Association between complementary use of Goreisan (a Japanese herbal Kampo medicine) and heart failure readmission: A nationwide propensity score-matched study.

Background: Goreisan, a Japanese herbal medicine, possesses aquaretic properties to regulate body fluid homeostasis and may therefore be effective as a complement to standard therapy in improving outcomes in patients with heart failure (HF).

Methods: We retrospectively identified 431,393 patients (mean age 79.2 ± 12.6 years; male 52.3 %) who were admitted for HF for the first time and were discharged alive with standard HF medications between April 2016 and March 2022, using the Japanese Diagnosis Procedure Combination database. We divided patients into two groups according to the prescription of Goreisan at discharge: patients who received standard HF medications plus Goreisan and those who received standard medications alone. We compared the incidence of HF readmission within 1 year after discharge between the groups using propensity score matching.

Results: Overall, Goreisan was prescribed in 1957 (0.45 %) patients at discharge. Patients who received Goreisan were older and received diuretics more frequently than those who did not. One-to-four propensity score matching created a cohort of 1957 and 7828 patients treated with and without Goreisan, respectively. No significant difference was found in the incidence of 1-year HF readmission between the groups [22.1 % vs. 21.7 %; hazard ratio (HR) = 1.02, 95 % confidence interval (CI) = 0.92-1.13]. This result was consistent with that from competing risk analysis (subdistribution HR = 1.02, 95 % CI = 0.92-1.13) and across clinically relevant subgroups except for renal disease. Goreisan use was associated with a lower incidence of HF readmission among patients with renal disease (HR = 0.77, 95 % CI = 0.60-0.97), but not among those without (HR = 1.09, 95 % CI = 0.97-1.23; p for interaction = 0.009).

Conclusions: This nationwide propensity score-matched analysis did not demonstrate that complementary Goreisan use at discharge was associated with a lower incidence of 1-year HF readmission in patients with HF receiving standard medications. An ongoing randomized trial is awaited to establish the effectiveness of Goreisan use in patients with HF.