Dipyridamole-thallium/sestamibi before vascular surgery: A prospective blinded study in moderate-risk patients

Purpose: This study assessed in a prospective, blinded fashion whether a re versible defect on dipyridamole-thallium (DTHAL)/sestamibi (DMIBI) can pred ict adverse cardiac events after elective vascular surgery in patients with one or more clinical risk factors. Methods: Consecutive patients with one or more clinical risk factors underw ent a preoperative blinded DTHAL/DMIBI. Patients with recent congestive hea rt failure (CHP) or myocardial infarction (MI) or severe or unstable angina were excluded. Results: Eighty patients (78% men; mean age, 65 years) completed the study. Diabetes mellitus was the most frequent clinical risk factor (73%), follow ed by age older than 70 years (41%), angina (29%), Q wave on electrocardiog ram (26%), history of CHP (7%), and ventricular ectopy (3%). The results of DTHAL/DMIBI were normal in 36 patients (45%); a reversible plus or minus f ixed defect was demonstrated in 28 patients (36%), and a fixed defect alone was demonstrated in 15 patients (19%). Nine adverse cardiac events (11%) o ccurred, including three cases of CHF, and one case each of unstable angina , Q wave MI, non-Q wave MI, and cardiac arrest (successfully resuscitated). Two cardiac deaths occurred (2% overall mortality), one after a Q wave MI and one after CHF and a non-Q wave MI. The cardiac event rate was 14% for r eversible defect and 9.8% without reversible defect (P = .71). The cardiac event rate was 12.5% (one of eight cases) for two or more reversible defect s, versus 11.1% (eight of 72 cases) for fewer than two reversible defects ( P = 1.0). The sensitivity rate of two or more areas of redistribution was 1 1% (95% CI, 0.3%-48%), the specificity rate was 90%, and the positive and n egative predictive values were 12.5% and 89%, respectively. Conclusion: Our study demonstrated no association between reversible defect s on DTHAL/DMIBI and adverse cardiac events in moderate-risk patients under going elective vascular surgery.