Risk Factors of Readmission and the Impact of Outpatient Management in Heart Failure Patients: A National Study in Japan

AIMS: Heart failure is a significant disease, and its high readmission rate is a big concern. We must identify readmission risk factors and optimize outpatient management to prevent them. This study aims to investigate the readmission risk factors, including outpatient management represented by the number of outpatient visits, and to identify the factors related to frequent outpatient visits. METHODS AND RESULTS: We used the diagnosis-procedure-combination database between April 2016 and March 2022. Based on the number of outpatient visits within 60 days after discharge, we categorized patients into <1 visits/month, (1<, ≦2) visits/month, and <2 visits/month and observed the occurrence of 60 days readmission. We performed multiple logistic regression analyses to reveal the readmission risk factors and the association between the number of outpatient visits and readmission. As a subgroup analysis, we conducted the same research in the low- and high-readmission risk groups. We compared medical contents between (1<, ≦2) visits/month and <2 visits/month. We analysed 101 239 patients and identified the following factors as a risk of readmission: older age (P < 0.001), female (P = 0.009), longer length-of-hospital-stay (P < 0.001), artificial ventilator (P < 0.001), tolvaptan (P < 0.001), top 50% dosage of loop diuretics (P = 0.036), bottom 50% dosage of class III antiarrhythmic agents (P < 0.001), hypertension (P = 0.005), atrial fibrillation (P < 0.001), dilated cardiomyopathy (P < 0.001), valvular disease (P = 0.021), myocardial infarction (P < 0.001), diabetes (P < 0.001), and renal disease (P < 0.001). We revealed that the risk of readmission increases in <2 visits/month compared to (1<, ≦2) visits/month (P < 0.001), whereas the risk of readmission decreases in ≦1 visits/month compared with (1<, ≦2) visits/month (P < 0.001). In the subgroup analysis, we found the possibility that some risk factors are specific to the subgroup. We identified that the following factors were related to frequent outpatient visits: older age (P < 0.001), home medical care (P = 0.007), tolvaptan (P < 0.001), top 50% dosage of loop diuretics (P < 0.001), diabetes (P < 0.001), renal disease (P = 0.009), 0-2 weeks follow-up (P < 0.001), 2-4 weeks follow-up (P < 0.001), cardiac rehabilitation (P < 0.001), and echocardiography (P < 0.001). CONCLUSIONS: This study comprehensively identified risk factors for readmission and found outpatient visit is personalized by readmission risk. There is still room to optimize outpatient management. We suggest optimizing outpatient management according to our identified characteristics.