Grade 3 ischemia on admission electrocardiogram and chest pain duration predict failure of ST-segment resolution after primary percutaneous coronary intervention for acute myocardial infarction.

OBJECTIVES: ST resolution (STR) is a surrogate marker of myocardial tissue reperfusion and a predictor of outcome after primary percutaneous coronary intervention (pPCI) for ST-elevation myocardial infarction (STEMI). Terminal QRS distortion (grade 3 ischemia) has been shown to predict failure of STR after thrombolysis for STEMI, but the ability of grade 3 ischemia to predict STR with pPCI is unclear. METHODS: We retrospectively analyzed 155 patients who underwent pPCI and compared grade 2 ischemia (ST elevation without terminal QRS distortion; n = 89) to grade 3 ischemia (n = 66) on admission for baseline characteristics, in-hospital course, and STR immediately after pPCI and at 18 to 24 hours. RESULTS: Patients with grade 3 ischemia were older (60 +/- 12 vs 56 +/- 11 years; P = .018), had more anterior STEMI (42% vs 17%; P = .0004), and were less often smokers (41% vs 90%; P = .004). The grade 3 ischemic group had significantly less complete STR (35% vs 75% [P < .00001] immediately after pPCI and 33% vs 79% [P < .00001] 18-24 hours after pPCI), a longer hospital stay (6.4 +/- 4.1 vs 4.9 +/- 1.9 days; P = .008), and higher peak CKMB (292 +/- 231 vs 195 +/- 176 ng/mL; P = .0005). Duration of symptoms before pPCI (odds ratio [OR], 0.838; 95% confidence interval [CI], 0.724-0.969; P = .017) and grade 3 ischemia (OR, 0.181; 95% CI, 0.068-0.480; P < .001) were negative predictors of complete STR, whereas nonanterior STEMI (OR, 5.95; 95% CI, 2.154-16.436; P < .001) and initial sum of ST elevation (OR, 3.132; 95% CI, 1.140-8.605; P = .027) were positive predictors. CONCLUSION: Grade 3 ischemia on presentation of STEMI and duration of chest pain are strong independent predictors of failure to achieve complete STR after pPCI.

Duke Scholars

Author N. Alejandro (Alex) Barbagelata Medicine, Cardiology