What does this research mean for the field?

The introduction of new diagnostic criteria and cardiac troponin measurement significantly increased the reported hospitalization rate for acute myocardial infarction, but did not affect the steadily declining 28-day mortality rate. Novelty: ClaimNovelty.INCREMENTAL. Consensus alignment: ConsensusAlignment.NEUTRAL.

What question did this study set out to answer?

This analysis aims to evaluate how changes in diagnostic criteria and troponin use affect hospitalization and mortality rates after acute myocardial infarction (AMI).

June 14, 2026Open Access

Changes in hospitalization rate and mortality after acute myocardial infarction in Denmark after diagnostic criteria and methods changed

Q: What is the clinical evidence from this study?

Study design: Observational. Population: Acute myocardial infarction (AMI). Intervention: Use of troponin as a diagnostic marker vs. Before introduction of troponin. Primary outcome: Hospitalization rate (rate ratio 1.14, 95% CI 1.11-1.18).

Key Result

The use of troponin as a diagnostic marker was associated with a 14% increase in the hospitalization rate for acute myocardial infarction (rate ratio 1.14; 95% CI 1.11-1.18).

Key Points

This analysis aims to evaluate how changes in diagnostic criteria and troponin use affect hospitalization and mortality rates after acute myocardial infarction (AMI).
Patients aged ≥30 years with their first AMI were identified using the National Patient Registry in Denmark.
Troponin use as a diagnostic marker was registered at each hospital from 1994 to 2001.
Hospitalization and mortality rates were analyzed over the specified time period.
Hospitalization rate for AMI increased from 3472 to 4163 per million for men (19.9%) and from 1648 to 2020 per million for women (22.6%) post-criteria change.
Troponin use correlated with a 14% increase in hospitalization rate (rate ratio 1.14, 95% CI 1.11-1.18).
28-day mortality decreased from 25.9% in 1994 to 17.5% in 2002 without influence from troponin use.

Study Design

Type

Observational

Multicenter

Yes

PICO

Population

Patients aged ≥30 years admitted for their first acute myocardial infarction in Denmark between 1994 and 2001.

Exposure / Comparator

Use of troponin as a diagnostic marker vs Before introduction of troponin

Primary Outcome

Hospitalization rate — rate ratio 1.14 (1.11-1.18)

Main Result

Relative Risk: 1.14 (95% CI 1.11–1.18)

Abstract

AIMS: To analyse the effect of the change in diagnostic criteria for acute myocardial infarction (AMI) and the use of troponin as a diagnostic marker on the hospitalization rate and mortality of hospitalized AMI patients from 1994 to 2001. METHODS AND RESULTS: Patients (> or =30 years) admitted for their first AMI were identified using the National Patient Registry in Denmark. We registered when each hospital introduced troponin as a diagnostic marker. The reported hospitalization rate decreased until 1998 and then increased substantially from 1999 to 2001 from 3472 to 4163 per million inhabitants (19.9%) for men and from 1648 to 2020 per million inhabitants (22.6%) for women. Troponin use was associated with a significant 14% increase in hospitalization rate in this period rate ratio 1.14, 95% confidence interval (CI) 1.11-1.18. The effect of troponin was greatest among patients 70 years and older (rate ratio 1.19, 95% CI 1.14-1.23). The 28 day mortality decreased steadily from 25.9% in 1994 to 17.5% in 2002 (32.4%) and was not affected by troponin use. CONCLUSION: The reported hospitalization rate for AMI increased significantly after the new diagnostic criteria for AMI were introduced. The measurement of cardiac troponins further increased the hospitalization rate. The mortality among hospitalized patients with AMI declined steadily and was not affected by the use of troponins.