Association of diabetes mellitus with myocardial collagen accumulation and relaxation impairment in patients with dilated cardiomyopathy

AimsTo assess the effects of diabetes mellitus (DM) on myocardial collagen accumulation, myocardial relaxation, and prognosis in patients with dilated cardiomyopathy (DCM).MethodsA total of 102 consecutive DCM patients with a New York Heart Association functional class of I or II were enrolled. Patients were allocated to two groups on the basis of the presence (DCM + DM group, n = 30) or absence (DCM − DM group, n = 72) of DM. Cardiac catheterization performed and left ventricular pressure were measured in all patients. The pressure half-time (T1/2) was determined as an index of myocardial relaxation function. Endomyocardial specimens were subjected to histological analysis.ResultsThe T1/2 was significantly longer (P < 0.001) and the collagen volume fraction was significantly greater (P = 0.018) in the DCM + DM group than in the DCM − DM group. Multivariate analysis showed that DM was significantly associated with increased incidence of cardiac events (hazard ratio, 3.7; 95% confidence interval, 1.05 to 13.16; P = 0.03).ConclusionsThe prognosis of DCM patients with DM was worse than that of those without DM. Impairment of myocardial relaxation, increased myocardial fibrosis, and mitochondrial degeneration associated with DM may underlie this difference.