CARDIAC COMPLICATIONS IN NONCARDIAC SURGERY - VALUE OF DOBUTAMINE STRESS ECHOCARDIOGRAPHY VERSUS DIPYRIDAMOLE-THALLIUM IMAGING

Objectives: The objective of this study was to determine the relative value of dobutamine stress echocardiography (DSE) and dipyridamole tha llium imaging (DT) in the preoperative assessment of cardiovascular ri sk before noncardiac surgery. Design: Prospectively DSE was performed in patients who had undergone DT as a part of their preoperative evalu ation. Setting: A large urban veterans' affairs medical center. Partic ipants: Thirty-seven patients undergoing major noncardiac surgery were assessed for complications during a 1-month follow-up period. Interve ntions: Both DSE and DT were performed before surgery. The medium inte rval between the two tests were 15.5 days. Measurements: Left ventricu lar wall motion was assessed at baseline and peak dobutamine dose in a standard fashion. Wail motion was scored and indexed using a 18-segme nt model. A positive DSE was defined as failure of augmentation, new o r worsening of baseline wall motion abnormalities in two or more conti guous segments. Myocardial perfusion studies after DT were performed a ccording to conventional method. A positive DT was defined as a revers ible perfusion defect, increased lung uptake, and/or transient left ve ntricular dilatation, Complications were defined as myocardial infarct ion or cardiac death occurring as a result of the operation, or need f or revascularization before surgery. Results: DSE was positive in 19 p atients, whereas DT was positive in 25 patients. Fourteen patients had both an abnormal DSE and DT. Five patients had major postoperative ca rdiac complications: fatal myocardial infarction (1); fatal cardiac ar rest (1); and severe coronary artery disease necessitating coronary ar tery bypass surgery (2) or percutaneous transluminal coronary angiopla sty (1). DSE was positive in all 5 (100%), whereas DT was positive in 4 of 5 (80%) patients with complications. The sensitivity for each tes t was comparable: for DSE it was 100% (95% C.I. 56% to 100%) and for D T 80% (37% to 96%). Specificity for DSE (60%, 43%-74%) was somewhat hi gher than DT (38%, 24% to 54%), although this did not reach statistica l significance (P = 0.06). Conclusions: The ability of DSE to predict major cardiac complications related to noncardiac surgery appears to b e similar to DT and may be used as an alternative to DT imaging in the preoperative risk assessment of patients undergoing noncardiac surger y. Copyright (C) 1996 by W.B. Saunders Company.