Individualized Venous Thromboembolism Risk Stratification Using the 2005 Caprini Score to Identify the Benefits and Harms of Chemoprophylaxis in Surgical Patients A Meta-analysis

Objective: We performed a meta-analysis to investigate benefits and harms of chemoprophylaxis among surgical patients individually risk stratified for venous thromboembolism (VTE) using Caprini scores. Summary of Background Data: Individualized VTE risk stratification may identify high risk surgical patients who benefit from peri-operative chemoprophylaxis. Methods: MEDLINE, EMBASE, and the Cochrane Library (CENTRAL) databases were queried. Eligible studies contained data on postoperative VTE and/or bleeding events with and without chemoprophylaxis. Primary outcomes included rates of VTE and clinically relevant bleeding after surgical procedures, stratified by Caprini score. A meta-analysis was conducted using a random-effects model. Results: Among 13 included studies, 11 (n = 14,776) contained data for VTE events and 8 (n = 7590) contained data for clinically relevant bleeding with and without chemoprophylaxis. The majority of patients received mechanical prophylaxis. A 14-fold variation in VTE risk (from 0.7% to 10.7%) was identified among surgical patients who did not receive chemoprophylaxis, and patients at increased levels of Caprini risk were significantly more likely to have VTE. Patients with Caprini scores of 7 to 8 [odds ratio (OR) 0.60, 95% confidence interval (95% CI) 0.37-0.97] and >8 (OR 0.41, 95% CI 0.26-0.65) had significant VTE risk reduction after surgery with chemoprophylaxis. Patients with Caprini scores <= 6 comprised 75% of the overall population, and these patients did not have a significantVTE risk reduction with chemoprophylaxis. No association between postoperative bleeding risk and Caprini score was identified. Conclusions: The benefit of peri-operative VTE chemoprophylaxis was only found among surgical patients with Caprini scores >= 7. Precision medicine using individualized VTE risk stratification helps ensure that chemoprophylaxis is used only in appropriate surgical patients and may minimize bleeding complications.