Unplanned Readmissions After Acute Myocardial Infarction: 1-Year Trajectory Following Discharge From a Safety Net Hospital.

Background: Financial penalties rendered by the Centers for Medicare and Medicaid Services have brought about new challenges for safety net hospitals that serve a vulnerable patient population with risk factors associated with high readmission rates. Our goal was to determine the 1-year trajectory of unplanned readmissions in post-myocardial infarction (MI) patients, and to identify factors associated with readmission.
Methods: A total of 261 acute MI patients admitted from April 2015 to April 2016 were evaluated in a multidisciplinary cardiology clinic within 10 days of hospital discharge and baseline characteristics and medical comorbidities were collected. Readmission and mortality data were obtained at 1 year through chart review and telephone follow-up.
Results: At 1 year, there were 90 (34%) unplanned readmissions of which half were for noncardiac diagnoses. Of these, 69 patients (77%) were readmitted once, 16 (18%) were readmitted twice, 2 (2%) were readmitted 3 times, and 3 (3%) were readmitted 4 times over the subsequent year. Cardiac causes of 1-year readmission included recurrent MI in 23 (9%) and decompensated heart failure in 18 (7%) patients. Depressed left ventricular systolic function (hazard ratio, 2.23; 95% confidence interval, 2.00-2.44; P = 0.0003) and diabetes mellitus (hazard ratio, 1.60; 95% confidence interval, 1.38-1.82; P = 0.029) were associated with a significantly higher risk of readmission at 1 year.
Conclusion: Following acute MI, patients are readmitted for cardiac and noncardiac diagnoses well beyond the 30-day mark. This is likely a function of the vulnerability of the patient population rather than a reflection of the medical care provided. More frequent surveillance may attenuate this problem.