Thigh intramuscular fat predicts the prognosis in patients in non-ischemic cardiomyopathy with reduced ejection fraction

Abstract

Abstract Background Skeletal muscle atrophy is an independent prognostic predictor for patients with chronic heart failure, and the concept of sarcopenia is drawing attention. Furthermore, the importance of not only muscle mass but also intramuscular fat (IMF) has been pointed out. However, there is a lack of consensus on the implications of ectopic fat for the prognosis in patients with non-ischemic cardiomyopathy. Purpose We investigated whether ectopic fat in the thigh affects the prognosis with non-ischemic cardiomyopathy. Methods We recruited 105 patients who were diagnosed with non-ischemic cardiomyopathy by cardiac catheterization and echocardiographic date between September 2017 and November 2019. Finally 73 patients with reduced EF (EF 40% or less) enrolled in this prospective study. Functional status was evaluated by using cardiopulmonary exercise test at baseline. All patients were measured quantity of epicardial fat and thigh IMF percentage (%IMF) using computed tomography scan. Demographic, laboratory and echocardiographic date were collected from the patients' medical records. Clinical endpoints were unexpected readmission. Results During the follow-up period 18 patients had adverse events. The %IMF was significantly higher in the group with adverse events than without (5.57±5.70 and 3.02±2.44%, respectively; p<0.01). Spearman correlation coefficient analysis showed a modest correlation between %IMF and lower limb extension strength (Spearman r=−0.280; p=0.0315), but there was no significant correlation between %IMF and exercise tolerance such as anaerobic threshold and peak oxygen uptake. Patients were divided into 2 groups according to the median values of %IMF. Kaplan-Meier analysis demonstrated that events were significantly higher in the high %IMF group (log-rank p=0.033). Multivariate Cox regression analysis adjusted for left ventricular end-diastolic diameter and peak ventricular oxygen consumption found %IMF as an independent factor of adverse events (hazard ratio 1.545; 95% confidential interval 1.151–2.087; p=0.004). Conclusions In non-ischemic cardiomyopathy patients with reduced EF, %IMF may have important adverse consequences such as increased cardiac-related events. Kaplan-Meier curves Funding Acknowledgement Type of funding source: None