Background: We assessed the impact of remodeling patterns on pre- and post-procedural intravascular ultrasound (IVUS) findings and cardiac enzyme elevation after stenting in 310 acute myocardial infarction (AMI) patients.
Methods: The positive remodeling (PR) (PR group, n=113) was defined as remodeling index (lesion/reference external elastic membrane cross-sectional area) >1.05, intermediate remodeling (IR) as between 0.95 and 1.05, and negative remodeling (NR) as<0.95 (IR/NR group, n=197). IVUS findings included ruptured plaque (a cavity that communicated with the lumen with an overlying residual fibrous cap fragment), multiple ruptured plaques (different plaque ruptures separated by a >5-mm length of artery containing smooth lumen contours), thrombus (discrete intraluminal filling defects), and plaque prolapse (tissue extrusion through the stent strut at post-stenting). We compared pre- and post-procedural IVUS findings and cardiac-specific troponin I (cTnI) elevation after stenting according to the remodeling pattern.
Results: The plaque rupture (60% vs. 42%, p=0.004), multiple plaque ruptures (22% vs. 14%, p=0.014), and IVUS-detected thrombus (42% vs. 28%, p=0.012) were more common in the PR group compared with the IR/NR group. Post-stenting plaque prolapse was observed more frequently (36% vs. 22%, p=0.008), and cTnI was elevated more significantly after stenting in the PR group compared with the IR/NR group (DeltacTnI; +7.8+/-51.1 ng/ml vs. +0.9+/-41.1 ng/ml, p=0.008). Multivariate analysis showed that PR [odds ratio (OR)=1.92; 95% CI 1.04-2.98, p=0.028], plaque rupture (OR 1.98; 95% CI 1.16-3.45, p=0.025), IVUS-detected thrombus (OR 2.30; 95% CI 1.22-3.98, p=0.008), and plaque prolapse (OR 8.40; 95% CI 4.19-16.84, p<0.001) were independently associated with post-stenting cTnI elevation.
Conclusions: AMI patients with PR have more plaque vulnerability and higher frequency of plaque prolapse accompanied by post-procedural cardiac enzyme elevation compared with AMI patients with IR/NR.