Multifactorial Index of Cardiac Risk in Noncardiac Surgical Procedures

To determine which preoperative factors might affect the development of cardiac complications after major noncardiac operations, we prospectively studied 1001 patients over 40 years of age. By multivariate discriminant analysis, we identified nine independent significant correlates of life-threatening and fatal cardiac complications: preoperative third heart sound or jugular venous distention; myocardial infarction in the preceding six months; more than five premature ventricular contractions per minute documented at any time before operation; rhythm other than sinus or presence of premature atrial contractions on preoperative electrocardiogram; age over 70 years; intraperitoneal, intrathoracic or aortic operation; emergency operation; important valvular aortic stenosis; and poor general medical condition. Patients could be separated into four classes of significantly different risk. Ten of the 19 postoperative cardiac fatalities occurred in the 18 patients at highest risk. If validated by prospective application, the multifactorial index may allow preoperative estimation of cardiac risk independent of direct surgical risk. (N Engl J Med 297:845–850, 1977) The most widely used technic for the preoperative assessment of surgical risk, the Dripps-American Surgical Association,^1,2 is an excellent predictor of perioperative noncardiac complications³ but not necessarily of perioperative cardiac problems.⁴ Existing data have shown that a recent preoperative myocardial infarction^{5 6 7 8} and most other signs and symptoms of cardiac disease⁹ correlate with overall surgical and usually with specific cardiac risk, but these reports have been limited to univariate analysis and are from before the present era of widespread cardiac surgery. The present study attempts a multifactorial approach to the estimation of cardiac risk in noncardiac surgical procedures. Materials and Methods.