Arterial stiffness indexes in acute ischemic stroke: Relationship with stroke subtype

Aortic Stiffness and Plasma Brain Natriuretic Peptide Predicts Mortality in Acute Ischemic Stroke

Background

The study aimed to evaluate the prognostic role and discriminative power of aortic stiffness and plasma brain natriuretic peptide levels in a cohort of patients hospitalized for acute ischemic stroke.

Methods and Results

Three hundred and ten consecutive patients aged 50 years and older with a first episode of acute ischemic stroke were prospectively evaluated. All patients were admitted to the hospital within 24 h of the onset of stroke symptoms. The type of acute ischemic stroke was classified according to the Trial of Org 10172 in Acute Stroke Treatment classification. Blood samples were taken for measurement of brain natriuretic peptide levels at admission. Aortic stiffness indices, aortic strain and distensibility, were calculated from the aortic diameters measured by transthoracic echocardiography. The patients were followed for one-year or until death, whichever came first. Death occurred in 51 (16·5%) patients. On multivariate logistic regression analysis, National Institutes of Health Stroke Scale score >13, diabetes, brain natriuretic peptide >235 pg/mL, aortic distensibility, and aortic strain were associated with all-cause mortality. The optimal cutoff level of brain natriuretic peptide to distinguish the deceased group from the survival group was 235 pg/mL (sensitivity 71·0% and specificity 63·0%) and to distinguish cardioembolic stroke from noncardioembolic stroke was 155 pg/mL (sensitivity 81% and specificity 63%).

Conclusions

Aortic stiffness and brain natriuretic peptide predict mortality in patients with first-ever acute ischemic stroke. Brain natriuretic peptide also differentiates cardioembolic stroke from noncardioembolic stroke.

Endothelial Dysfunction and Arterial Stiffness in Ischemic Stroke

Background and Purpose—

Sleep-disordered breathing (SDB) represents a risk factor for cardiovascular morbidity after a cerebral ischemic event (acute ischemic event, ischemic stroke, or transient ischemic attack). In the present study, endothelial function and arterial stiffness were analyzed in patients who experienced a postacute ischemic event with relation to SDB, sleep disruption, and nocturnal oxygenation parameters.

Methods—

SDB was assessed by full polysomnography in patients with acute ischemic event 3 months after the admission at our stroke unit. Moderate-severe SDB was defined according to the apnea-hypopnea index as apnea-hypopnea index ≥20. Endothelial function and arterial stiffness were assessed by peripheral arterial tonometry using Endo-PAT 2000.

Results—

Thirty-seven patients were included. The augmentation index was significantly different between patients with apnea-hypopnea index <20 and apnea-hypopnea index ≥20 (22.4±15.6% versus 34.6±21.6%; P =0.042), whereas reactive hyperemia index level was not (2.02±0.65 versus 2.31±0.61; P =0.127). Patients with apnea-hypopnea index ≥20 showed an increased risk for arterial stiffness (odds ratio, 5.98 [95% CI, 1.11–41.72]) even when controlling for age, sex, body mass index, hypertension, and diabetes mellitus. The augmentation index was correlated with the arousal index ( P =0.010) and with mean O 2 saturation ( P =0.043).

Conclusions—

Poststroke patients with moderate-severe SDB were more prone to have increased arterial stiffness, although we did not find significant differences in endothelial function. Arterial stiffness also correlated with sleep disruption (arousal index) and mean O 2 saturation.

Physical activity correlates with arterial stiffness in community-dwelling individuals with stroke

BACKGROUND

Physical inactivity contributes to atherosclerotic processes, which manifest as increased arterial stiffness. Arterial stiffness is associated with myocardial demand and coronary perfusion and is a risk factor for stroke and other adverse cardiac outcomes. Poststroke mobility limitations often lead to physical inactivity and sedentary behaviors. This exploratory study aimed to identify functional correlates, reflective of daily physical activity levels, with arterial stiffness in community-dwelling individuals >1 year poststroke.

METHODS

Carotid-femoral pulse wave velocity (cfPWV) was measured in 35 participants (65% men; mean ± SD age 66.9 ± 6.9 years; median time poststroke 3.7 years). Multivariable regression analyses examined the relationships between cfPWV and factors associated with daily physical activity: aerobic capacity (VO2 peak), gait speed, and balance ability (Berg Balance Scale). Age and the use of antihypertensive medications, known to be associated with pulse wave velocity, were also included in the model.

RESULTS

Mean cfPWV was 11.2 ± 2.4 m/s. VO2 peak and age were correlated with cfPWV (r = -0.45 [P = .006] and r = 0.46 [P = .004], respectively). In the multivariable regression analyses, age and the use of antihypertensive medication accounted for 20.4% of the variance of cfPWV, and the addition of VO2 peak explained an additional 4.5% of the variance (R2 = 0.249).

CONCLUSIONS

We found that arterial stiffness is elevated in community-dwelling, ambulatory individuals with stroke relative to healthy people. Multivariable regression analysis suggests that aerobic capacity (VO2 peak) may contribute to the variance of cfPWV after accounting for the effects of age and medication use. Whether intense risk modification and augmented physical activity will improve arterial stiffness in this population remains to be determined.

Differences of aortic stiffness and aortic intima-media thickness according to the type of initial presentation in patients with ischemic stroke

BACKGROUND

Aortic stiffness and intima-media thickness (IMT) are known to be associated with ischemic stroke. The aim of the present study was to investigate the differences of aortic stiffness and IMT between cerebral infarction (CI) and transient ischemic attack (TIA).

METHODS

A total of 500 patients with acute stroke were divided into 2 groups: the TIA group (n = 230, 62.4 ± 12 years, 144 males) versus CI group (n = 270, 63.4 ± 11 years, 181 males). Aortic stiffness index and IMT, as well as conventional cardiovascular risk factors, were compared.

RESULTS

The prevalence of hypertension, diabetes, and dyslipidemia were significantly higher, and left atrial volume and E/E' were significantly elevated in the CI group than in the TIA group. Carotid IMT was significantly thicker in the CI group than in the TIA group. Aortic stiffness index β was significantly higher (7.99 ± 2.70 vs. 7.02 ± 4.30, p = 0.043) and aortic IMT was significantly thicker (1.53 ± 0.41 vs. 1.45 ± 0.39 mm, p = 0.040) in the CI group than in the TIA group. Aortic stiffness index β was significantly correlated with the IMT of the aorta (r = 0.279, p = 0.014), right (r = 412, p < 0.001) and left carotid artery (r = 441, p < 0.001).

CONCLUSION

Aortic stiffness index β and IMT were significantly higher in patients with CI than TIA. The result of the present study suggested that CI is associated with more advanced degree of atherosclerotic and arteriosclerotic process than TIA.

Increased cerebral arterial pulsatility in patients with leukoaraiosis: arterial stiffness enhances transmission of aortic pulsatility

BACKGROUND AND PURPOSE

Arterial stiffening reduces damping of the arterial waveform and hence increases pulsatility of cerebral blood flow, potentially damaging small vessels. In the absence of previous studies in patients with recent transient ischemic attack or stroke, we determined the associations between leukoaraiosis and aortic and middle cerebral artery stiffness and pulsatility.

METHODS

Patients were recruited from the Oxford Vascular Study within 6 weeks of a transient ischemic attack or minor stroke. Leukoaraiosis was categorized on MRI by 2 independent observers with the Fazekas and age-related white matter change scales. Middle cerebral artery (MCA) stiffness (transit time) and pulsatility (Gosling's index: MCA-PI) were measured with transcranial ultrasound and aortic pulse wave velocity and aortic systolic, diastolic, and pulse pressure with applanation tonometry (Sphygmocor).

RESULTS

In 100 patients, MCA-PI was significantly greater in patients with leukoaraiosis (0.91 versus 0.73, P<0.0001). Severity of leukoaraiosis was associated with MCA-PI and aortic pulse wave velocity (Fazekas: χ(2)=0.39, MCA-PI P=0.01, aortic pulse wave velocity P=0.06; age-related white matter change: χ(2)=0.38, MCA-PI P=0.015; aortic pulse wave velocity P=0.026) for periventricular and deep white matter lesions independent of aortic systolic blood pressure, diastolic blood pressure, and pulse pressure and MCA transit time with MCA-PI independent of age. In a multivariate model (r(2)=0.68, P<0.0001), MCA-PI was independently associated with aortic pulse wave velocity (P=0.016) and aortic pulse pressure (P<0.0001) and inversely associated with aortic diastolic blood pressure (P<0.0001) and MCA transit time (P=0.001).

CONCLUSIONS

MCA pulsatility was the strongest physiological correlate of leukoaraiosis, independent of age, and was dependent on aortic diastolic blood pressure and pulse pressure and aortic and MCA stiffness, supporting the hypothesis that large artery stiffening results in increased arterial pulsatility with transmission to the cerebral small vessels resulting in leukoaraiosis.

Endogenous granulocyte colony-stimulating factor: a biomarker in acute ischemic stroke

Granulocyte colony-stimulating factor (G-CSF) may protect ischemic brain injury either in animal or human. No studies have reported that endogenous G-CSF (enG-CSF) level is related to the severity of ischemic stroke. This study was designed to assess the severity of ischemic patients correlated with the alteration of enG-CSF on the 1st day after an ischemic event. Patient's plasma enG-CSF and scoring of National Institute of Health Stroke Scale were measured on the 1st day after ischemic stroke. The acute ischemic stroke could significantly induce enG-GCF secretion as compared with healthy control group (16.77 vs. 22.86 μg/L, p = 0.001). Elevated enG-CSF concentration was positively correlated with the severity of stroke patients on day 1 after the event (p = 0.006; Spearman correlation coefficient = 0.268). The enG-CSF is a good biomarker for prediction of severity of acute ischemic stroke.

A brief journey into the history of the arterial pulse

Objective. This paper illustrates the evolution of our knowledge of the arterial pulse from ancient times to the present. Several techniques for arterial pulse evaluation throughout history are discussed. Methods. Using databases including Worldcat, Pubmed, and Emory University Libraries' Catalogue, the significance of the arterial pulse is discussed in three historical eras of medicine: ancient, medieval, and modern. Summary. Techniques used over time to analyze arterial pulse and its characteristics have advanced from simple evaluation by touch to complex methodologies such as ultrasonography and plethysmography. Today's understanding of the various characteristics of the arterial pulse relies on our ancestors' observations and experiments. The pursuit of science continues to lead to major advancements in our knowledge of the arterial pulse and its application in diagnosis of atherosclerotic disease.

Profiles of lacunar and nonlacunar stroke

OBJECTIVE

Determining which small deep infarcts (SDIs) are of lacunar, arterial, or cardioembolic etiology is challenging, but important in delivering optimal stroke prevention therapy. We sought to distinguish lacunar from nonlacunar causes of SDIs using a gene expression profile.

METHODS

A total of 184 ischemic strokes were analyzed. Lacunar stroke was defined as a lacunar syndrome with infarction <15mm in a region supplied by penetrating arteries. RNA from blood was processed on whole genome microarrays. Genes differentially expressed between lacunar (n = 30) and nonlacunar strokes (n = 86) were identified (false discovery rate ≤ 0.05, fold change >|1.5|) and used to develop a prediction model. The model was evaluated by cross-validation and in a second test cohort (n = 36). The etiology of SDIs of unclear cause (SDIs ≥ 15mm or SDIs with potential embolic source) (n = 32) was predicted using the derived model.

RESULTS

A 41-gene profile discriminated lacunar from nonlacunar stroke with >90% sensitivity and specificity. Of the 32 SDIs of unclear cause, 15 were predicted to be lacunar, and 17 were predicted to be nonlacunar. The identified profile represents differences in immune response between lacunar and nonlacunar stroke.

INTERPRETATION

Profiles of differentially expressed genes can distinguish lacunar from nonlacunar stroke. SDIs of unclear cause were frequently predicted to be of nonlacunar etiology, suggesting that comprehensive workup of SDIs is important to identify potential cardioembolic and arterial causes. Further study is required to evaluate the gene profile in an independent cohort and determine the clinical and treatment implications of SDIs of predicted nonlacunar etiology.