Fate of stent-related side branches after coronary intervention in patients with in-stent restenosis

OBJECTIVES We sought to assess the fate of stent (ST)-related side branches (SB) after coronary intervention in patients with in-ST restenosis. BACKGROUND In-ST restenosis constitutes a therapeutic challenge. Although t he fate of lesion-related SE after conventional angioplasty or initial coro nary stenting is well established, the outcome of ST-related SE in patients with in-ST restenosis undergoing repeat intervention is unknown. METHODS One hundred consecutive patients (age 61 +/- 11 years, 22 women) un dergoing repeat intervention for in-ST restenosis (101 ST) were prospective ly studied. Two hundred and twenty-six SB spanned by the ST were identified . The SB size, type, ostium involvement, location within the ST and take-of f angle were evaluated. The SB TIMI (Thrombolysis in Myocardial Infarction trial) flow grade was studied in detail before, during, immediately after t he procedure, and at late angiography. RESULTS Occlusion (TIMI flow grade = 0) was produced in 24 (10%) SB, wherea s some degree of flow deterioration (greater than or equal to1 TIMI flow gr ade) was observed in 57 SB (25%). The SB occlusion was associated with non- Q wave myocardial infarction in two patients (both had large and diseased S B). Side-branch occlusion at the time of initial stenting (RR [relative ris k] 11.1, 95% CI [confidence interval] 3.5-35.5, p < 0.001), diabetes (RR 3. 5, 95% CI 1.1-10.5, p = 0.02), SB ostium involvement (RR 5.0, 95% CI 1.4-17 .2, p = 0.004), baseline SB TIMI flow grade <3 (RR 5.5, 95% CI 1.7-18.1, p = 0.005), and restenosis length (RR 1.05 95% CI 1.01-1.11, p = 0.03) were i dentified as independent predictors of SB occlusion. Late angiography in 19 initially occluded SB revealed that 17 (89%) were patent again. The long-t erm clinical event-free survival (81% vs. 82% at two years) in patients wit h and without initial SB occlusion was similar. CONCLUSIONS Occlusion or flow deterioration of SB spanned by the ST is rela tively common during repeat intervention for in-ST restenosis. Several fact ors (mainly anatomic features) are useful predictors of this event. However , most SB occlusions are clinically silent and frequently reappear at follo w-up. (C) 2000 by the American College of Cardiology.