Cardiorenal outcomes and all-cause mortality in patients with comorbid heart failure and chronic kidney disease across three countries (The CaRe Study)

Abstract Background The cardiorenal diseases heart failure (HF) and chronic kidney disease (CKD) often coexist, and the presence of both conditions complicates patient management. The real-world cardiorenal and mortality outcomes of patients with comorbid HF and CKD are not well characterized. Purpose This analysis from The CaRe Study describes the patient profiles and outcomes in contemporary cohorts of patients with HF only, CKD only or comorbid HF and CKD in Japan, Sweden and the USA. Methods This was an observational longitudinal cohort study using data from electronic health records in Japan (Medical Data Vision database), Sweden (nationwide administrative registries) and the USA (Optum’s de-identified Clinformatics® Data Mart Database). Adults were included if they had HF only, CKD only, or comorbid HF and CKD as of 1 January 2022. HF and CKD were defined according to the respective recorded diagnosis codes. Study endpoints included time-to-first event for hospitalization for HF (hHF), hospitalization for CKD (hCKD) and all-cause mortality. Differences in outcome risks for patients with comorbid HF and CKD versus those with HF only or CKD only were estimated by age/sex adjusted Cox regression. Results In total, 3 404 714 patients were included from Japan (n = 993 660), Sweden (n = 313 976) and the USA (n = 2 097 078) (Table), of whom 17% (n = 592 219) had comorbid HF and CKD: 11% (n = 105 252) in Japan, 15% (n = 45 961) in Sweden and 21% (n = 441 006) in the USA. Median age was 75, 76 and 75 years, respectively. In each country, patients with comorbid HF and CKD were older and had more additional comorbidities than those with HF only or CKD only (Table). Patients with comorbid HF and CKD versus those with HF or CKD alone had higher rates of hHF, hCKD and all-cause mortality in all three countries (Figure). Conclusion In this large, multinational, observational study, cardiorenal outcomes and all-cause mortality were significantly higher in patients with comorbid HF and CKD than in those with HF or CKD alone. These findings highlight the prognostic significance of comorbid HF and CKD and emphasize the importance of optimal management in these high-risk patients.