Assessment of possible predictors of occlusion of jailed side branches following main vessel coronary artery stenting and detection of clinical, electrocardiographic and echocardiographic changes following occlusion of jailed side branches postprocedural and at 3 months follow-up.

Coronary bifurcation lesion (CBL) involves coronary artery stenosis adjacent to and/or including the origin of a significant side branch (SB) 1. Treatment of bifurcation lesions constitute about 15% of coronary interventions and are consequently of major clinical interest 2. Even in the modern era of per-cutaneous coronary intervention(PCI) with stent implantation, treatment of bifurcations is hampered by a higher event rate and requires longer procedure time, more radiation exposure, and higher volumes of contrast material compared with non-bifurcation lesions 3 .

Occlusion of large side branches (SBs) may result in significant adverse clinical events 4. Occlusion of jailed sizable septal and right ventricular (RV) side branches (non-classic bifurcations) is often overlooked following left anterior descending (LAD) and right coronary artery (RCA) main vessel stenting, respectively. Most of the operators decline intervening in these side branches on contrary to classic bifurcations as diagonals and obtuse marginal branches, for example. Whether or not intervening with these occluded jailed side branches have clinical implications or even sub clinical left ventricular (LV) dysfunction was not previously elucidated and warrants studying.

Left ventricular function is an important predictor of outcome in patients with coronary artery disease (CAD). Extensive myocardial ischemia can cause decreased LV contractility and function 5. Conventional echocardiography enables us to identify significant left ventricular dysfunction but not sub-clinical dysfunction [10]. Two-dimensional speckle tracking echocardiography (2D-STE) allows for an angle-independent evaluation of myocardial strain, and provides comprehensive information on LV myocardial contractility. Thus, 2DSTE is superior in detecting subtle deterioration of contractility 6 .

In this study, investigators tried to explore the possible predictors and outcomes following occlusion of jailed side branches after main vessel coronary artery stenting, in both classic and non-classic bifurcations, and whether intervening via various techniques would have clinical benefit.

Inclusion Criteria:

• Patients presenting to cathlab for elective PCI along one year duration
• patients who have significant main vessel lesion subtending large, sizable (≥2mm) side branches (Medina 1,0,0 / 1,1,0 / 0,1,0)

Exclusion Criteria:

• acute myocardial infarction
• previous CABG
• LV EF<50%
• baseline SWMA in the territory of the vessel to be stented
• totally occluded main vessel.
• small (<2mm) side branch
• any ostial, mid or distal significant side branch disease at baseline.
• true bifurcation lesions (Medina 1,0,1 / 1,1,1 / 0,1,1) with upfront 2-stent strategy.
• advanced renal impairement

patients presenting for elective PCI will undergo 2D-STE before the procedure and if found to have bifurcation lesion will undergo 2D-STE within 24 hours after the procedure and after 3 months