Simple mechanical-chemical systemic pressure-control device

An implantable mechanical-chemical device was constructed to act as a feedback mechanism in controlling the blood pressure. It consisted of a balloon connected to a rubber catheter ending in a slit valve. Flow-pressure curves were derived fromin vitro testings for three valve thresholds (120, 140 and 170 mmHg). Five fast-acting hypotensive drugs subsequently filled the device during 40 noradrenaline infusions in 25 dogs, with the balloon in the abdominal aorta and the catheter in the inferior vena cava. The results were as follows: (i) Following a short initial increase in systolic aortic pressure, significantly lower (p<0·001) than in control experiments, the device prevented any pressure rise above its threshold. (ii) The time needed for pressure lowering at the device's threshold depended on the drug used being 3·34±0·84 (mean ± s.e. in minutes) for sodium nitroprusside, 5·99±0·96 for phentolamin, 11·63±2·97 for hydralazine, 14·54±2·43 for a-methyl-dopa and 23·32±2·07 for diazoxide.     

Predictors of common bile duct lithiasis in laparoscopic era

AIM:To analyze retrospectively the records of 294 conse-cutive patients operated upon for gallbladder stones, to determine the predictive factors of synchronous common bile duct (CBD) stones and validate prospectively the generated model. METHODS: The prognostic estimation of a biochemical test and ultrasonography alone to differentiate between the absence and presence of choledocholithiasis was assessed using receiver operating characteristics curve analysis. Multivariate analysis was employed using discriminant analysis for establishment of a best model.Prospective validation of the model was made. RESULTS: Discriminant forward stepwise analysis disclosed that high values (≥2×normal) of SGOT,ALP, conjugated bilirubin and CBD diameter on ultrasound ≥10 mm were all prognostic factors of CBD lithiasis in univariate and multivariate analysis, P<0.01. History was not included in the model.Prospective validation of the model was performed by multivariate analysis using Visual General Stepwise Regression. Positive predictive value, when considering all these predictors,was 93.3%,while the negative predictive value was 88.8%.Sensitivity of the model was 96.5% and specificity 80%. CONCLUSION: The above model can be objectively applied to predict the presence of CBD stones.     

Imaging the myocardial ischemic cascade

Non-invasive imaging plays a growing role in the diagnosis and management of ischemic heart disease from its earliest manifestations of endothelial dysfunction to myocardial infarction along the myocardial ischemic cascade. Experts representing the North American Society for Cardiovascular Imaging and the European Society of Cardiac Radiology have worked together to organize the role of non-invasive imaging along the framework of the ischemic cascade. The current status of non-invasive imaging for ischemic heart disease is reviewed along with the role of imaging for guiding surgical planning. The issue of cost effectiveness is also considered. Preclinical disease is primarily assessed through the coronary artery calcium score and used for risk assessment. Once the patient becomes symptomatic, other imaging tests including echocardiography, CCTA, SPECT, PET and CMR may be useful. CCTA appears to be a cost-effective gatekeeper. Post infarction CMR and PET are the preferred modalities. Imaging is increasingly used for surgical planning of patients who may require coronary artery bypass.     

Relative Efficacy of Sacubitril-Valsartan,Vericiguat, and SGLT2 Inhibitors in Heart Failure with Reduced Ejection Fraction: a Systematic Review and Network Meta-Analysis

Cardiovascular Drugs and Therapy - Sacubitril/valsartan, vericiguat, and the sodium-glucose co-transporter-2 inhibitors (SGLT2i) dapagliflozin and empagliflozin proved effective in phase 3 trials...     

Pulse pressure and left ventricular diastolic dysfunction in hypertensive patients

BACKGROUND: Impaired left ventricular diastolic function is a common finding in essential hypertension. METHODS: In order to investigate possible relationships between flow velocity through the mitral valve (E/A; index of left ventricular diastolic function) and 24-hour blood pressure and heart rate variations, 198 patients with mild to moderate essential hypertension were studied by Doppler echocardiography and ambulatory blood pressure monitoring. They were divided according to age into group 1 (n = 88, age 40-54 years) and group 2 (n = 110, age 55-79 years). Each group was divided into subgroups with (1a, 2a) or without (1b, 2b) left ventricular hypertrophy according to the end-diastolic posterior wall thickness and/or the interventricular septum thickness. RESULTS: In a multivariate stepwise regression analysis, age (beta = -0.25, p < 0.0001), posterior wall thickness (beta = -0.31, p < 0.0057) and mean heart rate during the day (beta = -0.34, p < 0.0284) were the independent predictors of E/A in the pooled population. In group 1a (young subjects with left ventricular hypertrophy), mean systolic blood pressure during the night (beta = -0.33, p < 0.041) was the only independent predictor of E/A. In the elderly group without left ventricular hypertrophy (group 2b), the mean heart rate during the day (beta = -0.44, p < 0.0000) and mean pulse pressure during the night (beta = -0.60, p < 0.0007) were the independent predictors of E/A. CONCLUSIONS: The new finding provided by this study is that in elderly hypertensive patients without left ventricular hypertrophy, a large pulse pressure at night may serve as an independent predictor of abnormal left ventricular diastolic filling.     

Clinical outcomes three years after PLAATO implantation.

BACKGROUND: The percutaneous left atrial appendage transcatheter occlusion system (PLAATO) is an alternative to coumadin in patients with atrial fibrillation (AF) and contraindications to anticoagulation. It appears to be protective against stroke in intermediate follow-up studies. Hypothesis: The PLAATO system is protective against stroke and is safe in long-term follow-up. METHODS: Eleven patients (age 72 +/- 9 years) enrolled in the PLAATO feasibility and safety trial at our institution were followed (36 +/- 1.4) months. All patients had contraindications to anticoagulation and had at least one risk factor for stroke. The predicted stroke risk for this cohort was 8.6% per year as calculated using the CHADS2 score (A validated scoring system assigning 1 point for CHF, hypertension, diabetes, and age >75 years, and 2 points for history of stroke). The primary end-point was the incidence of stroke, and secondary end points were complications related to PLAATO device and systemic embolic events. RESULTS: There was one stroke during follow-up; the stroke risk in our population was 3% per year. Interestingly, the observed stroke risk in these patients after occluding the left atrial appendage is comparable to what would have been observed with warfarin. No systemic embolic events were noted in our cohort and no long term complications related to PLAATO were seen. CONCLUSION: The PLAATO device decreases the risk of stroke in a high-risk cohort of AF patients. Furthermore, the safety of this device is confirmed during this long-term follow-up study. A larger trial is needed to validate these findings.     

Incremental value of arterial wave reflections in the determination of left ventricular diastolic dysfunction in untreated patients with essential hypertension

Systemic arterial stiffness is an indicator of cardiovascular disease and an independent marker of morbidity and cardiovascular mortality. We investigated the association of arterial wave reflections with left ventricular (LV) diastolic dysfunction and their incremental value to other determinants of LV diastolic dysfunction in patients with essential hypertension. In total 143 patients and 20 controls with similar atherosclerotic risk factors were examined by applanation tonometry of the radial artery (Sphygmocor) and echocardiography. Central augmentation index (CAI%) of reflected arterial waves as well as aortic strain (AoS) assessed by echocardiography were estimated. Doppler diastolic abnormalities were defined as proposed by the European Study Group on diastolic heart failure by measurement of E/A ratio (the ratio of the mitral inflow velocities), isovolumic relaxation time, deceleration time and flow propagation velocity. AoS and CAI were impaired in patients compared with controls (4.67 +/- 2.94 vs 6.06 +/- 4.91% and 145.8 +/- 22.7 vs. 135.7 +/- 20.3%, P < 0.01) as well as in patients with LV diastolic dysfunction compared to patients without, (5.52 +/- 4.29 vs. 10.73 +/- 5.77% and 139.5 +/- 21.7 vs. 124.5 +/- 17.0%, P < 0.05). The odds ratio (OR) of AoS and CAI for diastolic dysfunction was OR:0.918, 95% confidence interval (CI):0.837-0.99, P = 0.04 and OR:1.023, 95% CI: 1.023-1.040 P = 0.010, respectively. The addition of CAI to the multivariable model including age, LV mass index, AoS and mean arterial pressure increased the power of the model for determination of LV diastolic dysfunction (-2 log likelihood = 139.368, change of chi2 = 4.2, P-value for change=0.04). In untreated patients with newly diagnosed essential hypertension, wave reflections are independent and additive determinants of LV diastolic dysfunction.     

Oral L-arginine improves endothelial dysfunction in patients with essential hypertension

BACKGROUND: L-Arginine is a nitric oxide precursor, which augments endothelium-dependent vasodilatation in hypercholesterolemic humans and animals. Endothelium-dependent vasodilation is attenuated in patients with hypertension; however the effects of oral L-arginine on endothelial function of the conduit arteries in patients with essential hypertension have not previously been investigated. METHODS: In a prospective randomized double blind trial, 35 patients with essential hypertension received either 6 g L-arginine (18 subjects) or placebo (17 subjects). Patients were examined for flow-mediated endothelium-dependent dilatation of the brachial artery before and 1.5 h after administration of L-arginine or placebo. At the end of the protocol the nitrate-induced, endothelium-independent vasodilatation was evaluated. RESULTS: Two groups of L-arginine and placebo were similar regarding age, sex, blood lipids, smoking, diabetes, coronary artery disease, body mass index, intima-media thickness of the common carotid artery, clinics blood pressure and baseline brachial artery parameters. Administration of L-arginine or placebo did not change significantly heart rate, blood pressure, baseline diameter, blood flow or reactive hyperemia. L-Arginine resulted in a significant improvement of flow-mediated dilatation (1.7+/-3.4 vs. 5.9+/-5.4%, P=0.008) while placebo did not significantly change this parameter (3.0+/-2.7 vs. 3.1+/-2.2%, P=ns). The effect of L-arginine on flow-mediated dilatation was significantly different from the effect of placebo (P=0.05). L-Arginine did not significantly influence nitrate-induced dilatation (16+/-6.9 vs. 17.7+/-6.7%, P=ns). CONCLUSIONS: Oral administration of L-arginine acutely improves endothelium-dependent, flow-mediated dilatation of the brachial artery in patients with essential hypertension. The long-term effects of L-arginine in these patients require further investigation.     

Can premenstrual syndrome affect arterial stiffness or blood pressure?

ObjectiveWe tested the hypotheses that monthly fluctuations in markers of arterial stiffness and blood pressure hemodynamics differ between women with and without premenstrual syndrome. We also assessed hypertension prevalence and arterial stiffening in postmenopausal women with or without history of premenstrual symptoms.MethodsTwenty one pre-menopausal women with premenstrual syndrome and 15 women without were prospectively examined in three distinct phases of their menstrual cycle (menses, late follicular and luteal phase). Pulse-wave velocity and analysis were used to assess arterial stiffness and wave reflection indices, respectively. Endothelial function was evaluated by flow-mediated vasodilation. In a cross-sectional substudy, 156 postmenopausal women were assessed for possible associations between retrospectively reported PMS symptoms and hypertension.ResultsIn women with premenstrual syndrome, arterial stiffness significantly increased during the luteal and menses phase (late follicular: 6.48 ± 1.07, luteal: 7.1 ± 1.26, menstruation: 7.12 ± 1.19 m/s, p = 0.003), while blood pressure peaked at the menses phase. Significant interactions between PMS and changes in arterial stiffness and blood pressure but not endothelial function, were observed. Changes in PWV were significantly associated with concomitant changes in blood pressure, C-reactive protein and the severity of PMS symptoms. The prevalence of hypertension (20.9% vs. 40.9%, p = 0.041) and pulse-wave velocity values (8.64 ± 1.52 vs. 9.37 ± 1.1, p = 0.046) were higher in postmenopausal women with 7 or more reported PMS symptoms. Arterial stiffness differences remained significant after adjustment for confounding factors.ConclusionThese results imply that PMS may affect arterial stiffness and BP monthly variability. Whether PMS is associated with new onset hypertension later in life needs further evaluation.