Clinical and Biochemical Markers of Cardiovascular Structure and Function in Women With the Metabolic Syndrome.

The pathobiological impact of individual components of the metabolic syndrome (MS) on cardiac structural and functional parameters in women with isolated MS is not known. The objectives of this study were (1) to compare biochemical (prothrombotic, lipogenic, and inflammatory) and imaging (carotid intima-media thickening and basic cardiac structural measurements) markers in women with and without MS and (2) to examine if any of these markers associated or predicted cardiac structural differences between the 2 groups. This cross-sectional pilot study included 88 women with MS and 35 women without it. MS was defined according to the National Cholesterol Education Program Adult Treatment Panel III criteria. Patients with diagnosis of diabetes were excluded. Compared with healthy subjects, women with MS had higher levels of intercellular adhesion molecule, myeloperoxidase, C-reactive protein, plasminogen activator inhibitor-1, leptin, apolipoprotein-B, and lower levels of apolipoprotein-A1 (p <0.001 for all). They also had higher mean ventricular septum, posterior wall thickness, left ventricular (LV) mass, carotid intima-media thickness (p <0.001 for all), and left atrial diameter (p = 0.015). In multivariable regression models, waist circumference and systolic blood pressure (BP) were significant predictors of: ventricular septum (p = 0.005 and p = 0.001, respectively), posterior wall thickness (p = 0.008 and p = 0.040, respectively), and LV mass (p <0.001 and p = 0.013, respectively). Significant predictors for carotid intima-media thickness were systolic BP, glucose, and leptin (p <0.0001, p = 0.034, and p = 0.002, respectively). In conclusion, there are significant clinical, biochemical, and cardiovascular structural differences in women with isolated MS compared with those without. Waist circumference and systolic BP had the strongest association with cardiac structural differences in this group of women.

Brachial artery reactivity in patients with severe sepsis: an observational study.

INTRODUCTION: Ultrasound measurements of brachial artery reactivity in response to stagnant ischemia provide estimates of microvascular function and conduit artery endothelial function. We hypothesized that brachial artery reactivity would independently predict severe sepsis and severe sepsis mortality. METHODS: This was a combined case-control and prospective cohort study. We measured brachial artery reactivity in 95 severe sepsis patients admitted to the medical and surgical intensive care units of an academic medical center and in 52 control subjects without acute illness. Measurements were compared in severe sepsis patients versus control subjects and in severe sepsis survivors versus nonsurvivors. Multivariable analyses were also conducted. RESULTS: Hyperemic velocity (centimeters per cardiac cycle) and flow-mediated dilation (percentage) were significantly lower in severe sepsis patients versus control subjects (hyperemic velocity: severe sepsis = 34 (25 to 48) versus controls = 63 (52 to 81), P < 0.001; flow-mediated dilation: severe sepsis = 2.65 (0.81 to 4.79) versus controls = 4.11 (3.06 to 6.78), P < 0.001; values expressed as median (interquartile range)). Hyperemic velocity, but not flow-mediated dilation, was significantly lower in hospital nonsurvivors versus survivors (hyperemic velocity: nonsurvivors = 25 (16 to 28) versus survivors = 39 (30 to 50), P < 0.001; flow-mediated dilation: nonsurvivors = 1.90 (0.68 to 3.41) versus survivors = 2.96 (0.91 to 4.86), P = 0.12). Lower hyperemic velocity was independently associated with hospital mortality in multivariable analysis (odds ratio = 1.11 (95% confidence interval = 1.04 to 1.19) per 1 cm/cardiac cycle decrease in hyperemic velocity; P = 0.003). CONCLUSIONS: Brachial artery hyperemic blood velocity is a noninvasive index of microvascular function that independently predicts mortality in severe sepsis. In contrast, brachial artery flow-mediated dilation, reflecting conduit artery endothelial function, was not associated with mortality in our severe sepsis cohort. Brachial artery hyperemic velocity may be a useful measurement to identify patients who could benefit from novel therapies designed to reverse microvascular dysfunction in severe sepsis and to assess the physiologic efficacy of these treatments.

Non-invasive flow measurement of a rotary pump ventricular assist device using quantitative contrast echocardiography.

BACKGROUND: Many implantable ventricular assist devices (VADs) have no direct measurement of pump output. The aim of this study was to test the hypothesis that quantitative contrast echocardiography can be used to measure VAD output. METHODS: Contrast-enhanced Doppler velocity-time integral (VTI) was measured in the VAD inlet and outlet cannulae. Doppler flow (Doppler Q=Doppler VTIxcannula area) was compared with measured flow (Q). A total of 130 flow measurements were made (at 6400 and 12,000 rpm). RESULTS: Doppler Q in the outflow and inflow cannulae showed an excellent correlation with measured Q (outlet Doppler Q=1.0052 xQ+0.048, R2=0.9865; inlet Doppler Q=1.5043 xQ+0.003, R2=0.9904), but inlet Doppler Q was 50% higher. Correcting for the flow profile of the conical inlet tube yielded excellent correlation (inlet Doppler Q=1.0029 xQ+0.002, R2=0.9904). CONCLUSION: Noninvasive Doppler flow techniques can be used to accurately measure VAD flow, but the flow profile in the cannula needs to be taken into account.

Prognostic value of contrast stress echocardiography in patients with image quality too limited for traditional noncontrast harmonic echocardiography.

Clinical data and contrast stress echocardiography (CSE) results were analyzed in 283 patients to establish the prognostic value of CSE for patients with limited echocardiogram image quality at baseline. The mean follow-up period was 736 +/- 337 days. Only 7 patients (2.5%) had nondiagnostic image quality with contrast enhancement. During follow-up, 24 cardiac events (8.5%) occurred (5 cardiac-related deaths, 2 nonfatal myocardial infarction, 17 coronary revascularizations). Overall sensitivity, specificity, and positive and negative predictive values were 60.9%, 76.8%, 19.7%, and 95.5%, respectively. Kaplan-Meier event-free survival was higher for patients with a negative CSE result as compared with those with a positive CSE finding (P <.0001). In a multivariate Cox proportional hazards model, positive CSE was the strongest predictor of cardiac events (risk ratio 3.7; 95% confidence interval 1.6-8.7). CSE can successfully predict cardiac events for patients with limited noncontrast echocardiographic image quality. A negative CSE result conferred a good prognosis.

The effect of echo contrast agent on Doppler velocity measurements.

The purpose of this investigation was to determine the effect of echo contrast agents on spectral Doppler velocity measurements. SH U 508A was administered by IV injection in 15 patients. The transmitral flow velocity was measured at the E- and A-wave peaks before the start and at the peak of the contrast effect. The Doppler velocity was determined from the Doppler video spectral display and from power spectral analysis of the audio Doppler signal. The Doppler signal intensity was also measured. The Doppler signal intensity increased 17.4 +/- 3.5 dB (p < 0.0001) following echo contrast injection. This was associated with a significant increase in the spectral peak velocity as determined from either the video display or audio analysis. (p < 0.0001). The velocity corresponding to the audio power peak frequency (the modal velocity) did not change significantly (p = NS) and was independent of Doppler signal strength.