Purpose: To investigate the frequency of and risk factors for hypotension and bradycardia in response to elective carotid stenting and their association with neurological complications.
Methods: A retrospective analysis was conducted of 471 patients (321 men; median age 72 years, interquartile range 64-77) who underwent elective carotid artery stenting without cerebral protection for high-grade (>70%) symptomatic (n=147) or asymptomatic (n=324) internal carotid artery stenosis at a single center. Frequency and potential risk factors for severe hypotension (systolic blood pressure <80 mmHg) or bradycardia (heart rate <50 bpm) were studied.
Results: Thirty-four (7%) patients had severe hypotension (n=23), bradycardia (n=2), or both (n=9) despite routine premedication with atropine and adequate fluid balance. Intravenous catecholamines (dopamine) were necessary in 8 patients with prolonged hypotension; none of the patients with bradycardia needed pacemaker support. Neurological complications (transient ischemic attack, minor stroke, major stroke, death) occurring in 33 (7%) patients were not significantly associated with hemodynamic instability (4/34 [12%] versus 29/437 [7%], p=0.26). Age >77 years (fourth quartile; OR 6.40, 95% CI 1.80 to 22.78, p=0.004) and coronary artery disease (OR 2.81, 95% CI 1.29 to 6.14, p=0.010) were associated with an increased adjusted risk for hypotension or bradycardia.
Conclusions: Hemodynamic instability due to hypotension and bradycardia in response to carotid artery stenting occurs in a relatively low proportion of patients. Elderly patients and those with coronary artery disease are at highest risk. Although the rate of neurological complications was not significantly increased in patients with hemodynamic instability, the higher frequencies of neurological complications in these patients admonish us to be careful.