Abstract 15665: Lack of Association Between Inpatient Percutaneous Coronary Intervention Volume and Thirty-Day Readmissions After Acute Myocardial Infarction- Cardiogenic Shock

Introduction: Volume-outcome relationship data is limited for acute myocardial infarction-cardiogenic shock (AMI-CS). Revascularization is mainstay of therapy in AMI-CS.

Objectives: Authors sought to examine relation between hospital inpatient percutaneous coronary intervention (PCI) volume and 30-day readmissions after an AMI-CS admission.

Methods: Nationwide Readmissions Database (NRD) 2016-2019 was analyzed. Hospitals were categorized into quartiles (Q1, lowest to Q4, highest) based on annual inpatient PCI volume. Primary outcome of interest was 30-day unplanned all-cause readmissions. Secondary outcomes included cardiac, non-cardiac and heart-failure (HF) readmissions at 30-days.

Results: A total of 49,558 index AMI-CS admissions were present in 3,954 PCI performing hospitals. Median hospital PCI volume was 174 (inter-quartile range 70-316). 59% admissions for AMI-CS were present in quartile Q4. Overall, 30-day readmission rate was 18.5% (n=9,179); of which 56.2% were cardiac, 43.8% were non-cardiac and 25.8% were related to HF. We did not find any difference in 30-day all-cause readmissions (Q1 = 17.6% vs. Q2 = 18.4% vs. Q3 = 18.2% vs. Q4 = 18.7%, p=0.55). Similarly, cardiac (Q1 = 10.9% vs. Q2 = 11.0% vs. Q3 = 10.6% vs. Q4 = 10.2%, p=0.29), and HF (Q1 = 5.0% vs. Q2 = 4.8% vs. Q3 = 4.8% vs. Q4 = 4.8%, p=0.99) readmissions were not different across quartiles. Non-cardiac readmissions were more-commonly observed in higher quartiles (Q1 = 6.7% vs. Q2 = 7.4% vs. Q3 = 7.7% vs. Q4 = 8.5%, p=0.001). However, no significance was noted with any outcome after multivariable adjustment. Similarly, no relationship was observed between hospital PCI volume as continuous variable and all-cause or cause-specific readmissions on restricted cubic spline analysis.

Conclusions: In a national representative sample of 3,954 hospitals with 49,558 AMI-CS admissions, we found lack of an association between hospital PCI volume and 30-day all cause or cause-specific readmissions.