# Admission Day and Outcomes in Myocardial Infarction With Cardiogenic Shock: A Nationwide Propensity Score-Matched Study

## TL;DR

This study finds that hospital admission timing affects in-hospital mortality for patients with heart attacks and cardiogenic shock, with differences observed between two types of heart attacks.

## Contribution

The study reveals contrasting mortality trends based on admission timing in STEMI-CS and NSTEMI-CS patients using nationwide data and propensity score matching.

## Key findings

- Weekday admissions were linked to higher mortality in STEMI-CS patients compared to weekend admissions.
- Weekend admissions were associated with higher mortality in NSTEMI-CS patients compared to weekday admissions.
- Pacemaker implantation was less frequent during weekday admissions for STEMI-CS patients.

## Abstract

Background: The "weekend effect" refers to potential disparities in clinical outcomes based on the timing of hospital admission, with prior studies offering conflicting results, particularly in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS). This study evaluates the impact of admission timing on outcomes in patients with ST-elevation myocardial infarction and CS (STEMI-CS) and patients with non-STEMI and CS (NSTEMI-CS).

Methods: We conducted a retrospective analysis using the Nationwide Inpatient Sample from 2016 to 2021. Patients with STEMI-CS and NSTEMI-CS were identified using ICD-10 (International Classification of Diseases, Tenth Revision) codes and stratified by weekday versus weekend admissions. Propensity score matching and multivariable logistic regression were employed to adjust for confounders. The primary outcome was in-hospital mortality; secondary outcomes included acute stroke, pacemaker implantation, and resource utilization.

Results: Among 14,060 propensity-matched STEMI-CS patients (7,030 weekday and 7,030 weekend admissions), in-hospital mortality was higher in weekday compared to weekend admissions (2,373 (33.8%) vs. 2,261 (32.2%), p=0.044). Pacemaker implantation was less frequent in weekday admissions (28 (0.4%) vs. 55 (0.8%), p=0.003). Other outcomes, including percutaneous coronary intervention, acute stroke, sudden cardiac arrest, sepsis, pulmonary embolism, arrhythmias, and device implantation, were comparable between groups. Among 9,490 propensity-matched NSTEMI-CS patients (4,745 weekday and 4,745 weekend admissions), weekend admissions were associated with higher in-hospital mortality compared to weekdays (1,485 (31.3%) vs. 1,372 (28.9%), p=0.011), while other outcomes remained similar between groups.

Conclusion: Admission timing influences in-hospital mortality in patients with CS secondary to AMI, with contrasting trends observed between STEMI-CS and NSTEMI-CS cohorts. These findings suggest that variations in hospital protocols, staffing, or resource availability may contribute to these differences. Further research is warranted to elucidate the underlying mechanisms and develop strategies to optimize care delivery across all admission times.