2007 Abstracts: Determinants of Hypotension and Bradycardia following Carotid Angioplasty and Stenting

Background: Acute procedural-induced hemodynamic depression can occur following carotid angioplasty and stenting (CAS). This study was performed to determine the frequency and risk factors for hypotension and bradycardia following CAS procedure.
Methods: Clinical variables and angiographic data of all patients undergoing elective CAS with neuroprotection were reviewed during a recent 58 month period. Intravenous atropine was given selectively in cases of hemodynamic depression, which was defined by severe hypotension (systolic blood pressure <50mmHg) or bradycardia (heart rate <50 bpm). Frequency and potential risk factors for hemodynamic depression were analyzed by logistic regression.
Results: A total of 410 CAS procedures were performed in 376 patients (mean age 73 +/- 11 years, and 97% male). The median degree of stenosis was 92% (range, 60%-99%). CAS indications included high risk medical comorbidities (n = 298, 73%), prior CEA (n = 94, 23%), s/p tracheostomy (n=5, 1%), high carotid bifurcation (n=47,11%), and prior neck radiation and/or dissection (n=8, 2%). Symptomatic lesions occurred in 107 cases (26%). The frequency of post-CAS hemodynamic depression include: hypotension (n=54, 13.2%); bradycardia (n=108, 26.3%), or both (n=18, 4.4%). Intra-procedural atropine was given in all bradycardic patients with uniformly normalized the heart rate. Demographic factors were not predictive for CAS-induced bradycardia or hypotension. However, adjusted risk factors associated with hemodynamic depression include age > 78 years (OR 4.55, 95% CI 1.5 to 14.43, p=0.002) and low ejection fraction (<25%, OR 3.21, 95% CI 2.1 to 5.22; p =0.01). Patients with CEA-related restenosis were associated with reduced risk of HD (OR 0.92, 95% CI 0.67 to 1.32, p=0.001). Patients who developed persistent hypotension following CAS were associated with an increased risk of an adverse clinical event (OR 2.67, 95% CI 1.38 to 6.32, p=0.01).
Conclusions: Hemodynamic depression including hypotension and bradycardia is frequent following CAS. However, CAS-induced hemodynamic depression is rare in patients with post-endarterectomy stenosis. Patients with compromised ejection fraction and increased age are at a higher risk of developing CAS-induced hemodynamic instability. Persistent hypotension following CAS is associated with peri-procedural cardiac and neurological complications.