Anemia but not iron deficiency predicts outcomes after tricuspid edge-to-edge repair: insights from the Euro-TR registry

Background Anemia and iron deficiency (ID) are common in patients with cardiovascular disease, particularly heart failure, and are associated with impaired functional status and adverse outcomes. Patients undergoing transcatheter edge-to-edge repair (T-TEER) represent a high-risk population with heterogeneous clinical trajectories. However, the prognostic relevance of anemia and ID in patients treated with T-TEER remains poorly defined. Purpose This study evaluated the association of baseline anemia and ID with clinical outcomes after T-TEER using data from a large, multicenter registry. Methods The Euro-TR (European Registry of Transcatheter Repair for Tricuspid Regurgitation) registry includes 3,048 patients undergoing T-TEER between 2016 and 2022. For this analysis, 2945 patients with available hemoglobin status were included. Anemia was defined according to World Health Organization criteria (hemoglobin <12g/L in women and <13g/L in men). In a subgroup of 476 patients with available ferritin and transferrin measurements, iron deficiency (ID) was defined according to guideline-recommended threshold. The primary endpoints were all-cause mortality and the composite of all-cause mortality or heart failure rehospitalization (HFH). Kaplan–Meier analyses and multivariable Cox proportional hazards models were used to assess associations between anemia, ID, and outcomes. Results Among 2945 patients (median age: 80 [IQR 76-83] years; 45.7% male; median EuroSCORE II: 4.5% [IQR 2.6-7.7], anemia was highly prevalent (57.2%). Patients with anemia had worse baseline functional status and showed less functional improvement following T-TEER (NYHA improvement ≥ 1 stage 61.1% vs. 54.0%, p = 0.004). Anemia was independently associated with higher all-cause mortality (HR = 2.11; 95%-CI [1.69-2.63], p < 0.001 and with the composite endpoint of all-cause mortality or HFH (HR = 2.01; 95%-CI [1.68-2.39, p < 0.001) at 3 years follow-up even after adjustment for relevant comorbidities (sex, BMI, LVEF, CKD, AFib). Although ID was highly prevalent in the subgroup with available ferritin and transferrin saturation measurements (318/476 patients, 66.8%), it was not associated with either endpoint. Conclusion Baseline anemia, but not iron deficiency, identifies patients undergoing T-TEER at higher risk of adverse events. As an easily available and routinely measured parameter, hemoglobin may support risk stratification and complex clinical decision-making, while these findings should be considered hypothesis-generating and warrant prospective evaluation.