Anatomical, physiological and clinical relevance of a side branch : Which branch really needs a stent? Bon-Kwon Koo, MD, PhD, Seoul, Korea
Bifurcation lesion: The GREAT EQUALIZER! No intervention = Balloon angioplasty = Stenting Most Conservative Most Aggressive NORDIC III (No tx) NORDIC I (Angioplasty in <TIMI 3 flow) CACTUS (Angioplasty) CACTUS (SB stent) NORDIC III: Leave it alone vs. Kissing CACTUS: Crush vs. Provisional Cardiovascular Center 2 2
Why we can NOT improve the prognosis of a side branch lesions with revascularization? Anatomy Physiology Bifurcation puzzle Cardiovascular Center 3
Significant stenosis? Anatomically! Physiologically! Clinically! Prognostically! Stenosis à Ischemia à Clinical relevance à Revascularization à Prognosis Cardiovascular Center 4
Significant stenosis? Anatomically! Physiologically Clinically Prognostically Min Lumen Area: 2.0mm 2 MLD: 1.2mm Cardiovascular Center 5
Anatomical severity = Physiological significance % diameter stenosis vs. FFR in Jailed side branches SNUH SB-FFR registry Fractional Flow Reserve Fractional Fractional Flow Flow Reserve Reserve % diameter stenosis Park SH & Koo BK, J Ger Cardiol 2012 Ahn JM, et al. JACC intv 2012 Bellenger, et al. Heart 2007 % diameter stenosis Kumsars I, et al. Eurointervention 2011 Cardiovascular Center 7
Anatomical vs. Physiological significance Diagnostic performance of angio/ivus parameters of side branches to define the presence of clinical ischemia (FFR<0.8) Koh JS, Koo BK, et al., JACC Intv, 2012 Cardiovascular Center 8
Anatomical severity = Physiological significance 3D OCT lumen area vs. FFR in Jailed side branches Best cutoff value of OCT MLA: 2.1mm 2 Ha J, Kim JS, et al. JACC Img 2014 Cardiovascular Center 9
Anatomical severity = Physiological significance Min Lumen Area: 2.0mm 2 MLD: 1.2mm Cardiovascular Center 10
Anatomical severity = Physiological significance Can FFR-guided SB intervention strategy improve patients outcome like FAME I (and II)? Probably, NO in (general) bifurcation lesions. Koo BK, Korean Bifurcation Club meeting 2010 Cardiovascular Center 11
Cardiovascular Center 12
Significant stenosis? FFR = 0.60 Anatomically! Physiologically (by FFR)! Clinically? Prognostically? Cardiovascular Center 13
Clinical significance: Main vs. Side branch - Responses to 1-minute balloon occlusion - LAD Diagonal P value Chest pain (VAS score) 5 2 <0.0001 ST elevation 1mm 92.3% 35.4% 0.001 QTc interval, msec 454.0±45.4 440.4±35.7 0.07 QTc dispersion, msec 83.8±39.2 70.7±28.5 <0.0001 Side branch has much less clinical relevance in terms of symptom, ischemia and arrhythmic potentials Koo BK, et al., JACC Intv, 2012 Cardiovascular Center 14
Significant stenosis? FFR = 0.60 Anatomically! Physiologically! Clinically! Prognostically? Cardiovascular Center 15
Determinants of prognosis in a cath lab : Ischemic burden, collateral recruitability and treatment strategy Low collateral flow index (<0.25) High collateral flow index ( 0.25) Cardiovascular Center Meier, Circulation 2007 16
Collateral recruitability assessment using simplified collateral flow index (Pw/Pa) LAD Pw 23mmHg, Pw/Pa 0.26 Diagonal Pw 39mmHg, Pw/Pa 0.36 Pw: coronary wedge pressure, Pa: aortic pressure Cardiovascular Center 17
Difference in collateral recruitability - LAD vs. Diagonals - LAD Diagonal P Pre-intervention FFR 0.67±0.10 0.71±0.11 0.02 Wedge pressure (Pw), mmhg 21.0±6.5 26.7±9.4 <0.001 Collateral flow index (Pw/Pa) 0.22±0.07 0.27±0.08 0.001 Pw: coronary wedge pressure, Pa: aortic pressure Diagonal branches may have better collateral recruitability and more protection from ischemia (hypothesis generating ). Koo BK, et al., JACC Intv, 2012 Cardiovascular Center 18
Determinants of prognosis : Ischemic burden, collateral recruitability and treatment strategy Can OUR revascularization improve the prognosis? Do it well! Cardiovascular Center 19
Anatomical, physiological and clinical relevance of bi furcation lesions If you want to do PCI for angiographically significant SB, à Acknowledge that the side branch is different from the main branch. General 2 nd EBC, side branches: 2006 DES = Balloon angioplasty = Medical à Assess myocardial mass at risk (>10% by MPI estimation). If you still want to do, à Remind that there can be discrepancy between anatomical severity and physiological severity. Measure and follow FFR! à Consider the possibility that the side branch is naturally protected. If you still want to do, Seoul à National Do University it (very) Hospital well. Cardiovascular Center 20 20
Anatomical, physiological and clinical relevance of bi furcation lesions If you want to do PCI for angiographically significant SB, à Acknowledge that the side branch is different from the main branch. : General side branches: DES = Balloon angioplasty = Medical Clinical relevance: main branch >> side branch à Assess the clinical relevance (myocardial mass at risk >10% by MPI estimation) of the side branch first. If you still want to do, à Remind that there can be discrepancy between anatomical severity and physiological severity. When doubtful, measure FFR (Adequate experience and knowledge is required). à Consider the possibility that the side branch is naturally protected. If you still want to do, à Do it (very) well and be ready to use IVUS or OCT.
Thank you for your kind attention