Abstract
Introduction: Cardiovascular (CV) hospital readmissions significantly burden the U.S. healthcare system, particularly among patients with heart failure. While previous studies have evaluated all-cause readmission, there is limited understanding of the specific CV diagnoses responsible for short- and long-term hospital returns. This study aimed to identify the leading CV-specific diagnoses contributing to 30-day and 1-year readmissions following an index hospitalization for heart failure to inform targeted interventions and reduce repeat hospitalizations. Methods: We conducted a retrospective cohort analysis using the Nationwide Readmissions Database (NRD) from 2016 to 2022. A total of 31,886,859 weighted hospitalizations were included. Adult patients (≥18 years) admitted with a primary diagnosis of heart failure were included. The primary outcome was CV-specific readmission within 30 days and 1 year, based on ICD-10 codes for heart failure/pulmonary edema, hypertension and hypertensive crisis, myocardial infarction, arrhythmias/conduction disorders, stroke, pulmonary circulation disorders, and venous thromboembolism. Survey-weighted descriptive statistics, stratified by 30-day and 1-year CV-specific readmission status, identified leading diagnoses. Adjusted models accounted for demographics, comorbidity burden (Charlson Comorbidity Index), and hospital characteristics. Chi-square tests and phi-coefficients (φ) quantified associations, with statistical significance set at p < 0.001. Results: Among patients initially hospitalized for heart failure, hypertension or hypertensive crisis accounted for the majority of CV-specific readmissions at both 30 days (64.8%) and 1 year (65.1%). Recurrent heart failure or pulmonary edema was the second most common cause, followed by arrhythmias, acute myocardial infarction, and stroke. All comparisons versus hypertension or hypertensive crisis were statistically significant (p < 0.001; φ = 0.53–0.69). These diagnostic patterns remained consistent over time. Conclusion: Hypertension-related complications and recurrent decompensated heart failure are the predominant causes of early and late CV-specific readmissions. These findings emphasize the need for robust post-discharge blood pressure control and longitudinal heart failure management. By identifying high-yield targets for intervention, this study supports the development of more effective care models aimed at reducing the CV readmission burden in this vulnerable population. Table 1. Thirty-Day and One-Year Readmission Rates Across Cardiovascular Conditions Compared with Hypertension N = 31,886,859 30-Day Readmission % (N) SE χ²(1) vs. HTN p-values vs. HTN φ-coefficient vs. HTN Acute Myocardial Infarction 5.90 (1,881,325) 0.024 24,202,174 < 0.001 0.62 Arrhythmias / Conduction 9.24 (2,946,346) 0.030 21,108,975 < 0.001 0.58 Heart Failure / Pulmonary Edema 12.90 (4,113,504) 0.035 18,076,867 < 0.001 0.53 Hypertension / Hypertensive Crisis (HTN) 64.80 (20,662,685) 0.049 Pulmonary Circulation 0.62 (197,699) 0.008 29,836,652 < 0.001 0.68 Stroke / Transient Ischemic Attack 5.61 (1,788,853) 0.024 24,486,831 < 0.001 0.62 Venous Thromboembolism 0.84 (267,850) 0.009 29,581,492 < 0.001 0.68 1-Year Readmission Acute Myocardial Infarction 6.37 (2,031,193) 0.017 23,946,025 < 0.001 0.61 Arrhythmias / Conduction 8.79 (2,802,855) 0.020 21,700,892 < 0.001 0.58 Heart Failure / Pulmonary Edema 12.10 (3,858,310) 0.023 18,896,344 < 0.001 0.54 Hypertension / Hypertensive Crisis 65.10 (20,758,345) 0.034 Pulmonary Circulation 0.61 (194,510) 0.006 30,057,395 < 0.001 0.69 Stroke / Transient Ischemic Attack 6.14 (1,957,853) 0.017 24,168,617 < 0.001 0.62 Venous Thromboembolism 0.79 (251,906) 0.006 29,848,196 < 0.001 0.68