Contract and react: exploring MCF and HRV in asymptomatic aortic stenosis

Abstract Objectives Myocardial contraction fraction (MCF), a volumetric index of myocardial performance independent of chamber size, is significantly reduced in patients with severe aortic stenosis (AS) and has been proposed as a prognostic marker1,2. Heart rate variability (HRV), reflecting autonomic regulation of cardiac function, is similarly decreased in severe AS due to reduced parasympathetic activity and has demonstrated prognostic relevance, with improvements noted following intervention3–5. Nevertheless, current management algorithms for severe AS primarily emphasize symptomatic status and left ventricular ejection fraction6,7. In this study, we aimed to assess the correlation between MCF and HRV in asymptomatic AS patients with preserved ejection fraction. Methods A total of 79 patients were retrospectively included in the study. Participants with a diagnosis of hypertension and without significant valvular disease comprised the control group. The study population was classified into three groups: mild aortic stenosis, moderate-to-severe aortic stenosis, and controls. Conventional echocardiographic parameters, as well as MCF and HRV indices, were compared across the groups. Additionally, the correlation between MCF and HRV parameters was assessed. Results Moderate-to-severe aortic stenosis group exhibited significantly lower MCF compared to the mild AS and controls (31.95 ± 6.1% vs. 35.35 ± 5.2% and 40.72 ± 4.9%, respectively; p < 0.001). HRV parameters were also significantly reduced in AS patients: SDNN-24 (p = 0.038), SDNN index (p = 0.006), RMSSD (p = 0.016), and pNN50 (p = 0.018). No significant differences were observed in LVEF, LVEDV, or LVESV between groups. MCF demonstrated a significant positive correlation with SDNN-24 (r = 0.375, p = 0.009), SDANN index (r = 0.385, p = 0.008), and SDNN index (r = 0.416, p = 0.004). Conclusion Reduced MCF was associated with impaired HRV in aortic stenosis patients, indicating early physiologic dysfunction. MCF and HRV may assist in risk stratification of asymptomatic individuals.Correlation of MCF with SDNN MCF by groups