Preoperative cardiac risk assessment with adenosine stress dual-isotope myocardial single-photon emission computed tomography

Background: Previous studies have demonstrated that pharmacologic stress thallium-201 (²⁰¹Tl) myocardial scintigraphy is a useful tool to evaluate preoperative cardiac risk. Hypothesis: The purpose of this study was to assess the utility of adenosine stress dual-isotope [rest ²⁰¹Tl/stress technetium-99m (^99mTc) sestamibi] myocardial single-photon emission computed tomography (SPECT) in predicting the risk of perioperative cardiac events (unstable angina, myocardial infarction, cardiac death) in patients undergoing major noncardiac surgery. Methods: We evaluated 43 consecutive patients (20 men, 23 women, mean age 64 years, range 30-83 years) within 8 weeks prior to major noncardiac surgery requiring general anesthesia. SPECT imaging was performed with 111 MBq (3 mCi) ²⁰¹Tl at rest and 925 MBq (25 mCi) ^99mTc sestamibi during adenosine stress. Results: Of the 43 patients, 15 (35%) had stress-induced ischemia and 28 (65%) did not. Perioperative cardiac events occurred in 4 (27%) of the 15 patients with stress-induced ischemia 12 unstable angina, 2 nonfatal myocardial infarctions) and in none of the 28 patients without inducible ischemia (p = 0.02). Conclusion: Adenosine stress dual-isotope myocardial SPECT is useful in determining the preoperative cardiac risk of patients undergoing major noncardiac surgery.