Ischemia-Guided Coronary Revascularization Following Lower-Extremity Revascularization Improves 5-Year Survival of Patients With Chronic Limb-Threatening Ischemia

Abstract

Purpose:

To determine whether diagnosis of asymptomatic (silent) coronary ischemia using coronary computed tomography (CT)-derived fractional flow reserve (FFR_CT) together with targeted coronary revascularization of ischemia-producing coronary lesions following lower-extremity revascularization can reduce adverse cardiac events and improve long-term survival of patients with chronic limb-threatening ischemia (CLTI).

Materials and methods:

Prospective cohort study of CLTI patients with no cardiac history or symptoms undergoing elective lower-extremity revascularization. Patients with pre-operative coronary computed tomography angiography (CTA) and FFR_CT evaluation with selective post-operative coronary revascularization (FFR_CT group) were compared with patients with standard pre-operative evaluation and no post-operative coronary revascularization (control group). Lesion-specific coronary ischemia was defined as FFR_CT≤0.80 distal to a coronary stenosis with FFR_CT≤0.75 indicating severe ischemia. Endpoints included all-cause death, cardiac death, myocardial infarction (MI) and major adverse cardiovascular (CV) events (MACE=CV death, MI, stroke, or unplanned coronary revascularization) during 5 year follow-up.

Results:

In the FFR_CT group (n=111), FFR_CT analysis revealed asymptomatic (silent) coronary ischemia (FFR_CT≤0.80) in 69% of patients, with severe ischemia (FFR_CT≤0.75) in 58%, left main ischemia in 8%, and multivessel ischemia in 40% of patients. The status of coronary ischemia in the control group (n=120) was unknown. Following lower-extremity revascularization, 42% of patients in FFR_CT had elective coronary revascularization with no elective revascularization in controls. Both groups received guideline-directed medical therapy. During 5 year follow-up, compared with control, the FFR_CT group had fewer all-cause deaths (24% vs 47%, hazard ratio [HR]=0.43 [95% confidence interval [CI]=0.27-0.69], p<0.001), fewer cardiac deaths (5% vs 26%, HR=0.18 [95% CI=0.07-0.45], p<0.001), fewer MIs (7% vs 28%, HR=0.21 [95% CI=0.10-0.47], p<0.001), and fewer MACE events (14% vs 39%, HR=0.28 [95% CI=0.15-0.51], p<0.001).

Conclusions:

Ischemia-guided coronary revascularization of CLTI patients with asymptomatic (silent) coronary ischemia following lower-extremity revascularization resulted in more than 2-fold reduction in all-cause death, cardiac death, MI, and MACE with improved 5 year survival compared with patients with standard cardiac evaluation and care (76% vs 53%, p<0.001).

Clinical Impact

Silent coronary ischemia in patients with chronic limb-threatening ischemia (CLTI) is common even in the absence of cardiac history or symptoms. FFRCT is a convenient tool to diagnose silent coronary ischemia perioperatively. Our data suggest that post-surgery elective FFRCT-guided coronary revascularization reduces adverse cardiac events and improves long-term survival in this very-high risk patient group. Randomized study is warranted to finally test this concept.