Apolipoproteins as Predictors of Ischaemic Stroke in Patients with a Previous Transient Ischaemic Attack

Abstract

Background: Weak associations between total and LDL cholesterol and ischaemic stroke compared with coronary heart disease (CHD) are at odds with the similar effectiveness of statin drugs in preventing ischaemic stroke and CHD, suggesting that other lipid sub-fractions that are affected by statins might be better predictors of ischaemic stroke. Apolipoprotein B levels are reduced by statins and are a stronger predictor of CHD than total and LDL cholesterol in patients both on and off statins. However, there are very few published data on apolipoproteins and stroke risk and no studies in patients with previous transient ischaemic attack (TIA). Methods: We performed a prospective cohort study of the associations of baseline total cholesterol, LDL, HDL, apolipoproteins A1 and B (apo A1; apo B) and risk of ischaemic stroke in 261 patients with previous TIA. Cox proportional hazards models were used to determine crude and multivariate-adjusted hazard ratios (HR) above versus below median values at 10-years follow-up. Results: The apo B/apo A1 ratio was the strongest independent predictor of ischaemic stroke (HR = 2.94, 95% CI 1.43–5.88, p = 0.003) followed by apo B (HR = 2.26, 95% CI 1.16–4.38, p = 0.02). The associations between total cholesterol, LDL, HDL, LDL/HDL ratio and apo A1 and ischaemic stroke risk did not reach statistical significance. Conclusions: Apo B and the apo B/apo A1 ratio are predictive of ischaemic stroke in patients with previous TIA. Further studies are required to determine whether the prognostic value of apolipoprotein levels is maintained in patients on statins.

Apolipoproteins B and AI and the risk of ischemic cerebrovascular events in patients with pre-existing atherothrombotic disease

“…The association between apolipoproteins and cardiovascular disease has been frequently studied [8][9][10][11][12][13][14][15][16][17], but for stroke the evidence has been scant and less conclusive [18][19][20][21][22]. Substantial heterogeneity of the study population, design, end-point definition, and analytical approach preclude a meaningful synthesis of these data.…”

“…In the Third National Health and Nutrition Examination survey [19] increasing Apo A-I/Apo B ratio was associated with decreasing likelihood for a history of stroke, while in the Atherosclerosis Risk in Communities Study weak and inconsistent associations were found between lipid factors including apolipoproteins and ischemic stroke [20]. More recently, in an analysis based on the AMORIS study an association was observed between these apolipoproteins and stroke mortality [21], and in a series of hospital-referred TIA patients an association observed with recurrent events [22]. Our findings further support these observations and expand them to patients with preexisting coronary heart disease.…”

“…A growing body of evidence suggests that blood levels of Apo B, Apo A-1 and the Apo A-I/Apo B ratio, as do blood lipids, predict cardiovascular disease [8][9][10][11][12][13][14][15][16][17]. Studies on the relationship of apolipoproteins and stroke have been sparse and less conclusive [18][19][20][21][22], but recent reports have suggested an association also with cerebrovascular events [21,22]. Moreover, the Apo B/Apo A-I ratio was found to be related to the change in carotid artery intima-media thickness [23] and to carotid atheroma [24].…”

The apoB/apoA-I Ratio is a Strong Predictor of Cardiovascular Risk

“…However, LDL-C is rarely increased in those who suffer any type of stroke. A low HDL-C and some abnormalities in either apoB and/or apoA-I have previously been found in patients with ischaemic stroke (94)(95)(96)(97)(98)(99). In 2006 Walldius et al published the first report on risk of stroke based on the AMORIS-population (100).…”

Índice apo B/apo A-I e predição de risco cardiovascular

“…In a study by Bhatia et al 39 with 261 patients with previous transient ischemia and followed up for 10 years, the apo B/apo A-I ratio was the best independent predictor for ischemic stroke in this group of patients, followed by apo B, when the data were analyzed along with lipids, lipoproteins and traditional lipid ratios. This observation was confirmed by the AMORIS study 40 that showed a strong association between apo B/apo A-I ratio and risk of stroke, ischemic or not, suggesting that this association would be similar to that reported for CAD.…”