 78 years. Mortality was 56.4% over 9 years, with 29% of deaths in the first year. Pre-TAVR median MCF (45.9%) was low, while mean left ventricular ejection fraction (LVEF) was normal (57.0%). In patients who survived after the procedure, MCF increased post-TAVR, but in those who died, it decreased (49.3% vs 45.1%). Conclusions: MCF may demonstrate left ventricular dysfunction unrecognized by LVEF measurement in patients undergoing TAVR, and may be a prognostic marker in this patient population.

Keywords

• transcatheter aortic valve replacement
• aortic stenosis
• myocardial contraction fraction
• ventricular function