Long-term prognostic value of Duke treadmill score and exercise thallium-201 imaging performed one to three years after percutaneous transluminal coronary angioplasty

The value of exercise nuclear perfusion imaging performed beyond the 6- month restenosis window for percutaneous transluminal coronary angioplasty (PTCA) has not been explored. This study evaluates the long-term prognostic value of exercise thallium (Tl)-201 imaging after PTCA. We studied the late outcome of a series of 211 patients with tomographic Tl-201 exercise studies performed between 1 to 3 years after PTCA. Follow-up was 96% complete at a median duration of 7.3 years. Most (73%) had 1- or 2-vessel coronary artery disease and normal left ventricular function and 193 (91%) had successful PTCA. Two thirds of the patients were symptomatic at the time of testing. The mean Duke score was 5 ± 6 and 125 (60%) patients had a low-risk Duke score. Mean summed stress score was 50 ± 9 and mean summed reversibility score was 3 ± 4. The 5-year overall survival was 95%, yielding a low annual mortality rate of 1%/year. The summed stress score exhibited a significant association (p = 0.047) with the end point of cardiac death or myocardial infarction. The Duke score was predictive of the combination end point of hard and soft cardiac events (p = 0.002). This study demonstrates that exercise Tl-201 perfusion imaging performed 1 to 3 years after PTCA was predictive of cardiac events.