Subclinical Peripheral Arterial Disease and Incompressible Ankle Arteries Are Both Long-Term Prognostic Factors in Patients Undergoing Coronary Artery Bypass Grafting

Abstract

This study was designed to determine the prevalence of peripheral arterial disease (PAD) in candidates for coronary artery bypass grafting (CABG) and to assess the predictive value of different types of subclinical PAD (peripheral occlusive disease and medial arterial calcification [incompressible ankle arteries]). Observational studies report poor prognosis after CABG in the presence of clinical PAD, but data on subclinical PAD are scarce. We prospectively enrolled CABG candidates and measured ankle-brachial index (ABI) preoperatively. Patients were divided into four groups: clinical PAD, subclinical PAD (ABI <0.85), incompressible arteries (ABI >1.5), and no PAD. The primary end point was a composite combining death, acute coronary syndrome, stroke or transient ischemic attack (TIA), and coronary or peripheral revascularization. Secondary end points were overall and cardiovascular death, acute coronary syndrome, and stroke or TIA. Statistical analyses were performed using the Cox regression model. We consecutively enrolled 1,022 patients (mean age 66.9 +/- 9.2 years). In addition to the 14% with clinical PAD, we detected subclinical PAD in 13% and medial artery calcification in 12%. During an actuarial follow-up of 4.4 years, 81.2% of patients remained event-free. Adverse factors were (p < 0.05) supraventricular arrhythmia (odds ratio [OR] 2.5), ejection fraction <0.40 (OR 2.3), combined valvular surgery (OR 2.5), clinical PAD (OR 3.6), subclinical PAD (OR 3.3), and medial artery calcification (OR 1.9). The latter three factors were also independently predictive for overall and cardiovascular death. Beyond clinical PAD, the measurement of ABI before coronary surgery provides substantial information on long-term postoperative prognosis. To our knowledge, this is the first study highlighting the prognostic role of incompressible ankle arteries in secondary prevention.