Predictors of progression of native coronary narrowing to total occlusion after coronary artery bypass grafting

Non-invasive Ischaemia Testing in Patients With Prior Coronary Artery Bypass Graft Surgery: Technical Challenges, Limitations, and Future Directions

Coronary artery bypass graft (CABG) surgery effectively relieves symptoms and improves outcomes. However, patients undergoing CABG surgery typically have advanced coronary atherosclerotic disease and remain at high risk for symptom recurrence and adverse events. Functional non-invasive testing for ischaemia is commonly used as a gatekeeper for invasive coronary and graft angiography, and for guiding subsequent revascularisation decisions. However, performing and interpreting non-invasive ischaemia testing in patients post CABG is challenging, irrespective of the imaging modality used. Multiple factors including advanced multi-vessel native vessel disease, variability in coronary hemodynamics post-surgery, differences in graft lengths and vasomotor properties, and complex myocardial scar morphology are only some of the pathophysiological mechanisms that complicate ischaemia evaluation in this patient population. Systematic assessment of the impact of these challenges in relation to each imaging modality may help optimize diagnostic test selection by incorporating clinical information and individual patient characteristics. At the same time, recent technological advances in cardiac imaging including improvements in image quality, wider availability of quantitative techniques for measuring myocardial blood flow and the introduction of artificial intelligence-based approaches for image analysis offer the opportunity to re-evaluate the value of ischaemia testing, providing new insights into the pathophysiological processes that determine outcomes in this patient population.

Native Coronary Disease Progression Post Coronary Artery Bypass Grafting

BACKGROUND

It remains unclear if graft type impacts native disease progression in the target coronary artery post coronary artery bypass grafting (CABG).

METHODS

Patients who underwent repeat angiograms at least 6 months post CABG with ≥1 arterial graft were included. Pre/post CABG angiograms were examined by 2 experienced readers. Progression was defined as new stenosis of ≥50% in a previously normal coronary, an increase in previous stenosis of ≥20%, or a new occlusion. Primary outcome was the occurrence of native disease progression in bypassed vessels. Secondary outcomes included complete occlusion, left main (LM) and distal disease progression. Cox-proportional hazard regression models were used for time-to-event outcomes.

RESULTS

Study population included 98 patients comprising 263 grafts (143 arterial/120 venous grafts). Median time from surgery to catheterization was 559 days (Interquartile Range 374,910).Ninety-one target vessels showed progression (34.6%) with 75 to complete occlusion (28.5%). Progression was not associated with graft choice (HR 0.74(0.49,1.13) p = 0.163),but was significantly associated with age(p = 0.034),previous PCI(p = 0.002),ACE inhibitor (ACEi) use(p < 0.001),CAD severity (p < 0.001),CCS class III/IV(p = 0.016) and NYHA class III/IV(p < 0.001). Progression to occlusion was significantly associated with SVG (p = 0.019), as well as previous percutaneous coronary intervention (p = 0.007) and ACEi use (p < 0.001). LM disease progression was significantly associated with peripheral vascular disease (HR 5.44(1.92, 15.46), p = 0.001), and not affected by graft type (p = 0.754).

CONCLUSIONS

Native CAD progression in non-LM coronaries is multifactorial, while SVG use was only associated with occlusion of non-LM coronaries. The implications of this study warrant consideration for increased arterial grafting in CABG patients, while the negative associations of previous PCI and ACEi use carry important clinical implications, which require further investigation.

Percutaneous revascularization strategies in a patient with previous coronary artery bypass surgery: technical and patho-physiological insights

Occasionally, in post-coronary artery bypass patients multiple percutaneous revascularization choices (treatment of the native artery versus treatment of the bypass graft) are available in order to obtain adequate blood supply of the ischemic myocardial region and relief of the anginal symptoms. Once a strategy has been chosen, the possibility to switch to the alternative plan should be considered in case unpredictable complications occur during the first treatment choice. A step-by-step assessment and prediction of the possible acute and long-term outcomes and complications should always be performed in order to optimize the results.