Lee Cardiac Risk Index Calculator

The Revised Cardiac Risk Index estimates the probability of a major cardiac complication after elective noncardiac surgery, defined in the original work as myocardial infarction, pulmonary edema, ventricular fibrillation or primary cardiac arrest, or complete heart block. Its appeal is that six equally weighted binary predictors capture most of the discriminative information. High-risk surgery means intraperitoneal, intrathoracic, or suprainguinal vascular procedures. Ischemic heart disease is defined by prior myocardial infarction, positive stress test, current ischemic chest pain, nitrate use, or pathological Q waves. Congestive heart failure counts if there is a history of failure, pulmonary edema, paroxysmal nocturnal dyspnea, bilateral rales or an S3 gallop, or radiographic pulmonary vascular redistribution. Cerebrovascular disease means prior stroke or transient ischemic attack. The remaining two are preoperative insulin therapy for diabetes and a preoperative serum creatinine above 2 mg/dL, roughly 177 micromol/L. Each factor adds one point, and the original cohort produced event rates of approximately 0.4 percent for zero factors, 0.9 percent for one, 6.6 percent for two, and 11 percent or more for three or more. In practice a score of 0 to 1 supports proceeding without further cardiac testing, while 2 or more prompts assessment of functional capacity, usually expressed in metabolic equivalents, with 4 METs, the equivalent of climbing two flights of stairs, as the customary threshold below which noninvasive testing may change management. The index has limits worth knowing: it was derived in stable elective patients aged 50 and over and does not apply to emergency surgery, it excludes vascular surgery patients undergoing aortic aneurysm repair from some validation samples, and pooled meta-analyses have found only moderate discrimination, with an area under the curve around 0.75 overall and weaker performance in vascular surgery specifically.

The index has a direct ancestor. In 1977 Lee Goldman and colleagues at Massachusetts General Hospital published the original multifactorial cardiac risk index in the New England Journal of Medicine, derived from about 1,000 patients over 40 undergoing noncardiac surgery. It used nine weighted variables including an S3 gallop, jugular venous distension, recent myocardial infarction, rhythm, age over 70, emergency status, procedure site, and general medical condition. Detsky and colleagues at the University of Toronto modified it in 1986, adding angina class and refining the weights. Thomas Lee, working with colleagues at Brigham and Women's Hospital in Boston, undertook a fresh derivation because surgical and anesthetic practice had changed substantially in the intervening two decades and the older indices had lost calibration. His group prospectively studied 4,315 patients aged 50 and over undergoing elective major noncardiac procedures, derived the six-factor model in roughly half the cohort, and validated it in the remainder. The results appeared in Circulation in 1999. Because the six predictors carried similar odds ratios, the authors chose simple unweighted summation, which is much of the reason the tool survived in daily use. The American College of Cardiology and American Heart Association perioperative guidelines, notably the 2014 revision, embedded RCRI as a first step in the stepwise preoperative algorithm, alongside newer alternatives such as the National Surgical Quality Improvement Program myocardial infarction and cardiac arrest model published by Gupta and colleagues in 2011.