International Normalized Ratio (INR) is Comparable to MELD in Predicting Mortality after Cholecystectomy

Abstract

Guidelines suggest targeting a preoperative international normalized ratio (INR) < 1.5. We examined and compared the predictive value of INR relative to the Model for End-Stage Liver Disease (MELD). We reviewed the American College of Surgeons NSQIP from 2005 to 2016 for adult patients undergoing open or laparoscopic cholecystectomy. Patients with a preoperative INR were stratified into groups: ≤1, >1 to ≤1.5, >1.5 to ≤2, and >2. Thirty day postoperative mortality was the primary outcome. Multivariable logistic regressions controlled for baseline differences. Of 58,177 cholecystectomy patients, 15.2 per cent had INR ≤ 1, 80.4 per cent had INR > 1 to ≤1.5, 3.7 per cent had INR > 1.5 to ≤2, and 0.7 per cent had INR > 2. Patients with INR > 2 were older and more likely to have diabetes and hypertension (P < 0.001). Multivariable regression demonstrated a stepwise increase in mortality for INR > 1 to ≤1.5 (odds ratio (OR) = 1.50 [1.10-2.05]), INR > 1.5 to ≤2 (OR = 2.96 [1.97-4.45]), and INR > 2 (OR = 3.21 [1.64-6.31]) relative to INR ≤ 1. C-statistic for INR (0.910) and MELD (0.906) models indicated a similar value in predicting mortality. INR groups also faced an incremental, increased risk of bleeding. Although unable to track preoperative correction of INR, this analysis identifies that INR remains an excellent predictor of postoperative mortality and bleeding after both open and laparoscopic cholecystectomies and is comparable to MELD.