1. Importance Of Proximal Angle And Interpolated Minimal Luminal Diameter In Coronary Bifurcation Lesions Bhaktha M.D. Maddhavapeddy Aditya M.D. Maddury Jyotsna M.D. Nizam’s Institute of Medical Sciences Hyderabad, Andhra Pradesh, India.

2. INTRODUCTION Angioplasty of bifurcation lesions represents a continuing challenge. Bifurcation interventions vs. Non-bifurcation interventions Lower rate of procedural success Higher procedural costs Longer hospitalization Higher rate of clinical and angiographic restenosis. Side branch compromization. We require definitive predictors for side branch pinching for adaptation of better treatment strategy.

3. AIM We hypothesized proximal angle and interpolated minimal luminal diameter are additional important factors in predicting the pinching of side branch.

4. METHODOLOGY Bifurcation lesion was classified according to ICPS classification. We calculated the  Diameter of vessels with percentage stenosis Proximal main vessel Distal main vessel Side branch Interpolated minimal luminal diameter  Bifurcation angle BA- angle between distal main vessel and side branch PA- angle angle between proximal main vessel and side branch.

5. RESULTS Analyzed 56 bifurcation lesions under went PCI. Draw the diagram of bifurcation and label it.

6. Table Combine the reference vessel diameter and percetage stenosis and make a single table

7. TABLE-1 VesselRef.Diameter (mm) Main Proximal2.99 ± 0.98 Main Distal2.51 ± 0.30 Side branch2.20 ± 0.90 Interpolated minimal luminal 1.21 ± 0.60

8. Vessel (n=56) Percentage (stenosis) Main Branch 85.3 Side branch33.6 Side branch disease 78.3 ICPSPinching I16/19 II10/20 III0/1 IV1/3 IV a1/13

9. Icps classification Different no. Then pinching

10. ParameterTotalPinching No Pinchingp- value PA (≤130 0 )2710170.031 PA (>130 0 )29209 BA (≤ 45 0 )2919100.031 BA (>45 0 )27918 Side branch size ≤2.0 (mm) 2919100.031 Side branch size >2.0 (mm) 27918 Interpolated diameter ≤ 1 (mm) 2919100.031 Interpolated diameter > 1 (mm) 27918 Side branch diseased 241860.003 Side branch normal321121

11. Draw a curve with side branch diameter on x axis and pa angle on y axis and ba angle on z axis.

12. Pinching of the side branch occurred after stenting of main branch – already known conventional factors Smaller the size of side branch diameter disease in side branch Type 1 bifurcation has more pinching after main vessel stenting followed by type 2

13. Cont…. In general - pinching of the side branch occurred after stenting of main branch – proposed factors PA angle is >130º BA angle < 45º interpolated minimal diameter is <1 mm In patients with normal side branch - Pinching of side branch is not determinant by neither BA angle (59º vs. 60º) nor PA angle (with pinching 131º vs without pinching 127º). Effect of different angles on TIMI flows- PA angle is >130º then final TIMI 3 flow is good BA angle doesn’t determine the final TIMI flow

14. CONCLUSIONS It is important to observe PA angle and interpolated minimal luminal diameter along with bifurcation angle and disease in side branch to predict the compromization of side branch.