Continuum of left ventricular mass in the general population

Introduction Myocardial mass mostly reflects a continuous structural adaptation to chronic hemodynamic load. Increased left ventricular mass is categorically classified as left ventricular hypertrophy being associated with higher risk of mortality. Purpose We aimed to characterize the distinct distribution of left ventricular mass index (LVMI) and to examine its continuous association with mortality and cardiovascular outcomes in a general population. Methods We analysed transthoracic echocardiography data from the prospective Hamburg City Health Study, a population-based cohort of adults aged 45–74 years between 2016 to 2021 with a median follow up of 4.8 (IQR 3.0-5.9) years. LVMI was calculated as: LVMI (g/m2) = (0.8 × [1.04 × ((Interventricular Septal Diameter + Left Ventricular End-Diastolic Diameter + Posterior Wall Diameter)3 − (Left Ventricular End-Diastolic Diameter)3)] + 0.6) / Body Surface Area (m2)). The primary outcome was all-cause mortality (ACM) and the secondary outcome a composite of incident cardiovascular disease (heart failure, myocardial infarction, atrial fibrillation, pulmonary embolism, or stroke) and ACM. Associations were assessed with Cox proportional-hazards models using age as the time-scale and adjusted for sex. Continuous variables are presented as medians (interquartile ranges; IQR) unless otherwise specified. Results A total of 12,046 participants with complete echocardiographic data were included; 50.8% were women, the median age was 60 (IQR 14.5) years, and median body mass index was 25.8 (23-28.1) kg/m2. The median LVMI was 79.6 (69–93) g/m2 overall, 73.9 (65–85) g/m2 in women, and 86.6 (75–101) g/m2 in men. LVMI was continuously associated with overall mortality and the composite outcome (Figure 1), with an approximately linear relation and progressively higher risk at increasing LVMI values. The risk of mortality or composite primary outcome was already higher at conventional hypertrophy cut-offs in women (95 g/m2; hazard ratio [HR] 1.15 95% Confidence Interval [CI] 1.09–1.22) and in men (115 g/m2; HR 1.376, 95% CI 1.205–1.571). Conclusion With increasing LVMI, risk of mortality or incident cardiovascular disease increased continuously exceeding with higher values. LVMI values below established cutoffs were already associated with higher risk, supporting consideration of myocardial mass across its full spectrum and suggesting potential value of earlier risk stratification.