946-103 Incremental Prognostic Power for Perioperative Cardiac Events of Clinical History and Semi·Quantitative Dobutamine Before Major Vascular Surgery

Using the presence of stress induced ischemia with dobutamine-atropine stress echocardiography (DSE) for predicting perioperative cardiac events (CE) in patients undergoing major vascular surgery has a high negative but low positive predictive value (PPV).Aim of the studyto improve the PPV of DSE by combining the value of clinical markers and DSE.Methodsin 300 consecutive patients clinical risk factors (diabetes, angina, Q waves on ECG, age>70 years, and history of ventricular arrhythmias) where assessed. DSE results were analyzed by quantifying the extent and severity of new wall motion abnormalities (NWMA) at peak stress. Also, heart rate threshold (HR-Thres) at which NWMA occurred was noted. Low HR-Thres was defined as NWMA at<70% of maximal age and sex related heart rate.Results27 CE occurred of which 5 cardiac deaths, 12 myocardial infarctions and 10 patients with unstable angina. One-hundred patients had no clinical risk factors, 200 one or more. All but 1 CE occurred in patients with 1 Or more risk factors. In 27 of 72 patients with a positive DSE a CE occurred (PPV 38%). Quantifying the extent and severity of NWMA at peak stress provided no additional information. The HR-Thres at which ischemia occurred improved PPV In 30 patients with a low HR-Thres, 20 CE occurred (PPV 67%). In the remaining 42 patients with a high HR-Thres, only 7 CE occurred (16%). The improvement of PPV from 38% to 67% is statistically highly significant (P < 0.01). All patients with a fatal CE and 8 of 12 patients with a myocardial infarction had a low HR-threshold.Conclusions1) in patients with no clinical risk factors additional stress testing is not efficient. 2) in patients with one or more risk factors semiquantitative DSE allows stratification of patients in low, intermediate, and high risk groups for CE