title: 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.
abstract: OBJECTIVE
  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.
  
  
  CONCLUSIONS
  Grade 3 ischemia on presentation of STEMI and duration of chest pain are strong independent predictors of failure to achieve complete STR after pPCI.
authors.affiliation: The Division of Cardiology, The Department of Internal Medicine, University of Texas Medical Branch, Galveston, TX, USA.
authors.forename: Jarrett T
authors.initials: JT
authors.lastname: McGehee
authors.forename: Umamahesh C
authors.initials: UC
authors.lastname: Rangasetty
authors.forename: Shaul
authors.initials: S
authors.lastname: Atar
authors.forename: Nestor N
authors.initials: NN
authors.lastname: Barbagelata
authors.forename: Barry F
authors.initials: BF
authors.lastname: Uretsky
authors.forename: Yochai
authors.initials: Y
authors.lastname: Birnbaum
mesh_terms: D015906:Angioplasty, Balloon, Coronary / Q000706:statistics & numerical data*; D002637:Chest Pain / Q000175:diagnosis / Q000453:epidemiology*; D004562:Electrocardiography / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000453:epidemiology* / Q000601:surgery*; D017202:Myocardial Ischemia / Q000145:classification / Q000453:epidemiology*; D017063:Outcome Assessment, Health Care / Q000379:methods; D011379:Prognosis; D015203:Reproducibility of Results; D012189:Retrospective Studies; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013781:Texas / Q000453:epidemiology