Cholesterol levels and the benefit of statins in heart failure.

lesterol levels and cardiovascular disease is indisputable. High cholesterol is a major, modifiable risk factor for the development of coronary artery disease. Randomised studies have shown the benefit of the pharmacological modification of cholesterol in patients with established coronary artery disease (secondary prevention), as well as in healthy individuals with a high risk of coronary artery disease (primary prevention). The large clinical studies WOSCOPS, 4S, LIPID and CARE showed that a reduction in cholesterol levels of >25% resulted in an overall reduction in the incidence of cardiac events. Statins are the most effective hypolipidaemic drugs. Their main mechanism of action involves inhibition of methylglutaryl-coenzyme reductase, which is the enzyme controlling cholesterol synthesis. Heart failure (HF) is a health problem world wide. The risk of developing heart failure is strongly correlated with the presence of coronary artery disease and statin administration has been shown to prevent the development of new HF. In the randomised GREACE study (1600 patients), the administration of atorvastatin (mean daily dose 24 mg) to patients with coronary artery disease led to a significant reduction in overall mortality, coronary morbidity and mortality, cerebrovascular episodes and the incidence of congestive HF over a threeyear follow up period. The multicentre, randomised, controlled ASCOT-LLA study (10305 subjects) assessed the benefit of cholesterol reduction using a statin (10 mg atorvastatin) in hypertensive patients with normal or slightly elevated levels of total cholesterol (≤250 mg/dl). The patients were not known to have coronary artery disease or HF. The study was interrupted at 3.3 years, instead of the 5 years originally planned, because of the significant reduction in coronary and cerebrovascular episodes seen in the atorvastatin group. The development of fatal and non-fatal HF was included as a secondary endpoint of the study, but the two groups showed no statistically significant difference in its incidence. Since coronary artery disease is a primary cause of HF, it is reasonable to expect that high cholesterol could have a detrimental effect on the mortality of patients with confirmed HF. However, advanced HF is associated with low cholesterol concentrations and the higher mortality among patients with HF and low cholesterol has been confirmed by research. Vredevoe et al recorded higher mortality in 109 patients with severe HF due to dilated cardiomyopathy and low levels of total cholesterol, LDL, HDL and triglycerides, while Richartz et al found that low cholesterol levels were associated with higher mortality in 45 patients with ischaemic