“Is metabolic syndrome greater than the sum of its parts?” The answer is unclear, according to Dr. Ovbiagele, but the recommendation “reminds the clinician to be aware of these five important criteria and to make sure the patient is within goal for each one of them,” he says. Otherwise, there is a tendency to focus on major risk factors (hypertension, LDL) at the expense of such issues as obesity and triglycerides.

Atrial fibrillation

The updated guidelines emphasize the complexity of managing atrial fibrillation (AF), which must include reducing stroke risk amid the dangers of hemorrhagic complications.

Continue Reading

For initial therapy, the authors recommend anticoagulation with a vitamin K antagonist (typically warfarin), with a target international normalized ratio (INR) of 2.5.

Aspirin is the preferred alternative for patients who are unable to take oral anticoagulants. It offers a lower level of protection against ischemic stroke but carries less bleeding risk. The safety/efficacy ratio appears most favorable at a daily dosage of 75-100 mg.

Aspirin combined with clopidogrel is about as effective as warfarin for stroke prevention. But because it confers comparable bleeding risks, the authors do not recommend this regimen for patients in whom warfarin is contraindicated by hemorrhagic risk.

Stroke risk rises for patients with AF when anticoagulation therapy is temporarily interrupted for surgery or other reasons. The guidelines advocate “bridging therapy” with low-molecular weight heparin at such times for individuals whose risk is deemed to be particularly high, such as those who had experienced stroke or TIA within the prior three months or have mechanical or rheumatic valve disease.

Antiplatelet therapy

For most patients (those whose stroke or TIA was caused by a clot from the heart are an exception), antiplatelet prophylaxis is preferable to anticoagulation. The guidelines endorse aspirin (50-325 mg/day) alone; aspirin (25 g) and dipyridamole (200 mg) b.i.d.; or clopidogrel (75 mg) as “acceptable options” for initial therapy.

No regimen has a clear advantage in efficacy, and deciding among them can be complicated by patient factors, acknowledges Dr. Ovbiagele. “Things like compliance level come into play in choosing between a once- and twice-a-day regimen. If a patient has a lot of headaches, I’d be cautious about aspirin/dipyridamole.”

On the more difficult question of how best to modify prophylaxis for a patient who has a stroke while on aspirin, there are essentially no data to guide clinicians, the authors write.

Carotid artery disease

The revised guidelines include data that lend stronger support to carotid angioplasty and stenting (CAS) as an alternative to carotid endarterectomy (CEA) for patients with a recent stroke or TIA (occurring within the past six months) and severe carotid stenosis.

In particular, CAS should be considered whenever medical conditions make CEA hazardous or under such special circumstances as radiation-induced stenosis or restenosis after CEA.

The authors specify that CAS is reasonable only when performed by operators with perioprocedural morbidity and mortality rates no greater than 4%-6%.

The guidelines assert that patients who are treated with either procedure should have optimal medical support, including antiplatelet and statin therapy and appropriate risk-factor modification. 

Mr. Sherman is a freelance medical writer in New York City.