PREVENT III Shows Racial, Site Inequality for CLI Medical Therapy

By Mark S. Lesney

Although the PREVENT III trial was designed to study edifoligide for the prevention of vein graft failure, demographic and comorbidity studies on the baseline cohort showed that a significant percentage of the population that undergoes surgical revascularization for critical limb ischemia is not prescribed therapies of proven benefit for reducing cardiovascular risk, reported Michael S. Conte, M.D., and his colleagues.

Additionally, the data from the Project of Ex-Vivo Vein Graft Engineering via Transfection III (PREVENT III) trial indicated that African American patients with critical limb ischemia (CLI) were at greater risk for undertreatment with antithrombotics, and that patients undergoing treatment at university hospitals receive more comprehensive medical treatment of atherosclerosis, according to the report published in the Journal of Vascular Surgery (2005;42:456-64).

According to the report, the study is the largest prospective trial in patients undergoing lower limb bypass surgery in North America and reflects current practice trends in treating advanced peripheral artery disease (PAD). The racial breakdown of the study cohort was 72% Caucasian, nearly 18% African American, nearly 8% Hispanic, less than 1% Asian, and the rest other.

"Despite the frequent presence of other recognized cardiovascular risk factors among this cohort and the growing recognition of PAD itself as a risk factor equivalent to CAD [coronary artery disease], a significant underutilization of standard medical therapy was observed. Approximately one in four patients with CLI were not receiving antithrombotic medications at baseline, and more than half did not receive b-blocker or lipid-lowering therapies," stated Dr. Conte, division of vascular surgery, Brigham and Women's Hospital, Boston, and his colleagues.

Although 76% of patients were taking an antithrombotic at the time of trial entry, African American race was significantly and negatively associated with antithrombotic use at baseline (63% vs. 79% Caucasian/other). In addition, although antithrombotic drugs were overall positively associated with use at hospital discharge, African American race had a negative association (OR 0.6; 95% CI) with the use of antithrombotics at discharge, although overall use increased from 63% at baseline to 81% at discharge.

For all three drug categories, reduced rates of use in nonuniversity settings were observed, with the most dramatic differences being in discharge medications. This suggested to the authors "that the aggressiveness of perioperative management, as opposed to variations in the populations treated among sites, was most likely responsible."

The results show that hospitalization for peripheral vascular disease presents "a critical opportunity...to optimize the management of all atherosclerosis risk factors," because this patient cohort tends to be underprescribed.

The researchers concluded, "This study has potentially important implications for all practitioners involved in the treatment of patients with PAD and for vascular surgeons in particular. Prior studies have demonstrated that PAD patients commonly identify vascular surgeons as their primary physician."