PHILADELPHIA — Statin use cut the incidence of major vascular events in patients with peripheral arterial disease in a subanalysis of results from the Heart Protection Study.
The results show that “all patients with peripheral arterial disease [PAD] should be on a statin regardless of their baseline lipid level,” Dr. Richard Bulbulia said at the Vascular Annual Meeting.
“This is probably the first study to show the benefit of statin treatment in a predominantly PAD group. [These are] very important data,” commented Dr. Thomas F. Lindsay, director of the vascular center at Toronto General Hospital.
The study used data collected in the Heart Protection Study, a British trial with more than 20,000 patients that compared treatment with 40 mg of simvastatin daily with placebo (Lancet 2002; 360:7–22). The total group included patients with coronary disease, other occlusive arterial disease, or diabetes. In the overall study, treatment with the statin was linked to a relative cut in deaths of 13% and lowered major vascular events by 24% during 5 years of follow-up.
The new analysis focused on the 6,748 patients who entered the study with documented PAD. This subgroup included patients with coincident coronary disease, coincident cerebrovascular disease, coincident diabetes, and more than 1,400 patients who had PAD as their only preexisting disorder.
During 5 years of follow-up of the entire PAD subgroup, the rate of major vascular events (coronary death, nonfatal myocardial infarction, stroke, or revascularization) was 26% in the statin-treated group and 33% in the placebo group, a statistically significant difference, reported Dr. Bulbulia, a researcher with the clinical trial service unit of the University of Oxford (England).
The degree of event reduction from statin therapy in this subgroup was very similar to what was seen in the entire study, and in the subset of patients who did not have PAD at entry.
Statin treatment led to a significant reduction in vascular events regardless of whether patients started with a serum level of low density lipoprotein (LDL) cholesterol above or below 116 mg/dL.
These results also probably underestimated the impact of simvastatin treatment because some patients in the statin group stopped taking their drugs, and some patients in the placebo group eventually started on a statin, Dr. Bulbulia said.
Another analysis of the data, using the entire study group, looked at the ability of statin treatment to cut the incidence of major peripheral vascular events. These were defined as noncoronary revascularizations, aneurysm repair, major amputations, or deaths due to PAD.
These events occurred in 4.7% of the statin-treated patients and in 5.5% of those on placebo, a statistically significant difference. The impact of statin therapy on reducing peripheral vascular events has not been previously reported in any other statin-treatment study, Dr. Bulbulia said. This effect by simvastatin treatment was primarily driven by a lower rate of peripheral revascularization procedures.
These results, along with other recent findings on statin therapy, suggest that the lower the level of LDL cholesterol in patients with PAD the better.