NEW YORK (Reuters Health) – When patients who need coronary artery bypass grafts or an aortic valve have significant carotid stenosis, some surgeons combine the cardiac surgery with carotid endarterectomy to decrease the risk of stroke – but as a report in the September Archives of Neurology shows, this approach actually increases the risk of stroke, rather than decreasing it.

“Combining carotid and cardiac procedures is neither necessary nor effective in reducing postoperative stroke in patients with asymptomatic carotid stenosis,” Dr. John E. Castaldo, from Lehigh Valley Hospital and Health Network, Allentown, Pennsylvania, and colleagues conclude.

In a retrospective study, the researchers analyzed 4335 patients who underwent coronary artery bypass grafting, aortic valve replacement, or both at a single tertiary care hospital. In 3942 patients, carotid artery ultrasonography was done preoperatively.

The overall rate of clinical strokes was 1.8%. Roughly three-quarters (76.3%) were in patients without significant carotid stenosis. Just 5.3% were of the large-vessel type, according to the authors. In 60% of stroke patients, the infarct was not confined to the territory of a single carotid artery.

“According to clinical data, in 94.7% of patients, stroke occurred without direct correlation to significant carotid stenosis,” the investigators said.

In fact, just the opposite was true: in 104 patients with carotid stenosis of 70% or more, the stroke rate was higher in the 53 patients who had both operations than in the 51 who underwent cardiac surgery alone: 15.0% vs. 0% (p = 0.004). For this reason, the authors conclude that such combined procedures “should be avoided.”

“Preoperative studies, such as echocardiography or CT or MRI of the heart and aorta could identify disease-free areas for manipulation and clamping to prevent postoperative strokes,” the researchers state.

Reference:
Arch Neurol 2009;66:1091-1096.