Impact of multiple complex plaques on short- and long-term clinical outcomes in patients presenting with ST-segment elevation myocardial infarction (from the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction [HORIZONS-AMI] Trial).

It is not known whether the extent and severity of nonculprit coronary lesions correlate with outcomes in patients with ST-segment elevation myocardial infarction (STEMI) referred for primary percutaneous coronary intervention (PCI). We sought to quantify complex plaques in patients with STEMI referred for primary PCI and to determine their effect on short- and long-term clinical outcomes by examining the core laboratory database for plaque analysis from the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction study. Baseline demographic, angiographic, and procedural details were compared between patients with single versus multiple complex plaques who underwent single-vessel PCI. Multivariable analysis was performed for predictors of long-term major adverse cardiac events (MACEs), a combined end point of death, reinfarction, ischemic target-vessel revascularization, or stroke, and for death alone. Single-vessel PCI was performed in 3,137 patients (87%): 2,174 (69%) had multiple complex plaques and 963 (31%) had a single complex plaque. Compared with those with a single complex plaque, patients with multiple complex plaques were older (p <0.0001) and had more co-morbidities. The presence of multiple complex plaques was an independent predictor of 3-year MACE (hazard ratio 1.58, 95% confidence interval 1.26 to 1.98, p <0.0001), and death alone (hazard ratio 1.68, 95% confidence interval 1.05 to 2.70, p = 0.03). In conclusion, multiple complex plaques are present in the majority of patients with STEMI who underwent primary PCI, and their presence is an independent predictor of short- and long-term MACE, including death (Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction; NCT00433966).