title: The usefulness of dipyridamole thallium-201 single photon emission computed tomography for predicting perioperative cardiac events in patients undergoing non-cardiac vascular surgery.
abstract: The aim of this study was to evaluate the usefulness of dipyridamole Tl-201 myocardium single photon emission computed tomography (201Tl-SPECT) for predicting perioperative cardiac events in patients with arteriosclerosis obliterans (ASO) and abdominal aortic aneurysm (AAA) undergoing non-cardiac vascular surgery.
  
  
  METHODS
  Preoperative dipyridamole 201Tl-SPECT imaging in association with clinical risk assessment was performed in 224 consecutive patients (97 ASO and 127 AAA).
  
  
  RESULTS
  The patients were classified into three groups, including low-risk (n = 173, 77%), intermediate-risk (n = 39, 18%), and high-risk (n = 12, 5%) groups according to the clinical risk stratification. The prevalence of reversible Tl-201 defect was significantly higher in the high-risk group than that in the low-risk group (83% vs. 14%, p < 0.001). In 180 patients who underwent vascular surgery, 9 patients (5.0%) had perioperative cardiac events, including heart failure (n = 1), unstable angina (n = 2), and other cardiac events such as arrhythmias (n = 6). The clinical variables including the clinical risk stratification did not significantly correlate with the perioperative cardiac events. In contrast, the reversible defect on 201Tl-SPECT was the only variable to predict perioperative cardiac events by a stepwise logistic regression analysis (odds ratio 7.0, 95% confidence interval 1.7-28.0, p = 0.007). It was also a significant predictor of perioperative cardiac events in a subgroup of low risk patients (odds ratio 11.6, 95% confidence interval 2.3-57.4, p = 0.004). The sensitivity and specificity of the reversible defect for predicting perioperative cardiac events were 55.6% and 84.8% in all operated patients, and 57.1% and 89.7% in low risk patients, respectively.
  
  
  CONCLUSIONS
  The preoperative dipyridamole 201Tl-SPECT was useful for predicting perioperative cardiac events in patients with vascular diseases, even in patients identified as having a low risk based on the clinical risk assessment.
authors.affiliation: Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. chentao@radiol.med.kyushu-u.ac.jp
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Kuwabara
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsutsui
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sasaki
authors.forename: Makoto
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Koga
authors.forename: Kouichirou
authors.initials: K
authors.lastname: Kaneko
authors.forename: Kimihiro
authors.initials: K
authors.lastname: Komori
authors.forename: Kouji
authors.initials: K
authors.lastname: Masuda
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D001162:Arteriosclerosis Obliterans / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000601:surgery*; D015897:Comorbidity; D004176:Dipyridamole / Q000008:administration & dosage; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000601:surgery; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D019990:Perioperative Care / Q000379:methods; D011183:Postoperative Complications / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D015995:Prevalence; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013794:Thallium Radioisotopes; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014656:Vascular Surgical Procedures / Q000145:classification / Q000706:statistics & numerical data*
chemical_list: D013794:Thallium Radioisotopes; D004176:Dipyridamole