Objective: To derive risk models for percutaneous coronary intervention (PCI) outcomes from clinical and laboratory variables available before the procedure so they can be used for preprocedure risk stratification.
Patients and methods: Using the Mayo Clinic registry, we analyzed 9035 PCIs on 7640 unique patients from January 1, 2000, through April 30, 2005. We included only the first PCI per patient (n=7457). Logistic regression was used to model the calculated risk score and major procedural complications. Separate risk models were made for mortality and major adverse cardiovascular events (MACE) derived solely from baseline and laboratory characteristics. Final risk scores for procedural death, defined as any death during the index hospitalization, and MACE contained the same 7 variables (age, myocardial infarction less than or equal to 24 hours, preprocedural shock, serum creatinine level, left ventricular ejection fraction, congestive heart failure, and peripheral artery disease).
Results: Models had adequate goodness of fit, and areas under the receiver operating characteristic curve were 0.74 and 0.89 for MACE and procedural death, respectively, indicating excellent overall discrimination. The model was robust across many subgroups, including those undergoing elective PCI, those having diabetes mellitus, and elderly patients. Bootstrap analysis indicated that the model was not overfit to the available data set.
Conclusion: Before coronary angiography is performed, a risk-scoring system based on 7 variables can be used conveniently to predict cardiovascular complications after PCI. This model may be useful for providing patients with individualized, evidence-based estimates of procedural risk as part of the informed consent process.