Prognostic Impact of Baseline Anemia on Outcomes After Elective PCI in Men: A US Retrospective Cohort Study

BACKGROUND: It is unclear whether preprocedural anemia independently affects outcomes after elective PCI in men with stable CAD. METHODS: Using the TriNetX US Collaborative Network, we identified adult men undergoing first-time elective PCI (2016-2024) and compared those with hemoglobin < 13 g/dL (1-7 days pre-PCI) to non-anemic controls. Propensity-score matching produced two balanced cohorts (n = 1424). Outcomes at 7 days, 30 days, 6 months, and 12 months were analyzed with univariate and multivariable Cox models. Residual confounding was assessed with falsification endpoints and E-values, and multiplicity with Bonferroni and Benjamini-Hochberg adjustments. RESULTS: After propensity-score matching, 7-day outcomes were similar between groups. At 30 days, anemia was associated with higher risks of AKI (HR 1.92; 95% CI 1.35-2.72) and major bleeding (HR 2.49; 95% CI 1.48-4.19); however, the 30-day association with all-cause hospitalization (HR 1.32; 95% CI 1.05-1.66) did not remain statistically significant after multiplicity adjustment. At 6 months, anemia was linked to higher risks of AKI (HR 2.34; 95% CI 1.84-2.97), mortality (HR 2.63; 95% CI 1.63-4.26), hospitalization (HR 1.56; 95% CI 1.34-1.80), major bleeding (HR 3.28; 95% CI 2.34-4.61), and transfusion (HR 5.47; 95% CI 3.31-9.06); the association with MACE (HR 1.37; 95% CI 1.10-1.70) was sensitive to multiplicity adjustment (significant under false-discovery-rate control but not Bonferroni). At 12 months, anemia remained associated with higher risks of AKI (HR 1.96; 95% CI 1.60-2.41), mortality (HR 1.88; 95% CI 1.31-2.70), hospitalization (HR 1.41; 95% CI 1.23-1.62), major bleeding (HR 2.16; 95% CI 1.66-2.81), and transfusion (HR 3.35; 95% CI 2.31-4.85); the association with MACE (HR 1.26; 95% CI 1.03-1.53) did not persist after multiplicity adjustment. Each 1 g/dL increase in hemoglobin was associated with lower risks of AKI and transfusion in univariate Cox models, with similar directionality after adjustment. CONCLUSIONS: In men undergoing first-time elective PCI for stable CAD, baseline anemia was associated with higher 12-month risks of AKI, major bleeding, transfusion, hospitalization, and death-especially with recent (≤ 1 year) bleeding or transfusion.