Cardiovascular

Exploratory clinical predictors and internally validated models of in-hospital mortality after PCI in obese patients with acute myocardial infarction and documented cardiogenic shock: a single-center retrospective study.

TL;DR

In obese patients with AMI-CS undergoing PCI, heart rate, hypertension, diabetes mellitus, malignant arrhythmia, and multivessel disease were associated with in-hospital mortality, and logistic regression showed more favorable internally validated predictive performance than regularized XGBoost using the same routinely available predictors; findings are exploratory and internally validated only.

Key Findings

Among 265 obese patients with documented AMI-CS treated with PCI, in-hospital mortality was 63 deaths (23.8%).

  • The archived dataset had 268 patients; three with BMI <28 kg/m² were excluded after eligibility re-audit, leaving 265.
  • 202 patients survived and 63 died during hospitalization.
  • Single-center retrospective design.

Higher heart rate, hypertension, diabetes mellitus, malignant arrhythmia, and multivessel disease were associated with in-hospital mortality.

  • Seven routinely available candidate variables were evaluated in multivariable association analyses.
  • The abstract identifies these five as associated with in-hospital death.
  • The seven candidate predictors were originally nominated in an outcome-informed manner, which the authors list as a limitation.

The seven-variable logistic regression model outperformed regularized XGBoost in internally validated discrimination and calibration.

  • Logistic regression: AUC 0.767 (95% CI, 0.696-0.831), Brier score 0.152.
  • Regularized XGBoost: AUC 0.712 (95% CI, 0.641-0.779), Brier score 0.169.
  • Models were compared using 20 repetitions of stratified five-fold nested cross-validation, with all tuning confined to inner training folds.

Serial lactate concentrations were consistently higher in non-survivors, and cardiac power output was modestly lower.

  • Lactate was higher in non-survivors at admission, peak, 6 h, 12 h, and 24 h.
  • Supplemental data on shock severity, vasoactive therapy, mechanical circulatory support, ventilation, renal replacement therapy, and hemodynamics were evaluated descriptively and in a post hoc sensitivity analysis.

A post hoc severity-augmented logistic model had high discrimination but poor calibration, so it was not sufficiently calibrated for clinical deployment.

  • AUC 0.922 (95% CI, 0.888-0.951).
  • Calibration slope was 2.077.
  • The authors state the model is not sufficiently calibrated for clinical deployment.

The authors suggest diabetes, hypertension, and perfusion abnormalities are biologically compatible with endothelial dysfunction, but endothelial function was not measured.

  • Endothelial function and endothelial biomarkers were not directly assessed.
  • External multicenter validation and studies incorporating endothelial biomarkers are called for.

The findings are exploratory and limited by sample size, lack of external validation, and outcome-informed predictor selection, precluding claims of clinical readiness.

  • Single-center study with a modest sample size (n=265).
  • Only internal validation was performed.
  • Seven candidate predictors were originally nominated in an outcome-informed manner.

What This Means

This study looked at 265 obese patients who had a heart attack complicated by cardiogenic shock (when the heart cannot pump enough blood) and were treated with a procedure to open blocked arteries (PCI). About 24% (63 patients) died in the hospital. Higher heart rate, high blood pressure, diabetes, dangerous heart rhythm problems, and disease in multiple coronary vessels were linked with a higher chance of dying in the hospital. Blood lactate, a marker of poor tissue blood flow, was higher in those who died at every time point measured over 24 hours. The researchers also compared a traditional statistical model (logistic regression) with a machine-learning method (XGBoost) for predicting death using seven routine measures. The traditional model did somewhat better (AUC 0.767 vs 0.712, where 1.0 is perfect). A further model that added shock severity information looked much more accurate (AUC 0.922), but it was poorly calibrated, meaning its predicted risks were not reliable enough for use in practice. This research suggests that simple, routinely collected information may help identify high-risk patients, but the results are preliminary. The study came from one hospital, was retrospective, had a modest number of patients, and was not tested in other settings. The authors speculate that damage to blood vessel lining (endothelial dysfunction) may play a role, but they did not measure it. Larger multicenter studies are needed before any such model could be used in clinical care.

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Citation

Maimaitiniyazi M, Yisimitila T, Maimaitiniyazi M, Maisuti M, Haibier A, Yushanjiang P, et al.. (2026). Exploratory clinical predictors and internally validated models of in-hospital mortality after PCI in obese patients with acute myocardial infarction and documented cardiogenic shock: a single-center retrospective study.. BMC cardiovascular disorders. https://doi.org/10.1186/s12872-026-06838-x