Impact of Inpatient Percutaneous Coronary Intervention Volume on 30-Day Readmissions After Acute Myocardial Infarction-Cardiogenic Shock.

Background: There are limited data on volume-outcome relationships in acute myocardial infarction (AMI) with cardiogenic shock (CS).

Objectives: In this study, the authors sought to evaluate the association between hospital percutaneous coronary intervention (PCI) volume and readmission after AMI-CS.

Methods: Adult AMI-CS patients were identified from the Nationwide Readmissions Database for 2016-2019 and were categorized into hospital quartiles (Q1 lowest volume to Q4 highest) based on annual inpatient PCI volume. Outcomes of interest included 30-day all-cause, cardiac, noncardiac, and heart-failure (HF) readmissions.

Results: There were 49,558 AMI-CS admissions at 3,954 PCI-performing hospitals. Median annual PCI volume was 174 (Q1-Q3: 70-316). Patients treated at Q1 hospitals were on average older, female, and with higher comorbidity burden. Patients at Q4 hospitals had higher rates of noncardiac organ dysfunction, complications, and use of cardiac support therapies. Overall, 30-day readmission rate was 18.5% (n = 9,179), of which cardiac, noncardiac, and HF readmissions constituted 56.2%, 43.8%, and 25.8%, respectively. From Q1 to Q4, there were no differences in 30-day all-cause (17.6%, 18.4%, 18.2%, 18.7%; P = 0.55), cardiac (10.9%, 11.0%, 10.6%, 10.2%; P = 0.29), and HF (5.0%, 4.8%, 4.8%, 4.8%; P = 0.99) readmissions. Noncardiac readmissions were noted more commonly in higher quartiles (6.7%, 7.4%, 7.7%, 8.5%; P = 0.001) but was not significant after multivariable adjustment. No relationship was noted between hospital PCI volume as a continuous variable and readmissions.

Conclusions: In AMI-CS, there was no association between hospital annual PCI volume and 30-day readmissions despite higher acuity in the higher volume PCI centers suggestive of better care pathways for CS at higher volume centers.