Impact of anemia on in-stent restenosis after percutaneous coronary intervention

BACKGROUND: Anemia is a common risk factor for post-percutaneous coronary intervention (PCI) adverse events; however, data on its association with in-stent restenosis (ISR) is limited. METHODS: 538 patients who underwent PCI between January 2017 and September 2019 and follow-up angiography 9–12 months after the initial PCI were enrolled in this study. Baseline clinical and procedural characteristics were compared between the ISR and non-ISR groups, and independent predictors of ISR were determined using propensity score matching. RESULTS: The incidence of anemia was 53.5% in patients with ISR and 19.0% in those without ISR. Univariable logistic regression analyses showed that anemia (OR, 4.283; 95% CI, 1.949–9.410; P < 0.001), diabetes mellitus (OR, 2.588; 95% CI, 1.176–5.696; P = 0.018), chronic kidney disease (OR, 3.058; 95% CI, 1.289–7.252; P = 0.011), multiple stenting (OR, 2.592; 95% CI, 1.205–5.573; P = 0.015), bifurcation lesion (OR, 2.669; 95% CI, 1.236–5.763; P = 0.012), and calcification (OR, 3.529; 95% CI, 1.131–11.014; P = 0.030) were closely associated with ISR. Low-density lipoprotein cholesterol (LDL-c) levels and stent diameter were also significantly linked to ISR, as was anemia (P = 0.009) after propensity score matching. CONCLUSION: Anemia is closely associated with post-PCI ISR, and patients with lower hemoglobin levels are at a higher risk of ISR.