Influence of contralateral carotid artery occlusions on short- and long-term outcomes of carotid artery stenting : a retrospective single-centre analysis and review of literature

Background: In the current literature, correlations between a contralateral carotid artery occlusion (CCO) with mortality and major adverse cardiac or cerebrovascular events (MACCE) rates after carotid artery stenting (CAS) are often described with controversial conclusions. Moreover, long-term results of mortality, MACCE and restenosis rate are scarcely reported. This study examined the association between a CCO and the short- and long-term outcomes after CAS. Methods: One hundred and forty-six patients with CCO and without (No-CCO) who underwent between 2010 and 2017 to a CAS procedure in a single institution were retrospectively evaluated. The primary aim of the study was to evaluate mortality and MACCE rates in the short-term (defined as the occurrence during hospitalization and within 30-day) and after 3-year follow up. The secondary aim of the study was to examine the restenosis rates in the short- and long-term period. Results: The overall success of CAS was 99.3% and the 30-day all-cause mortality rate was 0.7% (one death). About MACCE, there were no major strokes in the CCO groups and 1 (1.4%) in the No-CCO group (p = 1.00). The rate of 30-day minor strokes was 1.4% (1 patient) in the CCO group and 2.7% (2 patients) in the No-CCO group (p = 1.00). In the 3-year follow up, death occurred in 11 CCO vs 6 No-CCO patients, respectively (15.1% vs 8.2%, p = 0.30). Regarding MACCE, major stroke occurred in 6 CCO vs 2 No-CCO patients (8.2% vs 2.7%, p = 0.27), minor stroke in 6 CCO vs 6 No-CCO (8.2% vs 8.2%, p = 1.0) and myocardial infarction in 6 CCO (8.2%) vs 3 No-CCO patients (8.2 vs 4.1%, p = 0.49), respectively. Regarding the 30-day restenosis rate, it was observed in one patient (1.4%) in the CCO group while no cases were recorded in the No-CCO group, respectively (p = 1.00). In the 3-year follow up, greater than >50% restenosis was observed in 7 patients (9.6%) in the CCO group and in one patient (1.4%) in the No-CCO group (p = 0.06), respectively. Kaplan-Meier survival analysis revealed that CCO patients had a lower 3-year freedom from restenosis rate with respect to the No-CCO group (87.6% vs 98.6%, p = 0.024). A Cox regression model on 3-year restenosis highlighted female gender and hypertension to be statistically significant predictors of restenosis. Conclusions: Patients with a preexisting CCO didn't show a significative increased risk of procedural adverse events after CAS both in the immediate and long-term follow up, but on the long term they are more likely to experience restenosis. CCO condition should be considered always as a clinical manifestation of a more aggressive carotid atherosclerosis.