CHICAGO—Atorvastatin (Lipitor) is as effective in preventing major cardiovascular events in type 2 diabetics who have impaired renal function as it is in those with normal renal function, according to data presented here at the 67th Scientific Sessions of the American Diabetes Association.
Helen M. Colhoun, MD, professor of genetic epidemiology at UniversityCollege in Dublin, Ireland, and her colleagues elsewhere examined the effectiveness of lipid-lowering drug therapy in diabetic patients with impaired renal function using data from the Collaborative Atorvastatin Diabetes Study (CARDS).
This trial, enrolling 2,838 patients, demonstrated that atorvastatin 10 mg/day decreased the risk of a first major cardiovascular event by 37% in type 2 diabetics. The study was the first primary-prevention trial of cholesterol-lowering specifically in type 2 diabetics who have not experienced a cardiovascular event.
“There is now a large evidence base from trials in over 20,000 patients showing that statins are effective in preventing cardiovascular events,” Dr. Colhoun observed. “However, whether these protective effects are present in all subgroups of diabetic patients has been questioned. In particular, there has been skepticism about whether statins are effective in reducing CVD in patients with impaired renal status.”
In fact, the National Kidney Foundation (NKF) guidelines for treating CKD has voiced concern about the lack of data on this question and considers only “moderate” the evidence that LDL-cholesterol therapy reduces CVD in diabetics with CKD stages 1-3.
In the new analysis, Dr. Colhoun’s group looked at whether the absolute risk of major cardiovascular events varied by baseline estimated glomerular filtration rate (eGFR) in CARDS and whether the effect of atorvastatin 10 mg/day on CVD in the trial varied by baseline eGFR. In the CARDS trial, eGFR was assessed at baseline in 2,744 patients with renal data using the Modification of Diet in Renal Disease (MDRD) study and Cockcroft-Gault equations. Although the total mortality during follow-up was higher in patients with a baseline eGFR less than 60 mL/min/1.73 m2, the finding was not significant, Dr. Colhoun said.
Patients with a baseline eGFR less than 60 mL/min/1.73 m2 were not at increased risk of major cardiovascular events or death compared with patients with a higher eGFR. The findings were similar when the Cockcroft-Gault equation was used to estimate GFR.
The reduction in major cardiovascular events in all participants with available baseline renal data was 41%. The subset of patients with reduced renal function had the same substantial reduction (48%) in CVD end points, including a 42% reduction in acute coronary heart disease events, a 62% reduction in stroke, and a 59% reduction in coronary revascularization as the overall study population.
The absolute risk reduction in major cardiovascular events associated with atorvastatin treatment over four years was 3.8% in patients with a higher eGFR versus 3.0% in those with a lower eGFR. Based on the findings, Dr. Colhoun urged the NKF to consider as strong the evidence showing that lipid-lowering therapy reduces CVD in diabetics with stages 1-3 CKD.