Differential effects of anaemia and iron deficiency on long-term outcomes following transcatheter edge-to-edge repair in degenerative vs. secondary mitral regurgitation: results from a large single-center study.

Abstract

Anaemia and iron deficiency (ID) are independently associated with adverse outcomes in patients with cardiovascular diseases, especially in those with heart failure. Here, we aimed to clarify the long-term effect of anaemia and ID on outcomes in patients undergoing transcatheter mitral edge-to-edge repair (TEER) for relevant mitral regurgitation (MR) as well as to relate these to the underlying MR aetiology. 833 patients (median age 77.1years, 40.7% women, 63.3% secondary MR) treated by TEER between 09/2008 and 07/2019 were included and stratified according to baseline anaemia (hemoglobin < 12g/dL in women and < 13g/dL in men) or ID. Anaemia and ID were frequent with 61.6% and 68.1%, respectively. Anaemic patients had a lower functional status at baseline and were less likely to improve after TEER. In addition, anaemia was associated with all-cause mortality (hazard ratio [HR] = 1.68, 95% confidence interval [CI] 1.36-2.07, p < 0.001) and the composite endpoint of death or heart failure (HF) rehospitalization (HR = 1.30, 95% CI 1.10-1.54, p = 0.002). In contrast, ID was not associated with either all-cause mortality or the composite endpoint of death or HF rehospitalization. Patients undergoing TEER have high rates of both anaemia and ID. However, anaemia is associated with worse functional baseline status and post-interventional improvements compared to ID. Furthermore, anaemia is linked to higher rates of mortality and HF rehospitalization, particularly in those with secondary MR.