Fat around the heart on routine chest CT flags risk after heart attack stenting

Patients who survive a heart attack and undergo a stent procedure are not out of the woods once the blocked artery is reopened. A retrospective cohort study published in BMC Cardiovascular Disorders reports that the amount of fat surrounding the heart, measured on ordinary non-contrast chest CT scans, is associated with the risk of major adverse cardiovascular events in the months and years after percutaneous coronary intervention for acute myocardial infarction.

The research team enrolled 367 patients with acute myocardial infarction who were treated with PCI between January 2023 and December 2024 and who had available chest CT scans. Rather than requiring a dedicated cardiac imaging protocol, the investigators used semi-automatic segmentation of epicardial adipose tissue volume from existing non-contrast chest CT, then indexed that volume to body surface area to produce the epicardial adipose tissue volume index, or EATVI. According to the study's background, epicardial adipose tissue volume index derived from non-contrast chest CT may reflect residual cardiovascular risk after PCI, but its association with post-PCI major adverse cardiovascular events had remained incompletely understood.

During a median follow-up of 26.38 months, 91 patients, or 24.8 percent of the cohort, experienced a major adverse cardiovascular event. After adjusting for covariates in multivariable Cox regression, each increase of 22.91 mL/m² in EATVI, corresponding to one standard deviation, was associated with a higher hazard of MACE, with a hazard ratio of 1.45 and a 95 percent confidence interval of 1.17 to 1.79, and a P value below 0.001. The association held in a model that accounted for conventional clinical factors, suggesting that the fat index captured risk information the standard variables did not.

The prognostic gain, however, was modest. Adding EATVI to a clinical base model raised Harrell’s C-index from 0.676 to 0.690, an increment of 0.014 with a confidence interval spanning from −0.002 to 0.048, meaning the improvement in discrimination could plausibly be negligible. Reclassification metrics told a somewhat more encouraging story: at 12 months, the category-free net reclassification improvement was 0.365 (95 percent CI 0.078 to 0.720) and the integrated discrimination improvement was 0.030 (95 percent CI 0.004 to 0.074). EATV without indexing to body surface area provided broadly similar incremental prognostic information.

The study also explored a more ambitious modeling strategy. Using least absolute shrinkage and selection operator regression, the investigators built an exploratory LASSO-Cox model that retained four predictors in the full cohort: EATVI, diabetes mellitus, Killip class of II or higher, and the Gensini score, a measure of coronary disease severity. But when the entire modeling procedure, including variable selection itself, was internally validated through 1,000 bootstrap resamples, the result was sobering. No predictors were retained in 85.2 percent of resamples, demonstrating substantial selection instability. In other words, the specific set of variables the model picked depended heavily on which patients happened to be in the sample, a caution against treating the exploratory model as a ready-made clinical tool.

The authors conclude that non-contrast chest CT-derived EATVI was associated with post-PCI MACE and provided modest incremental prognostic information beyond conventional clinical factors, and they state that its potential role in post-PCI risk assessment warrants prospective external validation. The study design deserves emphasis: this is a retrospective, single-cohort analysis of 367 patients, not a randomized trial or a prospective validation study, and the association between epicardial fat and events does not establish that the fat itself causes poor outcomes. The bootstrap findings further underline that the model-building exercise was exploratory.

For now, the measurement is best viewed as a promising risk marker whose clinical usefulness is still unproven.

Subject of Research: Epicardial adipose tissue volume measured on non-contrast chest CT and its association with major adverse cardiovascular events after PCI for acute myocardial infarction.

Article Title: Non-contrast chest CT-derived epicardial adipose tissue volume index and major adverse cardiovascular events after PCI for acute myocardial infarction: a retrospective cohort study

Article References: Zhang, J., Wang, Y., Wang, Y., Yang, L., Li, X., & Hu, Z. (2026). Non-contrast chest CT-derived epicardial adipose tissue volume index and major adverse cardiovascular events after PCI for acute myocardial infarction: a retrospective cohort study. BMC Cardiovascular Disorders. https://doi.org/10.1186/s12872-026-06897-0

Image Credits: AI Generated

DOI: 10.1186/s12872-026-06897-0

Keywords: epicardial adipose tissue, chest CT, acute myocardial infarction, percutaneous coronary intervention, major adverse cardiovascular events, risk prediction, Cox regression, retrospective cohort study, prognostic modeling, cardiovascular risk, Non-contrast, chest