High prevalence of asymptomatic ischemia-producing coronary stenosis in patients with critical limb ischemia: Anatomic and functional assessment with coronary CT-derived fractional flow reserve (FFR_CT)

Objectives. The purpose of this study was to determine the prevalence of unsuspected hemodynamically significant coronary stenosis in patients with no cardiac history who are undergoing surgery for critical limb ischemia (CLI) and to assess the potential benefit of FFR_CT analysis in patient management. Methods. Stable CLI patients with no evidence of coronary artery disease (CAD) who were scheduled for lower extremity revascularization underwent pre-op evaluation with coronary CT angiography-derived fractional flow reserve (FFR_CT) in a prospective IRB-approved study. Ischemia-producing coronary stenosis was defined as FFR_CT ≤0.80 distal to >30% CT stenosis with severe ischemia defined as FFR_CT ≤0.70. Major adverse coronary events (MACE) were evaluated at 30 and 90 days. Results. Asymptomatic, ischemia-producing coronary stenosis was found in 37 of 54 patients (69%), and severe lesion-specific ischemia was present in 23 patients (43%). Multi-vessel ischemia was present in 21 patients (38%). Lower extremity revascularization was performed as scheduled in 49 patients (91%) and postponed in 5 (1 with PCI, 1 with CABG, 3 with medical treatment). In 24 patients with severe or multi-vessel ischemia, elective coronary angiography was performed post-operatively with coronary revascularization in 16 (12 with PCI and 4 with CABG). There have been no MACE events at 30- and 90-day follow-up. Conclusions. CLI patients with no cardiac history undergoing limb salvage surgery have a high prevalence of asymptomatic ischemia-producing coronary stenosis which may put them at increased risk. Pre-operative diagnosis with FFR_CT analysis may increase focus on peri- and post-operative cardiac care and improve outcomes. The value of selective post-op coronary revascularization to improve survival of CLI patients requires further study.