Accuracy of Echocardiography to Estimate Pulmonary Artery Pressures With Exercise: A Simultaneous Invasive-Noninvasive Comparison.

BACKGROUND: Exercise echocardiography is often applied as a noninvasive strategy to screen for abnormal pulmonary hemodynamic response, but it is technically challenging, and limited data exist regarding its accuracy to estimate pulmonary arterial pressure during exercise. METHODS AND RESULTS: Among 65 patients with exertional intolerance undergoing upright invasive exercise testing, tricuspid regurgitation (TR) Doppler estimates and invasive measurement of pulmonary arterial pressure at rest and peak exercise were simultaneously obtained. TR Doppler envelopes were assessed for quality. Correlation, Bland-Altman, and receiver-operating characteristic curve analyses were performed to evaluate agreement and diagnostic accuracy. Mean age was 62±13 years, and 31% were male. High-quality (grade A) TR Doppler was present in 68% at rest and 34% at peak exercise. For grade A TR signals, echocardiographic measures of systolic pulmonary arterial pressure correlated reasonably well with invasive measurement at rest (r=0.72, P<0.001; bias, -2.9±8.0 mm Hg) and peak exercise (r=0.75, P<0.001; bias, -1.9±15.6 mm Hg). Lower quality TR signals (grade B and C) correlated poorly with invasive measurements overall. In patients with grade A TR signals, mean pulmonary arterial pressure-to-workload ratio at a threshold of 1.4 mm Hg/10 W was able to identify abnormal pulmonary hemodynamic response during exercise (>3.0 mm Hg/L per minute increase), with 91% sensitivity and 82% specificity (area under the curve, 0.90; 95% confidence interval, 0.77-1.0; P=0.001). CONCLUSIONS: Agreement between echocardiographic and invasive measures of pulmonary pressures during upright exercise is good among the subset of patients with high-quality TR Doppler signal. While the limits of agreement are broad, our results suggest that in those patients, sensitivity is adequate to screen for abnormal pulmonary hemodynamic response during exercise.

Left ventricular dimension decrement index early after axial flow assist device implantation: A novel risk marker for late pump thrombosis.

BACKGROUND: It is increasingly recognized that pump thrombosis most likely represents the end stage of a complex interaction between the patient-pump interface. We hypothesized that early patient/pump mismatch, as manifested by suboptimal left ventricular (LV) unloading early after left ventricular assist device (LVAD) implantation, may be a harbinger of increased risk for later LVAD thrombosis. METHODS: In 64 patients (59 ± 11 years old, 78% men, 44% destination therapy) discharged alive without thrombosis or other device malfunction after first HeartMate II LVAD implantation (between January 2011 and June 2014), LV dimensions in end diastole (LVIDd) and end systole (LVIDs) were compared between pre-implant and optimal set speed pre-discharge echocardiography. LV dimension decrement indices (pre-implant dimension - optimal set speed dimension ÷ pre-implant dimension × 100) for LVIDd [LVIDdDI] and LVIDs [LVIDsDI] were calculated. RESULTS: The incidence of pump thrombosis was 0.06 per patient year (n = 18, median time 8 [interquartile range 2, 17] months). Baseline characteristics including pre-operative LVIDd and LVIDs were similar between LVAD thrombosis and no thrombosis groups. After ventricular assist device implantation, set speed and other ramp parameters did not differ between groups. However, LVIDdDI (19 ± 13% vs 25 ± 11%, p = 0.04) and LVIDsDI (16 ± 16% vs 27 ± 13%, p = 0.008) were significantly lower in patients with later pump thrombosis. A cutoff value of ≤15% using receiver operating characteristic curve analysis was 83% sensitive for LVIDdDI and LVIDsDI for predicting pump thrombosis. Patients with LVIDdDI of >15% vs ≤15% were significantly more likely to be free of pump thrombosis over a median follow-up period of 15 (interquartile range 9, 26) months (log-rank test, p = 0.045). CONCLUSIONS: LV dimension decrement index at optimized speed setting on pre-discharge echocardiography is associated with LVAD thrombosis.

Angiotensin II receptor blockade and skeletal muscle metabolism in overweight and obese adults with elevated blood pressure.

OBJECTIVES: Whether angiotensin II receptor blockade improves skeletal muscle fatty acid oxidation in overweight and obese humans is unknown. The purpose of the study was to test the hypothesis that the angiotensin II receptor blocker, olmesartan, would increase fatty acid oxidation and the activity of enzymes associated with oxidative metabolism in skeletal muscle of overweight and obese humans. METHODS: A total of 12 individuals (6 men and 6 women) aged 18-75 and with a body mass index ⩾25 kg/m2 were assigned to olmesartan or placebo for 8 weeks in a crossover fashion. Fatty acid oxidation was measured before and after each intervention by counting the (14)CO2 produced from [1-(14)C] palmitic acid in skeletal muscle homogenates. RESULTS: Fatty acid oxidation was not significantly different between treatment periods at baseline and post intervention. In addition, the enzyme activities of citrate synthase and ß-hydroxyacyl-coenzyme A dehydrogenase in skeletal muscle homogenates did not differ between treatment periods at baseline or post intervention. CONCLUSIONS: Treatment with olmesartan for 8 weeks does not improve fatty acid oxidation or the activity of enzymes associated with oxidative metabolism in skeletal muscle from overweight and obese individuals. Taken together, our results indicate that improvements in skeletal muscle metabolism are not among the additional benefits of olmesartan that extend beyond blood pressure reduction.

Valoración del Estrés en Toros Brasileros y Venezolanos Mediante la Evaluación de las Concentraciones de Cortisol y el Recuento Leucocitario / Assessment of stress in Brazilian and Venezuelan Bulls by the evaluation of cortisol concentrations and leucocytes count

A fin de valorar el estrés en toros, se seleccionaron al azar de un matadero de la región centro occidental de Venezuela, un total de 40 toros mestizos Brahman (16 de Brasil y 24 de Venezuela). Se tomaron muestras de sangre para realizar el recuento leucocitario. Igualmente, se determinó la concentración de cortisol mediante la técnica del ELISA competitivo. Los datos fueron analizados usando la prueba no paramétrica U de Mann Whitney. Los resultados del estudio muestran que hubo un incremento no estadísticamente significativo en el recuento diferencial de neutrófilos (53,13% y 43,19%) en toros venezolanos y brasileños, respectivamente. Al mismo tiempo, los toros venezolanos arrojaron un valor de cortisol que fue superior (59,44 ng/dL) y estadísticamente significativo (P≤0,05), cuando se comparó con el de los toros brasileños (40,50 ng/dL). Además, se produjo una disminución no significativa, en el recuento diferencial de eosinófilos (eosinopenia) en ambos grupos, con un promedio de 0,78%. Por otra parte, el recuento diferencial de linfocitos solamente disminuyó significativamente (P≤0,05), en los toros venezolanos (43,25%), mientras que el porcentaje correspondiente a linfocitos de los toros brasileños, se ubicó dentro de los valores normales para la especie (56,19%). Se concluye que los valores elevados de cortisol y neutrófilos, así como también, la eosinopenia y linfopenia encontradas en los toros venezolanos, sugieren un leucograma de estrés, compatible con la conducta nerviosa observada en esos animales. El estrés en los toros brasileños sólo se asoció con una alteración (aumento) de las concentraciones de cortisol y en los valores de eosinófilos. La procedencia y/o tiempo de transporte afectó por igual las concentraciones de cortisol, especialmente en los toros venezolanos. Los cambios sociales observados en los toros venezolanos y brasileños, sugieren la presencia de estrés agudo en los primeros y de estrés crónico en los segundos.

A study was conducted to assess stress in bulls. A total of 40 crossbred Brahman bulls (16 from Brazil and 24 from Venezuela) were selected at random from a slaughterhouse in the Midwestern region of Venezuela. Blood samples were taken for leukocytes count. Also, the cortisol concentration was determined by competitive ELISA technique. Data were analyzed using the nonparametric Mann Whitney U test. The results of the present study show that there was a non-statistically significant increase in neutrophil count (53.13% and 43.19%) in Venezuelan and Brazilian bulls, respectively. At the same time, Venezuelan bulls showed a higher (59.44 ng / dL) cortisol value that was statistically significant (P≤ 0.05), when compared with the Brazilian bulls (40.50 ng/dL). There was also a non- significant decrease in the differential eosinophil count (eosinopenia) in both groups, with an average of 0.78%. On the other hand, the lymphocytes differential count significantly diminished (P≤0.05) in Venezuelan bulls (43.25%) only, while in Brazilian bulls, the percentage corresponding to lymphocytes, was within the normal range for the species (56.19%). It is concluded that that the elevated cortisol and neutrophils levels, as well as the eosinopenia and lymphopenia found in Venezuelan bulls, suggest a stress leukogram, compatible with the nervous behavior observed in those animals. Stress in Brazilian bulls was only associated with an alteration (increase) in cortisol concentrations and in eosinophil values. Both the origin and/or transport time equally affected cortisol concentrations, especially in the Venezuelan bulls. Social changes observed in the Venezuelan and Brazilian bulls, suggest the presence of acute stress in the first and of chronic stress in the latter.

Providing initial transthoracic echocardiography training for anesthesiologists: simulator training is not inferior to live training.

OBJECTIVE: Transthoracic echocardiography (TTE) is finding increased use in anesthesia and critical care. Efficient options for training anesthesiologists should be explored. Simulator mannequins allow for training of manual acquisition and image recognition skills and may be suitable due to ease of scheduling. The authors tested the hypothesis that training with a simulator would not be inferior to training using a live volunteer. DESIGN: Prospective, randomized trial. SETTING: University hospital. PARTICIPANTS: Forty-six anesthesia residents, fellows, and faculty. INTERVENTIONS: After preparation with a written and video tutorial, study subjects received 80 minutes of TTE training using either a simulator or live volunteer. Practical and written tests were completed before and after training to assess improvement in manual image acquisition skills and theoretic knowledge. The written test was repeated 4 weeks later. MEASUREMENTS AND MAIN RESULTS: Performance in the practical image-acquisition test improved significantly after training using both the live volunteer and the simulator, improving by 4.0 and 4.3 points out of 15, respectively. Simulator training was found not to be inferior to live training, with a mean difference of -0.30 points and 95% confidence intervals that did not cross the predefined non-inferiority margin. Performance in the written retention test also improved significantly immediately after training for both groups but declined similarly upon repeat testing 4 weeks later. CONCLUSIONS: When providing initial TTE training to anesthesiologists, training using a simulator was not inferior to using live volunteers.

Singular and combined effects of nebivolol and lifestyle modification on large artery stiffness in hypertensive adults.

BACKGROUND: We hypothesized that the combination of nebivolol and lifestyle modification would reduce large artery stiffness in middle-aged and older hypertensive adults more than either intervention alone. METHODS: To address this, 45 men and women (age 40-75 years) with stage I hypertension were randomized to receive either nebivolol (NB; forced titration to 10 mg OD; n = 15; age 57.2 ± 11.4 years; body mass index [BMI] 30.8 ± 5.8 kg/m(2)), lifestyle modification (LM; 5-10% weight loss via calorie restriction and physical activity; n = 15; age 52.7 ± 8.5 years; BMI 33.9 ± 7.2 kg/m(2)) or nebivolol plus lifestyle modification (NBLM; n = 15; age 58.9 ± 9.4 years; BMI 32.5 ± 4.9 kg/m(2)) for 12 weeks. ß-stiffness index, a blood-pressure-independent measure of arterial stiffness, and arterial compliance were measured via high-resolution ultrasound and tonometry at baseline and after the 12-week intervention. There was no difference between groups in age, body weight or composition, blood pressure, or in ß-stiffness index or arterial compliance at baseline (all p > 0.05). RESULTS: Following the 12-week intervention, body weight decreased ~5% (p < 0.05) in the LM and NBLM groups but did not change from baseline in the NB group (p > 0.05). Supine brachial and carotid systolic and diastolic blood pressure declined following treatment in each of the groups (p < 0.05). However, the magnitude of reduction was not different (p < 0.05) between groups. ß-stiffness index declined (-2.03 ± 0.60, -1.87 ± 0.83 and -2.51 ± 0.90 U) and arterial compliance increased similarly (both p > 0.05) in the NB, LM and NBLM groups, respectively. CONCLUSION: In summary, our findings indicate that the combination of nebivolol and lifestyle modification reduced large artery stiffness to a similar degree as either intervention alone in middle-aged and older hypertensive adults.

Angiotensin II receptor blockade and insulin sensitivity in overweight and obese adults with elevated blood pressure.

We tested the hypothesis that olmesartan, an angiotensin II receptor blocker (ARB) devoid of peroxisome proliferator-activated receptor γ agonist activity, would improve whole-body insulin sensitivity in overweight and obese individuals with elevated blood pressure (BP). Sixteen individuals (8 women, 8 men; age=49.5 ± 2.9 years; body mass index=33.0 ± 1.7 kg/m2) were randomly assigned in a crossover manner to control and ARB interventions. Insulin sensitivity was determined from intravenous glucose tolerances tests before and after each 8-week intervention. BP, body weight, body fat, lipid and lipoprotein concentrations, and insulin sensitivity were similar at baseline for both treatments (all p > 0.05). Diastolic BP and triglyceride concentrations were higher (p = 0.007 and 0.042 respectively) at baseline for the ARB compared with the control intervention. Systolic (-11.7 mmHg; p = 0.008) and diastolic (-12.1 mmHg; p = 0.0001) BP decreased, however insulin sensitivity did not change (p > 0.05) following ARB treatment. Furthermore, there were no significant correlates of changes in insulin sensitivity following the ARB intervention. In summary, our findings indicate that short-term ARB treatment did not affect whole-body insulin sensitivity in overweight or obese individuals with elevated BP. Future studies are needed to clarify the effect of individual ARBs on insulin sensitivity in obesity.

Arterial destiffening with atorvastatin in overweight and obese middle-aged and older adults.

We hypothesized that atorvastatin (ATOR) treatment would reduce arterial stiffness in overweight and obese middle-aged and older adults. Twenty-six (11 men and 15 women) overweight or obese (body mass index: 31.6+/-0.7 kg/m(2)) middle-aged and older adults (age: 54+/-2 years) were randomly assigned to receive either ATOR (80 mg/d) or placebo for 12 weeks. Arterial stiffness (beta-stiffness and pulse wave velocity) was measured before and after the intervention. At baseline, the ATOR (n=16) and placebo (n=10) groups did not differ with respect to age, body mass index, blood pressure, serum lipid and lipoprotein concentrations, high-sensitivity C-reactive protein, indices of arterial stiffness, or compliance (all P>0.05). After the 12-week treatment period, the ATOR group experienced a 47% reduction in low-density lipoprotein cholesterol (149+/-6 to 80+/-8 mg/dL) and a 42% reduction in high-sensitivity C-reactive protein (3.6+/-0.8 to 2.1+/-0.5 mg/L; both P<0.05). In addition, beta-stiffness (9.4+/-0.6 to 7.6+/-0.5 U) and aortic pulse wave velocity (1096+/-36 to 932+/-32 cm/s), but not brachial pulse wave velocity, decreased (both P<0.05) with ATOR. In contrast, there were no significant changes in beta-stiffness (9.1+/-0.8 to 9.1+/-0.7 U) or aortic pulse wave velocity (1238+/-89 to 1191+/-90 cm/s; both P>0.05) in the placebo group. There were no relations between the reductions in arterial stiffness indices and any of the baseline cardiometabolic risk factors (all P>0.05). However, the reductions in arterial stiffness were correlated with the reduction in low-density lipoprotein cholesterol but not high-sensitivity C-reactive protein or any other cardiometabolic variables (all P<0.05). Taken together, these findings suggest that ATOR reduces arterial stiffness in overweight and obese middle-aged and older adults, and these favorable changes occur irrespective of baseline cardiometabolic risk factors.