The Comorbidity-Polypharmacy Score is an Objective and Practical Predictor of Outcomes and Mortality after Vascular Surgery

Abstract

The comorbidity-polypharmacy score (CPPS) was developed to quantify the severity of comorbidities of patients with geriatric trauma. CPPS is the sum of the number of medications and comorbidities, and is thus objective, user-friendly, and potentially adaptable to many clinical situations. We sought to understand if CPPS associates with outcomes and mortality after common vascular surgery procedures. This is a retrospective single-center study. A total of 466 patients who underwent carotid endarterectomy, infrainguinal bypass, percutaneous lower extremity revascularization, or endovascular abdominal aortic aneurysm repair at a single medical center were included. CPPS were classified as mild, moderate, severe, and morbid based on scores of 0-7, 8-15, 15-21, and ≥21, respectively. End points were reinterventions, 30-day readmission, and mortality. We used chi-squared tests to analyze differences in categorical variables; Kruskal-Wallis tests to analyze differences in continuous variables; Kaplan-Meier estimation and Cox proportional hazard modeling to examine survival data; and receiver operator characteristic (ROC) curve analyses to assess sensitivity and specificity. The mean preoperative CPPS was 14.1±6.1. Higher CPPS were associated with longer hospital and postoperative length of stay (P<0.001). Severe and morbid CPPS categories had higher rates of ICU admission, reintervention, and 30-day readmission which did not reach statistical significance after correction for multiple comparisons. CPPS was independently associated with 1- and 5-year mortality in a multivariable Cox model (hazard ratio=2.2, 95% confidence interval: 1.3-3.3). ROC analysis revealed C-statistics of 0.81 and 0.72 for 1-year and 5-year all-cause mortality, respectively (P<0.001). CPPS is a simple and pragmatic clinical tool for quantifying risk of postoperative outcomes and mortality after common vascular surgery procedures. Further investigation is needed to validate the use of CPPS in enhancing existing predictors of patient outcomes and in serving as an adjunctive tool for determining resource allocation and discharge planning in patients who underwent vascular surgery.