Clinical likelihood models calibrated against observed obstructive coronary artery disease on computed tomography

Laust D Rasmussen1,2, Samuel Emil Schmidt3, Juhani Knuuti4

  • 1Department of Cardiology, Gødstrup Hospital, Hospitalsparken 15, DK-7400 Herning, Denmark.

Insights

New clinical likelihood models, calibrated for coronary computed tomography angiography (CCTA), accurately predict obstructive coronary artery disease (CAD). These models, including risk-factor and coronary artery calcium score versions, offer improved diagnostic performance over existing methods for chest pain patients.

Area of Science:

  • Cardiology
  • Medical Imaging
  • Machine Learning in Healthcare

Background:

  • Existing models for obstructive coronary artery disease (CAD) likelihood are primarily based on invasive coronary angiography.
  • Patients with stable, new-onset chest pain often have lower clinical likelihood and undergo non-invasive testing like coronary computed tomography angiography (CCTA).
  • There is a need for clinical likelihood models specifically calibrated for obstructive CAD detected by CCTA.

Purpose of the Study:

  • To develop and validate clinical likelihood models for obstructive CAD, calibrated against CCTA findings.
  • To create risk-factor-based (RF-CLCCTA) and coronary artery calcium score-based (CACS-CLCCTA) models.
  • To compare the performance of these new models against a basic pre-test probability (Basic PTP) model.

Main Methods:

  • An advanced machine learning algorithm was used to develop RF-CLCCTA and CACS-CLCCTA models.
  • The models were trained on a cohort of 38,269 symptomatic outpatients with suspected obstructive CAD.
  • Validation was performed on separate cohorts totaling 28,340 patients; obstructive CAD was defined as >50% diameter stenosis on CCTA.

Main Results:

  • The RF-CLCCTA and CACS-CLCCTA models demonstrated superior calibration compared to the Basic PTP model, which underestimated obstructive CAD prevalence.
  • Both new models showed significantly improved discrimination compared to the Basic PTP model.
  • Area under the receiver operating curves (AUC) for RF-CLCCTA was 0.74 (95% CI 0.73-0.75) and for CACS-CLCCTA was 0.87 (95% CI 0.86-0.87), versus 0.71 (95% CI 0.70-0.72) for Basic PTP.

Conclusions:

  • Clinical likelihood models calibrated for CCTA significantly enhance the calibration and discrimination of obstructive CAD detection.
  • The developed RF-CLCCTA and CACS-CLCCTA models provide more accurate pre-test probability assessments for patients undergoing CCTA.
  • These improved models can aid in more precise diagnosis and management of suspected coronary artery disease.
Abstract