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Investigators in the Netherlands targeted only vascular surgery patients identified from a computerized hospital information system. From a system, 2,310 patients who underwent 2,758 noncardiac vascular surgeries during a 10-year period in the 1990s were selected. Clinical risk factors, data on noninvasive stress testing, and long-term medication use, including statin agents, beta-blockers, calcium channel blockers, diuretics, insulin, nitrate, and aspirin, were abstracted. Outcome measures were all-cause mortality before discharge or within 30 days after surgery. The proposed model (see Figure) was based on modifications of the original Goldman Index, with the addition of more precise surgery risk stratification and statin and beta-blocker use. The specific types of vascular surgeries: carotid endarterectomy, infrainguinal bypass, abdominal aortic surgery, thoracoabdominal surgery, and acute abdominal aortic aneurysm rupture repair, carried systematically increased risk in expected fashion. Upon univariate analysis in the derivation cohort (n = 1,537), most of the clinical predictors from the Goldman Index were associated with increased perioperative mortality. Similar conclusions persisted in multivariate logistic regression analysis. Risk of surgical procedures, cardiovascular morbidity (ischemic heart disease, congestive heart failure, history of cerebrovascular event, and hypertension), renal dysfunction, and chronic pulmonary disease are independent predictors of increased all-cause perioperative mortality. In contrast, use of beta-blockers and statins were associated with reduced incidence of perioperative mortality. The final model included a scoring system with points assigned according to risk estimates of individual predictors. Beta-blocker and statin use in this model are assigned negative scores as their use lowers risk. For example, a patient with ischemic heart disease and hypertension undergoing abdominal aortic surgery would have a score of 46, corresponding to a 14% probability of mortality. That risk would be reduced to about 4% (score of 31) by use of beta-blockers (−15). In the same database, with 773 patients as the validation cohort, this prediction model performed nearly as well as the derivation model. Hypertension was not found to be an independent predictor in this validation cohort.
This tool appears provide robust risk assessment for vascular surgery patients. The inclusion of estimated benefit-of-statin and beta-blocker use may allow a more accurate “net” risk assessment. Those patients who are already on these 2 agents but still deemed at higher risk can be informed and may benefit from close monitoring. Additional preoperative interventions may include revascularization, if these high-risk patients have a decompensated cardiac status.