title: The predictive value of exercise QRS duration changes for post-PTCA coronary events.
abstract: BACKGROUND
  The sensitivity and predictive values of exercise ECG testing using ST-T criteria after percutaneous transluminal coronary angioplasty (PTCA) are low, precluding its routine use for screening for restenosis. The predictive value of QRS duration criteria during exercise testing (ET) ECG after PTCA for future coronary events has not been reported. The aim of the study was to compare QRS duration changes with ST-T criteria during ET, as a predictor of coronary events after PTCA.
  
  
  METHODS
  A prospective study of 206 consecutive patients who underwent ET at a mean of 34 +/- 14 days after their first PTCA, and were the followed for a mean of 23 +/- 9 months. Patients were divided by QRS duration into two groups-Q1: ischemic response (QRS duration prolongation of more than 3 ms relative to the resting duration), and Q2: normal response (QRS duration shortening or without change from resting duration). Patients were also divided by their ST-T response, S1: ischemic response, and S2: normal response.
  
  
  RESULTS
  During follow-up 52 patients (58%) experienced restenosis or MI, or underwent CABG-Q1: 44 (85%), Q2: 8(15%) (P < 0.0002), S1: 8 (15%), S2: 44 (85%), (P < 0.641), two patients died-Q1: 1 (1%) and Q2: 1 (1%). For QRS and ST-T, the relative risk of having at least one of the coronary events was 4.02 (CI 2.1-9.9) versus 1.13 (CI 0.8-2.9), respectively. The sensitivity for future coronary events was 85% and 52% and the specificity was 48% and 98% for the QRS and ST-T criteria, respectively.
  
  
  CONCLUSIONS
  QRS prolongation during peak ET ECG after PTCA is a more sensitive marker than ST-T criteria for detection of patients at risk for later coronary events.
authors.affiliation: Exercise Testing Unit, Cardiology Department, Soroka University Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel. efratishai@barak-online.net
authors.forename: Shai
authors.initials: S
authors.lastname: Efrati
authors.forename: Angel
authors.initials: A
authors.lastname: Cantor
authors.forename: Benjamin
authors.initials: B
authors.lastname: Goldfarb
authors.forename: Reuben
authors.initials: R
authors.lastname: Ilia
mesh_terms: D015906:Angioplasty, Balloon, Coronary; D001026:Coronary Artery Bypass; D003327:Coronary Disease / Q000175:diagnosis* / Q000628:therapy; D023903:Coronary Restenosis / Q000175:diagnosis / Q000453:epidemiology; D004562:Electrocardiography; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis / Q000453:epidemiology; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment