Significance of dyslipidaemia in patients with heart failure of unexplained aetiology

Abstract

Background: Dyslipidaemia has been studied in the prognosis of heart failure (HF). Little is known about the role of dyslipidaemia in the aetiopathogenesis of dilated cardiomyopathy (DCM).

Aim: To assess (1) serum lipid levels in DCM considering the severity of heart failure; (2) the association between DCM and lipid abnormalities; (3) prognostic significance of lipids in DCM.

Methods: The study group consisted of 100 patients with angiographically proven DCM [mean age 42 years, 80% males, 65% in NYHA class III-IV, mean left ventricular ejection fraction (LVEF) 32%], whose fasting serum lipids had been assessed during diagnosis between 1992 and 2001. Patients' lipid levels were compared with those observed in healthy controls (n=100), age-, gender-, and BMI-matched and related to findings reported in population samples from WHO Pol-MONICA studies from: 1993 (n=526), 1997/1998 (n=526) and 2001 (n=1364). Three (3%) patients received lipid-lowering drugs. Transplant-free survival was assessed in the study group. In the statistical analysis, nonparametric Wilcoxon test and uni- and multivariate logistic and Cox regression analyses were used.

Results: Serum total cholesterol (TC), LDL (LDL-C) and HDL cholesterol (HDL-C) tended to be lower (differences NS) in NYHA class III-IV patients vs. class I-II (TC: 196.9+/-45.5 vs. 207.9+/-47.1 mg/dl, LDL-C 126.2+/-37.5 vs. 128.5+/-42.7 mg/dl, HDL-C 44.2+/-11.3 vs. 44.7+/- +/-13.7 mg/dl, respectively), and triglycerides (TG) were lower in advanced HF vs. NYHA class I-II (135.9+/-51 vs. 170.3+/-63.4 mg/dl, p=0.004). In DCM patients HDL-C was lower than in controls (44.1+/-12.1 vs. 54.3+/-17.6 mg/dl, p <0.001), and TG level was higher (147.9+/-58.1 vs. 114.1+/-61.6 mg/dl, p <0.001). HDL-C and TG levels in controls were similar to those observed in population samples. Multivariate analysis with age, low HDL (defined as <40 mg/dl for males, and <50 mg/dl for females), and hyperTG (TG ł150 mg/dl) showed that both low HDL-C (OR=2.31; 95% CI 1.2-4.457, p=0.0122), and hyperTG (OR=1.978, 95% CI 1.029-3.799, p=0.0407) were independently associated with DCM. Low HDL-C level occurred more frequently in female DCM patients vs. in males (65 vs. 33.8%, p=0.022). There was a trend towards more frequent occurrence of hyperTG in male patients vs. females (42.5 vs. 20%, p=0.11). The mean follow-up time was 7.32+/-4.7 years. In Cox univariate analysis low TC tended to be a prognostic factor (p=0.067), but in Cox multivariate analysis only NYHA class (HR=1.7, 95% CI 1.136-2.541; p=0.01) and LVEF (HR=0.963, 95% CI 0.932-0.996; p=0.027) turned out to be independent predictors of poor outcome.

Conclusion: Dyslipidaemia might play a role in the aetiopathogenesis of DCM. Low TC is not an independent prognostic factor in DCM.