Ischemic outcomes after coronary intervention of calcified vessels in acute coronary syndromes. Pooled analysis from the HORIZONS-AMI (Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction) and ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) TRIALS

Objectives: This study sought to determine the frequency and impact of coronary calcification among patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndromes (ACS).

Background: Small studies in patients with stable coronary artery disease have suggested a worse prognosis after PCI of calcified compared with noncalcified lesions. Little is known about the impact of coronary calcification on outcomes after PCI for patients presenting with non-ST-segment elevation and ST-segment elevation ACS.

Methods: Data from 6,855 patients presenting with ACS in whom PCI was performed were pooled from 2 large-scale randomized, controlled trials, ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) and HORIZONS-AMI (Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction). One-year outcomes were analyzed according to the severity of PCI target lesion calcification (none/mild, moderate, or severe) as assessed by an independent angiographic core laboratory.

Results: Target lesion calcification was severe in 402 patients (5.9%), moderate in 1,788 (26.1%), and none/mild in 4,665 (68.1%). Moderate/severe target lesion calcification was more frequent in older patients, men, hypertensive patients, and those presenting with ST-segment elevation myocardial infarction (STEMI). The unadjusted 1-year rates of death, cardiac death, definite stent thrombosis, and ischemic target lesion revascularization (TLR) and target vessel revascularization were significantly increased in patients with moderate/severe target lesion calcification. By multivariable analysis, the presence of moderate/severe target lesion calcification was an independent predictor of 1-year definite stent thrombosis (hazard ratio [HR]: 1.62; 95% confidence interval [CI]: 1.14 to 2.30; p = 0.007) and ischemic TLR (HR: 1.44; 95% CI: 1.17 to 1.78; p = 0.0007).

Conclusions: Moderate/severe lesion calcification was relatively frequent in patients with non-ST-segment elevation ACS and STEMI and was strongly predictive of stent thrombosis and ischemic TLR at 1 year. (Comparison of Angiomax Versus Heparin in Acute Coronary Syndromes [ACS]; NCT00093158; Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction; NCT00433966).