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 SB after conventional angioplasty or initial coronary stenting is well established, the outcome of ST-related SB 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 (> or = 1 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.