Significance of dyslipidaemia in patients with heart failure of unexplained aetiology.

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.