Background and purpose: Reliable data concerning prognosis of patients with intracranial in-stent restenosis (ISR) is lacking. We prospectively studied long-term outcomes of patients with and without a catheter angiography-verified ISR.
Methods: Between September 2001 and May 2009, 540 consecutive patients with symptomatic intracranial atherosclerosis received stenting treatment at our institute. Of them, 226 patients with 233 stented arteries had catheter angiography follow-up after stenting and were enrolled into this study. They were clinically followed up until the end of December 2011. Primary end point was ischemic stroke or transient ischemic attack in the territory of the stented artery after the catheter angiography follow-up. ISR was defined as a catheter angiography-verified stenosis of ≥50% within or immediately adjacent (within range of 3 mm) to the implanted stent.
Results: During a mean follow-up of 38.9 months, 27 (11.6%, 27/233) primary end point events were recorded. The risk of primary end point in ISR group was higher compared with non-ISR group (21.1% [12/57] versus 8.5% [15/176]; hazard ratio, 2.94; 95% confidence interval, 1.37-6.30; P=0.005). Multivariable analysis showed that the ISR was an independent risk factor for the primary end point (hazard ratio, 2.79; 95% confidence interval, 1.20-6.49; P=0.017). The median occurrence time of primary end point was 9.9 (interquartile range, 5.0, 21.1) months in ISR group, earlier than that in non-ISR group (26.6 [13.1, 52.9] months; P=0.01).
Conclusions: In-stent restenosis after stenting of intracranial atherosclerosis is significantly associated with an increased risk and an earlier occurrence of recurrent ischemic events in the territory of the stented intracranial artery.
Keywords: angioplasty; intracranial arterial disorders; natural history; outcome measures.