Abstract P178: Echocardiographic Correlates of Persistent Q-Waves in Patients With ST-Elevation Myocardial Infarction Treated With Primary Percutaneous Coronary Intervention

Abstract

Background Historic data suggests 65-70% prevalence of Q-waves and concurrent wall motion abnormalities in patients with ST-elevation myocardial infarction (STEMI) treated with thrombolytics. We investigated prevalence of post-MI Q-waves and correlation between Q-waves and left ventricular wall motion abnormalities in STEMI patients treated with primary percutaneous coronary intervention (PCI). Study Design A retrospective study cohort included 145 patients (24% females, 57+/-13 years old) without prior Q-wave MI who underwent successful primary PCI for STEMI at a single academic tertiary center. New York State Angioplasty Registry endpoints were utilized. Echocardiograms and ECGs (median 53 days post STEMI) were reviewed for presence or absence of segmental wall motion abnormalities (WMAs) and Q-waves. ANOVA and chi-square analyses were performed. Results Prevalence of post PCI Q-waves in STEMI patients was 69%, similar to historic 64% in TIMI 14 trial patients (p=0.258). Timing of PCI was not a significant predictor of Q-waves, but there was a trend towards higher pre- and post-PCI creatine kinase and troponin levels in patients with Q-waves. Patients with history of hypertension were less likely to develop Q-waves (62% vs. 77%, p=0.048), while age, gender, history of CHF, COPD, diabetes, renal failure, smoking, and admission hemodynamic status were not predictive of post-PCI Q-waves. WMAs were present in 38% of patients with Q-waves vs. 9% in the rest of the cohort (p=0.0003). Q-waves were equally likely to develop regardless of location of ST elevations at presentation; however, WMAs were more likely in patients with Q-waves in leads II-III-AVF (p=0.008) and V1-2-3 (p<0.0001), V4-5-6 (p=0.008), but not I-AVL (p=0.07). Positive predictive value for WMAs in patients with Q waves was 38%, while negative predictive value for lack of WMAs in patients without Q waves was 91%. Conclusions Prevalence of Q waves, reflective of myocardial damage, in STEMI patients treated with primary coronary intervention is similar to such observed in thrombolysis trials. Positive predictive value of Q-waves for WMAs is low. In CAD patients without Q-waves segmental WMAs are unlikely.