Hemodynamic instability after elective carotid stenting: frequency and risk factors.

The objective of this study is to investigate the frequency and risk factors for hemodynamic instability (hypotension and/or bradycardia) in response to elective carotid stenting and their association with neurological complications. Carotid artery stenting implies instrumentation of the carotid bulb where the baroreceptors are placed and therefore baroceptor's dysfunction may provoke hemodynamic instability. The study started in the Neurology Clinic of the Emergency University Hospital, Bucharest as a retrospective analysis of the charts of 130 patients (110 men with mean age of 55 years) who underwent elective carotid artery stenting with cerebral protection for high-grade (>70%) symptomatic internal carotid artery stenosis. By hemodynamic instability one can understand the drop in systolic blood pressure of more than 30mmHG and bradycardia. 20% of patients had a drop in systolic blood pressure beyond 30 mmHg and/or bradycardia despite an adequate fluid balance. We did't use atropine as premedication before carotid stenting. There was no need for aggressive resuscitation (dopamine) and none of the patients with bradycardia needed pacemaker support. Neurological complications (transient ischemic attack, minor stroke, major stroke) occurred in 9% of patients and were not significantly associated with hemodynamic instability. Extensive carotid artery manipulation, a long stenosis situated at the bifurcation and the prior use of beta-blockers were associated with an increased adjusted risk for hypotension or bradycardia. Hemodynamic instability due to hypotension and bradycardia in response to carotid artery stenting occurs in a relatively low proportion of patients. Patients who had a long (over 6 mm) stenosis situated near the common carotid artery's bifurcation and therefore underwent extensive carotid manipulation or those who were on beta-blockers were at high risk for hypotension or bradycardia. The preadministrations of intravenous fluids didn't prevent the periprocedural hypotensive response.