Impact of Calcified Target Lesions on the Outcome of Percutaneous Coronary Intervention for Acute Coronary Syndrome: Insights From the BASE ACS Trial.

Abstract

We performed a post hoc analysis of outcome in patients with, versus those without, calcified target lesions from the BASE ACS trial. The outcome of contemporary stent implantation in patients with calcified lesions presenting with acute coronary syndrome is unknown. The BASE ACS trial randomized 827 patients (1:1) presenting with acute coronary syndrome to receive either titanium-nitride-oxide-coated stents or everolimus-eluting stents. Calcified lesions were defined as moderate or severe calcification in the vessel wall by coronary angiography. The primary endpoint was major adverse cardiac events (MACE): a composite of cardiac death, non-fatal myocardial infarction or ischemia-driven target lesion revascularization. Follow-up was planned at 12 months, and yearly thereafter for up to 7 years. Of 827 patients enrolled in the trial, 352 (42.6%) had calcified target lesions. Median follow-up was 5.0 years. The incidence of MACE was higher in patients with, versus those without, calcified target lesions (19.6% vs. 12.2%, respectively, P = 0.004). This was driven by more frequent cardiac death and non-fatal myocardial infarction events (P < 0.05, both). The rates of ischemia-driven target lesion revascularization were comparable (P > 0.05). MACE and the other endpoints were comparable between the 2 propensity-score matched subgroups (P > 0.05 for all). Hypertension and smaller vessel size independently predicted MACE in patients treated for calcified lesions. Patients presenting with acute coronary syndrome who were treated for calcified lesions had worse long-term clinical outcome, compared with those treated for non-calcified lesions, mainly due to more frequent safety events. In the propensity score-matched analysis, the outcome was comparable.