Early Post-discharge Glycemic Control and Cardiovascular Event Readmission in Patients With Heart Failure and Type 2 Diabetes: A Single-center Retrospective Cohort Study

Background Heart failure (HF) patients with type 2 diabetes mellitus (T2DM) are at high risk of hospital readmission due to cardiovascular events. Glycemic control may play a key role in reducing this risk, but the optimal glycemic control threshold for preventing readmissions remains unclear.Material and methods This single-center, retrospective cohort study included 160 adult patients with HF and type 2 diabetes mellitus (T2DM). Patients were classified into two groups based on HbA1c measured 3 months after discharge: poor glycemic control (HbA1c ≥ 7.0 %) and good glycemic control (HbA1c < 7.0 %). Data were collected from electronic medical records, and cardiovascular event readmissions were tracked over a one-year follow-up period. Kaplan-Meier event-free survival (EFS) analysis and Cox regression models were used to examine the relationship between the three-month HbA1c and cardiovascular event readmission. A Fine-Gray competing-risk model was additionally applied to provide a more robust estimate of the cumulative incidence of cardiovascular readmission.Results Among the 160 patients, 56 (35 %) were readmitted due to cardiovascular events, including HF exacerbation (39.3 %), myocardial infarction (25.0 %), arrhythmias (14.3 %), and coronary artery disease (8.9 %). Their median EFS time was 121 days. The readmission rate was significantly higher in patients with poor glycemic control (HbA1c ≥7.0 %), with 58.8 % of the patients being readmitted compared to 17.4 % in the group with good glycemic control (HbA1c <7.0 %, p<0.001). Kaplan-Meier EFS analysis confirmed a significantly shorter EFS in patients with poor glycemic control. Cox regression analysis identified the three-month HbA1c value as an independent predictor of cardiovascular event readmission (HR=3.41, 95 % CI 2.15-5.29, p<0.001), which was consistent with the Fine-Gray competing-risk analysis (sub-distribution HR = 3.12, 95 % CI 1.95-4.98, p<0.001).Conclusion Early glycemic control, particularly the three-month HbA1c value, is a strong predictor of cardiovascular event readmission in HF patients with DM. Optimizing glycemic control within the first three months post-discharge may significantly reduce readmission risk and improve clinical outcomes.