Myocardial Contraction fraction for risk stratification in low-gradient aortic stenosis with preserved ejection fraction

Introduction Myocardial contraction fraction(MCF), the ratio of stroke volume to myocardial volume is a volumetric measure of myocardial shortening and thickening independent of left ventricular size and geometry. The prognostic value of MCF in low-gradient severe aortic stenosis with preserved ejection fraction(LGSAS-PEF) is unknown. Method We included 643 patients with LGSAS-PEF in whom MCF was computed at baseline and analyzed mortality during follow-up. Results Throughout follow-up with medical and surgical management [median: 34.9(16.1–65.3) months], lower MCF tertiles had higher mortality than the highest tertile. 80-month survival was 56 ± 4% for MCF > 41%, 41 ± 4% for MCF 30–41%, and 40 ± 4% for MCF   41%. The optimal MCF cut-off point for mortality prediction was 41%. Age, body mass index, Charlson index, peak aortic jet velocity, and LVEF were independently associated with mortality. MCF (chi-square to improve 10.39; P = 0.001), provided greater additional prognostic value (P   41%, higher for patients with SV index ≥ 30 ml/m2 and MCF ≤ 41% [adjusted HR 1.47 (1.05–2.07)] and extremely high for patients with SV index  Fig. 1 ). Conclusion MCF is a valuable risk marker in LGSAS-PEF and could improve clinical decision-making, especially for patients with normal-flow. Survival curves.