Quantitative Association between Computed-Tomography-Based L1 Skeletal Muscle Indices and Major Adverse Clinical Events Following Percutaneous Coronary Intervention

Sarcopenia is as a non-traditional risk factor for atherosclerotic cardiovascular disease. Further investigation is required to elucidate the prognostic significance of computed tomography (CT)-based sarcopenia assessment in coronary artery disease (CAD). We prospectively enrolled 475 patients, who underwent coronary stent implantation and peri-procedural CT scans within one month. Skeletal muscle index (SMI) was assessed cross-sectionally at the first lumbar vertebra (L1) level. The participants were grouped based on sex-specific L1 SMI quartiles. The primary endpoint was all-cause mortality, and the secondary composite endpoint was major adverse cardiovascular events (MACEs) over a 3-year follow-up period. Three-year all-cause mortality and MACE incidence increased significantly in patients in the lower L1 SMI quartiles compared to those of patients in the higher quartiles (p < 0.001). The individual composite endpoints consistently showed a higher incidence in the lower quartiles of L1 SMI (p < 0.001). In multivariable analysis, the lower L1 SMI quartiles independently predicted 3-year all-cause mortality and MACEs (lowest vs. highest quartiles, respectively: OR 4.90 (95% CI 1.54–15.5), p = 0.007; and OR 12.3 (95% CI 4.99–30.4), p < 0.001). In conclusion, CT-based L1 SMI demonstrated a distinct dose-dependent relationship with future MACEs in CAD patients undergoing percutaneous coronary intervention, thereby enhancing cardiovascular risk stratification.