Transfusion and clinical outcomes after percutaneous coronary intervention

We investigated the long-term patterns and effects of transfusion on the clinical outcome of patients undergoing percutaneous coronary intervention (PCI) using a nationwide registry. Five-year clinical outcome of all Koreans undergoing PCI using stent in year 2011 (n = 48,786) was investigated. Primary outcome was the incidence density of transfusion. The association of transfusion with major adverse clinical event (MACE) consisting all-cause death, revascularization, critically ill cardiovascular status, or stroke was assessed after adjusting the propensity of each patient for transfusion. The 5-year incidence density of transfusion was 4.74 (95% confidence interval [CI] 4.70–4.79) per 100 person-year. Patients who received transfusion were older and had higher frequency of clinical risk factors (p < 0.001, all). Transfusion was associated with MACE (hazard ratio [HR] 3.2, 95% CI 3.2–3.3, p < 0.001) and all other clinical events (HR 1.5–6.9, p < 0.001, all). The period of transfusion coincided with the period of highest MACE incidence density. Subgroup analyses showed consistent results. Within 5 years after PCI, a total of 22.9% of patients received transfusion and had a 3.2-fold higher risk of MACE compared to patients without transfusion.