Exercise capacity is associated with rest and peak-exercise left ventricular global longitudinal strain in patients with hypertrophic cardiomyopathy

Abstract

Abstract Background Patients with hypertrophic cardiomyopathy (HCM) frequently have reduced exercise capacity, which can be associated with subclinical cardiac dysfunction. Left ventricle global myocardial strain (LV-GLS) is a sensitive index to detect subclinical myocardial dysfunction. However, the clinical utility of LV-GLS during exercise test remains uncertain. Purpose We assessed the association of functional capacity with LV-GLS at rest and at the peak of stress in HCM patients. Methods We examined 566 asymptomatic/minimally symptomatic HCM patients (54±14 years, 57% men, body mass index 30±6 kg/m2, 84% on beta-blockers) by echo at rest and following maximal exercise. We recorded clinical, echo variables (LV ejection fraction [LVEF], LV thickness, left ventricle mass index [LVMI], left ventricle outflow tract [LVOT] gradient, LV-GLS at rest and at peak stress), and exercise variables (percent of age-gender predicted metabolic equivalents [AGP-METs]). Results Echo parameters were as follows: LVEF at rest of 62±6%, wall thickness of 16.9±0.4 mm, LVMI of 117±47 g/m2, LVOT gradient at rest of 27±33 mmHg, LV-GLS at rest of −15.9±3.6%, LV-GLS at peak of stress of −17.4±4.3%, and change in LV strain from rest to stress of −1.9±2.3%. Only 41% of patients achieved >85% of AGP-METs. Logistic regression demonstrating an association between AGP-METs less than 85% and various predictors are shown in Table 1. Conclusion Impaired deformation at peak of stress assessed by LV-GLS was associated with reduced exercise capacity measured as AGP-METs less than 85%. These findings suggest that early systolic cardiac deterioration should be considered as a cause of exercise impairment in patients with HCM. Funding Acknowledgement Type of funding source: None