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 the fate of lesion-related SE after conventional angioplasty or initial coronary 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) undergoing repeat intervention for in-ST restenosis (101 ST) were prospectively 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-off angle were evaluated. The SB TIMI (Thrombolysis in Myocardial Infarction trial) flow grade was studied in detail before, during, immediately after the procedure, and at late angiography. RESULTS Occlusion (TIMI flow grade = 0) was produced in 24 (10%) SB, whereas some degree of flow deterioration (greater than or equal to1 TIMI flow grade) 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 SB). Side-branch occlusion at the time of initial stenting (RR [relative risk] 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 identified as independent predictors of SB occlusion. Late angiography in 19 initially occluded SB revealed that 17 (89%) were patent again. The long-term clinical event-free survival (81% vs. 82% at two years) in patients with and without initial SB occlusion was similar. CONCLUSIONS Occlusion or flow deterioration of SB spanned by the ST is relatively common during repeat intervention for in-ST restenosis. Several factors (mainly anatomic features) are useful predictors of this event. However, most SB occlusions are clinically silent and frequently reappear at follow-up. (C) 2000 by the American College of Cardiology.