In the setting of single stent strategy for treatment of bifurcation, we investigate to compare simple strategy as "provisional final kissing balloon technique(fKBT)" to complex one as "routine FKBT", focusing on actual myocardial ischemia assessed by scintigraphy in 7-month and to examine optimal endpoint of side branch ostium.

Final kissing balloon technique (FKBT) is effective and accepted technique for the treatment of bifurcation. However, in complex lesion or anatomy, much procedure-time and contrast media are needed to accomplish this technique. Recent FFR study for jailed side branch (SB) demonstrated that angiographic severe stenosis at SB ostium includes "pseudo-stenosis" and stent-deployment jailing SB without FKBT has comparable impact on clinical outcome with FKBT strategy. Considering simple technique for bifurcation, we sought to investigate to compare "provisional FKBT" with "routine FKBT", focusing on actual myocardial ischemia assessed by scintigraphy in 7 month and to examine optimal endpoint of SB ostium.

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,