Impact of baseline anemia on outcomes following chronic total occlusion percutaneous coronary intervention

Anemia is a common comorbidity in patients undergoing percutaneous coronary intervention (PCI) and may signal worse post-procedural outcomes. Its prognostic impact in the context of chronic total occlusion (CTO) PCI remains underexplored. To evaluate procedural and clinical outcomes following CTO PCI in patients with and without anemia using real-world data from a high-volume tertiary care center. We conducted a retrospective observational study using data from 504 patients who underwent CTO PCI between January 2018 and December 2023 at Houston Methodist. Patients were stratified by anemia status, defined using World Health Organization hemoglobin thresholds. Primary endpoints included procedural success, one-year all-cause mortality, and target lesion revascularization (TLR). Secondary endpoints included target lesion failure (TLF) and in-hospital complications. Of the cohort, 163 patients (32.3 %) had anemia. Patients with anemia were older, more often female, and had a greater burden of comorbidities, including CKD and heart failure. Despite similar lesion complexity and procedural success rates (80.4 % vs. 81.5 %; p = 0.79), patients with anemia had higher rates of in-hospital complications and one-year mortality (18.1 % vs. 5.0 %; HR = 4.0, p < 0.001)one-year target lesion failure (HR = 1.9; 95 % CI [1.2–2.9]; p = 0.005). Multivariate analysis identified age, heart failure, anemia and multivessel PCI as independent predictors of mortality at one-year, while CKD, and ISR lesion were predictors of TLF at one-year. The severity of anemia was not independently associated with all-cause mortality. Pre-procedural anemia is associated with markedly worse in-hospital and long-term outcomes in patients undergoing CTO PCI, despite comparable technical success. These findings highlight anemia as a marker of systemic vulnerability and underscore the need for comprehensive risk stratification and multidisciplinary care in this high-risk population. • Anemia was present in over a quarter of CTO PCI patients and was associated with significantly higher one-year mortality and heart failure hospitalizations. • Despite similar lesion complexity and procedural success, anemic patients experienced more in-hospital complications and adverse long-term outcomes. • Anemia, along with heart failure and CKD, emerged as key predictors of poor prognosis, underscoring the need for improved risk stratification in this high-risk population.