Physician estimates of perioperative cardiac risk in patients undergoing noncardiac surgery

Background: We know little about how physicians assess perioperative cardia c risk in patients undergoing noncardiac surgery. Objectives: To evaluate preoperative medical consultations and determine th e extent to which consultants used validated cardiac risk indices and speci alized noninvasive cardiac tests, and to assess agreement between physician ratings of cardiac risk (low, moderate, or high) and risk estimates derive d using validated cardiac risk indices or, in the case of vascular surgery, a risk index. Methods: This observational study was conducted at 5 Canadian teaching hosp itals affiliated with 2 universities. We retrospectively evaluated 308 preo perative consultations performed in 297 patients and examined the frequency with which consultants recorded the use of validated cardiac risk indices. We used kappa statistics to quantify the extent to which physician ratings of cardiac risk agreed with risk estimates derived using validated cardiac risk indices. Results: Physicians recorded use of a risk index in 31% of the consultation s, but the index used was almost always the suboptimal classification of th e American Society of Anesthesiologists. The agreement between physician es timates of cardiac risk and the validated cardiac risk indices was only fai r, with a weighted kappa of 0.38 (95% confidence interval, 0.28-0.49). Over estimation and underestimation of cardiac risk occurred in 16% and 13% of t he consultations, respectively. Consultants did not order dipyridamole thal lium imaging or dobutamine stress echocardiography for any moderate-risk pa tients undergoing vascular surgery. Conclusions: Physicians underuse validated cardiac risk indices, and the ag reement between the cardiac risk estimates and risk as determined by valida ted cardiac indices is suboptimal. Physicians are also underusing dipyridam ole thallium imaging and dobutamine stress echocardiography for moderate-ri sk patients undergoing vascular surgery.