Relation of Renal Function with Left Ventricular Systolic Function and NT-proBNP Level and Its Prognostic Implication in Heart Failure with Preserved versus Reduced Ejection Fraction: an analysis from the Korean Heart Failure (KorHF) Registry

Abstract

Background and objectives: The relationship between ejection fraction (EF), N-terminal pro-brain natriuretic peptide (NT-proBNP) levels and renal function is unknown as stratified by heart failure (HF) type. We investigated their relation and the prognostic value of renal function in heart failure with preserved ejection fraction (HFpEF) vs. reduced ejection fraction (HFrEF).

Materials and methods: NT-proBNP, glomerular filtration rate (GFR), and EF were obtained in 1,932 acute heart failure (AHF) patients. HFrEF was defined as EF<50%, and renal dysfunction as GFR<60 mL/min/1.73 m² (mild renal dysfunction: 30≤GFR<60 mL/min/1.73 m²; severe renal dysfunction: GFR<30 mL/min/1.73 m²). The primary outcome was 12-month all-cause death.

Results: There was an inverse correlation between GFR and log NT-proBNP level (r=-0.298, p<0.001), and between EF and log NT-proBNP (r=-0.238, p<0.001), but no correlation between EF and GFR (r=0.017, p=0.458). Interestingly, the prevalence of renal dysfunction did not differ between HFpEF and HFrEF (49% vs. 52%, p=0.210). Patients with renal dysfunction had higher 12-month mortality in both HFpEF (7.9% vs. 15.2%, log-rank p=0.008) and HFrEF (8.6% vs. 16.8%, log-rank p<0.001). Multivariate analysis showed severe renal dysfunction was an independent predictor of 12-month mortality (hazard ratio [HR], 2.08; 95% confidence interval [CI], 1.40-3.11). When stratified according to EF: the prognostic value of severe renal dysfunction was attenuated in HFpEF patients (HR, 1.46; 95% CI, 0.66-3.21) contrary to HFrEF patients (HR, 2.43; 95% CI, 1.52-3.89).

Conclusion: In AHF patients, the prevalence of renal dysfunction did not differ between HFpEF and HFrEF patients. However, the prognostic value of renal dysfunction was attenuated in HFpEF patients.

Keywords: Ejection fraction; Heart failure; Pro-brain natriuretic peptide (1-76); Prognosis; Renal dysfunction.

Figure 1

Association between renal dysfunction according to log NT-proBNP and LVEF. In receiver-operating-curves analysis, the AUC of log NT-proBNP (A) and LVEF (B) to predict renal dysfunction are presented. AUC = area under the curve; CI = confidence interval; EF = ejection fraction; HFpEF = heart failure with preserved ejection fraction; HFrEF = heart failure reduced ejection fraction; LVEF = left ventricular ejection fraction; NT-proBNP = N-terminal pro-brain natriuretic peptide.

Figure 2

Association of NT-proBNP and LVEF with renal dysfunction. Patients were divided in quartiles according to LVEF and NT-proBNP. Risk on the y-axis is HR±95% CIs using a logistic regression model. CI = confidence interval; HR = hazard ratio; LVEF = left ventricular ejection fraction; NT-proBNP = N-terminal pro-brain natriuretic peptide; OR = odds ratio.

Figure 3

Survival rates according to renal dysfunction. Kaplan-Meier curves of the 12-month survival rates according to renal dysfunction in all (A), HFpEF (B), and HFrEF (C) patients are presented. GFR = glomerular filtration rate; HFpEF = heart failure with preserved ejection fraction; HFrEF = heart failure with reduced ejection fraction.

Figure 4

Readmission free survival rates according to renal dysfunction. Kaplan-Meier curves for 12-month readmission free survival rates according to renal dysfunction in all (A), HFpEF (B), and HFrEF (C) patients are presented. GFR = glomerular filtration rate; HFpEF = heart failure with preserved ejection fraction; HFrEF = heart failure with reduced ejection fraction.