Background —Cardiac complications are important causes of morbidity after noncardiac surgery. The purpose of this prospective cohort study was to develop and validate an index for risk of cardiac complications. Methods and Results —We studied 4315 patients aged ≥50 years undergoing elective major noncardiac procedures in a tertiary-care teaching hospital. The main outcome measures were major cardiac complications. Major cardiac complications occurred in 56 (2%) of 2893 patients assigned to the derivation cohort. Six independent predictors of complications were identified and included in a Revised Cardiac Risk Index: high-risk type of surgery, history of ischemic heart disease, history of congestive heart failure, history of cerebrovascular disease, preoperative treatment with insulin, and preoperative serum creatinine >2.0 mg/dL. Rates of major cardiac complication with 0, 1, 2, or ≥3 of these factors were 0.5%, 1.3%, 4%, and 9%, respectively, in the derivation cohort and 0.4%, 0.9%, 7%, and 11%, respectively, among 1422 patients in the validation cohort. Receiver operating characteristic curve analysis in the validation cohort indicated that the diagnostic performance of the Revised Cardiac Risk Index was superior to other published risk-prediction indexes. Conclusions —In stable patients undergoing nonurgent major noncardiac surgery, this index can identify patients at higher risk for complications. This index may be useful for identification of candidates for further risk stratification with noninvasive technologies or other management strategies, as well as low-risk patients in whom additional evaluation is unlikely to be helpful.

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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.

To determine whether advances in diagnostic procedures have reduced the value of autopsies, we analyzed 100 randomly selected autopsies from each of the academic years 1960, 1970, and 1980 at one university teaching hospital. In all three eras about 10 per cent of the autopsies revealed a major diagnosis that, if known before death, might have led to a change in therapy and prolonged survival; another 12 per cent showed a clinically missed major diagnosis for which treatment would not have been changed. Among 1980 autopsies, renal disease and pulmonary embolus were less common causes of death than before, but systemic bacterial, viral, and fungal infections increased significantly and were missed clinically 24 per cent of the time. The introduction of radionuclide scans, ultrasound, and computerized tomography as diagnostic procedures did not reduce the use of conventional tests in patients who subsequently died and were studied by autopsy. Over-reliance on these new procedures occasionally contributed directly to missed major diagnoses. We conclude that advances in diagnostic technology have not reduced the value of the autopsy, and that a goal-directed autopsy remains a vital component in the assurance of good medical care.

ContextSubstantial discrepanies exist between clinical diagnoses and findings at autopsy. Autopsy may be used as a tool for quality management to analyze diagnostic discrepanies.ObjectiveTo determine the rate at which autopsies detect important, clinically missed diagnoses, and the extent to which this rate has changed over time.Data SourcesA systematic literature search for English-language articles available on MEDLINE from 1966 to April 2002, using the search terms autopsy, postmortem changes, post-mortem, postmortem, necropsy, and posthumous, identified 45 studies reporting 53 distinct autopsy series meeting prospectively defined criteria. Reference lists were reviewed to identify additional studies, and the final bibliography was distributed to experts in the field to identify missing or unpublished studies.Study SelectionIncluded studies reported clinically missed diagnoses involving a primary cause of death (major errors), with the most serious being those likely to have affected patient outcome (class I errors).Data ExtractionLogistic regression was performed using data from 53 distinct autopsy series over a 40-year period and adjusting for the effects of changes in autopsy rates, country, case mix (general autopsies; adult medical; adult intensive care; adult or pediatric surgery; general pediatrics or pediatric inpatients; neonatal or pediatric intensive care; and other autopsy), and important methodological features of the primary studies.Data SynthesisOf 53 autopsy series identified, 42 reported major errors and 37 reported class I errors. Twenty-six autopsy series reported both major and class I error rates. The median error rate was 23.5% (range, 4.1%-49.8%) for major errors and 9.0% (range, 0%-20.7%) for class I errors. Analyses of diagnostic error rates adjusting for the effects of case mix, country, and autopsy rate yielded relative decreases per decade of 19.4% (95% confidence interval [CI], 1.8%-33.8%) for major errors and 33.4% (95% [CI], 8.4%-51.6%) for class I errors. Despite these decreases, we estimated that a contemporary US institution (based on autopsy rates ranging from 100% [the extrapolated extreme at which clinical selection is eliminated] to 5% [roughly the national average]), could observe a major error rate from 8.4% to 24.4% and a class I error rate from 4.1% to 6.7%.ConclusionThe possibility that a given autopsy will reveal important unsuspected diagnoses has decreased over time, but remains sufficiently high that encouraging ongoing use of the autopsy appears warranted.

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Reproducibility and validity are prerequisites for a useful clinical scale. We therefore prospectively tested the reproducibility and validity of the New York Heart Association criteria and the Canadian Cardiovascular Society criteria for the assessment of cardiac functional class and compared these criteria with a new Specific Activity Scale based on the metabolic costs of specific activities. The New York Heart Association estimates made by two physicians had a reproducibility of only 56%, and only 51% of the estimates agreed with treadmill exercise performance. Functional estimates based on the Canadian Cardiovascular Society criteria were significantly more reproducible (73%), but not significantly more valid. The Specific Activity Scale was as reproducible as the Canadian Cardiovascular Society criteria, and its 68% validity was significantly higher than the validities of the other systems. The easily administered Specific Activity Scale was equally reproducible and valid when used by a nonphysician. It was especially better than the other systems for the evaluation of true class II patients and was significantly less likely to underestimate treadmill performance. Although no set of questions can perfectly predict exercise tolerance, the Specific Activity Scale deserves wider prospective testing.