Comparison of outcome of percutaneous coronary intervention in chronic total occlusion in patients with and without previous coronary artery bypass graft surgery

Background: Coronary artery disease (CAD) is defined by the progressive accumulation of atheromatous lesions within the intima of the coronary arteries. These lesions can induce luminal stenosis, resulting in myocardial ischemia secondary to reduced coronary blood flow. At the other hand, acute myocardial infarction (AMI) can occur when the thrombogenic subendothelial matrix is exposed due to plaque rupture or erosion. This triggers platelet aggregation and thrombus formation. Coronary chronic total occlusions (CTOs) were established by angiographical criteria, which included a Thrombolysis in Myocardial Infarction (TIMI) flow grade of 0, indicating full occlusion, and the presence of coronary artery lesions for a minimum of three months. Coronary angiography will reveal three or more CTOs in approximately half of all patients who have had a previous CABG procedure. Interventions on the native coronary vasculature are often technically challenging, and patients in this demographic are at increased risk of procedural complications during percutaneous coronary intervention (PCI). The primary objective of this study was to compare the initial procedural success of PCI in treating CTOs of native coronary arteries in patients with and without a history of CABG. A secondary objective was to assess clinical outcomes in both groups at 6-month follow-up. Methods: This prospective study was carried out on 100 patients who undeerwent PCI for CTO lesions at National Heart Institute & Benha university hospital. There were two equal groups of patients: those who had undergone previous CABG (nCABG group) and those who had not (pCABG group). Results: The pCABG group had a somewhat higher rate of six-month mortality at 8% vs 0% (P=0.04) and a significantly higher incidence of six-month myocardial infarction (MI) at 12% vs 2% (P=0.049) against the nCABG group. However there was similar incidience of six-month stroke 2% v. 2% (P= 1.0) between the two groups. Conclusions: The groups exhibited comparable rates of in-hospital MACE. Nevertheless, the procedural and technical success rates of patients who had undergone a previous CABG were significantly reduced. Furthermore, and perhaps most importantly, they experienced significantly higher rates of MI and mortality at six-month follow-up. Although the immediate procedural issues are similar, the data suggests that a history of CABG is associated with a higher risk of unfavorable clinical outcomes in the months following CTO PCI. This investigation emphasizes the significance of ongoing research and the implementation of enhanced procedures to improve the outcomes of this high-risk population.