Theodoros G. Papaioannou

Ankle-brachial index as a predictor of the extent of coronary atherosclerosis and cardiovascular events in patients with coronary artery disease

Resting ankle-brachial pressure index (ABI) is a noninvasive method to assess the patency of the lower extremity arterial system. This study aimed to examine the relation between ABI and the extent of coronary atherosclerosis, the extracoronary atherosclerosis lesions, and the prognosis of patients referred for elective coronary angiography. One hundred sixty-five consecutive patients underwent coronary angiography, ultrasound imaging for intima-media thickness measurement of carotid and femoral arteries and ABI evaluation; subjects were followed up for 14.5 +/- 2.4 months. With regard to vascular risk factors, only smoking (p = 0.025) and diabetes (p = 0.01) were related to ABI in the multiple regression analysis. ABI was independently and inversely related to carotid bifurcation (p = 0.0002) and common femoral artery intima-media thickness (p = 0.018). ABI was related to the extent of coronary artery disease as measured by number of coronary arteries diseased (analysis of variance, p = 0.04) and Gensini angiographic score (p = 0.01). In the follow-up study ABI < 0.90 was a univariate predictor of cardiovascular events (cardiac death, nonfatal myocardial infarction, unstable angina) and revascularization procedures. The estimated cumulative rate free of cardiovascular events was 90% for ABI > 0.90 and 73% for ABI < 0.90 (p = 0.02). In logistic regression analysis, ABI < 0.90 was an independent predictor for cardiovascular events after adjustment for age, low-density lipoprotein cholesterol, carotid and femoral intima-media thickness, and Gensini score. Further adjustment for the confounding effect of insulin weakened the relation between ABI and cardiovascular events (p = 0.1). In conclusion, ABI is a simple index related to the extent of atherosclerosis in coronary and noncoronary arterial beds, reflecting generalized atherosclerosis. ABI could be useful in assessing the risk for cardiovascular events in patients with coronary artery disease.

Atherosclerotic changes of extracoronary arteries are associated with the extent of coronary atherosclerosis.

The aim of the present study was to examine the association between carotid and femoral artery intima media thickness (IMT) and the extent and severity of coronary artery disease (CAD) as well as the effects of traditional vascular risk factors on the atherosclerotic changes in the carotid and femoral arteries. Two hundred twenty-four patients who underwent coronary angiography for suspected CAD were evaluated by B-mode ultrasound imaging of the common carotid, internal carotid, carotid bifurcation, and femoral artery for measurement of IMT; traditional vascular risk factors were also evaluated in these patients. CAD extent was evaluated by the number of diseased vessels and by Gensini score. Age, male gender, and diabetes were common risk factors for higher CAD extent and higher carotid and femoral IMT. Insulin levels were correlated with femoral IMT and CAD extent, whereas blood lipids were correlated predominantly with carotid IMT. IMT from carotid and femoral arteries increased significantly with an increase in CAD extent. Using multiple stepwise regression analysis, the following parameters were found to be independent predictors of CAD extent: male gender (p<0.0001), common femoral artery IMT (p = 0.0028), common carotid artery IMT (p = 0.015), age (p = 0.02), diabetes mellitus (p = 0.035), and carotid artery bulb IMT (p = 0.04). Common femoral IMT was the only independent parameter for predicting Gensini score (p<0.0001). In conclusion, there are territorial differences in the various arterial beds regarding their response to risk factors. Femoral artery and carotid bulb are independent predictors of CAD extent and the inclusion of these measurements would add information to that provided by the common carotid artery.

Red wine's antioxidants counteract acute endothelial dysfunction caused by cigarette smoking in healthy nonsmokers

BACKGROUND Long-term smoking is believed to cause endothelial dysfunction via increased oxidative stress, whereas short-term smoking impairs vasodilatation through an as yet undefined mechanism. However, red wine and its constituents have a powerful antioxidant effect both in long-term and acute consumption. The aim of the current study was to investigate whether red wine, with or without alcohol, influences endothelial dysfunction induced by acute cigarette smoking. METHODS Sixteen healthy volunteers (8 males and 8 females) were recruited for a double-blind, crossover study, comprising 3 study days. Each subject smoked 1 cigarette, or smoked and drank 250 mL of red wine, or smoked and drank 250 mL of dealcoholized red wine. Flow-mediated dilatation (FMD) was measured after fasting and 15, 30, 60, and 90 minutes after each trial (smoke or smoke and drink either beverage). RESULTS Acute smoking of 1 cigarette caused a reduction in FMD (P <.001), which was statistically significant 15, 30, and 60 minutes after the inhalation of smoke compared to baseline levels (P <.001, P <.001, P =.043, respectively). However, simultaneous ingestion of either red wine or dealcoholized red wine with smoking did not lead to a change in FMD. CONCLUSIONS Acute smoking caused a significant impairment in endothelial function. Simultaneous consumption of red wine or dealcoholized red wine with smoking decreased smokes harmful effect on endothelium.

Left-ventricular hypertrophy is associated better with 24-h aortic pressure than 24-h brachial pressure in hypertensive patients: the SAFAR study.

Objective: To test the hypothesis that left-ventricular hypertrophy (LVH) is better associated with aortic, than brachial, 24-h average blood pressure (BP) in individuals with hypertension. Background: The office aortic BP is associated better with organ damage, such as LVH, than the office brachial BP; whether the 24-h average aortic BP associates better with LVH, than the 24-h average brachial BP, has never been tested. Methods: Aortic ambulatory BP monitoring (ABPM) was performed with a novel validated oscillometric cuff-based BP recording device, also used for simultaneous brachial ABPM, and the application of pulse wave analysis method. Office brachial and aortic BP were assessed with validated oscillometric recording device and pulse wave analysis, respectively; left-ventricular mass was measured by ultrasound. Results: Regression analysis performed in 229 individuals (aged 54.3 ± 14.6 years; 56% men; 75% hypertensive patients) showed that the 24-h average aortic SBP was significantly better associated with left-ventricular mass index and LVH than the 24-h average brachial, as well as, office (brachial or aortic) SBP, independently of age, sex, obesity or treatment. Receiver operator characteristics curve analysis showed a higher discriminatory ability of 24-h average aortic than brachial SBP to detect the presence of LVH (area under the curve: 0.73 versus 0.69; P = 0.007). A high degree of interindividual overlap regarding aortic 24-h average SBP level was found in individuals in whom the corresponding brachial measurements denoted different hypertension levels. Conclusion: These data suggest that aortic ABPM, when compared to brachial ABPM, improves the individualized assessment of the BP-associated heart damage.

Feasibility and Reproducibility of Noninvasive 24-h Ambulatory Aortic Blood Pressure Monitoring With a Brachial Cuff-Based Oscillometric Device

BACKGROUND Accumulating evidence suggests the potential superiority of office aortic blood pressure (BP) over brachial in the management of arterial hypertension. The noninvasive aortic 24-h ambulatory brachial BP monitoring (ABPM) is potentially the optimal method for assessing BP profile. The objective of the present study was to investigate the feasibility and reproducibility to perform noninvasively 24-h aortic ABPM with a novel validated brachial cuff-based automatic oscillometric device (Mobilo-O-Graph) which records brachial BP and waveforms and assesses aortic BP via mathematical transformation. METHODS Thirty consecutive subjects (mean age: 53.6 ± 11.6 years, 17 men) had a test-retest ABPM with at least 1-week interval. No modification of vasoactive drug treatment during the interval was allowed while similar 24-h activity during both recording days was recommended. RESULTS The average number of valid readings for brachial vs. aortic BP were 69.9 ± 10.4 vs. 58.0 ± 13.3 in the initial 24-h assessment (P < 0.001) and 68.3 ± 10.8 vs. 56.4 ± 13.6 in the repeat assessment (P < 0.001). No differences in average 24 h aortic BP values were observed between the two assessments (systolic blood pressure (SBP) 115.9 ± 7.7 vs. 115.1 ± 6.0 mm Hg, respectively, P = 0.48, and diastolic 79.7 ± 7.4 vs. 79.2 ± 8.7, P = 0.54). Reproducibility indices of aortic pressure including, intraclass coefficient of variation (SBP: 0.80 (95% confidence interval 0.58-0.90); diastolic: 0.92 (0.83-0.96)) and s.d. of differences (SBP/diastolic: 6.0/4.5 mm Hg) indicated acceptable reproducibility. The Bland-Altman plots indicated no evidence of systemic bias. CONCLUSIONS In conclusion, these data suggest that noninvasive 24-h ABPM is feasible and provides reproducible values. Future studies should validate the prognostic ability of 24-h aortic hemodynamics.

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.

Validation of non-invasive central blood pressure devices: ARTERY Society task force consensus statement on protocol standardization

This article was published in European Heart Journal on 30 January 2017, available open access at https://doi.org/10.1093/eurheartj/ehw632

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 Al 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 Al was associated with age, female gender, heart rate, mean blood pressure, hyperlipidaemia, and use of statins (regression coefficient (β) = 0.50, β = 0.15, β=-0.60, β = 0.23, β = 0.16 and β=-0.14, respectively, P<0.05). Increasing Al 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 Al 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.

Towards fast 3D ear recognition for real-life biometric applications

Three-dimensional data are increasingly being used for biometric purposes as they offer resilience to problems common in two-dimensional data. They have been successfully applied to face recognition and more recently to ear recognition. However, real-life biometric applications require algorithms that are both robust and efficient so that they scale well with the size of the databases. A novel ear recognition method is presented that uses a generic annotated ear model to register and fit each ear dataset. Then a compact biometric signature is extracted that retains 3D information. The proposed method is evaluated using the largest publicly available 3D ear database appended with our own database, resulting in a database containing data from multiple 3D sensor types. Using this database it is shown that the proposed method is not only robust, accurate and sensor invariant but also extremely efficient, thus making it suitable for real-life biometric applications.

Association of nighttime hypertension with central arterial stiffness and urinary albumin excretion in dipper hypertensive subjects

Both blood pressure (BP) non-dipping and nighttime hypertension have been associated with accelerated target-organ damage (TOD). However, increased nighttime BP in subjects with a dipping circadian BP profile has never been reported or associated with TOD. Here, we investigated the relationships of nighttime BP with indices of vascular and kidney damage in dipper hypertensive subjects. We studied 402 subjects with untreated stage I-II essential hypertension. According to ambulatory BP recordings, 127 dipper subjects were selected and subdivided into nighttime hypertensives (NH, n=69) (nighttime BP ⩾120/70) and nighttime normotensives (NN, n=50) (nighttime BP <120/70 mm Hg). All participants underwent echocardiographic examination and assessments of carotid-to-femoral pulse wave velocity (c-f PWV), albumin-to-creatinine ratio (ACR), metabolic profile and high sensitivity C-reactive protein (hs-CRP) level. Compared with NN dippers, NH dippers had higher c-f PWV (P<0.001), ACR values (P=0.01) and hs-CRP levels (P<0.001). Multiple regression analysis showed that nighttime BP was more correlated with c-f PWV and ACR than was daytime BP. Among dippers, nighttime BP is associated more closely with c-f PWV and ACR than is daytime BP. These findings imply that even in dippers, absolute nighttime BP values should be taken into account when predicting surrogate end points such as arterial stiffness and urinary albumin excretion.