Early Treatment Needed for Patients
with Severe Carotid Artery Disease
Earlier treatment can prevent significantly more strokes in symptomatic patients.
Cardiologists should not delay treating symptomatic patients with severe carotid artery disease.
Klaus D. Mathias, MD, of the University of Muenster and the Academic Teaching Hospital of Dortmund, Germany, offered a review of published research yesterday morning, discussing the predictive variables and risk-benefit considerations of carotid artery stenting (CAS) and carotid endarterectomy (CEA).
Symptomatic patients
According to the 2006 AHA Guidelines, patients with transient ischemic attack or ischemic stroke within the last six months and severe ipsilateral stenosis (70% to 99%) should receive CEA, provided there is a perioperative morbidity/mortality rate of less than 6%.
The same guidelines indicate that for similar patients with moderate ipsilateral stenosis (50% to 69%), CEA is recommended, depending on patient-specific factors such as age, gender, comorbidity and severity of initial symptoms.
“The assumption that all symptomatic patients have the same risk/benefit is flawed,” Mathias said. “You cannot treat symptomatic patients with 50% to 99% stenoses as being a homogenous group of equal risk.”
Age should not be used to rule out patients. “The general feeling that elderly patients do not gain significant benefit because of an increased procedural risk is unsustainable,” Mathias said. “They have the most to gain, but CAS must keep the 6% limit.”
Speed to intervention is a significant factor. According to a recent study, intervention at zero to two weeks prevented more than 300 strokes per 1,000 CEAs at three years. The number of strokes prevented declined to slightly more than 150 per 1,000 for interventions within two to four weeks and then leveled out at about 100 strokes prevented per 1,000 CEAs for interventions at four to 12 weeks and more than 12 weeks (Figure).
“Every third stroke is a [recurrent] stroke,” Mathias said. “Internal carotid artery stenosis should be treated as early as reasonably possible, regardless of the invasive method used.”
Further observations from the literature are that women with moderate stenoses should receive treatment within a month of symptoms or they stand to gain little preventive benefit.
Additionally, an assessment of plaque morphology could have immense predictive benefit. When observed with plaque irregularity, the presence of contralateral occlusion is the single biggest predictor of benefit from intervention.
Asymptomatic or high risk
There are far less data for asymptomatic or high-risk patients, Mathias said. In two older trials, the maximum benefit derived in asymptomatic subgroups was seen in patients younger than age 75 with no evidence of benefit in patients older than age 75.
There has been some debate about performing CEA or CAS in high-risk patients. The 2006 AHA Guidelines indicate that, “Among patients with a severe (>70%) symptomatic stenosis in whom the stenosis is difficult to access surgically, major medical conditions are present, or other specific circumstances exist (eg, radiation arteritis, recurrent stenosis), CAS is not inferior to CEA and may be considered provided CAS is performed with established peri-procedural risks of 4% to 6%.”
However, Mathias said that physicians should be cautious since the clinical guidelines for treating high-risk patients (including all symptomatic patients) were informed by the SAPPHIRE trial in which the patient population was more than 70% asymptomatic and which had a 6% procedural risk.
“Irrespective of any debate about which asymptomatic patient should be treated, whether carotid endarterectomy or carotid artery stenting is safer, how and by whom carotid artery stenting should be performed, all of these pale in significance compared with the repercussions of delaying treatment for symptomatic patients with severe carotid artery disease,” Mathias said.