Abstract 2499: Intravascular Ultrasound Analysis of Culprit Lesion in Young Population with Acute Myocardial Infarction
Background: A minority of acute myocardial infarction (AMI) occur in pts younger than 45 or older than 80. We hypothesized that these “outliers” might have age-dependent differences in culprit lesion morphology.
Methods: We used pre-intervention intravascular ultrasound to compare 49 pts younger than 45 yrs (mean 40 ± 3.8yrs) vs 42 pts older than 80 years (mean age 85 ± 3.9). Presence of ST elevation MI was similar in younger and in octogenarian population (28% vs 37%). Standard IVUS qualitative and quantitative measurements were performed at lesion site and references.
Results: As shown in the Table⇓, compared to octogenarians, culprit lesions in younger patients were shorter, lumen area was larger, plaque rupture was more common (35% vs 9%, p=0.004 ), thrombus formation more common (24% vs 2%, p=0.002), and positive remodeling more common. Moreover, younger patients had more soft plaque (47% vs 19%, p=0.005 ) and fibrous plaque (20% vs 5%, p=0.027) while octogenarians more often had calcified plaque (57% vs 8%, p=0.000 ).
Conclusion: Morphology of culprit lesion in AMI depends on pts age with higher incidence of ruptures plaques, thrombus formation, and positive remodeling and shorter lesions in younger population. This suggests that the mechanism of AMI in these two patient groups is also different.