The South African vascular surgical cardiac risk index (SAVS-CRI): A prospective observational study

Abstract

Background. Recent evidence suggests that application of the Revised Cardiac Risk Index (RCRI) for peri-operative cardiovascular risk stratification in vascular surgery patients may be inappropriate, necessitating the development of risk indices specific to vascular surgery patients. Objectives. To identify risk factors for cardiovascular morbidity and mortality in South African patients undergoing major vascular surgery, and to develop an appropriate cardiovascular risk stratification index, the South African Vascular Surgical Cardiac Risk Index (SAVS-CRI), which could be used to predict the risk of peri-operative major adverse cardiovascular events (MACEs) in South African vascular surgery patients. Methods. We prospectively collected data related to peri-operative MACE occurrence and established risk factors for peri-operative MACEs from adult patients who underwent elective vascular surgery at a tertiary hospital in Durban, South Africa, between February 2008 and March 2011. We determined independent predictors of peri-operative MACEs in our cohort by binary logistic regression and used the identified predictors to create a risk index that stratified patients into low-, intermediate- or high-risk groups. Results. Six independent predictors of peri-operative MACEs were identified in the vascular surgery cohort: age >65 years, a history of ischaemic heart disease, a history of diabetes, chronic β-blockade, prior coronary revascularisation, and the vascular surgical procedure. The risk model derived from these risk factors appeared to discriminate between the three risk groups more accurately than the RCRI. Conclusion. The RCRI is not appropriate for peri-operative cardiovascular risk stratification in vascular surgery patients. The SAVS-CRI may be preferable for risk stratification in South African vascular surgery patients, although independent validation is required.