Associations Between Hospital Length of Stay, 30-Day Readmission, and Costs in ST-Segment-Elevation Myocardial Infarction After Primary Percutaneous Coronary Intervention: A Nationwide Readmissions Database Analysis

Abstract

Background Readmission after ST-segment-elevation myocardial infarction (STEMI) poses an enormous economic burden to the US healthcare system. There are limited data on the association between length of hospital stay (LOS), readmission rate, and overall costs in patients who underwent primary percutaneous coronary intervention for STEMI. Methods and Results All STEMI hospitalizations were selected in the Nationwide Readmissions Database from 2010 to 2014. From the patients who underwent primary percutaneous coronary intervention, we examined the 30-day outcomes including readmission, mortality, reinfarction, repeat revascularization, and hospital charges/costs according to LOS (1-2, 3, 4, 5, and >5 days) stratified by infarct locations. The 30-day readmission rate after percutaneous coronary intervention for STEMI was 12.0% in the anterior wall (AW) STEMI group and 9.9% in the non-AW STEMI group. Patients with a very short LOS (1-2 days) were readmitted less frequently than those with a longer LOS regardless of infarct locations. However, patients with a very short LOS had significantly increased 30-day readmission mortality versus an LOS of 3 days (hazard ratio, 1.91; CI, 1.16-3.16 [P=0.01]) only in the AW STEMI group. Total costs (index admission+readmission) were the lowest in the very short LOS cohort in both the AW STEMI group (P<0.001) and the non-AW STEMI group (P<0.001). Conclusions For patients who underwent primary percutaneous coronary intervention for STEMI, a very short LOS was associated with significantly lower 30-day readmission and lower cumulative cost. However, a very short LOS was associated with higher 30-day mortality compared with at least a 3-day stay in the AW STEMI cohort.

Keywords: PCI; STEMI; costs; length of hospital stay; readmission.

Figure 1. Histogram of length of hospital stay.

A, Density of length of stay (LOS) in overall patients. B, Density of LOS in patients with anterior wall (AW) myocardial infarction. C, Density of LOS in patients with non‐AW myocardial infarction.

Figure 2. Cumulative rates of 30‐day readmission, 30‐day mortality, 30‐day reinfarction, 30‐day repeat revascularization, and 30‐day major adverse cardiac events (MACE) according to hospital length of stay (LOS) and infarct location.

Data show unadjusted 30‐day readmission in anterior wall (AW) ST‐segment–elevation myocardial infarction (STEMI) (A) and non‐AW STEMI (B), 30‐day readmission mortality in AW STEMI (C) and non‐AW STEMI (D), 30‐day reinfarction in AW STEMI (E) and non‐AW STEMI (F), 30‐day repeat revascularization in AW STEMI (G) and non‐AW STEMI (H), and 30‐day MACE in AW STEMI (I) and non‐AW STEMI (J).

Figure 3. Forest plot of adjusted risk of 30‐day readmission, 30‐day mortality, 30‐day reinfarction, 30‐day repeat revascularization, and 30‐day major adverse cardiac events (MACE) according to hospital length of stay (LOS) and infarct location.

Adjusted covariates for each clinical outcome can be found in the supplemental material.

Figure 4. Plot of 30‐day mortality according to hospital length of stay (LOS).

A, Thirty‐day readmission mortality rate in patients with anterior wall (AW) ST‐segment–elevation myocardial infarction (STEMI) (red points). B, Thirty‐day readmission mortality rate in patients with non‐AW STEMI (red points). Box plot shows total number of patients in each LOS group.