Comprehensive Computed Tomography Guidance of Coronary Bypass Graft Surgery

The objective of this study is to integrate noninvasively acquired anatomical and functional information to develop clinically applicable tools for meaningful per-vessel revascularization decisions. The decisions will be based on quantitative lesion-specific ischemia and viability and flow simulations. These will be based on CT anatomy enhanced with a function for prediction of hemodynamic improvement after CABG.

Aim 1: Predict restoration of myocardial perfusion from coronary artery bypass graft surgery. The investigators will perform cardiac CT before and after CABG and measure absolute changes in myocardial perfusion as the functional outcome of CABG. The investigators will investigate clinical, surgical and imaging variables in association with post-CABG perfusion improvement on a per-vessel and per-patient level.

Aim 2: Non-invasively quantify vessel-specific ischemia for meaningful CABG decisions.

The investigators will develop and validate tools for assessment of vessel-specific ischemia and viability. The investigators will assess the potential impact of CT guided CABG by comparing the per-vessel need for grafting with standard care.

Aim 3: Predict CABG benefit through multi-parameter flow simulations Hypothesis: Integration of myocardial perfusion and viability can improve flow simulation models to predict CABG outcome. The investigators will develop new computational fluid dynamics models enriched with functional parameters and explore the potential of virtual grafting to improve hemodynamic outcomes.

Inclusion criteria

• Planned elective CABG for coronary artery disease.
• CABG is the primary indication for surgery (but may include treatment of mild-moderate valvular disease).
• Age: ≥40 years.

Exclusion criteria

• Technical feasibility of the cardiac CT exams: redo-CABG, significant arrhythmia/mal-conduction, congenital conditions, severe valvular disease or cardiomyopathy (to the extent that the CT acquisition is technically challenged), inadequate understanding of the English language (to provide consent or follow instructions during the exams).
• Overall safety: unstable clinical condition (clinical heart failure, unstable angina, myocardial infarction <1 month prior).
• Radiation risk: pregnancy (cannot be ruled out), body weight >100kg.
• CT contrast medium-related: known allergy, renal failure
• Vasodilator related: known allergy, bronchial asthma requiring daily use of bronchodilators, Mobitz II or 3rd degree AV block, sick sinus node disease, clinically significant carotid artery narrowing, severe aortic stenosis or LVOT narrowing, systolic blood pressure below 90mmHg, (continued) use of dipyridamole or aminophylline.
• Inability to provide informed consent.