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An R-Based Landscape Validation of a Competing Risk Model
Published on: September 16, 2022
Risk models including high-risk cardiovascular procedures: clinical predictors of mortality and morbidity
Hiroaki Miyata1, Noboru Motomura, Hiroyuki Tsukihara
1Department of Healthcare Quality Assessment, Graduate School of Medicine, University of Tokyo, Tokyo, Japan. hiroaki.miyata@gmail.com
Insights
Combined cardiovascular surgeries like CABG with valve or aortic procedures significantly increase mortality risk. Developing accurate risk models can help target interventions and improve patient outcomes in complex cardiac surgery.
Area of Science:
- Cardiovascular Surgery
- Medical Informatics
- Health Services Research
Background:
- Isolated coronary artery bypass grafting (CABG) carries inherent risks.
- Thoracic aortic surgery and combined CABG procedures are significant contributors to patient mortality and morbidity.
- Existing risk models may not adequately capture the complexities of high-risk cardiovascular procedures.
Purpose of the Study:
- To develop and validate robust risk models for cardiovascular surgery.
- To incorporate high-risk procedures such as thoracic aortic surgery and combined CABG into risk assessment.
- To improve quality of care and patient outcomes through enhanced risk prediction.
Main Methods:
- Utilized the Japan Cardiovascular Surgery Database (2005-2007) encompassing 36,780 procedures across 120 hospitals.
- Employed logistic regression to generate risk models.
- Validated models using split-sample validation and assessed predictive power with C-statistics.
Main Results:
- Isolated CABG involved 11,948 procedures; valve surgery (11,760) and thoracic aortic surgery (8,440) were analyzed.
- Combined CABG with other procedures (3,599) showed increased risks for reoperation (OR: 1.21), stroke (OR: 1.60), dialysis (OR: 1.23), infection (OR: 1.97), and prolonged ventilation (OR: 1.40).
- Thoracic aortic surgery demonstrated higher 30-day mortality odds ratios (e.g., 2.36 overall, up to 5.97 for thoraco-abdominal aorta).
Conclusions:
- While isolated CABG showed stable performance, combining it with valve or thoracic aortic surgery remains a high-risk endeavor.
- The developed risk models offer better recognition of high-risk patients.
- Targeted perioperative interventions informed by these models have the potential to reduce adverse events in complex cardiac surgeries.
Objective:
While isolated coronary artery bypass grafting (CABG) poses major risks as well as benefits to cardiovascular surgery, procedures such as thoracic aortic surgery and combined CABG surgeries are also important contributors to mortality and morbidity. The objective of this study was to create and validate risk models including high-risk cardiovascular procedures to improve quality.
Methods:
The Japan Cardiovascular Surgery Database of patients enrolled cardiovascular surgical patients between January 2005 and December 2007. Data were collected at presentation and by physician review of clinical records and were verified through third-party surgeons' auditing. We analyzed 36780 procedures in 120 hospitals. Using logistic regression, risk models were generated and validated by split-sample validation.
Results:
In this analysis, 11948 procedures were isolated CABG, 11760 were valve surgeries, and 8440 were thoracic aortic surgeries. In a 30-day operative mortality risk model, 37 variables were significantly associated with outcome. In comparison to isolated CABG, the odds ratios (ORs) for a 30-day mortality were 1.81 for valve surgery (2.62 in mitral valve replacement and 2.72 in aortic valve plus mitral valve procedures) and 2.36 for thoracic aortic surgery (4.34 if indicated by rupture, 3.16 if involving only arch, 4.38 if involving distal aorta, 3.75 if descending, and 5.97 if thoraco-abdominal aorta). CABG combined with other procedures (n=3599) had increased risks in each morbidity risk model (OR: 1.21 in reoperation, 1.60 in stroke, 1.23 in dialysis, 1.97 in infection, and 1.40 in prolonged ventilation). The predictive power of our models is valued by a C-statistic of 0.830 for a 30-day postoperative mortality, 0.639 for reoperation, 0.726 for stroke, 0.817 for dialysis, 0.692 for infection, and 0.796 for prolonged ventilation.
Conclusions:
Though performance of isolated CABG surgery was stable in this era, CABG combined with valve or thoracic aortic surgery was still a high-risk procedure. Given better recognition of high patient risk from these models, earlier targeted perioperative interventions may reduce adverse effects.
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