# Time to coronary angiography and revascularization in 575,247 patients with STEMI from 2012 to 2023: a retrospective population-based cohort study

## TL;DR

This study shows that hospital delays for heart attack treatment in Germany improved from 2012 to 2023, but challenges remain for older patients, women, and those with comorbidities.

## Contribution

The study combines hospital billing data with geographic routing to benchmark pre- and in-hospital delays in STEMI care over 11 years.

## Key findings

- In-hospital time to angiography improved from 73.1 to 46.4 minutes between 2012 and 2023.
- In-hospital mortality increased slightly despite faster treatment, linked to aging and comorbid patient populations.
- Shorter total time to treatment (TTH + IHTA) reduced in-hospital mortality risk.

## Abstract

Rapid primary percutaneous coronary intervention (PPCI) in patients with ST-elevation myocardial infarction (STEMI) reduces in-hospital and long-term mortality. This study analyzes time intervals to PPCI in STEMI, risk factors for delay of PPCI, and in-hospital mortality from 2012 to 2023.

This is a retrospective population-based analysis of hospital billing data of adult STEMI patients receiving PPCI in Germany. The time for transport to hospital (TTH) was estimated using geographic routing. The in-hospital time to angiography (IHTA) was calculated using time coding of PPCI in patient records.

A total of 575,247 patients were included. The median age was 64 years, 28.5% (164,016) were female. The population with IHTA ≤60 min increased from 44.5% (22,240/49,965) in 2012 to 57.7% (24,434/42,356) in 2023 with improved TTH + IHTA ≤120 min (56.6%, 28,280/49,965, in 2012–70.2%, 29,734/42,356, in 2023). IHTA improved from median 73.1 min (IQR 25.2–186.6) in 2012 to 46.4 min (IQR 17.5–111.6) in 2023 with a stable TTH (11.4–11.9 min). Risk factors for an IHTA >60 min included age, female sex, comorbidity, presentation out of regular hours, and low-volume hospitals. In-hospital mortality increased (8.8%, 4406/49,965, in 2012, 10.4%, 4822/46,203, in 2021, 10.1%, 4272/42,356, in 2023), paralleling a rise in patient age and comorbidity. Risk factors for in-hospital mortality included female sex, increased age, comorbidity, high-volume hospitals, intervention of multiple coronary arteries, weekend admission, and presentation out of regular hours. IHTA <40 min (90–120 min as reference) and TTH + IHTA <80 min (≥120 min as reference) reduced the risk of death.

Combining hospital billing records with geographic routing enables benchmarking of both pre- and in-hospital delays in STEMI care. In hospital delay decreased between 2012 and 2023. Important areas for improving time delays and STEMI-related mortality include the timeliness of care outside of regular hours and a focus on women, older patients, as well as individuals with comorbidities.

There was no funding for this project or this publication.