# Incidental Myocardial Infarction on Routine Non-Gated Thoracic Computed Tomography

## TL;DR

This study shows that incidental heart attacks found on routine chest CT scans are linked to worse heart outcomes and shorter survival.

## Contribution

It demonstrates the potential of routine non-gated CT scans for opportunistic cardiovascular risk screening.

## Key findings

- 12 individuals had incidental MI detected on non-gated thoracic CT scans.
- Individuals with incidental MI had significantly higher MACE rates and lower survival.
- All individuals with incidental MI had coronary calcification.

## Abstract

The aim of this study is to assess the identification of incidental myocardial infarction on non-electrocardiogram-gated computed tomographic scans of the chest and its prognostic significance.

The increased utilization and abundance of thoracic computed tomographic (CT) scans have provided a substrate for potential screening purposes.

The objective of this study was to evaluate the detection of incidental myocardial infarction on routine non-gated thoracic CT performed for non-cardiac reasons and its associated major cardiovascular events and survival.

We retrospectively assessed routine non-gated thoracic CT scans of all consecutive individuals aged 18 or above who underwent thoracic CT scans as outpatients at the University of California Davis from January 2015 to December 2015. We evaluated the presence and location of incidental MI on non-gated thoracic CT and compared major adverse cardiac events (MACE) and overall survival in CT-positive infarct individuals with a CT-negative infarct control group.

We reviewed routine thoracic CT scans of 1157 individuals and identified 12 individuals with incidental MI. The mean age of individuals with infarction was 71.4 ± 14.1 years, and 50% were female. All individuals with incidental MI had coronary calcification. Individuals with incidental MI had a higher rate of MACE endpoint (92% vs. 28%, p=0.0001), number of MACE events (1.1 vs. 0.3, p<0.001), and lower overall survival (median survival of 67 months vs. not reached, p=0.023) compared with age and sex-matched controls without incidental MI.

Although small in number relative to the total number of individuals evaluated, subjects with incidental MI on routine non-gated thoracic CT scans have worse cardiovascular outcomes and survival compared with controls without infarction. This study highlights the potential opportunistic screening utility of routine thoracic CTs, which could lead to improved risk stratification and intervention.