P6337Prognostic impacts of serum uric acid levels in patients with chronic heart failure: insights from the CHART-2 Study
Authors: Fujihashi T , Sataka Y , Nochioka K , Miura M , Kasahara S , Sato M , Aoyanagi H , Yamanaka S , Hayashi H , Shiroto T , Sugimura K , Takahashi J , Miyata S , Shimokawa H 
Published: October 2019

Abstract

Background
Prognostic impact of serum uric acid (UA) levels in patients with heart failure (HF) remains to be fully elucidated, as previous studies were inconclusive with small study sample sizes. Furthermore, although the J-curve relationship between serum UA levels and cardiovascular events has been suggested in patients with hypertension and those with diabetes, it is still unclear whether this is also the case for patients with HF.

Purpose
We examined the prognostic impacts of serum UA levels in HF patients, using the database of our Chronic Heart Failure Registry and Analysis in the Tohoku district (CHART)-2 Study, the largest multicenter, prospective, observational cohort study for cardiovascular patients with HF or those at risk of HF in Japan (N=10,219).

Methods
First, we determined the cut-off value of serum UA levels at baseline by the Classification and Regression Tree (CART). Then, we divided 4,652 consecutive HF patients in the CHART-2 Study into 4 groups; G1 (<3.8 mg/dL, N=313), G2 (3.8–7.1 mg/dL, N=3,070), G3 (7.2–9.2 mg/dL, N=1,018), and G4 (≥9.3 mg/dL, N=251). Among the 4 groups, we compared clinical characteristics and incidence of all-cause death, HF hospitalization, and a composite of all-cause death and HF hospitalization.

Results
Mean age in G1, G2, G3, and G4 was 71±12, 69±12, 68±13, and 69±15 years, respectively (P<0.001). G1 was characterized by a significantly high prevalence of women as compared with G2, G3 and G4 (59, 32, 24 and 23%, respectively). Serum creatinine levels (0.8±0.4, 0.9±0.4, 1.2±0.6 and 1.4±0.8 mg/dL, respectively), prevalence of atrial fibrillation (34, 39, 45 and 50%, respectively), and diuretics use (36, 45, 67, 89%, respectively) increased from G1, G2, G3 to G4 (all P<0.001), while left ventricular ejection fraction decreased from G1, G2, G3 to G4 (59±15, 58±15, 54±15, and 52±17%, respectively, P<0.001). Median BNP levels were comparably low in G1 and G2 and then increased to G3 and G4 (94.4, 91.5, 130 and 192.5 pg/mL, respectively, P<0.001). As a HF etiology, prevalence of ischemic heart disease was highest in G2 and lowest in G4 (48, 52, 48, 38%, respectively, P<0.001), while that of dilated cardiomyopathy increased from G1, G2, G3 to G4 (11, 12, 16 and 20%, respectively, P<0.001). During the median follow-up period of 6.3 years, in G1, G2, G3 and G4, 111 (35%), 905 (29%), 370 (36%) and 139 (55%) patients died and 79 (25%), 729 (24%), 300 (29%) and 115 (46%) experienced HF hospitalization, respectively (both P<0.001). Cox proportional hazard models adjusted for clinical backgrounds showed that, as compared with G2, both G1 and G4 had increased risk for all-cause death, HF hospitalization and a composite of all-cause death, and HF hospitalization, indicating the J-curve relationship between serum UA levels and prognosis (Figure).
Prognostic impacts of serum UA levels

Conclusions
Both decreased and increased UA levels were associated with increased incidence of death and HF hospitalization in HF patients.