● the investigators aims to study the impact of using drug coated balloon in coronary artery bifurcation lesions on the procedural success rate & short-term MACE.

Study Design:

A prospective study. Patients who met the inclusion criteria will be enrolled in our study will be subdivided into 2 groups :-

Group A: patient Who will undergo conventional provisional stenting using standard technique with plain balloon angioplasty Group B: patient Who will undergo provisional stenting using Drug coated balloon The patients will be randomly assigned for each group using a computer randomizing software application.

Both group with pass 3 stages: - Pre-procedural Interventional procedure Post -procedural Pre- procedural

History taking:

Age & sex. Family history. Smoking status. Medical history including hypertension (HTN), diabetes mellitus (DM), renal impairment, etc.

Previous history of coronary artery disease, myocardial infarctions (MI), revascularization procedures Medical treatment and any significant history of allergy Previous intervention history regarding (site, type, diameter and length of the stent , complications and TIMI flow ) if available

General &Physical examination:

with special emphasis on vital data, decubitus ,lung osculation and peripheral pulsation

Laboratory investigations:

Including kidney function, complete blood count, and High sensitive troponin in case of acute coronary syndrome Echocardiography will be done routinely for all patients with special emphasis on ejection fraction (to be assessed by modified Simpson's method), left ventricular dimensions, resting segmental wall motion abnormalities (RSWMAs).

Interventional procedure. Angiographic analysis. Serial coronary angiography will be performed at baseline (before and after intervention) and angiograms will be obtained in multiple views after intra-coronary nitrate if coronary spasm is suspected. coronary angiograms will be digitally recorded and analyzed by experienced personnel using a validated offline quantitative angiographic system and the following data will be collected: -

Bifurcation lesion distribution:

Left main artery bifurcation Left anterior descending artery/diagonal bifurcation Left circumflex artery/obtuse marginal bifurcation Right coronary artery/posterolateral branch

Medina classification the investigators will use Medina classification for coronary bifurcation lesion in which recording any narrowing more than 50% in each of the three arterial segments of the bifurcation in the following order: proximal main vessel (PMV). Distal main branch (DMV). Side branch (SB)

(1) is used to indicate the presence of a significant stenosis and (0) the absence of stenosis

Main vessel

Proximal reference diameter (mm) Distal reference diameter (mm) Mean reference diameter (mm) Minimal lumen diameter (mm) Percentage diameter stenosis (%)) Lesion length (mm) Angiographic restenosis (%)

Side branch

Reference diameter (mm) Minimal lumen diameter (mm) Percentage diameter stenosis (%) Lesion length (mm)

Type of drug-eluting stents Sirolimus-eluting stents Everolimus-eluting stents Zotrolimus-eluting stents Biolimus A9-eluting stent Number of stent/drug-eluting balloon used Stent/drug-eluting balloon size (mm) Stent/drug-eluting balloon length (mm) Maximum balloon size (mm) Maximum inflation pressure (atmosphere) other coronary lesions

Intervention

1. wire both branches, MV and SB, with two coronary guide wires.
2. Main branch pre-dilation
3. Side branch pre-dilation using (ordinary balloon in group "A" and Drug coated balloon in group "B" for the side branch)
4. Main vessel stenting
5. Proximal optimization technique (POT) of the main vessel stent

The following data will be recorded: -

1. Inflation time (Seconds.)
2. Inflation pressure (atmospheric pressure.)
3. Diameter of the stent after inflation
4. Time of the procedure After Intervention

1) Reference luminal diameter (mm) 2) Minimal luminal diameter in stent (mm) 3) Minimal luminal diameter in lesion (mm) 4) lesion success (attainment of >50% residual stenosis of the target lesion, as measured by quantitative coronary angiographic analysis) 5) procedure success (attainment of a final lesion success and no major angiographic complications as dissection or perforation ).

Post-procedural Medications will be prescribed according to 2018 ESC myocardial revascularization guidelines.

Patients will be assessed for immediate outcomes:

lesion success attainment of >50% residual stenosis of the target lesion, as measured by quantitative coronary angiographic analysis procedure success attainment of a final lesion success and no major complication as :-

A. Perforation with or without tamponade B. vascular access complications C. myocardial infarction D. contrast-induced nephropathy E. urgent coronary artery bypass grafting F. urgent repeat PCI G. Death.

Patients be assessed and monitor for 24 hours after the procedure and in the outpatient clinic after 6 months.

Follow up clinically after 6 months for MACEs

Study end points. Primary end point target is 6-month follow-up for:-

MACEs (major adverse cardiac events) defined as :-

1. Death
2. Non-fatal myocardial infarction
3. Target lesion re-vascularization (TLR) "defined as any clinically driven intervention (surgical or percutaneous) to the target lesion or any segment of the epicardial coronary artery containing the target lesion"
4. Stroke

Improvement or recurrence of symptoms (chest pain and dyspnea) Symptomatic patients will undergo coronary angiography and those who has no symptoms with undergo functional assessment using either (High dose dobutamine echo or Myocardial perfusion imaging )

Secondary end points included:

lesion success procedure success

Inclusion criteria:

1. Patients with age above 18 years indicated for elective coronary angiography according to ESC 2018 guidelines with a bifurcation lesion affected Side branch (SB)
2. Patient Who planned for provisional stenting technique from the start or shifted to 2-stent strategy as a bailout to the Side branch
3. Bifurcation lesion with medina classification (1,1,1), (1,0,1) and (0,1,1)

Exclusion criteria:

Angiographical exclusion criteria as follows

1. Medina classification (1,1,0) or (0,1,0) or (1,0,0)
2. Side branch less than 2 mm in diameter
3. Patients who have multiple lesions with high syntax score and clinical characteristics favoring coronary artery bypass grafting according to latest ESC guidelines 2018.
4. Need for concomitant valvular surgery