Comparison Between Provisional Versus Routine Kissing Balloon Technique After Main Vessel Crossover Stenting for Bifurcated Lesions.

Inclusion Criteria: (Patient) Patient who has angina or documented ischemia, Patients who are eligible for drug eluting stent, Age \>=18, Patient who received informed consent, Patient who can receive dipyridamole-stress-technetium scintigraphy. (Lesion) Non-left main bifurcation except for Medina class (0,0,1), De-Novo lesion, Vessel diameter in visual (main vessel\>2.5mm, side branch \>2.0mm), SB lesion length \<5mm in visual estimate, MB lesion length \< 46mm in visual, TIMI 3 in main vessel as well as side branch, Exclusion Criteria: (Patient) Patients who is pregnant, Patient contraindicated for antiplatelet therapy, Patients whose ejection fraction is less than 30%, Patients who has renal dysfunction, creatinine \>=2.3, Patients who has live dysfunction, Patients who cannot agree with informed consent, Patient whose life expectancy is less than 1 year, Patients contraindicated for dipyridamole-stress-technetium scintigraphy. (Lesion) Target site of acute myocardial infarction, Left main disease, In-Stent restenosis lesion, Bypass graft, Chronic total occlusion, Main vessel reference diameter \>4.5mm, Bifurcation lesion that needs intended 2 stent strategy, Highly tortus and calcified lesion,