Hypolipemic agents for stroke prevention

Eicosapentaenoic acid prevents memory impairment after ischemia by inhibiting inflammatory response and oxidative damage

Previous studies have demonstrated that the generation of reactive oxygen species and an excessive inflammatory reaction are involved in the progression of neural damage following brain ischemia. In this study, we focused on the anti-inflammatory and antioxidant properties of eicosapentaenoic acid (EPA). Gerbils were treated intraperitoneally with 500 mg/kg of EPA ethyl for 4 weeks until the day of forebrain ischemia, which was induced by occluding the bilateral common carotid artery for 5 minutes. In the first part of the 2-part experiment, the effect of EPA treatment was evaluated using hematoxylin and eosin staining and deoxynucleotidyl transferase-mediated dUTP nick-end labeling as a marker of cell death (n=3 per group). The inflammatory reaction was evaluated using anti-Iba1 immunohistochemistry, a marker of microglial activation (n=3 per group), and detection of 8-hydroxyl-2'-deoxyguanosine, a marker of oxidative DNA damage (n=4 per group). In the second part of the experiment, the effect of EPA treatment on memory function was examined using an 8-arm radial maze (n=6 per group). EPA treatment significantly inhibited DNA oxidative damage (P < .05) and accumulation of Iba1-positive cells in the CA1 area at 12 and 72 hours after the induction of ischemia, and also decreased apoptotic neurons and neuronal death (P < .001) at 72 hours after ischemia. EPA treatment also significantly improved memory function (P < .05). These findings suggest that EPA inhibits the inflammatory reaction and oxidative damage occurring after ischemic brain injury, and also may contribute to the prevention of neural damage and memory impairment following such injury.

Lipid assessment and treatment patterns in hospitalized TIA and ischemic stroke patients

BACKGROUND

Identification of dyslipidemia and treatment with lipid-lowering agents are established targets for quality performance during hospitalization for ischemic stroke and transient ischemic attack (TIA). We aimed to study the frequency and predictors of lipid assessment and discharge utilization of lipid-lowering therapies among patients hospitalized for stroke and TIA.

METHODS

Demographics, clinical findings, and laboratory data were documented as part of the California Acute Stroke Prototype Registry (CASPR). Frequency of low-density lipoprotein cholesterol (LDL-C) testing and the frequency and appropriate use of lipid-lowering treatment according to national cholesterol guidelines were determined. Multivariate models were generated to determine the contribution of clinical variables to LDL testing and prescription of lipid-lowering medications at discharge.

RESULTS

Data were collected on 764 consecutive patients with ischemic stroke or TIA treated at 11 hospitals over a 2-year period. LDL-C measurements were performed in only 50.1% during hospitalization. Measurement of LDL-C was most strongly and independently associated with diagnosis of ischemic stroke (vs. TIA, P = .02) and history of dyslipidemia (P = .05). Overall, 48.4% of the CASPR cohort received lipid-lowering medications at discharge. Independent predictors for being prescribed lipid-lowering agents at discharge were diagnosis of ischemic stroke (P = .0009), LDL-C testing (P = .0002), high risk of future coronary events according to national guidelines (P = .02), and history of dyslipidemia (P< .0001). Only 59% of patients at high risk for future coronary events were discharged on a lipid-lowering medication.

CONCLUSIONS

Serum cholesterol testing and treatment are underutilized during hospitalization for ischemic stroke or TIA.

Arterial hypertension and brain damage--evidence from animal models (review)

Hypertension is an important risk factor for cerebrovascular disease including stroke and has also a role in the development of vascular cognitive impairment (VCI) and vascular dementia (VaD). Research on pathophysiology and treatment of hypertensive brain damage may benefit from the availability of animal models. This paper has reviewed the main animal models of hypertension in which brain damage is documented. Spontaneously hypertensive rats (SHR) represent the animal model more largely used. In these rats cerebrovascular changes, brain atrophy, loss of nerve cells in cerebrocortical areas, and glial reaction were documented. Several changes observed in SHR are similar to those found by in vivo imaging studies in essential hypertensives. It is documented that brain gets benefit from lowering abnormally elevated blood pressure and that reduction of hypertension protects brain from stroke and probably reduces the incidence of VaD. The influence of anti-hypertensive treatment on brain structure and function in animal models of hypertension is reviewed. Among classes of drugs investigated, dihydropyridine-type Ca2+ antagonists were those with a most documented protective effect on hypertensive brain damage. Limits and perspectives in the use of animal models for assessing brain damage caused by hypertension and protection from it are discussed.

[Antilipemics: from prevention to protection]

Statins and fibrates have been demonstrated to prevent both cardiovascular events and stroke. While this preventive effect was initially thought to be related to their lipid-lowering effects, in particular hypocholesterolaemic effect, analysis of primary and secondary prevention trials suggest that these preventive effects could be partly independent of their effects on lipid disorders. The pleiotropic effects, such as vascular, anti-inflammatory or anti-oxidants effects, were described for both the statins and fibrates. In addition to the preventive effects, these pleiotropic effects could partially explain the decrease in myocardial or cerebral ischemia consequences in experimental models. These cellular protective effects may have a therapeutic interest to decrease severity of stroke or coronary acute syndrome. They could also explain the drugs' lipid-lowering preventive effects independent of the treatment of lipid disorders. Beyond vascular pathologies, the pleiotropic effects of lipid-lowering drugs could explain their potentially beneficial effect in different diseases, such as dementia or cancer.