Unplanned readmissions after Impella mechanical circulatory support.

Background: Early readmissions significantly impact on patient-wellbeing, burden the health-care system, and are important quality metrics. Data on 30-day readmission following Impella mechanical circulatory support (MCS) are unknown. We aimed to assess the rates, causes and clinical outcomes associated with 30-day unplanned readmissions after Impella mechanical circulatory support (MCS).

Methods: Discharged patients who underwent Impella MCS between 2016 and 2019 in the U.S. Nationwide Readmission Database were analyzed. Incidence, causes, and outcomes associated with 30-day unplanned readmissions were assessed.

Results: Of 22,055 patients who received Impella MCS, 2685 (12.2%) experienced 30-day readmissions. Cardiac readmissions accounted for 51.7% compared to 48.3% of non-cardiac readmissions, and most (70%) patients were readmitted back to the index hospital. Heart failure was the leading cause of cardiac readmissions accounting for 25% of them, whereas infections were the most common cause among non-cardiac readmissions. Patients who were readmitted were significantly older (median age 71 versus 68 years), more likely to be female (31% versus 26%) and had a shorter length-of-stay (index hospitalization, median 8 versus 9 days) compared to those who were not readmitted. Factors independently associated with 30-day readmissions were chronic renal (aOR: 1.46, 95% CI: 1.35-1.57), pulmonary (aOR: 1.23, 95% CI: 1.15-1.33), and liver disease (aOR: 1.38, 95% CI: 1.17-1.63), anemia (aOR: 1.35, 95% CI: 1.26-1.46), female sex (aOR: 1.21, 95% CI: 1.12-1.30), index admission on weekends (aOR: 1.23, 95% CI: 1.13-1.34), STEMI diagnosis (aOR: 1.16, 95% CI: 1.02-1.31), major adverse event during index hospitalization (aOR: 1.11, 95% CI: 1.00-1.24), prolonged length-of-stay (median 9 vs. 8 days, P < 0.001), and discharge against medical advice (aOR: 2.06, 95% CI: 1.37-3.09). Significantly higher mortality rates were overserved during readmissions to a hospital different than the MCS implanting hospital (12% versus 5.9%, P < 0.001).

Conclusion: Thirty-day readmissions after Impella MCS are relatively common and relate to sex, baseline comorbidities, presentation, expected primary payer, discharge destination and initial length of hospital stay. Heart failure was the leading cause of cardiac readmissions, whereas infections were the most common cause among non-cardiac readmissions. Most patients were readmitted to the same hospital as their index admission for MCS. Higher mortality rates were observed when patients were readmitted to a different hospital.