Decreased skeletal muscle density is an independent predictor of mortality in necrotizing pancreatitis- A single tertiary center experience in 507 patients.

BACKGROUND AND AIMS: Necrotizing pancreatitis has a variable clinical course and it is essential to identify determinants associated with high risk of mortality and poor clinical outcomes. The aim of this study is to evaluate the association between CT-assessed body composition parameters such as visceral fat area (VFA), skeletal muscle index (SMI) and skeletal muscle density (SMD) and inpatient mortality in NP patients. Secondary outcomes include organ failure on admission, persistent organ failure, length of stay (LOS), need for ICU admission, need for endoscopic, percutaneous or surgical interventions for NP and 30-day unplanned readmission.

METHODS: All NP patients managed at a single center between 2009 and 2019 with a CT scan within a week of admission were included. SMI, SMD and VFA was calculated from CT imaging at the third lumbar vertebra and multivariable analysis was performed after correcting for age, sex, BMI, ASA classification, multi- organ failure on admission to determine independent association with inpatient mortality and secondary outcomes.

RESULTS: 507 NP patients [males = 349 (68.8%), median age 53 (IQR 37-65) years were included in this study. The lowest tertile SMD was independently associated with inpatient mortality on multivariable analysis: adjusted OR 3.36 (1.57-7.2), P = 0.002. The lowest SMI tertile and highest VFA tertile were not independently associated with mortality. Lowest tertile SMD was significantly associated with persistent organ failure (OR 2.01, 95% CI 1.34-3.01, p = 0.001), need for percutaneous drainage (OR 1.84, 95% CI 1.21-2.8, p = 0.004), need for ICU admission (OR 2.32, 95% CI 1.59-3.38, p < 0.0001) and LOS.

CONCLUSION: Low SMD was independently associated with in-hospital mortality in NP patients and can be usefully incorporated in CT based predictive scoring models as a prognostic marker.