Myocardial active strain energy density and contractance: novel prognostic tools for left ventricular function and cardiovascular risk.

Myocardial active strain energy density (MASED), also known as contractance, is a novel measure of myocardial contractile function, defined by the area within the stress-strain loop; it quantifies the energy per unit volume of myocardium used to perform work. MASED applies the principle of strain energy density, which is grounded in engineering science, to cardiac tissue. Using cardiovascular magnetic resonance imaging, we demonstrate that global longitudinal active strain energy density (GLASED), a subtype of MASED, provides superior predictive value compared to conventional metrics such as ejection fraction and global longitudinal strain in predicting mortality among patients with hypertensive heart disease, dilated cardiomyopathy, and amyloid heart disease (n = 183). In a large community-based cohort (n = 44 957), GLASED was the strongest independent predictor of all-cause mortality and major adverse cardiovascular events among 23 left ventricular structural and functional metrics. Echocardiographic assessment of GLASED further revealed significant associations with age and sex in healthy individuals. These findings indicate that MASED, and specifically GLASED, provide a more accurate and mechanistically grounded assessment of left ventricular performance and cardiovascular risk than established measures. In clinical practice, MASED has the potential to enhance risk stratification, guide heart failure management, and differentiate pathological from physiological hypertrophy. Prospective prognostic studies in wider disease populations are warranted to validate its clinical utility.