Cardiac remodeling, prognostic markers, and cardiovascular outcomes across heart failure phenotypes in adults with congenital heart disease

BACKGROUND: Data comparing cardiac remodeling, prognostic markers, and cardiovascular outcomes across heart failure (HF) phenotypes in adults with congenital heart disease (CHD) are limited. METHODS: In this study, adults with CHD and HF were classified based on left ventricular ejection fraction (LVEF): HF with reduced EF (HFrEF; LVEF < 40%), HF with mildly reduced EF (HFmrEF; LVEF 41%-49%), and HF with preserved EF (HFpEF; LVEF ≥ 50% with pulmonary artery wedge pressure ≥15 mmHg). Cardiac function (strain imaging), prognostic markers (NT-proBNP and peak oxygen consumption), and cardiovascular outcomes (HF hospitalization and cardiovascular death/heart transplantation) were compared across groups. RESULTS: Among 1,303 patients, 304 (23%) had HFrEF, 551 (42%) had HFmrEF, and 448 (34%) had HFpEF. There was a graded worsening of biatrial and right ventricular function from HFpEF to HFmrEF to HFrEF (all P < .001). Despite less severe chamber dysfunction, HFpEF was characterized by higher NT-proBNP levels and lower peak oxygen consumption compared with HFmrEF. HFrEF was associated with the highest adjusted risk of HF hospitalization (hazard ratio, 1.52; P = .005) and cardiovascular death/heart transplantation (hazard ratio, 1.74; P = .002), compared to HFmrEF and HFpEF. HF therapy was associated with lower event rates overall, with the strongest association in HFrEF, a more modest association in HFmrEF, and no significant association in HFpEF. CONCLUSIONS: In adults with CHD and HF, LVEF-defined HF phenotypes identified distinct patterns of cardiac remodeling and prognosis, with worse cardiac remodeling and adverse outcomes observed in the HFrEF phenotype. These findings support use of EF phenotype-based approach to HF management in CHD.