Statin use in patients with extremely low low-density lipoprotein levels is associated with improved survival

Background - Aggressive lipid management has recently become the standard of care for patients with coronary heart disease. The safety and effectiveness of statin usage for patients with extremely low low- density lipoprotein (LDL) levels are less clear, however. The aim of this study was to investigate the safety and clinical outcomes of statin treatment in patients with LDL cholesterol levels below 60 mg/dL. Methods and Results - A total of 6107 consecutive patients with LDL levels less than 60 mg/ dL were identified from a tertiary care medical center or affiliated community clinic. Statin therapy was defined as a prescription during the 150 days after the low LDL value was obtained. The propensity to be treated with a statin was used to adjust the association of statin therapy and survival. A total of 4295 patients (70%) had at least 1 prescription for any medication during the 150- day observation period after the low LDL value. Their mean age was 65 years, 43% had prior ischemic heart disease, and 47% had diabetes mellitus. Statins were prescribed in 2564 patients (60%) after the low LDL value was observed. During a mean follow- up of 2.0 +/- 1.4 years after the observation period, there were 510 deaths. After controlling for the propensity to receive a statin, statin therapy was associated with improved survival (hazard ratio [HR], 0.65; 95% CI, 0.53 to 0.80). This lower mortality was also observed for subgroups of patients already taking statins at baseline (HR, 0.58; 95% CI, 0.38 to 0.88), those with extremely low LDL levels ( < 40 mg/ dL, n = 623; HR, 0.51; 95% CI, 0.33 to 0.79), and those without a history of ischemic heart disease ( n = 2438; HR, 0.58; 95% CI, 0.42 to 0.80). Statin use was not associated with an increase in malignancy, transaminase elevation, or rhabdomyolysis. Conclusions - Statin therapy in the setting of a very low LDL level appears to be safe and is associated with improved survival.