Combined evaluation of liver and kidney function improves prediction of clinical outcome in patients with chronic heart failure and reduced ejection fraction

Abstract Background/Introduction The liver and the kidneys are important organs for body homeostasis and are both affected by heart failure (HF) either by systemic venous congestion or hypoperfusion. Purpose We aimed to verify whether the Model for End-stage Liver Disease eXcluding International normalized ratio (MELD-XI), as well as a combination of cholestatic liver and kidney function tests carry prognostic value in patients with chronic HF with reduced ejection fraction (HFrEF). The liver parameters included alkaline phosphatase (ALP), gamma glutamyl-transpeptidase (GGT), and total bilirubin, while kidney parameters consisted of eGFR and the tubular damage markers urinary N-acetyl-beta-D-glucosaminidase (NAG) and kidney injury molecule (KIM)-1. Methods We categorized 250 patients with HFrEF on the basis of baseline biomarker levels. We assumed elevated NT-proBNP indicates hemodynamic congestion necessary to induce congestive liver or kidney dysfunction. Thus, in every organ damage category, NT-proBNP level above median was incorporated, next to any 2 out of 3: ALP, GGT or total bilirubin above median for liver dysfunction; any 2 out of 3 NAG or KIM-1 above median or eGFR below median for kidney dysfunction; or coexistence of liver and kidney dysfunction as defined above. Additionally, a subgroup of patients with both NT-proBNP and MELD-XI above the median was analyzed. The primary endpoint was a composite of cardiovascular death, heart transplantation, LVAD implantation, and hospitalization for acute or worsened HF, whichever occurred first. Univariable and multivariable Cox proportional hazard regression models were used. Results Median (Q1-Q3) age of the study population was 68 (58-76) years; 184 (74%) were men, 62 (25%) in NYHA class III or IV, and mean left ventricular ejection fraction (LVEF) was 31±9%. During a median (Q1-Q3) follow-up of 2.2 (1.4-2.5) years, 66 (26%) patients reached the primary endpoint. We observed that liver dysfunction, kidney dysfunction or their coexistence was associated with significantly higher risk of reaching the primary endpoint (HR 3.54, 95% CI 1.75–7.16; HR 1.85, 95% CI 1.00–3.41; HR 2.52, 95% CI 1.03–6.11 respectively) in the clinically adjusted model (Table 1). Higher MELD-XI was associated with higher risk of reaching the primary endpoint in an unadjusted model but not in a clinically adjusted model. Figure 1 presents event-free survival probability of patients falling into organ dysfunction categories. Conclusions Our results show that markers of cholestatic liver function and kidney function predict unfavorable clinical outcome and provide better prognostic value in chronic HFrEF patients than the MELD-XI alone. Thus, screening for liver and kidney damage may help identify high-risk patients in whom more careful observation and individualized therapy is warranted.Fig 1.Event-free survival probability