title: Prolonged QT interval in ST-elevation myocardial infarction: predictors and prognostic value in medium-term follow-up.
abstract: OBJECTIVE
  The prognostic role of corrected QT interval in ST-elevation myocardial infarction is still unknown. This study aims to identify the prognostic value of corrected QT interval prolongation (≥480 ms) in acute coronary syndrome.
  
  
  METHODS
  One hundred and eighty-five consecutive patients with ST-elevation myocardial infarction were prospectively enrolled and electrocardiographic monitoring of corrected QT interval was performed during the hospitalization.
  
  
  RESULTS
  Over a mean period of 17.6 ± 11 months, 16 (8.6%) patients died because of cardiovascular diseases, 6 (3.2%) patients experienced aborted sudden cardiac death, 3 (1.6%) cerebral ischemic strokes, 11 (6%) recurrent myocardial ischemia and 6 (3.2%) acute heart failure. At univariate analysis a corrected QT interval peak of at least 480 ms relates to cardiovascular death (P < 0.001), aborted sudden cardiac death (P = 0.037), cerebral ischemic stroke (P = 0.016) and recurrences of myocardial infarction (P = 0.032). Multivariate analysis confirms its role an independent predictor of cardiovascular death [odds ratio 6.38, 95% confidence interval (CI) 1.77-22.92, P = 0.004], together with an ejection fraction of 35% or less (odds ratio 4.20, 95% CI 1.24-14.16, P = 0.021). The presence of either corrected QT of at least 480 ms or ejection fraction of 35% or less increases the sensitivity and the accuracy to correctly predict cardiovascular death without a significant reduction in specificity (sensitivity 88%, specificity 69%, accuracy 88%, area under curve 0.83, 95% CI 0.72-0.94, P < 0.01).
  
  
  CONCLUSIONS
  A corrected QT interval peak of at least 480 ms in the acute phase of ST-elevation myocardial infarction is an independent predictor of cardiovascular death. Its association with reduced ejection fraction (≤35%) increases risk stratification accuracy.
authors.affiliation: Division of Cardiology, Department of Medical Sciences, Città della Salute e della Scienza Hospital, University of Turin, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Galluzzo
authors.forename: Cristina
authors.initials: C
authors.lastname: Gallo
authors.forename: Alberto
authors.initials: A
authors.lastname: Battaglia
authors.forename: Simone
authors.initials: S
authors.lastname: Frea
authors.forename: Federico G
authors.initials: FG
authors.lastname: Canavosio
authors.forename: Michela
authors.initials: M
authors.lastname: Botta
authors.forename: Serena
authors.initials: S
authors.lastname: Bergerone
authors.forename: Fiorenzo
authors.initials: F
authors.lastname: Gaita
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015906:Angioplasty, Balloon, Coronary; D004562:Electrocardiography / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D012307:Risk Factors; D000072657:ST Elevation Myocardial Infarction / Q000175:diagnosis* / Q000628:therapy; D012680:Sensitivity and Specificity