Cerebrovascular disorders: carotid-wall intima-media thickness, stroke recurrence, and β-blocker selectivity

Abstract

It is always amazing to see how many articles are published in the field of cerebrovascular disorders every month, even in very high-ranking journals. This is most certainly justified because daily clinical practice shows how relevant cerebrovascular disorders are. The three articles discussed in this month’s Journal Club primarily focus on primary or secondary prophylaxis. In the first study published in the New England Journal of Medicine, intima-media thickness of the walls of the common carotid artery and internal carotid artery, as well as the presence of plaque, were identified as a predictor for cardiovascular outcomes. The second article deals with stroke recurrence within the time window recommended for carotid endarterectomy, i.e. within 2 weeks after the first stroke due to a carotid stenosis. The article shows that early recurrent stroke risk was indeed high, particularly within the first 72 h, which has a considerable clinical impact. The final article, a systematic review on the effects of b-blocker selectivity on blood pressure variability and stroke also has clinical implications: non-selective b-blockers should be avoided in neurologic practice. In other words, b1-selective blockers can be used with the exception of atenolol, which has been shown not to be effective for stroke prevention. Carotid-wall intima-media thickness and cardiovascular events Known risk factors for cardiovascular events are increased systolic blood pressure, cholesterol, diabetes, cigarettesmoking, age, male sex, and history of cardiovascular disease. On the other hand, patients clearly benefit from hypertension treatment. In the current study, Polak and co-workers from Boston University examined whether intima-media thicknesses of the walls of the common carotid artery and internal carotid artery are independent risk factors and, further, if they may add to the Framingham risk score for predicting cardiovascular events. In 2,965 members of the Framingham Offspring Study cohort, the mean intima-media thickness of the common carotid artery and the maximum intima-media thickness of the internal carotid artery as well as the presence of plaque (defined as intima-media thickness of the internal carotid artery of more than 1.5 mm) were measured. Of these 2,965 participants a total of 296 had a cardiovascular event. The major findings were as follows: First, in the group of patients with no cardiovascular disease at follow-up the mean common carotid artery thickness was 0.59 ± 0.13 versus 0.66 ± 0.15 mm in the group of patients with cardiovascular disease at follow-up. Second, in those with no cardiovascular disease at follow-up the maximum internal carotid artery thickness was 1.30 ± 0.79 versus 1.9 ± 1.00 mm in those with cardiovascular disease at follow-up. Third, 27.4% of patients with no cardiovascular disease at follow-up had evidence of a plaque versus 59.6% of those with cardiovascular disease at follow-up. Fourth, the above-mentioned risk factors predicted the cardiovascular events with a so-called C statistic of 0.748. Fifth, the mean intima-media thickness of the common carotid artery and the maximum intima-media thickness of the internal