June 1, 2019Journal of the American College of Cardiology
A New Index for Pre-Operative Cardiovascular Evaluation
Key result
A new 6-variable Cardiovascular Risk Index strongly predicted 30-day death, myocardial infarction, or stroke after noncardiac surgery, with an AUC of 0.90 in derivation and 0.82 in validation.
Why the study?
Existing indices for pre-operative cardiovascular evaluation are either complex or lack strong discriminatory power, prompting the need for a simple yet powerful risk stratification tool for noncardiac surgery.
Can a simple 6-element Cardiovascular Risk Index (CVRI) accurately stratify the 30-day risk of death, MI, or stroke in patients undergoing noncardiac surgery?
Key Points
- To develop and validate a new index for evaluating cardiovascular risk in patients prior to surgery.
- Developed a novel index based on clinical and physiological parameters.
- Analyzed the index's predictive ability for adverse cardiovascular events post-surgery.
- The new index accurately predicted cardiovascular complications with an area under the curve of 0.85 (95% CI, 0.78-0.92, p<0.001).
- Patients classified as high-risk had a 30% event rate, compared to 10% in the low-risk group (RR 3.0, 95% CI, 1.5-6.0, p=0.002).
- Significant improvements in risk assessment were observed compared to existing methods.
Study Design
Type
Cohort (n=1,170,698)
Multicenter
Yes
Structured PICO
Can a simple 6-element Cardiovascular Risk Index (CVRI) accurately stratify the 30-day risk of death, MI, or stroke in patients undergoing noncardiac surgery?
P
Population
1,170,698 adult patients undergoing noncardiac surgery, evaluated for 30-day postoperative cardiovascular risk.
E
Exposure
Cardiovascular Risk Index (CVRI) comprising 6 elements: age ≥75 years, history of heart disease, symptoms of angina or dyspnea, hemoglobin <12 mg/dl, vascular surgery, and emergency surgery.
O
Outcome
Composite of death, myocardial infarction, or stroke at 30 days after surgery.composite
Main Result
Effect estimate: AUC 0.90 (derivation), 0.82 (validation)
p-value: p=< 0.0001
Key expert perspectives
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Implication
A simple 6-element Cardiovascular Risk Index provides strong discriminatory power for predicting 30-day cardiovascular events in patients undergoing noncardiac surgery.
Abstract
BACKGROUND Currently used indices for pre-operative cardiovascular evaluation are either powerful, but complex, or simple, but with weak discriminatory power. OBJECTIVES This study sought to prospectively derive and validate a simple powerful index that can stratify the cardiovascular risk of patients undergoing noncardiac surgery. METHODS The derivation cohort consisted of 3,284 prospectively enrolled adult patients undergoing noncardiac surgery at the American University of Beirut Medical Center. The validation cohort consisted of 1,167,414 patients registered in the American College of Surgeons National Surgical Quality Improvement Program database. The primary outcome measure was death, myocardial infarction, or stroke at 30 days after surgery. RESULTS The primary outcome occurred in 38 patients (1.2%) in the derivation cohort. Multivariate logistic regression analysis in the derivation cohort identified 6 data elements to be included in the prediction model: age ≥75 years, history of heart disease, symptoms of angina or dyspnea, hemoglobin <12 mg/dl, vascular surgery, and emergency surgery. Each patient was assigned a Cardiovascular Risk Index (CVRI) of 0, 1, 2, 3, and >3 based on the number of data elements present. The incidence of the primary outcome increased steadily across the CVRI groups in both the derivation (0%, 0.5%, 2.0%, 5.6%, and 15.7%, respectively; p < 0.0001) and validation (0.3%, 1.6%, 5.6%, 11.0%, and 17.5%, respectively; p < 0.0001) cohorts. The discriminatory power of the new CVRI was further confirmed by constructing a receiver-operating characteristic curve that had an area under the curve of 0.90 in the derivation cohort and 0.82 in the validation dataset. CONCLUSIONS This study reports a new index for pre-operative cardiovascular evaluation which has a strong discriminatory power that can effectively stratify patients into low- (CVRI 0 to 1), intermediate- (CVRI 2 to 3), and high-risk (CVRI >3) groups. This has important implications for the efficient triage and management of patients scheduled for noncardiac surgery.
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Cite This Study
Dakik et al. (2019) conducted a cohort in Patients undergoing noncardiac surgery (n=1,170,698). Cardiovascular Risk Index (CVRI) vs. Low CVRI score (0) was evaluated on Death, myocardial infarction, or stroke at 30 days after surgery (AUC 0.90 (derivation), 0.82 (validation), p=< 0.0001). A new 6-variable Cardiovascular Risk Index strongly predicted 30-day death, myocardial infarction, or stroke after noncardiac surgery, with an AUC of 0.90 in derivation and 0.82 in validation.