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The predictive value of exercise QRS duration changes for post-PTCA coronary events
Shai Efrati1, Angel Cantor, Benjamin Goldfarb
1Exercise 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
Summary
Exercise ECG testing using QRS duration changes after percutaneous transluminal coronary angioplasty (PTCA) is a more sensitive predictor of future coronary events than ST-T criteria. This finding aids in identifying patients at higher risk post-PTCA.
Area of Science:
- Cardiology
- Exercise Physiology
Background:
- Exercise electrocardiogram (ECG) testing with ST-T criteria has low sensitivity for detecting restenosis after percutaneous transluminal coronary angioplasty (PTCA).
- The predictive value of QRS duration changes during exercise testing (ET) for coronary events post-PTCA remains largely unreported.
Purpose of the Study:
- To compare the efficacy of QRS duration changes versus ST-T criteria during ET as predictors of coronary events after PTCA.
- To evaluate the sensitivity and specificity of QRS duration changes for identifying patients at risk for future coronary events post-PTCA.
Main Methods:
- A prospective study involving 206 patients who underwent ET 34 days post-PTCA, followed for 23 months.
- Patients were categorized based on QRS duration changes (prolongation: ischemic response; shortening/no change: normal response) and ST-T response (ischemic vs. normal).
Main Results:
- Patients with QRS duration prolongation (ischemic response) had a significantly higher incidence of restenosis, myocardial infarction (MI), or coronary artery bypass grafting (CABG) (85% vs. 15%, P < 0.0002).
- The relative risk of coronary events was 4.02 for QRS duration changes versus 1.13 for ST-T criteria.
- Sensitivity for future events was 85% for QRS duration and 52% for ST-T criteria; specificity was 48% for QRS duration and 98% for ST-T criteria.
Conclusions:
- QRS duration prolongation during peak ET ECG after PTCA is a more sensitive marker than ST-T criteria for detecting patients at risk for later coronary events.
- QRS duration criteria offer a valuable tool for risk stratification in patients post-PTCA.