Red blood cell distribution width/albumin ratio is a novel risk factor of incidence and long-term mortality in chronic heart failure patients: three large cohorts from China and America.

AimsRed blood cell distribution width/albumin ratio (RAR) is a novel parameter associated with inflammation. Previous studies have not focused on the role of RAR in the incidence and long-term prognosis of chronic heart failure (CHF). This study included three cohorts, two prospective and one retrospective study. The aim was to investigate the value of RAR in the incidence of CHF and the long-term prognosis of CHF. MethodsThree cohorts were investigated, including MIMIC, NHANES, and JHDH. The included patients of MIMIC, NHANES, and JHDH were 22,672 from 2001-2012, 60,754 from 1999-2020, and 15,102 from 2021-2022, respectively. According to whether the patients have CHF-related risk factors, the patients were classified into non-CHF, pre-CHF, and CHF groups. The median follow-up time of MIMIC and NHANES was 364 days and 62 months. Logistic regression, Cox regression, restricted cubic spline (RCS), and Kaplan-Meier (KM) curves were used to analyze the value of RAR in CHF patients. ResultIn NHANES, the CHF prevalence in quartiles of RAR (Q1, Q2, Q3, and Q4) were 8.88%, 16.86%, 27.65%, and 46.61%, respectively. MIMIC and JHDH showed a similar trend. Among the non-CHF and CHF patients, the odds ratio (OR) was 1.45 (JHDH 95% CI 1.33-1.58) and 1.93 (NHANES 95% CI 1.41-2.65). In NHANES, the RAR OR value of Q2, Q3 and Q4 were 2.02(CI 1.19-3.43), 3.24(CI 1.95-5.39), and 4.95(CI 2.44-10.02) compared with Q1, respectively. And the OR was 1.05 (MIMIC 95% CI 1.02-1.07) in pre-CHF and CHF patients. The CHF mortality showed an adjusted hazard ratio (HR) is 1.12 (MIMIC 95% CI 1.1-1.14) and 2.26 (NHANES 95% CI 1.52-3.36). KM demonstrates that higher RAR (>3.4 in NHANES and >5.06 in MIMIC) prognoses lead to poor survival in CHF patients. CHF mortality in the 19th quartile of the RAR was 1.4 times higher than in the first quartile, compared with 1.22 times in the red blood cell distribution width (RDW). The 19-quartile mortality curves of the RAR were more stable than RDW and albumin (ALB). ConclusionRAR is an independent risk factor for incidence and all-cause long-term mortality in CHF patients. The predictive value of RAR for all-cause mortality in CHF is superior to ALB and RDW. RAR may be a potential clinical indicator for future treatment of CHF.