You don't have to undergo heart surgery to experience cardiovascular complications. Even patients undergoing major noncardiac surgery may have such problems. However, the findings from a recent study may make it easier to predict which patients are at risk of developing cardiovascular complications. The researchers identified several risk factors that can be used as an index to predict cardiac risk in noncardiac surgery patients. They found that patients who undergo a high-risk type of surgery (intraperitoneal, intrathoracic, or suprainguinal vascular surgery), have a history of ischemic heart disease, history of congestive heart failure, history of cerebrovascular disease, preoperative treatment with insulin, or have preoperative serum creatinine greater than 2.0 mg/dL are at increased risk of cardiovascular complications.
Researchers from Brigham and Women's Hospital and Harvard Medical School studied 4,315 patients aged 50 years or older undergoing elective major noncardiac procedures in a tertiary-care teaching hospital. They identified major cardiac complications, which occurred in 2 percent of the 2,893 patients from whom they derived the cardiac risk index. They later validated the index in another group of 1,422 patients.
The rate of major cardiac complications with zero, one, two, or three or more of these factors were 0.5 percent, 1.3 percent, 4 percent, and 9 percent, respectively, in the derivation group and 0.4 percent, 0.9 percent, 7 percent, and 11 percent, respectively, in the validation group. The presence of two or more of these factors identified patients with moderate (7 percent) and high (11 percent) complication rates in the validation group. How this index should be used by clinicians remains to be defined. One approach would be to confine routine use of noninvasive testing to patients with moderate risk for complications. This study was supported by the Agency for Healthcare Research and Quality (HS06573).
See "Derivation and prospective validation of a simple index for prediction of cardiac risk of major noncardiac surgery," by Thomas H. Lee, M.D., S.M., Edward R. Marcantonio, M.D., S.M., Carol M. Mangione, M.D., S.M., and others, in the September 7, 1999 Circulation 100, pp. 1043-1049.