Development of Comorbidity Index for in-hospital mortality for patients who underwent coronary artery

Renxi Li1,2, Stephen Huddleston3

  • 1George Washington University School of Medicine and Health Sciences, Washington, DC, USA - renxili@gwu.edu.

PubMed

Insights

New mortality indices, Li CABG Mortality Index (LCMI) and Li PCI Mortality Index (LPMI), effectively predict in-hospital mortality after coronary revascularization. These validated indices outperform the Elixhauser Comorbidity Index (ECI) for improved patient risk assessment.

Area of Science:

  • Cardiology
  • Medical Informatics
  • Health Services Research

Background:

  • Coronary artery bypass grafting (CAGB) and percutaneous coronary intervention (PCI) are common myocardial revascularization procedures.
  • Both CAGB and PCI are associated with significant in-hospital mortality.
  • Existing comorbidity indices can aid in predicting mortality but may lack specificity for revascularization patients.

Purpose of the Study:

  • To develop and validate specific comorbidity indices for patients undergoing coronary artery revascularization.
  • To assess the predictive performance of these new indices against existing measures.
  • To provide tools for standardizing comorbidity assessment in cardiovascular surgery.

Main Methods:

  • Utilized the National Inpatient Sample database (Q4 2015-2020) for patients undergoing CABG or PCI.
  • Excluded patients under 40 with congenital heart defects.
  • Developed Li CABG Mortality Index (LCMI) and Li PCI Mortality Index (LPMI) using multivariable regression on 38 Elixhauser comorbidities, with a 70% experimental and 30% validation split.

Main Results:

  • LCMI demonstrated adequate discrimination for in-hospital mortality (c-statistic=0.691), outperforming the Elixhauser Comorbidity Index (ECI) (c-statistic=0.621).
  • LPMI showed moderate discrimination (c-statistic=0.666), also significantly better than ECI (c-statistic=0.610).
  • Both indices showed improved discrimination after age adjustment and were well-calibrated.

Conclusions:

  • LCMI and LPMI are effective tools for discriminating and predicting in-hospital mortality in revascularization patients.
  • These indices offer superior performance compared to the ECI.
  • LCMI and LPMI can standardize comorbidity measurement, facilitating comparable research outcomes.
Abstract