Antiplatelet agents
One or two associated drugs
Reduces risk of stroke and CV mortality
Antihypertensive agents
Reduction in systolic BP by 10 mmHg/diastolic by 5 mmHg or reduction to 120/80 mmHg in hypertensive
Reduces risk of stroke and CV mortality
Statins
Reduction of LDL by 50 % or to a value <70 mg/dL
Reduces risk of stroke and CV mortality. Even in normolipidemic patients
Diabetes mellitus | HgbA1c < 7 | Reduces risk of stroke and CV mortality |
Atrial fibrillation | Anticoagulation | Reduces risk of stroke |
Smoking | Total abstinence | Reduces risk of stroke and CV mortality |
Alcohol | Avoid excessive consumption | There is a reported increased risk of ischemic stroke with “irregular” drinking, including heavy and binge drinking. However, moderate drinking may be associated with a decreased risk of ischemic stroke [3] |
Statins have action in lowering cholesterol levels and anti-inflammatory effect. It has been shown to reduce the risk of subsequent neurological events in symptomatic patients after carotid surgery [26–28].
The acetylsalicylic acid is the most studied antiplatelet agent. It was demonstrated its benefit in the secondary prevention of stroke. It is effective in doses of 50–1500 mg, although higher doses lead to more frequent gastrointestinal effects. It is recommended dose of 81–325 mg/day [29].
Clopidogrel is an alternative for antiplatelet therapy and was superior to aspirin in preventing cardiovascular events [30]. However, the availability and low cost of aspirin made this drug choice for most patients with atherosclerotic disease and stroke [31]. The isolated use of aspirin, the isolated use of clopidogrel (75 mg/day), or aspirin use associated with extended release dipyridamole (25 and 200 mg/twice daily) is recommended in preference the combination of aspirin with clopidogrel (level of evidence A) in patients with extracranial carotid disease, occlusive and unocclusive who have suffered stroke or ministroke [32].
Surgical Treatment
To indicate the surgical treatment one should assess the risk of cerebral ischemia, compared to the risk of the proposed intervention.
As mentioned above, the most important indicator of future risk of brain ischemia is the presence of focal neurological symptoms in the last 6 months, particularly in the first month after the event.
In symptomatic patients with carotid stenosis from 70 to 99 %, the risk of new neurological events at 6 months is about 25 %. Moreover, in patients with symptomatic carotid stenosis from 50 to 69 %, the benefit from a carotid surgery is not so evident. In these cases, other causes of neurological symptoms should be investigated, such as, for example, pistons of cardiac origin [17, 18].
In asymptomatic patients, a linear relationship between the degree of stenosis and increased risk of stroke was not found, and in these patients, the risk of a neurological event per year is 1–2 % [33, 34]. Therefore, the benefit of surgical intervention is very low, with an NNT of about 20, and should be performed in vascular services with stroke and death rates less than or equal to 3 %.
The primary endpoint of carotid surgery is to reduce the risk of cerebral ischemia . The surgery does not improve existing sequelae of prior ischemia.
Therefore, in patients with non-disabling stroke or transient ischemic cerebral symptoms with low or moderate surgical risk, you can better indicate endarterectomy in the presence of stenosis of the internal carotid artery ipsilateral greater than or equal to 70 % [17, 18].
The endarterectomy was assessed by systematic review as beneficial procedure for symptomatic patients with 50–69 % of carotid stenosis and highly beneficial to those with 70–99 % stenoses [35, 36]; however, it does not add any benefit to asymptomatic patients [37].
Surgical intervention should preferably be done in the first 2 weeks after the neurological event, unless there are contraindications. It has excellent clinical and anatomical results in long term, with a survival rate of 82 % and stroke-free survival at 5 years of 92 % [38].
The American Heart Association recommends that only vascular services with a combined risk of stroke and mortality lower than 6 % for symptomatic patients and 3 % for asymptomatic patients should conduct carotid endarterectomy [39]. It is not indicated revascularization in patients with chronic occlusion of the internal carotid artery [40].
Acute myocardial infarction is responsible for most postoperative deaths (25–50 % of deaths) [41–43].
Angioplasty and stenting can be recommended as an alternative to carotid endarterectomy for symptomatic patients with low or moderate risk of complications associated with endovascular procedure in the presence of internal carotid artery stenosis greater than 70 % and in service with advance rate of stroke and operative mortality lower than 6 % [44]. Angioplasty is considered an alternative technique to endarterectomy in patients with decompensated heart disease, changes in cervical anatomy that increase the risk of cranial nerve injury, irradiated neck, prior radical neck surgery, tracheostomy, and high carotid bifurcation (above the mandibular angle) [40].
This is due to the fact that angioplasty was considered inferior to endarterectomy when compared the incidence of stroke or death, even if it is associated with less myocardial infarction rate [45].
Age greater than or equal to 68 years is associated with stroke risk increase and death in patients undergoing carotid angioplasty [46, 47].
What Generalist Doctor Can Do for This Patient?
The nonspecialist may be responsible for the conservative treatment of asymptomatic and symptomatic patients with carotid disease. Treatment is focused on control of modifiable risk factors for atherosclerosis, with emphasis on blood pressure and glycemic control, prescription of statins and antiplatelet, and quit smoking.
When Is the Time to Refer to Specialist?
Should be referred to specialists those patients who have surgical treatment indication ou dubious situations. Symptomatic patients—stroke (in recovery and not disabling) or ministroke —with internal carotid artery stenosis greater than 70 % should be referred for specialist assessment preferably within 2 weeks after onset of symptoms. Thus, it is possible for reduction of stroke and death rates [48].
References
1.
2.
Albers GW, Hart RG, Lutsep HL, Newell DW, Sacco RL. AHA Scientific Statement. Supplement to the guidelines for the management of transient ischemic attacks: a statement from the Ad Hoc Committee on Guidelines for the Management of Transient Ischemic Attacks, Stroke Council, American Heart Association. Stroke. 1999;30(11):2502–11.CrossRefPubMed
3.
Caron B, Rockman TSM. Cerebrovascular disease: general considerations. In: Jack L, Cronenwett KWJ, editors. Rutherford’s vascular surgery. 1. 8th ed. Philadelphia: Elsevier; 2014. p. 1456–72.
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