The additive values of left ventricular function and extent of myocardium at risk to dipyridamole perfusion imaging for optimal risk stratification prior to vascular surgery

Although the increased risk of cardiac complications in surgical patients w ith diminished left ventricular ejection fraction (LVEF) is well-establishe d, this met:hod has been supplanted in recent years by assessment of ischae mic burden using myocardial perfusion imaging (MPI). This study was conduct ed to determine if MPI and LVEF determination provide complementary of redu ndant information in preoperative evaluation of vascular surgery patients. A total of 101 patients were studied with dipyridamole MPI and radionuclide ventriculography before surgery. Single photon emission tomographic MPI im ages were scored for defect severity and categorized as either fixed or ref lecting ischaemia. Resting left ventricular cavity was also categorized as normal or dilated. LVEF was subdivided into normal (greater than or equal t o 50%) and abnormal (<50%). Seventeen patients had cardiac events. Events w ere more frequent in patients with ischaemia, in patients with a LVEF <50% and in those with dilated left ventricular chambers. The mean number of isc haemic segments was also higher in the cardiac event group. Higher event ra tes were seen when a combination of these factors was present. A history of myocardial infarct, congestive heart failure or coronary artery disease wa s also a significant predictor of subsequent events. Thus, both abnormal le ft ventricular function and extent of ischaemic myocardium have independent and complementary predictive power for cardiac events in vascular surgery patients. ((C) 1999 Lippincott Williams & Wilkins).