We aimed to elucidate the relationship between glycated hemoglobin (HbA1c), cardiac systolic/diastolic function, and heart failure (HF) prognosis during guideline-directed medical therapy in patients with nonischemic dilated cardiomyopathy (NIDCM). We evaluated 283 hospitalized NIDCM patients, who were grouped according to baseline (BL) and 1-year (1Y) levels of HbA1c (<6.0, 6.0-6.9, and ≥7.0 %). The primary endpoint was defined as either readmission for HF worsening or cardiac death. Approximately half of the patients had BL- or 1Y-HbA1c ≥6.0 % (31 % at BL, 34 % at 1Y had 6.0-6.9 %; 12 % at BL, 12 % at 1Y had ≥7.0 %). The absolute value of left ventricular ejection fraction (LVEF) and its improvement during 1 year showed no significant difference among the 1Y-HbA1c groups (p = 0.273), whereas a lower absolute value and a more significant reduction in the early diastolic velocity of the mitral annulus (E a) were seen in the group with 1Y-HbA1c ≥7.0 % (both p < 0.001). In multiple regression analysis, higher 1Y-plasma B-type natriuretic peptide and lower 1Y-Ea were independently associated with higher 1Y-HbA1c (both adjusted p < 0.05). The cumulative incidence of the primary endpoint was highest in the group with 1Y-HbA1c ≥7.0 % (log-rank p = 0.001). Multivariate analysis demonstrated that higher 1Y-HbA1c was independently associated with a higher incidence of the primary endpoint (adjusted p = 0.005). In conclusion, hyperglycemia during clinical follow-up is a risk factor for progression of concomitant LV abnormal relaxation, leading to poor HF prognosis in patients with NIDCM.
Keywords: Diabetes; Diastolic dysfunction; Dilated cardiomyopathy; Prognosis.