Impact of inflammation and oxidative stress on carotid intima-media thickness in obstructive sleep apnea patients without metabolic syndrome.

Obstructive sleep apnea (OSA) increases the risk of cardiovascular diseases, and carotid intima-media thickness (IMT) is a good indicator of the severity of atherosclerotic disease. This study tested the hypothesis that inflammation and oxidative stress determined carotid IMT in patients with OSA. The carotid IMT, mean systolic and diastolic pressure (night and morning) were significantly higher and the level of thiols and high-density lipoprotein were significantly lower in our 121 OSA patients than in 27 controls (P < 0.05). The apnea/hypopnea index was correlated positively with E-selectin (r = 0.222, P = 0.014), total cholesterol (r = 0.185, P = 0.042), low-density lipoprotein (r = 0.264, P = 0.003) and HbA1c levels (r = 0.304, P = 0.001), but inversely with high-density lipoprotein level (r = -0.203, P = 0.025) in the 121 patients with OSA. In OSA subjects, multiple linear regression analysis revealed that age, systolic blood pressure and intercellular cell adhesion molecule-1 level associated independently with carotid IMT. Besides both age and systolic blood pressure, our study demonstrated that intercellular cell adhesion molecule-1 level was associated significantly with carotid IMT in those patients who had OSA but without metabolic syndrome.

Detection of microembolic signals using power M-mode Doppler sonography in acute stroke patients with intracranial artery stenosis.

PURPOSE: Microembolic signals (MES) can be detected in a variety of clinical situations using conventional transcranial Doppler (TCD) sonography. We studied the prevalence of positive MESs in acute stroke patients with intracranial artery stenosis using power M-mode Doppler (PMD) sonography and also tested the feasibility of this new technique. METHOD: Thirty-three consecutive acute ischemic stroke or transient ischemic attack patients with intracranial large artery occlusive disease were enrolled. PMD/TCD monitoring for 30 minutes was used for MES detection downstream of the stenotic artery within 1 week after stroke onset. Clinical risk factors in emboli-positive and emboli-negative patients were assessed. RESULTS: MESs were detected in 21% (7/33) of patients. No significant differences were found in clinical risk factors between emboli-positive and emboli-negative patients. CONCLUSION: PMD sonography to detect MESs in acute stroke patients is feasible and may be used in future clinical trials regarding MES detection.

Pulsatile tinnitus in a case of traumatic temporal extradural arteriovenous fistula: carotid duplex sonography findings before and after embolization.

Carotid duplex sonography (CDS) is regarded as a screening tool for lateral dural arteriovenous fistulae (AVF). However, data on evaluating long-term effects of endovascular treatment are limited. We report the CDS findings in the feeding arteries of a traumatic temporal extradural AVF before and after transarterial embolization. Volume flow of the left common carotid artery was greater than the right (433 ml/minute versus 294 ml/minute right) and the resistance index of the left external carotid artery was lower than the right (0.69 left versus 0.84 right). Both parameters returned to normal 4 months after embolization, thus confirming successful endovascular treatment.

Lipid management in ischemic stroke patients.

OBJECTIVES: In-hospital initiation and maintaining of lipid-lowering therapy (LLT) after discharge is recommended for dyslipidemic stroke patients. However, little is known about actual adherence to treatment in Taiwan. This study aims to describe the current practice of lipid testing and LLT and to identify predictors for patient to receive LLT. METHODS: Between February 2001 and December 2002, a total of 1105 consecutive ischemic stroke patients were prospectively registered. Dyslipidemic ischemic stroke patients were recruited and followed over a 6 months period. RESULTS: In-hospital lipid testing was performed in 91% of all patients and LLT was initiated in 74% (350/476) of dyslipidemic patients. During the 6 months follow-up period, lipid testing was performed in 77% (266/345) and LLT was maintained in 45% (154/345) of patients. However, the target LDL cholesterol level (<100mg/dL) was achieved in only 30% (78/255) of patients. Older patients had a lower chance to receive LLT. CONCLUSIONS: The in-hospital initiation of LLT and lipid testing was considered adequate as compared to other studies. However, after discharge from the hospital, many patients, especially older patients remained untreated. Efforts to close treatment gaps in lipid management require sustained quality improvement efforts. More awareness in this area is needed.

Effect of lipid-lowering therapy on the progression of intracranial arterial stenosis.

OBJECTIVES: Intracranial arterial stenosis (IAS) is a severe disease with a high recurrent stroke rate even under the best medical treatment. Statins have been demonstrated to prevent stroke and to slow or halt atherosclerosis progression. This study was performed to observe the effect of atorvastatin on the progression of IAS, explore the factors associated with atherosclerosis regression and the recurrent rate of stroke. METHODS: A hospital-base observation study enrolled 40 stroke patients with middle cerebral artery (MCA) or/and basilar artery (BA) stenosis. All participants had hyperlipidemia and were given atorvastatin 40 mg per day for at least six months. IAS was assessed by magnetic resonance angiogram (MRA) at the time of enrollment and then at least six months later. The primary outcome was the progression of IAS. All patients were also given antiplatelet agents for stroke prevention. RESULTS: At the end of the study, 23 (58 %), 15 (38 %) and 2 (4 %) patients had regressed, stationary and progressed IAS, respectively. Females were likely to have regressed IAS. The recurrent stroke rate was 18 %. Among the 54 stenotic vessels, 29 (54 %) vessels were assessed as improvement in stenosis. CONCLUSION: Compared with other studies, more regressed, stationary IAS and less progressed IAS were found in our study. Female gender was likely to have regressed IAS after statin treatment. Further clinical outcome trials are required to assess the effects of such therapy on morbidity and mortality in this particular group of patients.

Hemodynamic effects of subclavian steal phenomenon on contralateral vertebral artery.

PURPOSE: Increased blood flow velocity in the contralateral vertebral artery (VA) is a common finding in subclavian steal syndrome, but its clinical relevance is not known. The aim of this study was to investigate whether the degree of velocity increase in the contralateral VA correlated with the severity of the steal. METHODS: In a retrospective study of 62 patients with subclavian steal phenomenon and 62 sex- and age-matched controls, we analyzed the peak systolic velocity (PSV), end diastolic velocity (EDV), mean velocity (MV), resistance index (RI), and pulsatility index (PI) of the Doppler spectrum of the VA contralateral to the subclavian steal phenomenon. Clinical information including sex, age, comorbidities and Doppler data were recorded from the sonography registration form. RESULTS: In patients with subclavian steal syndrome, Doppler spectral analysis showed a complete reversal of flow in the VA in 29 patients (group A) and an alternating flow in 33 patients (group B). The PSV, MV, RI, and PI of the contralateral VA of patients from both groups were higher than in controls (p < 0.01 for both comparisons). The PSV, EDV, and MV in the contralateral VA were higher in patients with reversed flow compared with those with alternating flow (p < 0.05). Comparisons of clinical symptoms and comorbidities between the two groups did not yield significant findings. CONCLUSIONS: The degree of flow velocity increase in the contralateral VA artery correlates well with the severity of subclavian steal phenomenon.