Prospective, controlled, double randomized, non-blinded, multicenter, investigator initiated, academic superiority trial comparing optical coherence tomography (OCT) guided vs. angiography guided wire recrossing in jailed side branches (SB) (1. randomization 1:1)(superiority) and comparing Medtronic Resolute Integrity and Xience Prime for stent strut apposition in the SB ostium (2. randomization 1:1) (superiority). Acute primary endpoint and 30 days clinical follow-up.

Hypothesis: OCT guided wire recrossing in bifurcation stenting results in less malapposed struts in the segment facing the SB ostium.

Secondary hypothesis: Treatment by Medtronic Resolute Integrity stent results in less malapposed struts at the bifurcation segment compared to treatment by the Abbott Xience Prime stent.

Purpose:

To assess the ability of OCT to guide wire recrossing and reduce stent strut malapposition after kissing balloon dilatation.

To compare stent strut apposition after treatment by two different stent designs using both guiding strategies of wire recrossing.

Inclusion Criteria:

• Stable or unstable angina pectoris or silent angina pectoris.
• De novo coronary bifurcation lesions at "LAD/diagonal", "Cx/obtuse marginal", "right coronary artery (RCA)- posterior descending artery (PDA)/posterolateral branch" or "left main (LM)/Cx/LAD".
• All Medina classes except Medina 0.0.1.
• Diameter of side branch ≥2.5 mm.
• Diameter stenosis >50% by operator's visual assessment
• Signed informed consent

Exclusion Criteria:

• ST-elevation infarction within 48 hours.
• Side branch lesion length >5 mm.
• Expected survival < 1 year
• Severe heart failure (NYHA≥III)
• S-creatinine >120 µmol/l.
• Allergy to Contrast media, Aspirin, Clopidogrel, Ticagrelor, Ticlopidine, Everolimus or Zotarolimus.