Predictive Value of the Intermountain Mortality Risk Score for Saphenous Vein Graft Degeneration: A Retrospective Cohort Analysis

Objective: The Intermountain Risk Score (IMRS), derived from routine laboratory parameters, predicts cardiovascular outcomes. Its association with saphenous vein graft degeneration (SVGD) post-coronary artery bypass grafting (CABG) remains underexplored. Methods: This retrospective cohort study analyzed data from 261 CABG patients who underwent coronary angiography. SVGD was defined as ≥50% graft stenosis. IMRS was calculated using laboratory data, age, and sex. Multivariate logistic regression and receiver operating characteristic (ROC) analyses were used to assess IMRS's predictive value for SVGD. Results: Of the 261 patients, 138 (52.9%) had SVGD. The SVGD group had higher median IMRS scores (12.5 vs. 10, p<0.001). After adjusting for confounders, IMRS was an independent predictor of SVGD (OR 1.640, 95% CI 1.310-2.054, p<0.001), as were chronic kidney disease and smoking. ROC analysis showed an area under the curve of 0.676, with a cutoff of IMRS >12 yielding a specificity of 83% and a sensitivity of 50%. Conclusions: Elevated IMRS independently predicts SVGD in post-CABG patients. As a cost-effective tool, IMRS may guide preoperative risk stratification and postoperative prevention strategies.