MINS-Related Risk-Factor Burden and Long-Term Outcomes After Curative Gastrectomy for Gastric Cancer

Background/Objectives: Cardiovascular vulnerability may influence long-term outcomes after cancer surgery, but the prognostic significance of risk factors associated with myocardial injury after noncardiac surgery (MINS) in gastric cancer is unclear. We investigated the association between MINS-related risk-factor burden and long-term outcomes after curative gastrectomy and evaluated its incremental prognostic information. Methods: We retrospectively analyzed 364 consecutive patients who underwent R0 gastrectomy for gastric adenocarcinoma between June 2016 and December 2023. Patients were categorized by MINS-related risk-factor count as 0–2, 3, or ≥4. Overall survival (OS) was the primary outcome; recurrence and cause-specific mortality were additionally evaluated using competing-risk methods. Cox regression, restricted cubic spline analysis, sensitivity analyses, and prognostic model comparisons were performed. Results: Five-year OS was 87.2%, 81.7%, and 66.6% in the 0–2, 3, and ≥4 groups, respectively (p < 0.001). Each additional MINS-related risk factor was associated with worse OS after adjustment for pathological stage and prognostic nutritional index (HR 1.25, 95% CI 1.08–1.46; p = 0.004), and the association remained consistent in expanded sensitivity models. The MINS-extended model improved overall model fit versus the base model (ΔLR χ2 = 8.17, p = 0.004; AIC 640.89 vs. 647.06), although the increase in C-index was modest (0.775 to 0.786; bootstrap 95% CI for ΔC-index, −0.005 to 0.041). Five-year cumulative incidence of non-cancer death was 5.2%, 11.9%, and 17.0% across the three groups (Gray’s p = 0.0098), whereas the MINS-related risk-factor group was not independently associated with gastric cancer death after adjustment for pathological stage. Conclusions: Greater MINS-related risk-factor burden was associated with poorer overall survival after curative gastrectomy, an association that appeared to be largely attributable to increased non-cancer mortality rather than gastric cancer-specific mortality. The measure overlaps substantially with conventional comorbidity and frailty indices but may provide a simple cardiovascular-oriented perspective on broader host vulnerability.