Dr Nakano said: "Many randomised clinical trials, such as Treating to New Targets (TNT) and PROVE IT-TIMI, have shown that aggressive cholesterol lowering with statins improves clinical outcomes in patients with CAD and high LDL-C levels.1,2 But until now it was not known whether aggressive lipid lowering with statins would also benefit CAD patients with very low LDL-C levels."
The current study used the Ibaraki Cardiovascular Assessment Study (ICAS), a registry of 2,238 patients from 12 hospitals in the Ibaraki region of Japan, who between 0 and 1 month underwent percutaneous coronary interventions. Based on serum LDL-C levels at initial presentation participants were classified into three groups: very low (<70 mg/dl, n=214); low (71-100 mg/dl, n=669); and high (>101 mg/dl, n= 1,355). Decisions of whether to prescribe statins or not, as well as the type and dose, were left to the discretion of treating physicians.
Patients were followed up for a maximum of 3 years. The efficacy of statin treatment was analysed on the composite outcome of Major Cardiovascular Events (MACE), defined as all cause mortality, non-fatal myocardial infarction and non-fatal stroke.
Statins were prescribed in 68% of patients (143) with very low LDL-C, 67% of patients (450) with low LDL-C and 67% of patients (913) with high LDL-C. A total of 204 patients experienced MACE during the median follow-up of 404 days.
The results of a Kaplan-Meier estimate show that three years of statin treatment produced significant reductions in the incidence of MACE in all three groups (p<0.001 for all groups). A Cox regression hazard analysis adjusted for age and gender showed that statins were the main determinant of better outcome regardless of the LDL-C level (p<0.01).
Dr Nakano said: "Our study shows that CAD patients with very low LDL-C levels at initial presentation also benefit from statin treatment. We speculate that statins prevent the enlargement of atherosclerotic plaques and plaque disruption in these patients."
She added: "Some doctors have been hesitant to prescribe statins in patients with very low LDL-C because of uncertain benefit and the risk of side effects with statins. But our findings suggest that all CAD patients should receive statins to reduce their risk of future cardiovascular events."
Dr Nakano concluded: "The next step should now be to initiate a randomised controlled trial of statin use in patients with CAD and very low LDL-C levels. This trial should be designed to confirm the benefits of statins for preventing future cardiovascular events in these patients, and to identify which type and dose of statins are most beneficial."