EXERCISE TECHNETIUM 99M SESTAMIBI SINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY LATE AFTER CORONARY-ARTERY BYPASS-SURGERY - LONG-TERM FOLLOW-UP

Background and hypothesis: The prognostic value of exercise technetium 99m sestamibi single-photon emission computed tomography (SPECT) imag ing in patients with previous bypass surgery is unknown. The aim of ou r study was to assess the prognostic information obtained with exercis e scintigraphy performed for routine follow-up or reappearance of symp toms. Methods: We studied 75 patients referred to our Center at a mean of 38 +/- 53 months from the revascularization procedure and prospect ively followed them for 38 +/- 24 months. Results: Fifteen patients (2 0%) had events at follow-up: there were 4 cardiac deaths, 3 nonfatal a cute myocardial infarctions, 8 late revascularization procedures (4 pe rcutaneous transluminal angioplasty and 4 repeat bypass surgery). Univ ariate analysis identified a history of typical angina (p = 0.001), a clinically positive ergometric test (p = 0.009), peak exercise heart r ate (p = 0.0003), percentage of maximal predicted heart rate (p = 0.00 01), peak exercise double product (p = 0.048), therapy during exercise (p = 0.003), scintigraphic summed reversibility score (i.e., the summ ation of the seg mental differences between stress and rest) (p = 0.01 4), as significant predictors of events. Three multivariate models wer e built, with clinical variables (Model 1, chi square 15.97), ergometr ic variables (Model 2, chi square 19.66), and with scintigraphic varia bles added to clinical/ergometric variables (Model 3, chi square 31.13 ). The scintigraphic variable selected in the model as significant pre dictor of events was the summed reversibility score (p = 0.008). Concl usions: Exercise sestamibi SPECT scintigraphy provides optimal prognos tic information after clinical and ergometric parameters in patients w ith previous bypass surgery.