Stroke meta-analysis studies

Dauchet, L. et al., Fruit and vegetable consumption and risk of stroke a meta-analysis of cohort studies, Neurology, 65, 1193, 2005. 

Hyperlipidemia has not clearly been established as a risk factor for stroke, although it is a modifiable risk factor for coronary heart disease. Recent studies show that statin use may reduce the incidence of a first stroke in high-risk patients (e.g., hypertension, coronary heart disease, or diabetes) including patients with normal lipid levels. A recent meta-analysis showed a 25% risk reduction for fatal and non-fatal strokes with statin use.4 Patients with a history of MI, elevated lipid levels, diabetes, and... 

The benefit of carotid endarterectomy for prevention of recurrent stroke has been studied previously in major trials.25,26 A recent meta-analysis has been completed that has combined these clinical trials to evaluate 6,092 patients.27 Carotid endarterectomy has been shown to be beneficial for preventing ipsilateral stroke in patients with symptomatic carotid artery stenosis of 70% or greater and is recommended in these patients. In patients with symptomatic stenosis of 50% to 69%, a moderate reduction in risk is seen in clinical trials. In all patients with stenosis of 50% to 69% and a recent stroke, carotid endarterectomy is appropriate. In other patients, surgical risk factors and surgeon skill should be considered prior to surgery. The patient should have, at a minimum, a life expectancy of 5 years, and the surgical risk of stroke and/or death should be less than 6%. Carotid endarterectomy is not beneficial for symptomatic carotid stenosis less than 50% and should not be considered in these patients. 

M. Etminan, B. Takkouche, F. C. Isoma and A. Samii, Risk of ischemic stroke in people with migraine systematic review and meta-analysis of observational studies. BM, 2005, 330,63-66. 

Homocysteine Studies Collaboration (2002) Homocysteine and risk of ischemic heart disease and stroke a meta-analysis. JAMA 288 2015-2022... 

The interest in dietary flavonoids has grown in the last 15 years after the publication of the study of Hertog et al. [1993] showing an inverse correlation between dietary consumption of flavonols and flavones and reduced incidence and mortality from ischemic heart disease. Most prospective epidemiological studies carried out have found a similar relationship regarding ischemic heart disease while a possible inverse relationship with stroke is less clear [Hertog et al., 1997 Knekt et al., 1996 Rimm et al., 1996 Yochum et al., 1999 Hirvonen et al., 2001 Arai et al., 2000 Mursu et al., 2008], The meta-analysis... 

Many studies published during the last few decades have suggested that hyperhomocysteinemia is a risk factor for coronary artery disease (CAD), stroke, and thromboembolic disease. The Homocysteine Studies Collaboration metaanalysis of 30 studies concluded that elevated tHcy is a moderate risk factor for ischemic heart disease a level 3 xmol/L lower reduces the risk with an odds ratio of 0.89 (95% Cl = 0.83-0.96). The same was true for homocysteine as a risk factor for stroke (odds ratio = 0.81 95%5CI = 0.69-0.95) (6). A meta-analysis of 40 studies of the MTHFR 677 C > T polymorphism demonstrated a mildly increased risk of coronary heart disease with an odds ratio of 1. 16 (95% Cl = 1.05-1.28) (25). 

Hajat C., Hajat S., and Sharma P. (2000) Effects of poststroke pyrexia on stroke outcome a meta-analysis of studies in patients. Stroke 31,410 414. 

Like cholesterol, tHcy appears to be a graded risk factor, and even mild hyperhomocysteinemia confers an increased risk of cardiovascular events. A meta-analysis concluded that a 25% elevation in plasma tHcy (about 3 ftmol/L) is predictive of about a 10% increased risk of myocardial infarction and a 20% increased risk of stroke (Homocysteine Studies Collaboration, 2002). 

Casas JP, Hingorani AD, Bautista LE et al. (2004). Meta-analysis of genetic studies in ischemic stroke thirty-two genes involving approximately 18 000 cases and 58 000 controls. Archives of Neurology 61 1652-1661 Casas JP, Cavalleri CL, Bautista LE et al. (2006). Endothelial nitric oxide synthase gene polymorphisms and cardiovascular disease ... 

Fig. 15.1. Stroke risks at two and seven days measured in a systematic review of 18 independent cohorts, stratified according to study method and setting (Giles and Rothwell 2007). Cl, confidence interval p (het), p value for heterogeneity between studies p (sig), p value for overall significance of the meta-analysis of comparisons between studies.

In a recent systematic review and meta-analysis of studies of the risk of myocardial infarction and vascular death after TIA and ischemic stroke (Touze et al. 2005), cohort studies including over 100 patients with TIA or ischemic stroke and reporting risks of myocardial infarction or non-stroke vascular death over at least one year of follow-up published between 1980 and 2005 were identified. The analysis included 39 studies reporting outcomes in 65 996 patients. The ranges of annual risks reported in individual studies were 0.4% to 3.8% for non-stroke vascular death, 0.5% to 4.7% for total myocardial infarction, 0.4% to 3.2% for non-fatal myocardial infarction and 0.2% to 3.7% for fatal myocardial infarction. The annual risks obtained through meta-regression were 2.1% (95% Cl, 1.9-2.4) for non-stroke vascular death (29 studies), 2.2% (95% Cl, 1.7-2.7) for total myocardial infarction (22 studies), 0.9% (95% Cl, 0.7-1.2) for non-fatal myocardial infarction (16 studies), and 1.1% (95% Cl, 0.8-1.5) for fatal myocardial infarction (19 studies) (Touze et al. 2005) (Fig. 17.2). 

Fig. 28.2. The overall results of a meta-analysis of the operative risk of death (a) and stroke and death (b) from all studies published between 1990 and 2000 inclusive that reported risks from carotid endarterectomy for asymptomatic stenosis (Bond et ai. 2003a) compared with the same risks in the ACAS Trial (Executive Committee for the Asymptomatic Carotid Atherosclerosis Study 1995). Studies in the analysis of risk of stroke and death are...

The ACAS reported a statistically borderline sex-treatment effect interaction, with no benefit from endarterectomy in women (Executive Committee for the Asymptomatic Carotid Atherosclerosis Study 1995). The same trend was seen in ACST (Halliday et al. 2004). A meta-analysis of the effect of endarterectomy on the five-year risk of any stroke and perioperative death in ACAS and ACST (Rothwell 2004) (Fig. 28.3) showed that benefit from surgery was greater in men than in women (pooled interaction, p = 0.01), and that it remained uncertain whether there is any worthwhile benefit in women at five years of follow-up, although some benefit may accrue with longer follow-up in ACST. 

Total tau protein concentration has been extensively studied as a nonspecific marker of neuronal destruction in AD. Recently published meta-analysis of Sunderland et al. (2003) was based on the data from 17 reports on A(342 and 34 reports on CSF tau in AD, and all studies included in this meta-analysis reported increased CSF total tau in AD. Since an age-related increase of tau concentration has been reported in nondementia controls by some investigators (Buerger et al, 2003), age-dependent reference values of total tau should be considered as recently suggested (Sjogren et al., 2001). Increased CSF total tau concentrations are observed in neuropsychiatric disorders other than AD, e.g., C JD and stroke (Hesse et al, 2001 Otto et al., 1997). Nevertheless, given the fact that tau most likely can be used to monitor the efficacy of neuron-protective drugs in AD patients, and that C JD and acute stroke are easily distinguishable from AD clinically, this should not dampen the value of this marker. 

Coenzyme QIO is a powerful antioxidant naturally occurring in the mitochondria of myocardium, and it is an electron carrier in the mitochondrial synthesis of ATP. Patients with heart failure have lower myocardial levels of coenzyme QIO, but supplementation has been demonstrated to have variable benefits in randomized controlled trials. One meta-analysis on the use in congestive heart failure showed improvements in stroke volume, ejection fraction, cardiac output, cardiac index, and end diastolic volume index. " Another antioxidant associated with beneficial effects in cardiac patients is lycopene, a natural constituent of tomatoes. Lycopene is the major carotenoid found in human serum, and epidemiological studies have indicated an effect of dietary supplementation in reducing heart disease. Few dietary interventions have been reported one study showed a mild but significant hypocholesterolemic effect, and another showed a significant reduction in LDL oxidation. " Animal studies show an antiatherogenic effect of DHEA, and a review of the clinical trials and studies on DHEA in males with coronary heart disease reported a favorable or neutral effect. Plasma levels of DHEA are decreased in patients with chronic heart failure in proportion to its severity. ... 

The best overall evidence of the safety of diuretics in old people comes from the large-scale outcome trials in hypertensive patients (11,13,15,17,18). These studies in over 10000 subjects aged over 60 years showed clearly that thiazide-based treatment reduces the risk of stroke, coronary heart disease events, and cardiovascular events in older hypertensive patients. A meta-analysis (163) of randomized trials lasting at least 1 year and involving 16164 individuals aged at least 60 years showed that diuretics were superior to beta-blockers with regard to all endpoints (stroke, coronary heart disease events, cardiovascular mortality, and all-cause mortality). The beneficial effects noted in these trials should dispel any doubts about the safety and efficacy of diuretics in old people. 

Elevated SBP has been shown to be associated with an increased risk of stroke, CHF, myocardial infarction and death [140,141]. The authors of the ALLHAT study suggested that a 3 mm Hg increase in SBP could explain a 10 % to 20% increase in the incidence of CHF [142]. In a meta-analysis of 15, 693 older patients with isolated systolic hypertension from 8 trials, a 10 mmHg higher initial SBP was associated with relative hazard rates of 1.26 (p=0.001) for total mortality, 1.22 (p=0.007) for cardiovascular mortality, and 1.22 (p=0.02) for stroke [143]. The recent meta-analysis by Aw et al [66A] involving 45451 patients found that rofecoxib was associated with a higher risk of developing hypertension compared to celecoxib. 

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