Renal dysfunction: a predictor of adverse outcomes in ACHD patients with acute decompensated heart failure

Abstract Background Renal dysfunction (RD) is a predictor of adverse outcomes in patients with acquired heart failure (HF). Studies in adult congenital heart disease (ACHD) have demonstrated the link between RD and increased mortality. However, there is a paucity of data regarding the prognostic significance of RD in ACHD and HF. We assessed the impact of RD on outcomes in ACHD patients presenting with acute decompensated HF requiring intravenous (IV) diuresis in a tertiary centre between 2010–2021. Methods This was a retrospective analysis on RD and outcomes during the index hospital admission and after discharge. Chronic kidney disease (CKD) was defined as an eGFR <60mL/min/1.73 m2 using the MDRD equation. Cox regression analysis was used to identify predictors of death after discharge. Results We included 176 HF admissions, 76 (43.2%) female, age 47.7±14.5 years. Complex CHD was present in 50.6%. The most frequent underlying congenital heart defects were: transposition of the great arteries (including congenitally corrected, 19.9%), univentricular (14.2%), and tetralogy of Fallot (13.6%). Eisenmenger syndrome was present in 18.8%, a systemic right ventricle in 22.2%, 40.9% had pulmonary arterial hypertension (PAH), and 38.1% were cyanotic. At the time of the index admission 92 (52.3%) had RD (eGFR <60 mL/min/1.73 m2 and/or serum creatinine >88 μmol/L), 63 (38.2%) had a history of CKD. Patients with RD on admission were older (49.8 [42.3–60.9] vs. 46.0 [33.8–53.6] years, p=0.02) and more likely to have a history of arrhythmia (71.7% vs. 53.6%, p=0.02), but did not differ to those without RD in terms of diabetes mellitus or systemic hypertension. Admission BNP was higher in patients with RD (594 [258–1216] vs. 354 [158–633] ng/L, p=0.01). Patients with RD were more likely to have at least moderate systemic (31.8% vs. 11.8%, p=0.005) or pulmonary (58.4% vs. 36.4%, p=0.01) ventricular dysfunction. They were also more likely to have systemic ventricular dilatation (28.6% vs. 11.8%, p=0.02) or a larger RA area (29 [21–34] vs. 21 [16–31] cm2, p=0.008). Inpatients with RD required higher doses of IV furosemide (160 [80–200] vs. 80 [70–160] mg, p=0.03) and there was a trend for more frequent inotropic support (19.6% vs. 8.3%, p=0.06). In-hospital mortality was relatively low (4.5%), however, 94 (56.0%) patients died and 73 (43.5%) were rehospitalised for HF at a median follow-up of 2.8 [0.01–12.0] years. CKD (HR 2.43, 95% CI: 1.59–3.71, p<0.0001) and RD on admission (HR 1.7, 95% CI: 1.13–2.58, p=0.01) were strong predictors of death (Figure 1). On multivariable Cox analysis, PAH, CKD, and peak inpatient diuretic dose remained predictive of mortality. Conclusions ACHD patients admitted with acute decompensated HF are a high-risk cohort for acute re-admission and mortality. Preexisting RD and need for high dose IV diuretics conveys an even worse prognosis. Earlier interventions based on evidence of RD in ACHD may modulate this spiral trajectory and warrants further investigation. Funding Acknowledgement Type of funding sources: None.