BACKGROUND: Cardiac dysfunction, commonly observed in sepsis patients, is associated with higher mortality rates. The left ventricular stroke work index (LVSWI), an integrated parameter reflecting overall left ventricular function, may serve as a reliable and practical prognosticator for sepsis. METHODS: Using the Medical Information Mart for Intensive Care (MIMIC III) database, we carried out a retrospective observational study that included adult patients who met the Sepsis-3 criteria. Kaplan-Meier survival curves and Cox proportional hazard models were applied to examine the association between LVSWI and 30-day all-cause mortality. Restricted cubic spline plots were used to assess the non-linear relationship between LVSWI and mortality, and subgroup analyses were conducted across various variables. RESULTS: A total of 1,348 septic patients were included, with 300 (22.3%) fatalities. In multivariate Cox proportional hazard models, a significant negative relationship between LVSWI and mortality was observed, with a 31% reduction in mortality risk associated with an increase of one standard deviation in LVSWI (hazard ratio [HR]: 0.69, 95% confidence interval [CI]: 0.51-0.93, p = 0.016), following adjustment for confounders. Restricted cubic spline plots unveiled a non-linear, L-shaped relationship between LVSWI and mortality. Furthermore, a two-piecewise regression model identified the critical inflection point at 27.83 g·m/m², with HR (95% CI) values of 0.93 (0.90-0.96
p <
0.001) on the left and 1.00 (0.99-1.01
p = 0.913) on the right. CONCLUSIONS: The LVSWI exhibited an L-shaped relationship with 30-day mortality in patients with sepsis, underscoring the potential of LVSWI as a dependable prognostic indicator for sepsis. Further studies are needed to confirm these findings and to investigate whether early interventions to optimize LVSWI could improve outcomes in this patient population.