Association of Pressure Wave Reflections With Left Ventricular Mass: a Systematic Review and Meta-Analysis

BACKGROUND

Pressure wave reflections (PWRs) within the circulation are assessed at various arterial sites by various noninvasive methods. We aimed at reviewing the conflicting data regarding the hypothesis that higher PWRs are associated with higher left ventricular mass and tested whether this association stands for all available indices of PWRs, all (proximal or distal to the heart) sites of assessment, and is modified by sex, age and heart rate.

METHODS

Based on a predefined protocol applying the Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines, we identified eligible for meta-analysis data regarding: augmentation index, augmentation pressure, backward pressure (Pb), reflection index, and their association with left ventricular mass index (19 studies, total population n=8686).

RESULTS

We found statistically significant associations, independent from blood pressure level, for all indices of PWRs at all arterial sites (carotid augmentation index; odds ratio; standardized beta coefficient [β]: 0.14 [95% CI, 0.07% to 0.21%], per SD increase), radial augmentation index (β: 0.21; 0.11 to 0.31), central augmentation pressure (β: 0.15; 0.03 to 0.27), central Pb (β: 0.23; 0.05 to 0.42), and central reflection index (β: 0.14; 0.06 to 0.22), except for aortic augmentation index as estimated by generalized transfer functions. Meta-regression analysis showed that the association between carotid augmentation index and left ventricular mass was higher among populations with higher heart rate (P=0.036, beta: 0.017 [95% CI, 0.001 to 0.033]) and tended to be higher in middle-aged (P=0.07, beta: -0.001; -0.021 to 0.001).

CONCLUSIONS

A clinically meaningful association between PWRs and left ventricular mass, assessed at either central or peripheral arterial sites by most available methods was shown, suggesting that PWR reduction strategies might be useful. Based on the present evidence, such trials should target middle-aged populations with high normal heart rate.

Closed-Loop Microreactor on PCB for Ultra-Fast DNA Amplification: Design and Thermal Validation

Polymerase chain reaction (PCR) is the most common method used for nucleic acid (DNA) amplification. The development of PCR-performing microfluidic reactors (μPCRs) has been of major importance, due to their crucial role in pathogen detection applications in medical diagnostics. Closed loop (CL) is an advantageous type of μPCR, which uses a circular microchannel, thus allowing the DNA sample to pass consecutively through the different temperature zones, in order to accomplish a PCR cycle. CL μPCR offers the main advantages of the traditional continuous-flow μPCR, eliminating at the same time most of the disadvantages associated with the long serpentine microchannel. In this work, the performance of three different CL μPCRs designed for fabrication on a printed circuit board (PCB) was evaluated by a computational study in terms of the residence time in each thermal zone. A 3D heat transfer model was used to calculate the temperature distribution in the microreactor, and the residence times were extracted by this distribution. The results of the computational study suggest that for the best-performing microreactor design, a PCR of 30 cycles can be achieved in less than 3 min. Subsequently, a PCB chip was fabricated based on the design that performed best in the computational study. PCB constitutes a great substrate as it allows for integrated microheaters inside the chip, permitting at the same time low-cost, reliable, reproducible, and mass-amenable fabrication. The fabricated chip, which, at the time of this writing, is the first CL μPCR chip fabricated on a PCB, was tested by measuring the temperatures on its surface with a thermal camera. These results were then compared with the ones of the computational study, in order to evaluate the reliability of the latter. The comparison of the calculated temperatures with the measured values verifies the accuracy of the developed model of the microreactor. As a result of that, a total power consumption of 1.521 W was experimentally measured, only ~7.3% larger than the one calculated (1.417 W). Full validation of the realized CL μPCR chip will be demonstrated in future work.

Assessment of Early Markers of Cardiovascular Risk in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous syndrome, with long-term sequelae from birth to senescence. The long-term effects of PCOS are attributed to several metabolic aberrations ensuing the syndrome. In a systematic review of literature regarding the cardiovascular risk factors that accompany PCOS, we found that macrovascular function has been assessed by flow-mediated dilatation (FMD), microvascular function by venous occlusion plethysmography (VOP), and arterial structure by ultrasonographic assessment of intima-media thickness (IMT) usually of the carotid artery. Contradictory results have been reported; however, in most studies, endothelial dysfunction, an early marker of atherosclerosis assessed either by haemodynamic methods such as FMD or by biochemical methods such as endothelin-1 levels, was found to be impaired. VOP is a less-studied method, with few indices altered. IMT was found to be altered in most of the included studies, but the population was more heterogeneous. Inflammatory markers, including C-reactive protein, were also found to be altered in most studies. On the other hand, a number of interventions have been shown beneficial for the markers of cardiovascular risk, in the context of insulin-sensitizers. However, other interventions such as oral contraceptive pills or statins did not consistently show a similar beneficial effect. In summary, the early identification and eventual treatment of cardiovascular clinical and biochemical risk factors may be used in clinical practice to prevent potential 'silent' triggers of cardiovascular disease.

Assessment of Early Markers of Cardiovascular Risk in Polycystic Ovary Syndrome

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Blood pressure variability within a single visit and all-cause mortality

BACKGROUND

Within-visit variability of repeated sequential readings of blood pressure (BP) is an important phenomenon that may affect precision of BP measurement and thus decision making concerning BP-related risk and hypertension management. However, limited data exist concerning predictive ability of within-visit BP variability for clinical outcomes. Therefore, we aimed to investigate the association between the variability of three repeated office BP measurements and the risk of all-cause mortality, independent of BP levels.

METHODS

Data collected through the National Health and Nutrition Examination Survey (NHANES) were analysed. NHANES is a program of studies designed to assess health and nutritional status of adults and children in the United States. A complete set of three sequential BP measurements, together with survival status, were available for 24969 individuals (age 46.8±;19.3 years, 49% males). Multivariable logistic regression models were used to determine the prognostic ability of the examined demographic, clinical, and haemodynamic indices.

RESULTS

Among various examined indices of variability of systolic (SBP) and diastolic (DBP) blood pressure measurements, the standard deviation of DBP (DBPSD) was the stronger independent predictor of mortality (odds ratio 1.064, 95% Confidence Interval: 1.011-1.12) after adjustment for age, sex, body mass index, smoking, SBP, heart rate, history of hypertension, diabetes mellitus, hypercholesterolaemia, and cardiovascular events.

CONCLUSION

Within-visit variability of three sequential office DBP readings may allow for the identification of high-risk patients better than mean SBP and DBP levels. The predictive value of within-visit BP variability and methods to improve its clinical application are worthy of further research.

Role of Receptor Profiling for Personalized Therapy in a Patient with a Growth Hormone-Secreting Macroadenoma Resistant to First-Generation Somatostatin Analogues

Background: Acromegaly is almost always caused by a pituitary adenoma and is associated with high morbidity and mortality when uncontrolled. Trans-sphenoidal removal of the adenoma is the mainstay of therapy, but fails to control the disease in a significant number of patients who require further treatment. Somatostatin analogues (SSAs) as monotherapy or in combination with growth hormone (GH)-receptor antagonists and/or dopamine agonists are used either alone or in combination following surgical failure to achieve disease control. The use of specific biomarkers may help to individualize the therapeutic plan after surgical failure and direct towards a more personalized approach. Methods: We report a 41-year-old man with acromegaly and residual disease after repeated surgery that was resistant to first-generation SSAs. Results: Biochemical and tumor control were achieved following the administration of a second-generation SSA, pasireotide, combined with pegvisomant, both at maximal doses and along with cabergoline. Histology specimens showed a sparsely-granulated GH-immunostaining pituitary adenoma with intense positivity for somatostatin receptors 2 and 5 and low levels of E-cadherin. Conclusion: Personalized medical therapy guided by currently available biomarkers, such as immunohistochemically-characterized receptor profiling or adhesion molecules, resulted in controlled insulin-like growth factor-1 (IGF-1) and GH levels and symptom alleviation following the combination of three drug-classes.

Effectiveness of artificial pancreas in the non-adult population: A systematic review and network meta-analysis

OBJECTIVE

Artificial pancreas is a technology that minimizes user input by bridging continuous glucose monitoring and insulin pump treatment, and has proven safety in the adult population. The purpose of this systematic review and meta-analysis is to evaluate the efficacy of closed-loop (CL) systems in the glycemic control of non-adult type 1 diabetes patients in both a pairwise and network meta-analysis (NMA) context and investigate various parameters potentially affecting the outcome.

METHODS

Literature was systematically searched using the MEDLINE (1966-2018), Scopus (2004-2018), Cochrane Central Register of Controlled Trials (CENTRAL) (1999-2018), Clinicaltrials.gov (2008-2018) and Google Scholar (2004-2018) databases. Studies comparing the glycemic control in CL (either single- or dual-hormone) with continuous subcutaneous insulin infusion (CSII) in people with diabetes (PWD) aged <18 years old were deemed eligible. The primary outcome analysis was conducted with regard to time spent in the target glycemic range. All outcomes were evaluated in NMA in order to investigate potential between-algorithm differences. Pairwise meta-analysis and meta-regression were performed using the RevMan 5.3 and Open Meta-Analyst software. For NMA, the package pcnetmetain R 3.5.1 was used.

RESULTS

The meta-analysis was based on 25 studies with a total of 504 PWD. The CL group was associated with significantly higher percentage of time spent in the target glycemic range (Mean (SD): 67.59% (SD: 8.07%) in the target range and OL PWD spending 55.77% (SD: 11.73%), MD: -11.97%, 95% CI [-18.40, -5.54%]) and with lower percentages of time in hyperglycemia (MD: 3.01%, 95% CI [1.68, 4.34%]) and hypoglycemia (MD: 0.67%, 95% CI [0.21, 1.13%]. Mean glucose was also decreased in the CL group (MD: 0.75 mmol/L, 95% CI [0.18-1.33]). The NMA arm of the study showed that the bihormonal modality was superior to other algorithms and standard treatment in lowering mean glucose and increasing time spent in the target range. The DiAs platform was superior to PID in controlling hypoglycemia and mean glucose. Time in target range and mean glucose were unaffected by the confounding factors tested.

CONCLUSIONS

The findings of this meta-analysis suggest that artificial pancreas systems are superior to the standard sensor-augmented pump treatment of type 1 diabetes mellitus in non-adult PWD. Between-algorithm differences are also addressed, implying a superiority of the bihormonal treatment modality. Future large-scale studies are needed in the field to verify these outcomes and to determine the optimal algorithm to be used in the clinical setting.

Differential Expression of Apoptotic and Low-Grade Inflammatory Markers in Alzheimer Disease Compared to Diabetes Mellitus Type 1 and 2

BACKGROUND

Neuroinflammation, impaired brain insulin signaling, and neuronal apoptosis may be interrelated in the pathophysiology of people with Alzheimer disease (AD) and diabetes, either type 1 or 2 diabetes (T1D or T2D, respectively).

METHODS

We studied 116 patients: 41 with AD, 20 with T1D, 21 with T2D, and 34 healthy controls. The number (n) of cytokine-secreting peripheral blood mononuclear cells (PBMCs) before and after mitogenic stimulation was determined for interleukin 1β (IL1β), interleukin 6 (IL6), tumor necrosis factor (TNF) by the enzyme-linked-immuno-spot assay. Serum concentrations of C-reactive protein (CRP) and Fas ligand (FASLG) were determined by ELISA.

RESULTS

The studied subgroups did not differ in sex but differed in age. Higher CRP concentrations were detected in the AD group than in the T1D group (P = 0.02) and lower in controls (P < 0.001). The nPBMCs was higher in AD patients after stimulation than in basal conditions: after stimulation in nTNF (P < 0.001 vs T2D; P < 0.001 vs T1D; P = 0.001 vs control), nIL6 (P = 0.039 vs T2D; P < 0.001 vs T1D; P = 0.007 vs control), and nIL1β (P = 0.03 vs control). The nPBMCs increased after stimulation with ΡΜA in all the subgroups (P < 0.001). FASLG in the AD group displayed statistically higher concentrations than in all other subgroups (P < 0.001 vs T2D; P < 0.001 vs T1D; P = 0.012 vs control). The nPBMCs was positively correlated with plasma concentrations of FASLG in the AD subgroup.

CONCLUSIONS

Patients with AD display a low-grade systemic inflammation compared to people with diabetes. The FAS-FASLG pathway has a potential role because FASLG concentrations are positively correlated with the inflammatory response in AD. However, this positive correlation cannot be seen in people with diabetes, at least not with the apoptotic markers used in the present study.

Prevalence, Incidence, and Contributors of Subclinical Atheromatosis, Arteriosclerosis, and Arterial Hypertrophy in HIV-Infected Individuals: A Single-Center, 3-Year Prospective Study

Cardiovascular disease (CVD) is an important comorbidity for people living with HIV infection (PLWH) in the combined antiretroviral therapy era. We prospectively examined the presence of subclinical arterial disease in 138 consecutive CVD-free, HIV-infected individuals compared to 664 HIV-negative individuals. We studied 10 arterial sites in 4 beds using 5 distinct biomarkers of subclinical atheromatosis, arteriosclerosis, and hypertrophy and evaluated the association of subclinical arterial damage with CVD-related and HIV-related factors at baseline and at 3-year follow-up. Atheromatosis, arteriosclerosis, and arterial hypertrophy were present in 36.1%, 59.7%, and 34.3% of HIV-infected individuals, respectively, at baseline. HIV infection was independently associated with carotid atheromatosis and hypertrophy. The presence of carotid atheromatosis was independently associated with age, years of smoking, and exposure to nonnucleoside reverse transcriptase inhibitors (NNRTIs). The annual incidence of atheromatosis, arteriosclerosis, and arterial hypertrophy was 5.5, 18.6, and 12.5 cases/100 patients, respectively. Carotid atheromatosis progression was significantly associated with NNRTI exposure. People living with HIV infection exhibited high prevalence and incidence of subclinical arterial damage and site-specific predilection for the carotids. These investigations may help optimize HIV-specific CVD prediction models. The NNRTIs may contribute to atheromatosis, emphasizing the need to consider the atherogenic potential of antiretroviral drugs in management strategies.

Hallmarks in history of esophageal carcinoma

Esophageal cancer is one of the deadliest cancers due to its aggressive behavior and poor survival. It was mentioned in the works of ancient Chinese and Arabo-islamic physicians, centuries before the recognition of high incidence in the Asian esophageal cancer belt. Till the 19th century the disease was considered incurable and the main goal of the proposed treatments was to alleviate dysphagia and pain. The introduction of esophagoscope in 1868 by Adolf Kussmaul (1822-1902) contributed to the observation of the living esophagus and to the diagnosis of esophageal pathologies, paving the way for new therapeutic approaches. In 1877, Vincenz Czerny (1842-1916) performed the first successful resection of the cervical esophagus for carcinoma, followed by Franz Torek (1861-1938) who carried out in 1913 the first successful subtotal thoracic esophagectomy and Tohru Ohsawa (1882-1984) who performed the world's first esophagectomy with an intrathoracic esophagogastric anastomosis. Nowadays, despite the advent of biomedical technology and the development of operation techniques, the surgical treatment of esophagus still remains a challenge.

Hippocratic views in the treatment of rectal prolapse

Known since antiquity, rectal prolapse was first studied systematically by Hippocrates (460-377 BC) who recognized the predisposing factors and proposed several therapeutic approaches such as defecation positions, manual retraction and specific herbal or mineral based anti-haemorrhagic and pain-killing poultices. Hippocratic medicine avoided invasive surgical procedures probably due to a lack of knowledge in human anatomy. However, Hippocrates' views astonishingly lasted in time, presenting similarities to current medical theories on rectal prolapse.

Concomitant alterations of metabolic parameters, cardiovascular risk factors and altered cortisol secretion in patients with adrenal incidentalomas during prolonged follow-up

OBJECTIVE

Adrenal incidentalomas (AI) are associated with metabolic and hormonal abnormalities, most commonly autonomous cortisol secretion (ACS). Data regarding alterations of insulin resistance (IR) and ACS after prolonged follow-up are limited. We investigated the evolution of IR, cortisol secretion and ACS development in patients with AI during prolonged follow-up.

DESIGN

Prospective study in a tertiary hospital.

PATIENTS AND MEASUREMENTS

Seventy-one patients with AI [51 nonfunctioning (NFAI) and 20 ACS] and 5·54 ± 1·7 years follow-up underwent testing for ACS and oral glucose tolerance test to determine IR indices and adrenal imaging.

RESULTS

At follow-up, 16/51 (31%) NFAI patients converted to ACS, while two with previous ACS reverted to NFAI; 21% (7/33) of patients who did not covert to ACS exhibited high urinary-free cortisol (H-UFC) levels. All AI patients developed deterioration of IR irrespective of their cortisol secretory status. Eight patients developed newly diagnosed type 2 diabetes (9·8% NFAI and 15% ACS, respectively) and 14 IR (17·6% NFAI and 25% ACS, respectively). Adenoma size increased from 2·1 ± 0·8 to 2·3 ± 0·8 cm, whereas IR correlated with postdexamethasone cortisol level and adenoma size increase. IR showed an incremental continuum trend from normal UFC (Ν-UFC), to H-UFC, C-ACS and ACS patients.

CONCLUSIONS

New-onset ACS developed in 31% patients with NFAI, whereas 21% of NFAI patients had H-UFC levels. All AI patients as a group and the subgroups of N-UFC, H-UFC, C-ACS and ACS patients developed deterioration of metabolic parameters during follow-up that was more prominent in ACS patients.

Theories About Blood Coagulation in the Writings of Ancient Greek Medico-philosophers

Anaxagoras and Empedocles both established during the Presocratic era a pioneering theory for the creation of everything in the universe. Macrocosmos' impact through the "Four Elements Theory" explained the conglomeration of the blood inside the vessels. Hippocrates, who instituted the "Four Humours theory", clearly understood blood's coagulation and introduced the term "thrombus". Plato, Aristotle and Galen, all engaged with the clotting phenomenon trying to interpret it. After eons of inquiry, it was the innovative thinking of the ancient Greek medico philosophers that set the scientific bases towards the understanding of a process that had been analyzing until our era.

Racial variation and cancer: a historical approach

At the end of the 19th century, in an attempt to define cancer's etiology, scientists considered that cancer was mainly affecting the white race and the temperate zone countries. In their turn, epidemiological studies held in the early 20th century sustained the dogma of cancer's racial distribution, targeting and stigmatizing ethnic groups.

Arterial wave reflection is associated with severity of extracoronary atherosclerosis in patients with coronary artery disease

BACKGROUND

Arterial wave reflection is a major determinant of left ventricular function, coronary perfusion and cardiovascular risk. We investigated whether arterial wave reflection may detect atherosclerosis of peripheral arteries in patients with documented coronary artery disease (CAD).

METHODS

Radial artery applanation tonometry and pulse wave analysis was performed in 184 patients with documented CAD at coronary angiography; central blood pressures and augmentation index (AI) were measured. Ankle-brachial (ABI) index and intima-media thickness (IMT) were used as indices of atherosclerosis of the lower limbs and the carotid arteries respectively.

RESULTS

Patients with abnormal IMT (> 0.7 mm, first tertile) or ABI (< 0.94, first tertile) had higher AI than patients with lower IMT or higher ABI (24 +/- 17 versus 17 +/- 16% and 23 +/- 18 versus 18 +/- 13%, respectively, P < 0.05). In multivariate analysis, increasing AI was associated with age, female gender, heart rate, mean blood pressure, hyperlipidaemia, and use of statins (regression coefficient (beta) = 0.50, beta = 0.15, beta = -0.60, beta = 0.23, beta = 0.16 and beta = -0.14, respectively, P < 0.05). Increasing AI was associated with an adjusted-odds ratio of 1.035 [95% confidence interval (CI), 1.005-1.066], P = 0.02 for an abnormal IMT and of 1.08 (95% CI, 1.024-1.146), P = 0.005 for ABI after adjustment for age, gender, heart rate, height, blood pressure, atherosclerotic risk factors, obesity and medication. No relation was found between AI and Gensini score or for the number of diseased coronary vessels.

CONCLUSION

Augmentation index is a marker of extensive extracoronary atherosclerosis in patients with CAD.

Effect of ascorbic acid on forearm reactive hyperaemia in patients with hypercholesterolaemia

BACKGROUND

This study was designed to research the effect of hypercholesterolaemia and ascorbic acid on forearm blood flow (FBF) reactive hyperaemia (RH). Reactive hyperaemia seems to be at least partly endothelium-dependent. Endothelial dysfunction has been described in patients with hypercholesterolaemia, and has been reversed with ascorbic acid administration.

METHOD

Forearm blood flow was studied with venous occlusion plethsmography in 26 healthy volunteers and 46 hypercholesterolaemic patients. Hypercholesterolaemic patients were divided into two groups. Group A comprised 25 patients, who received ascorbic acid and group B comprised 21 patients, who received placebo. All subjects underwent measurement of FBF at baseline and during RH (phase A). Forearm blood flow during RH was measured every 15 seconds for three minutes. Subsequently patients in group A received 2 g of ascorbic acid orally in the form of effervescent tablets, and patients in group B received placebo orally in the same form. Forearm blood flow measurements at baseline and during RH were repeated two hours later (phase B).

RESULTS

Maximal percent increase of FBF was significantly higher in healthy subjects than in hypercholesterolaemic patients (139.1+/-12.1% versus 73.1+/-11.0% respectively, P<0.05). Duration of RH was smaller in hypercholesterolaemic patients compared to normal subjects (60.9+/-17.1 seconds versus 105.6+/-10.2 seconds, P<0.05). Administration of ascorbic acid but not of placebo increased the duration of RH (69.1+/-11.1 seconds versus 104.1+/-12.2 seconds, P<0.05) but not of peak RH FBF.

CONCLUSION

Hypercholesterolaemia seems to impair both the early and late phase of RH. Ascorbic acid improves only the duration of RH, possibly due to its antioxidant effect on endothelium.

Ambulatory Aortic Stiffness Is Associated With Narrow Retinal Arteriolar Caliber in Hypertensives: The SAFAR Study

BACKGROUND

Arterial stiffness measured under static conditions reclassifies significantly cardiovascular (CV) risk and associates with narrower retinal arterioles. However, arterial stiffness exhibits circadian variation, thus single static stiffness recordings do not correspond to the "usual" 24 hr, awake, and asleep average arterial stiffness. We aimed to test the hypothesis that ambulatory 24 hr, awake, and asleep aortic (a) pulse wave velocity (PWV) associate with retinal vessel calibers, independently of confounders and of static arterial stiffness, in hypertensive individuals free from diabetes and CV disease.

METHODS

Digital retinal images were obtained (181 individuals, age: 53.9±10.7 years, 55.2% men) and retinal vessel calibers were measured with validated software to determine central retinal arteriolar and venular equivalents (CRAE and CRVE, respectively); ambulatory (24 hr, awake, asleep) and static office aPWV were estimated by Mobil-O-Graph; and static office carotid to femoral (cf) PWV by SphygmoCor.

RESULTS

Regression analysis performed in 320 gradable retinal images showed that, after adjustment for confounders: (i) ambulatory aPWV was significantly associated with narrower retinal arterioles but not with venules; (ii) asleep aPWV had stronger associations with CRAE than awake aPWV; (iii) both ambulatory aPWV and cfPWV were associated mutually independently with narrower retinal arterioles; aPWV introduction in the model of cfPWV, improved model's R2 (P = 0.012). Similar discriminatory ability of 24 hr aPWV and of cfPWV to detect the presence of retinal arteriolar narrowing was found.

CONCLUSION

Ambulatory aPWV, estimated by an operator-independent method, provides additional information to cfPWV regarding the associations of arterial stiffness with the retinal vessel calibers.

Intact calibers of retinal vessels in patients with systemic sclerosis

OBJECTIVE

A primary endothelial cell dysfunction is thought to be involved in systemic sclerosis (SSc)-associated fibroproliferative vasculopathy of the microcirculation and small arterioles, even in sites not affected by fibrosis. Because the role of fibroblasts in pathologic modifications and vascular wall remodeling is relatively unclear, and because the retina provides a unique opportunity to assess microcirculation in the absence of resident fibroblasts, we systematically evaluated retinal vessels in patients with SSc.

METHODS

Digital retinal images were obtained from both eyes of 93 consecutive patients with fully characterized SSc and 29 healthy controls matched 1:1 for age and sex with selected patients without diabetes, hypertension history, or antihypertensive treatment. Internal microvascular calibers (erythrocyte column width in μm) by central retinal arteriolar and venular equivalents and arteriolar to venular ratio were measured using validated software.

RESULTS

Arteriolar and venular calibers were similar in patients and their matched controls (mean ± SEM; 187 ± 2 vs 184 ± 3, p = 0.444, and 211 ± 2 vs 216 ± 3, p = 0.314, respectively). Both arteriolar and venular calibers and their ratio in patients with SSc were not associated with disease duration, extent of skin involvement, pulmonary fibrosis, digital ulcers or pitting scars, amputations, digital capillaroscopic findings, inflammatory indices, or autoantibodies.

CONCLUSION

The evidence that retinal microcirculation is spared in SSc suggests that fibroproliferative vasculopathy may depend on specific cellular or soluble factors not present in the retinal environment.

Association of left ventricular diastolic dysfunction with 24-h aortic ambulatory blood pressure: the SAFAR study

Aortic blood pressure (BP) and 24-h ambulatory BP are both better associated with target organ damage than office brachial BP. However, it remains unclear whether a combination of these two techniques would be the optimal methodology to evaluate patients' BP in terms of left ventricular diastolic dysfunction (LVDD) prevention. In 230 participants, office brachial and aortic BPs were measured by a validated BP monitor and a tonometry-based device, respectively. 24-h ambulatory brachial and aortic BPs were measured by a validated ambulatory BP monitor (Mobil-O-Graph, Germany). Systematic assessment of patients' LVDD was performed. After adjustment for age, gender, hypertension and antihypertensive treatment, septum and lateral E/Ea were significantly associated with office aortic systolic BP (SBP) and pulse pressure (PP) and 24-h brachial and aortic SBP and PP (P ⩽ 0.04), but not with office brachial BP (P ⩾ 0.09). Similarly, 1 standard deviation in SBP was significantly associated with 97.8 ± 20.9, 86.4 ± 22.9, 74.1 ± 23.3 and 51.3 ± 22.6 in septum E/Ea and 68.6 ± 2 0.1, 54.2 ± 21.9, 37.9 ± 22.4 and 23.1 ± 21.4 in lateral E/Ea, for office and 24-h aortic and brachial SBP, respectively. In qualitative analysis, except for office brachial BP, office aortic and 24-h brachial and aortic BPs were all significantly associated with LVDD (P ⩽ 0.03), with the highest odds ratio in 24-h aortic SBP. Furthermore, aortic BP, no matter in the office or 24-h ambulatory setting, showed the largest area under receiver operating characteristic curves (P ⩽ 0.02). In conclusion, 24-h aortic BP is superior to other BPs in the association with LVDD.

Specific electrocardiographic features associated with Cushing's disease

OBJECTIVE

Hypercortisolaemia is associated with an increased risk of cardiovascular disease (CVD), either through a direct action on the myocardium or by increased traditional cardiovascular risk factors. The aim of this study was to investigate whether the alterations in the ECG in Cushing's disease (CD) are predictable from risk factor analysis alone.

DESIGN

In 79 patients with a diagnosis of CD, retrospectively recruited, ECG features [corrected for heart rate QT (QTc), QTc dispersion (QTcd), left ventricular hypertrophy (ECG-LVH), right ventricular hypertrophy (ECG-RVH)], systolic (SBP) and diastolic (DBP) blood pressure were assessed. Biochemical, hormonal (cortisol at 09·00 h or cortisol day curve, CDC) and carbohydrate abnormalities (CHA), history of hypertension and cardiovascular disease were recorded. For comparison reasons, a group of 42 healthy subjects matched for gender, age and body mass index previously subjected to ECG assessment were selected.

RESULTS

In patients with CD, we noted the following prevalence: metabolic syndrome 39%, hypertension 81%, CVD 21·5%, hypercholesterolaemia 37%, hypertriglyceridaemia 29%, CHA 41%, but a history of cardiac dysrhythmia was only noted in a single patient. No difference in QTc or QTcd was shown between patients with normal or low potassium levels. QTcd >50 ms was associated with both increased ECG-LVH and ECG-RVH. When compared to the control group, patients had longer QTcd (P < 0·001), more prevalent LVH (P < 0·001) and RVH (P = 0·001), and higher SBP and DBP (P < 0·001), but similar QTc. Both CD and ECG evidence of LVH predicted prolonged QTcd, but the association of CD with a prolonged QTcd was independent of other risk factors, including hypertension.

CONCLUSIONS

Prolonged QTcd in association with ECG evidence of LVH appears to be the specific feature of CD. This may be relevant in the choice of medical therapy for CD and for consideration of treatment of the comorbidities that are associated with hypercortisolaemia.

Impaired aortic elastic properties in patients with systemic sarcoidosis

BACKGROUND

Systemic sarcoidosis (Sar) is a granulomatous disorder involving multiple organs. Widespread vascular involvement and microangiopathy are common in patients with Sar. In addition, subclinical cardiac involvement is increasingly recognized in patients with Sar. However, data on the effect of Sar on the elastic properties of the arteries and myocardial performance are limited. In this study we looked for differences in aortic distensibility (AoD) which is an index of aortic elasticity, and myocardial performance of the ventricles, between patients with Sar and healthy subjects. In addition, we examined potential associations between AoD and clinical, respiratory and echocardiographic findings in patients with Sar.

MATERIALS AND METHODS

A total of 83 consecutive patients (26 male/57 female, mean age 51.1 +/- 13.3 years) with Sar, without cardiac symptoms, were included. All patients underwent echocardiographic and respiratory evaluation including lung function tests. Additionally, 83 age- and sex-matched healthy subjects served as controls. AoD was determined non-invasively by ultrasonography.

RESULTS

AoD was lower in the Sar compared to the control group (2.29 +/- 0.26 vs. 2.45 +/- 0.20 .10(-) (6) cm2 x dyn(-1), P < 0.01), while left ventricular mass (LVM) was higher in the Sar group (221.3 +/- 50.2 vs. 195.6 +/- 31.3 g, P = 0.007). Furthermore, myocardial performance of both ventricles was impaired in the Sar group. Multivariate linear regression analysis in the total sample population demonstrated a significant and independent inverse relationship between AoD and the presence of Sar (P < 0.001). The same analysis in the Sar patients showed that AoD was associated significantly and independently with the stage of Sar, age, systolic blood pressure, LVM and myocardial performance of both ventricles. No significant relationship was found between AoD and disease duration, pulmonary artery pressure or lung function tests.

CONCLUSIONS

Presence and severity of Sar are associated with reduced aortic distensibility, irrespective of the disease duration, pulmonary artery pressure and lung function. In addition, patients with Sar have increased LVM and impaired myocardial performance.

Contrast-enhanced intravascular ultrasound: combining morphology with activity-based assessment of plaque vulnerability

Acute coronary syndromes are the result of coronary plaque rupture in the majority of cases. Available diagnostic techniques that focus on the early detection of plaques that are prone to rupture are still limited. Increased neovascularization in the vasa vasorum of the atherosclerotic plaque has been identified recently as a common feature of inflammation and plaque vulnerability. Microbubbles, which have been used for ultrasound imaging, can be used to trace neovascularization. We present recent advances in contrast agents and contrast-enhanced intravascular ultrasound that may be used for the detection of vasa vasorum, including fundamental and harmonic contrast imaging. Identification of vasa vasorum proliferation in atherosclerotic plaques presents important clinical implications; in particular it could provide a means to detect vulnerability in vivo, thereby guiding targeted treatments.

Abnormal endothelial function in female patients with hypothyroidism and borderline thyroid function

BACKGROUND

It has been suggested that hypothyroidism is associated with an increased risk for cardiovascular disease. The aim of this study was to assess non-invasively NO-dependent endothelial function of resistance arteries in subjects with hypothyroidism of varying severity.

METHODS

Ninety-six female subjects (aged: 42+/-13 years) comprised the study population. Subjects were divided into five groups based on TSH levels at presentation: Group 0 (n=23) with TSH: 0.3-2.0 microU/ml, Group 1 (n=22) with TSH: 2.1-4.0 microU/ml (upper normal), Group 2 (n=18) with TSH: 4.1-10 microU/ml (subclinical hypothyroidism), Group 3 (n=22) with TSH >10 microU/ml (overt hypothyroidism). One additional group with well-controlled hypothyroidism on L-thyroxine therapy (Group 4, n=11, TSH: 0.3-2.0 microU/ml) was also studied. Endothelial function of resistance arteries was assessed by measuring forearm blood flow response during reactive hyperemia utilizing venous occlusion strain-gauge plethysmography.

RESULTS

Duration of reactive hyperemia was significantly different among groups of subjects with varying hypothyroidism (83.7+/-58.3 s, 53.2+/-35.7 s, 52.8+/-47.5 s, 12.9+/-13.3 s and 69.5+/-26.2 s in Groups 0, 1, 2, 3 and 4, respectively, p<0.001, ANOVA). Duration of reactive hyperemia was significantly shorter in subjects with upper normal TSH values (Group 1) compared to controls (53.2+/-35.7 s vs. 83.7+/-58.3 s, p=0.013), while it was comparable to that of subjects with subclinical hypothyroidism (Group 2) (52.8+/-47.5 s). However, duration of reactive hyperemia in Group 1 was significantly longer compared to Group 3 (overt hypothyroidism) (53.2+/-35.7 s vs. 12.9+/-13.3 s, p=0.002). Similarly, duration of reactive hyperemia in subjects with subclinical hypothyroidism was significantly longer compared to subjects with overt hypothyroidism (52.8+/-47.5 s vs. 12.9+/-13.3 s, p=0.003). Duration of reactive hyperemia in Group 4 (well-controlled hypothyroidism on L-thyroxine therapy) did not differ significantly compared to controls. There was a highly significant linear correlation between duration of reactive hyperemia and TSH (r=-0.383, p<0.001).

CONCLUSION

Endothelial dysfunction was detected in the microvasculature of patients with hypothyroidism. Duration of reactive hyperemia decreased with increasing TSH levels. Since endothelial dysfunction is a factor leading to atherosclerosis, this abnormality may partly explain predisposition of patients with thyroid failure to cardiovascular disease.

Early microvascular and macrovascular dysfunction is not accompanied by structural arterial injury in polycystic ovary syndrome

OBJECTIVE

During the last decade cardiovascular risk factors and endothelial dysfunction have been shown to be present early in life in women with Polycystic Ovary Syndrome (PCOS). The aim of the present study was a global assessment of abnormalities in the arterial bed of young women with PCOS by non-invasive, reproducible methods.

DESIGN

27 women with PCOS and 27 control women of comparable age, body mass index and waist-to-hip ratio were studied. Macrovascular function was assessed by flow-mediated dilatation (FMD) on the brachial artery. Nitrate-induced dilatation (NID) was performed to exclude a vascular smooth muscle cells injury. Microvascular function was assessed by venous occlusion plethysmography studying forearm blood flow. Arterial structure was evaluated by ultrasonographic assessment of intima-media thickness (IMT) of the carotid artery.

RESULTS

FMD values were lower in women with PCOS compared to controls (PCOS: 3.84+/-0.74% vs. controls: 9.83+/-0.97%, P<0.001), but no difference was observed in NID (PCOS: 16.59+/-1.84% vs. controls: 16.64+/-2.05%, P=0.98) values. The time required for reactive hyperemia to reach peak value, a plethysmography parameter, was longer in PCOS women (PCOS: 20.63+/-4.67 sec vs. controls: 10.38+/-5.11 sec, P=0.02). No difference was observed in the combined IMT among the studied groups (PCOS: 0.49+/-0.01 mm v.s. controls: 0.51+/-0.02 mm, P=0.19).

CONCLUSIONS

Using non invasive methodologies endothelial dysfunction in the macrocirculation and early impairment in the microcirculation were demonstrated in young women with PCOS who had normal profile of glycemia, lipidemia and blood pressure, and no evidence of structural arterial impairment.

The combined effect of augmentation index and carotid intima-media thickness on cardiovascular risk in young and middle-aged men without cardiovascular disease

Carotid artery intima-media thickness (IMT) has been used as a surrogate marker of atherosclerosis and is related to cardiovascular risk. Indices of arterial stiffness are also associated with cardiovascular risk and atherosclerosis. The aim of this study was to assess the prognostic value of the combination of surrogate markers of cardiovascular disease measured non-invasively in subjects without cardiovascular disease. In this cross-sectional study, 81 young and middle aged males (39.2+/-6.3 years) without evidence of overt cardiovascular disease or diabetes mellitus were enrolled. High-resolution B-mode ultrasonography and pulse wave analysis were used to measure carotid artery IMT and augmentation index (AI), a measure of arterial stiffness. Framingham risk score (FRS) was used as an estimate of the risk for development of cardiovascular disease. Regional differences were observed in the carotid arteries' IMT regarding their relationship with FRS: combined (average from all sites) IMT and IMT in the carotid bulb (CB), but not in the common (CC) and internal carotid artery (IC), and AI showed significant increases of FRS by their tertiles. However, subjects with both AI and IMT at any site in the highest tertile (AI>15%, CC>0.65 mm, CB>0.8 mm, IC>0.65 mm) had an increased FRS compared to subjects with one or none of these parameters in the highest tertile. In conclusion, young and middle-aged men without overt cardiovascular disease with both high IMT and AI are in high cardiovascular risk, as assessed by FRS. Epidemiological studies are needed to further validate this combination.

Red wine acutely induces favorable effects on wave reflections and central pressures in coronary artery disease patients

BACKGROUND

To investigate red wine's acute effects on aortic pressures and arterial stiffness in patients with coronary artery disease (CAD).

METHODS

Fifteen patients with CAD were recruited in a double-blind, cross-over study, which was comprised of 2 study days. Each volunteer consumed either 250 mL of regular or 250 mL of dealcoholized red wine. Wave reflections, expressed as augmentation index (AIx), as well as central and peripheral blood pressures (BP) were assessed at fast and 30, 60, and 90 min postprandially.

RESULTS

Both regular and dealcoholized red wine caused a significant decrease in AIx by 10.5% +/- 1.4% (P = .001) and 6.1% +/- 1.4% (P = .011), respectively, whereas no significant change was induced in mean BP and timing of wave reflections expressing pulse wave velocity. Peripheral systolic BPs remained unaltered in both beverages, whereas a significant decrease in peripheral and central diastolic BPs was observed after the dealcoholized red wine consumption (P = .03 and P = .035, respectively). Central systolic BP was decreased after the consumption of regular (-7.4 +/- 2.4 mm Hg, P = .05) and dealcoholized red wine (-5.4 +/- 2.7 mm Hg, P = .019).

CONCLUSIONS

Both types of red wine provoked favorable acute effects on wave reflections and central systolic pressures, whereas no such effect was evident at the brachial artery. Therefore, these findings could be attributed mainly to red wine antioxidant substances, rendering it a possible means of at least acute attenuation of increased wave reflections, arterial stiffness, and central pressures in patients with coronary artery disease.

Red wine acutely induces favorable effects on wave reflections and central pressures in coronary artery disease patients

BACKGROUND

To investigate red wine's acute effects on aortic pressures and arterial stiffness in patients with coronary artery disease (CAD).

METHODS

Fifteen patients with CAD were recruited in a double-blind, cross-over study, which was comprised of 2 study days. Each volunteer consumed either 250 mL of regular or 250 mL of dealcoholized red wine. Wave reflections, expressed as augmentation index (AIx), as well as central and peripheral blood pressures (BP) were assessed at fast and 30, 60, and 90 min postprandially.

RESULTS

Both regular and dealcoholized red wine caused a significant decrease in AIx by 10.5% +/- 1.4% (P = .001) and 6.1% +/- 1.4% (P = .011), respectively, whereas no significant change was induced in mean BP and timing of wave reflections expressing pulse wave velocity. Peripheral systolic BPs remained unaltered in both beverages, whereas a significant decrease in peripheral and central diastolic BPs was observed after the dealcoholized red wine consumption (P = .03 and P = .035, respectively). Central systolic BP was decreased after the consumption of regular (-7.4 +/- 2.4 mm Hg, P = .05) and dealcoholized red wine (-5.4 +/- 2.7 mm Hg, P = .019).

CONCLUSIONS

Both types of red wine provoked favorable acute effects on wave reflections and central systolic pressures, whereas no such effect was evident at the brachial artery. Therefore, these findings could be attributed mainly to red wine antioxidant substances, rendering it a possible means of at least acute attenuation of increased wave reflections, arterial stiffness, and central pressures in patients with coronary artery disease.

Arterial stiffness assessed by pulse wave analysis in essential hypertension: relation to 24-h blood pressure profile

BACKGROUND

Arterial stiffness is a risk factor for cardiovascular morbidity and mortality and appears to be increased in arterial hypertension. The purpose of the present study was to relate systemic arterial stiffness assessed by pulse wave analysis to variables of 24-h ambulatory blood pressure monitoring (ABPM) in patients with essential hypertension.

METHODS

Seventy-two subjects with untreated mild to moderate arterial hypertension underwent evaluation with 24-h ambulatory blood pressure monitoring. In the same subjects, applanation tonometry and pulse wave analysis was performed for evaluation of systemic arterial stiffness expressed as augmentation index and estimated aortic pulse wave velocity.

RESULTS

Clinic systolic blood pressure, mean heart rate during 24-h blood pressure monitoring and height were independent predictors of augmentation index and estimated aortic pulse wave velocity. The 41 patients with blunted reduction in nighttime blood pressure (nondippers) showed higher mean systolic blood pressure (p=0.02), lower systolic and diastolic blood pressure variability (p<0.001), higher pulse pressure during 24-h monitoring (p=0.05) and higher estimated aortic pulse wave velocity (p=0.03), indicating stiffer arteries in this group.

CONCLUSIONS

These results suggest that blood pressure change from day- to nighttime is an important determinant of arterial stiffness assessed by pulse wave analysis; this association could contribute to the higher cardiovascular risk in nondippers.

Rapid effect of pravastatin on endothelial function and lipid peroxidation in unstable angina

BACKGROUND

Oxidative stress contributes to endothelial dysfunction, an important step to the pathogenesis of atherosclerosis and coronary events. Latest studies revealed the existence of pleiotropic and especially antioxidant properties of statins. We sought to examine the effects of pravastatin on lipid peroxidation and endothelial function, independently from lipid-lowering, in patients with unstable angina (UA).

METHODS

Thirty-seven patients (males), 64.46+/-9.09 years, suffering from UA enrolled in the study. Patients were not on statin medication before admission and they received after randomization either 40 mg pravastatin daily (group A, n = 20), or placebo (group B, n = 17). Malondialdehyde (MDA) concentration, an index of lipid peroxidation and plaque instability, flow-mediated dilatation (FMD) of the brachial artery and blood lipids were measured on the second day of hospitalization and 10 days later.

RESULTS

MDA decreased significantly in both groups (A, p = 0.008; B, p = 0.003). FMD increased significantly in group A (p = 0.007), whereas in group B it did not change. Serum lipids remained unaltered in all three groups.

CONCLUSIONS

Pravastatin administration improved FMD within 10 days and this favorable effect occurred before any significant reduction in blood lipids, revealing its pleiotropic effects during the early phase of an acute coronary syndrome. Circulating lipid peroxidation products in patients with UA decreased significantly during the same period independently of endothelial function and pravastatin therapy.

Basic Principles of the Intraaortic Balloon Pump and Mechanisms Affecting Its Performance

The intraaortic balloon pump (IABP) is the single most effective and widely used device for temporary mechanical assistance of the failing heart. Although the principles underlying IABP function are simple, various biologic factors often determine its performance in a particularly complicated way. We briefly describe the basic disciplines of counterpulsation by IABP and the induced hemodynamic changes while clarifying the biologic mechanisms that play a crucial role in the modification of IABP acute hemodynamic performance.

Experimental and clinical study of the combined effect of arterial stiffness and heart rate on pulse pressure: Differences between central and peripheral arteries

1. Pulse pressure (PP) constitutes an independent predictor of cardiovascular events and mortality in various populations. Heart rate (HR) and arterial stiffness, in addition to their independent predictive value for cardiovascular complications, seem to interact with regard to the modification of PP. The aim of the present study was to investigate the association of PP with HR under different levels of arterial compliance (AC), revealing their synergistic effects. 2. Seventy-one normotensive and untreated hypertensive subjects were examined. Arterial compliance was measured by the 'area' method, whereas central blood pressures and wave reflections were evaluated using the Sphygmocor system (AtCor Medical, Sydney, NSW, Australia). A hydraulic Windkessel model was also used to evaluate the independent effect of HR and AC on PP. Peripheral PP was associated only with mean pressure and AC. In contrast, central PP was further related to HR (20 b.p.m. decrease in HR resulted in central PP augmentation by 5.6 mmHg) regardless of mean pressure, stroke volume, age and gender. However, this association was statistically significant only for subjects with lower AC (< 1.1 mL/mmHg) and not for those with more compliant arteries. These findings are also in accordance with the experimental data. 3. Aortic PP is affected to a greater degree by HR changes compared with peripheral PP. This response was observed only at high levels of arterial stiffness. 4. The present study provides the first evidence regarding the combined effect of AC and HR on aortic PP, which may lead to larger clinical or epidemiological studies aiming to optimization of drug treatment and to a possible reduction of cardiovascular risk.

Oral folic acid enhances endothelial function in patients with hypercholesterolaemia receiving statins

BACKGROUND

Folic acid therapy has been shown to improve endothelial function in patients with familial hypercholesterolaemia via a possible antioxidant mechanism. Data on the possible role of folic acid in hypercholesterolaemic patients receiving statins are lacking. In the present study we tested the hypothesis that folic acid supplementation improves endothelial function in patients with hypercholesterolaemia and treatment with statins.

METHODS

Thirty-four hypercholesterolaemic patients receiving statins participated in the study; all subjects underwent measurement of endothelium-dependent, flow-mediated dilatation of the brachial artery and subsequently randomized to receive 5 mg of the folic acid (n=17) or placebo (n=17) for 4 weeks. Flow-mediated dilatation of the brachial artery was repeated at the end of the 4-week period.

RESULTS

Folic acid and placebo groups were comparable regarding age, sex, smoking, hypertension, coronary artery disease, obesity, family history and blood lipids. Folic acid administration resulted in an improvement of flow-mediated dilatation (4.7+/-3.2% to 7.1+/-3.1%, P=0.02), whereas there was no improvement after placebo administration (5.7+/-3.8% to 5.6+/-2.2%, ns). No significant change in nitrate-induced, endothelium- independent dilatation was observed after folic acid or placebo (ns).

CONCLUSIONS

Oral administration of folic acid (5 mg) for 4 weeks improves endothelial function in patients with hypercholesterolaemia treated with statins, with possible beneficial effects on the prognosis of these patients.

Endothelial dysfunction and type of cigarette smoked: the impact of 'light' versus regular cigarette smoking

Acute cigarette smoking leads to temporary endothelial dysfunction, which is an early event in atherogenesis. Sufficient data concerning the effect of cigarettes with low tar and nicotine yield are lacking. Seventeen healthy individuals (nine women, eight men, aged 27.8 +/- 3.6 years) were subjected to evaluation of endothelial function by means of endothelium-dependent, flow-mediated dilatation (FMD) of the brachial artery, before, immediately after and 30, 60 and 90 min after smoking a regular cigarette (nicotine 0.9 mg, tar 12 mg) orthe corresponding 'light' cigarette (nicotine 0.6 mg, tar 8 mg). The following day, measurements were repeated after smoking the opposite kind of cigarette. Baseline FMD was 6.1 +/- 1.6% and 7.2 +/- 2.0% in the light and regular cigarette groups, respectively (p = NS). The overall effect of the regular cigarette over time on FMD compared with the light cigarette was significantly different (F = 3.039, p = 0.023). FMD was significantly depressed after smoking both types (light: F = 8.192, p < 0.001; regular: F = 16.698, p < 0.001). Immediately after smoking, FMD declined in both groups (light: 3.0 +/- 2.4% and regular: 1.6 +/- 3.2%, p < 0.001 and p < 0.001, respectively), and it remained significantly depressed in the regular cigarette group at 30 min (0.75+/-1.5%, p < 0.001) and 60 min (3.5 +/- 3.1%, p = 0.024), while in the light cigarette group FMD differences were abolished at 30, 60 and 90 min after smoking. In conclusion, acute smoking of both regular and light cigarettes leads to temporary vasomotor dysfunction; its duration is shorter after smoking a 'light' cigarette.

Acute effects of caffeine on arterial stiffness, wave reflections, and central aortic pressures

Caffeine is considered to be the most widely consumed pharmacologic substance in the world. Several recent sources of evidence suggest that caffeine, besides its well-established pressor effects, provokes further alterations in arterial stiffness, wave reflections, and especially aortic blood pressures, which are often overlooked. The increasing evidence regarding the prognostic value of the latter cardiovascular factors prompted us to seek additional information concerning the relationship of aortic blood pressures to caffeine consumption. The main purpose of the present review was to evaluate the acute influence of caffeine on arterial stiffness, wave reflections, and central systolic pressures, which are involved in the pathogenesis and prognosis of cardiovascular diseases. Current evidence supports the hypothesis that caffeine influences the cardiovascular system at least acutely, not only through a peripheral blood pressure elevation but also through an increase in arterial stiffness and an enhancement of arterial wave reflections. Moreover, it seems that peripheral pressure measurements might have underestimated caffeine pressor effects, as a significantly greater response is observed in aortic pressures. The mechanisms explaining these effects of caffeine are not always clear, and neither is the role of caffeine in cardiovascular risk. However, it is concluded that strategies aiming at the control of dietary caffeine consumption merit serious consideration.

Monitoring of arterial stiffness indices by applanation tonometry and pulse wave analysis: reproducibility at low blood pressures

OBJECTIVE

Aortic pulse wave analysis (PWA) reveals valuable information related to several hemodynamic characteristics mainly in normotensive and hypertensive patients. The main indices determined by PWA are augmentation index (AI) and reflection time index (RTI), which provide an indirect estimate of arterial stiffness and pulse wave velocity. The objective of the present study was to assess the reproducibility of aortic AI and RTI obtained by an automated and commercially available system (SphygmoCor) applied in patients with low blood pressures where such data are lacking.

METHODS

The study population consisted of 19 patients with cardiogenic shock due to acute myocardial infarction who underwent mechanical assistance with intraaortic balloon pump. Aortic pressure waveforms were derived from peripheral waveforms--recorded by applanation tonometry of the radial artery--by applying generalized transfer functions. On every occasion, a well-trained operator performed two measurements with 2 min interval. Multiple pairs of measurements were obtained per patient in order to study a wide range of different hemodynamic conditions. Thus, a total of 91 pairs of measurements were performed and analyzed using Bland-Altman plots.

RESULTS

AI and RTI ranged within 30-184% and 10-27%, respectively. Within-observer difference was 0.10 +/- 5.82% for aortic AI and 0.14 +/- 1.2% for RTI.

CONCLUSION

Pulse wave analysis and radial artery tonometry can be used to measure AI and RTI with satisfactory reproducibility even in low blood pressures. Ongoing research is required to establish PWA utility in clinical practice especially at patients with low blood pressures.

New Aspects on the Role of Blood Pressure and Arterial Stiffness in Mechanical Assistance by Intra-aortic Balloon Pump: In-vitro Data and Their Application in Clinical Practice

Despite the well-known beneficial effects of the intra-aortic balloon pump (IABP) generally, there are still some clinical conditions accompanied by IABP ineffectiveness. The aim of this study was the investigation of the independent effects of arterial stiffness and blood pressure on acute IABP effectiveness. For this purpose, a mock circulatory system and 20 patients with cardiogenic shock due to acute myocardial infarction, were employed. It was shown that IABP acute efficiency was determined primarily by arterial compliance (AC) rather than blood pressure alone. IABP induced low hemodynamic effects in patients with systolic blood pressure > 80 mm Hg but with increased AC, whereas IABP resulted in greater hemodynamic effectiveness in cases with systolic pressure < 70 mm Hg but lower AC. The present study provides evidence concerning the hemodynamic conditions, which might lead to optimization of IABP or to the prediction of its acute hemodynamic performance, based on both measurements of AC and blood pressure.

Tamoxifen improves endothelial function and reduces carotid intima-media thickness in postmenopausal women

BACKGROUND

Tamoxifen is a selective estrogen-receptor modulator shown to improve several cardiovascular risk factors in postmenopausal women with breast cancer. In animal studies tamoxifen inhibits the progression of atherosclerosis. Although the presence of a history with tamoxifen treatment is related to a lower intima-media thickness (IMT) of the common carotid artery, data from controlled follow-up studies are lacking to support this observation.

METHODS

We examined 14 postmenopausal women with early stage breast cancer with indication for tamoxifen treatment (20 mg/d) and 13 healthy postmenopausal women. Flow-mediated dilatation (FMD) of the brachial artery, combined carotid IMT, and aortic pulse wave were measured before and 6 months after treatment in the tamoxifen group and at the same times in the control group.

RESULTS

FMD and IMT were significantly increased and decreased, respectively, in the treatment group compared to the control group (FMD: +2.2% +/- 0.9% vs +0.085% +/- 1%, P =.012; IMT: -0.088 +/- 0.03 mm vs +0.04 +/- 0.03 mm, P =.018, mean +/- standard error of the mean, treatment vs control group). These differences remained significant even when adjusted for age, duration of menopause, and cardiovascular risk factors. Low-density lipoprotein cholesterol was also significantly reduced after tamoxifen treatment.

CONCLUSIONS

Tamoxifen treatment slows the progression of atherosclerosis in postmenopausal women with breast cancer as assessed by changes in carotid IMT. An improvement in endothelial function and blood lipid profile may be the reason for this beneficial effect.

Simulation of systolic and diastolic left ventricular dysfunction in a mock circulation: the effect of arterial compliance

Arterial compliance (AC) is expected to play a major role on cardiac efficacy by acute or long-term mechanisms. The aim of this study was to investigate the purely mechanical effect of AC on left ventricular (LV) performance, for different conditions of LV dysfunction (systolic versus diastolic). A hydraulic, Windkessel model of systemic circulation was used. LV function and aortic flow were simulated using a left ventricular assist device (LVAD). Two cases of LV dysfunction were simulated: Case A, systolic and Case B, diastolic dysfunction. In Case A, AC increased from 1.14 to 2.85 ml mm Hg(-1) leading to an increase in LVAD stroke volume up to 6%, while no significant effect was observed in Case B. LVAD systolic work was decreased by 4% in systolic and by 11% in diastolic LVAD dysfunction. The purely mechanical effect of AC changes on LVAD function was different between systolic and diastolic dysfunction. It might be expected that even an acute reduction in arterial stiffness could enhance LV performance by different means in systolic compared to diastolic dysfunction.

P wave analysis indices in young healthy men: data from the digital electrocardiographic study in Hellenic Air Force Servicemen (DEHAS)

P wave analysis from the 12-lead ECG is a recent contribution of noninvasive electrocardiology. P wave analysis indices (maximum and minimum P wave duration, P wave dispersion [Pdis = Pmax-Pmin], adjusted P wave dispersion [APdis = Pdis/square root of measured leads], summated P wave duration [Psum], standard deviation of P wave duration [Psd], mean P wave duration [Pmean]) can predict atrial arrhythmias. However, the definitions of all these indices are based on few studies. The aim of this analysis was to define normal values of these indices and the examine possible associations between P wave indices and clinical variables. The study included 1,353 healthy men, 24 +/- 3 years of age, who answered a questionnaire and underwent a detailed physical examination and a digitized 12-lead surface ECG. All P wave indices were analyzed by two independent investigators. Mean values of the ECG indices were: Pmax: 96 +/- 11 ms, Pmin: 57 +/- 9 ms, Pdis: 38 +/- 10 ms, Psum: 924 +/- 96 ms, Psd: 12 +/- 3, APdis: 11 +/- 3 ms, and Pmean: 77 +/- 8 ms. Age was significantly related with Pmax (r = 0.277, P < 0.01), Pmin (r = 0.255, P < 0.001), Psum (r = 0.074, P < 0.01), and Pmean (r = 0.074, P < 0.01). All ECG indices were significantly associated with the R-R interval, and among each other. This study defined normal indices of wave duration and correlations among them. These markers may play an important predictive role in patients with atrial conduction abnormalities.

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.