Multi Modality Approach to Diagnosis of Ischemia in Post CABG Cases Dr. L.Alizadeh M.D. Dr.M.VejdanParast M.D.

Follow-up of patients after CABG should focus on secondary prevention, including careful attention to all modifiable risk factors for cardiovascular disease. Routine stress testing with or without imaging is usually not necessary if the patient is asymptomatic and engaging in normal physical activities, including moderate exercise without difficulty.

Problems with CABG can be divided into 3 phases: Early Phase Occlusion Recurrent myocardial ischemia following CABG can also be due to progression of native coronary artery disease or CABG failure. Problems with CABG can be divided into 3 phases: Early Phase Occlusion SVG: Nearly 10% are occluded prior to hospital discharge LIMA: Early patency for LIMA grafts LAD should approach 100% Intermediate Phase Occlusion SVG: 10% are occluded in the first year after surgery LIMA: rarely occlude during the first 5 years after surgery. Late Phase Occlusion SVG: continue to close at a rate of approximately 2% per year LIMA: The patency rate 95% at 10 years.

Asymptomatic Patients Post-CABG Current guidelines discourage routine stress testing for asymptomatic patients in the first 5 years after CABG It may be appropriate to perform stress testing on asymptomatic patients who are more than 5 years post CABG, as there is evidence of substantial benefit in risk stratification and guidance of therapy even in the absence of symptoms. Patients who were asymptomatic prior to revascularization may warrant special consideration for monitoring with stress testing. Those with abnormal resting ECGs, and those who are incapable of performing significant physical exertion because of noncardiac disease, are more likely to require imaging as part of the stress testing procedure.

Symptomatic Ischemic equivalent A Asymptomatic Stress Echocardiography for Risk Assessment: Post-Revascularization (PCI or CABG) AUC guideline Symptomatic Ischemic equivalent A Asymptomatic Incomplete revascularization Additional revascularization feasible A < 5 years after CABG I ≥ 5 years after CABG U < 2 years after PCI I ≥ 2 years after PCI U

Modalities for evaluation Exercise Tolerance Test Stress Echocardiography Nuclear Myocardial Perfusion Imaging Computed tomography coronary angiography Cardiac Magnetic Resonance Imaging

  Stress imaging studies are likely to provide more useful information regarding the site and extent of myocardial ischemia after coronary revascularization procedures than the exercise ECG, and are the preferred modality when noninvasive testing is performed for management decisions.

IS there a gold standard modality ….? Which one fits our situation… ? Any conclusion for our panel… ?

65 Years old man Exertional chest pain CCS II from 1 month PMH: CABG 14yrs ago No DM , No HTN DH: No medication since 3three yrs ago

Echo LV EF: 45% RWMA: hypokinesia at mid & base of antroseptal inferior wall Abnormal septal wall motion due to previous CABG No significant valvular diseases

ETT

indications for Repeat CABG How benefits ? left main disease, 3-vessel disease, and 2-vessel disease that includes the proximal LAD artery. At the same time, it is unknown if CABG provides a survival benefit compared with medical therapy in patients with these anatomic findings who have had previous CABG. It is Subjects with previous CABG and these anatomic findings would, in fact, derive a survival benefit from repeat CABG provided that CABG could be performed with an acceptable risk. The importance of recurrent MI in the distribution of the LAD artery has been shown to be associated with a poor prognosis in patients with previous CABG. A stenosis of a graft to the LAD artery was associated with decreased rates of survival, reoperation-free survival, and event-free survival. On the basis of these data, 50% stenosis in a graft to the LAD artery is an indication for reoperation. In contrast,patients without ischemia in the LAD artery distribution do not derive a survival benefit from repeat CABG.

Conclusion 1 Follow-up of patients after CABG should focus on secondary prevention, including careful attention to all modifiable risk factors for cardiovascular disease. Routine stress testing with or without imaging is usually not necessary if the patient is asymptomatic and engaging in normal physical activities including moderate exercise without difficulty.

Conclusion 2 Stress testing with ECG monitoring alone or in conjunction with nuclear myocardial perfusion imaging or echocardiography, is commonly used if a patient develops recurrent symptoms post-CABG or is at a particular high risk for complications. Role of CT FFR ? Role of stress CMR ? Is it cost benefit to move forward to more sophisticated imaging modalities ??

Conclusion 3 CTA is a new, very powerful noninvasive technique that can directly visualize both CABG and the native coronary arteries. CTA is complimentary to functional stress testing in that it provides anatomic information about graft patency and native coronary artery stenoses, but the functional significance of these findings may still require stress testing with nuclear or ultrasound imaging.