Assessment of Myocardial Work in sarcomere gene mutation carriers and overt hypertrophic cardiomyopathy

Abstract

Abstract Introduction Hypertrophic cardiomyopathy (HCM) is a common genetic heart disease defined by unexplained hypertrophy and often characterized by diastolic and systolic dysfunction. In recent studies, HCM patients were found to have impaired left ventricular (LV) myocardial work (MW), a more load-independent parameter compared to global longitudinal strain (GLS). MW was never studied in sarcomere mutation carriers. Aim To compare MW between sarcomere mutation carriers, healthy controls and overt HCM. Methods A single centre study with a case-control design. The study population comprised 3 groups: overt HCM patients with a likely pathogenic/pathogenic sarcomere gene variant (n=51), carriers (n=51) and age and sex matched (to the carriers) healthy controls (n=32). All participants (pts) underwent a transthoracic echocardiogram including myocardial deformation analysis to calculate global longitudinal strain (GLS) and MW. MW was calculated from same-day non-invasive blood pressure evaluation. Global work index (GWI), Global constructive work (GCW), Global work efficiency (GWE) and Global wasted work (GWW) were obtained. Results GWI (1695mmHg% vs 1869mmHg%, p=0.001) and GCW (1993mmHg% vs 2244mmHg%, p<0.001) were lower in sarcomere mutation carriers compared to controls. LVEF and GLS were similar between the two groups (p=0.233). HCM pts were older (p<0.001), less likely female (p=0.01) and had a higher prevalence of cardiovascular (Cv) comorbidities, including hypertension (p<0.001), compared with sarcomere gene mutation carriers. Global work index (GWI) (1209mmHg%vs1695mmHg%), global constructive work (1456mmHg% vs 1993mmHg%, p<0.001) and global work efficiency (GWE) (89% vs 95%, p<0.001) were significantly lower in overt HCM compared with sarcomere mutation carriers. GWW was higher (117mmHg% vs 95mmHg%, p=0.006) in overt HCM. Conclusion In this study, we show for the first time that MW indexes were significantly worse in sarcomere gene mutation carriers compared to controls. GLS and MW indexes were also significantly different between overt HCM and sarcomere gene mutation carriers. These data suggest that MW is more sensitive to early changes than GLS and could play a major role in the evaluation and follow-up of sarcomere mutation carriers.