Trial to Assess Whether Computed Tomography Cardiac Angiography Can Improve Invasive Coronary Angiography in Bypass Surgery Patients

Exclusion Criteria

• •1. Subjects presenting with ST elevation myocardial infarction, cardiogenic shock (systolic blood pressure \<80 mmHg for \>30 minutes, or requiring inotropes or emergency intra aortic balloon pump for hypotension treatment) or cardiopulmonary resuscitation.
• •2. Subjects with eGFR \<20ml/min or on renal replacement therapy.
• •3. Current life-threatening condition other than vascular disease that may prevent a subject completing the study.
• •4. Clinical instability including cardiogenic shock, hypotension (low blood pressure-systolic blood pressure less than 90 mmHg), sustained ventricular or atrial arrhythmia requiring intravenous medications.
• •5. Inability to tolerate beta-blockers, including those with chronic obstructive pulmonary disease or asthma, complete heart block, second-degree atrioventricular block
• •6. Known contrast dye allergy.
• •7. Pregnancy or unknown pregnancy status.
• •8. Patients considered unsuitable to participate by the research team (e.g., due to medical reasons, laboratory abnormalities, or subject's unwillingness to comply with all study related procedures).
• •9. Inability or refusal to provide informed consent.