Defining the Intrinsic Cardiac Risks of Operations to Improve Preoperative Cardiac Risk Assessments

Area of Science:

• Cardiology
• Surgical Risk Assessment
• Health Services Research

Background:

• Current preoperative cardiac risk stratification relies on broad surgical categories.
• These broad categories may not accurately reflect the intrinsic cardiac risks of individual surgical procedures.
• This can lead to imprecise perioperative cardiac risk estimates.

Purpose of the Study:

• To define the intrinsic cardiac risks associated with individual surgical operations.
• To demonstrate how grouping operations can lead to imprecise perioperative cardiac risk estimations.
• To inform more accurate cardiac risk stratification for surgical patients.

Main Methods:

• Analysis of elective operations from 2010-2015 using the American College of Surgeons National Surgical Quality Improvement Program data.
• Definition of a composite endpoint for adverse cardiac events (cardiac arrest or myocardial infarction).
• Use of mixed-effects models to derive intrinsic operative cardiac risks, controlling for patient mix.

Main Results:

• Identification of 66 low, 30 intermediate, and 106 high intrinsic cardiac risk operations.
• Excisional breast biopsy showed the lowest risk (0.01%), while aorto-bifemoral bypass grafting had the highest (4.1%).
• Significant variation in intrinsic cardiac risk was observed within common surgical groupings (median OR 1.40).

Conclusions:

• A continuous spectrum of intrinsic cardiac risk exists across different surgical operations.
• Broad categorization of operations inadequately accounts for the nuanced, individual cardiac risks.
• Refined risk assessment considering specific operative risks is necessary for improved patient safety.