Background: Ruptured plaques are associated with elevated C-reactive protein (CRP) that, in turn, are associated with a poor prognosis in acute myocardial infarction (AMI) patients.
Objectives: The purpose of this study was to evaluate the impact of plaque rupture and elevated CRP on major adverse cardiac events (MACE) in patients with AMI treated with coronary stenting.
Methods: We used pre-intervention intravascular ultrasound (IVUS) to evaluate infarct-related arteries in 72 AMI patients treated with coronary stenting to study the impact of plaque rupture and CRP levels on MACE.
Results: Infarct-related artery plaque rupture was observed in 30 patients (42%), and multiple infarct-related artery plaque ruptures were observed in 10 patients (14%). The CRP level was higher in patients with plaque rupture than in those without plaque rupture (31.3 +/- 20.3 vs. 4.2 +/- 5.8 mg/l; p < 0.001). Patients with elevated CRP levels had more plaque rupture and more multiple plaque ruptures than the normal CRP group (26/42 [62%] vs. 4/30 [13%]; p < 0.001, and 10/42 [24%] vs. 0/30 [0%]; p = 0.004, respectively). Plaque rupture and ST-segment elevation MI independently predicted CRP elevation (Hazard ratio [HR] = 5.329; p < 0.001 and HR = 3.790; p = 0.032, respectively). At 1-year follow up, MACE occurred in 9 plaque-rupture patients (30%), in 5 non-plaque rupture patients (12%) and in 29% of elevated CRP patients versus 7% of normal CRP patients. Patients with elevated CRP plus plaque rupture had more MACE than patients with normal CRP and no plaque rupture (31% vs. 4%; p = 0.010). In the multivariate analysis, an elevated CRP was the only independent predictor of MACE (HR = 6.561; p = 0.012).
Conclusions: Plaque rupture and elevated CRP were associated with poor prognosis; however, an elevated CRP was the only independent predictor of 1-year MACE in AMI patients treated with coronary stenting.