Aortic Pulse Pressure Research Articles

Central aortic pulse pressure, thrombogenicity and cardiovascular risk.

High central aortic pulse pressure (CPP) and thrombin-induced platelet-fibrin clot strength (TIP-FCS) have been associated with ischemic outcomes in patients with coronary artery disease in separate studies. But, the ischemic risk associated with these factors has never been analyzed in a single study and their interrelation is unknown. The primary aim of the study was to establish cut points for CPP and TIP-FCS measured at the time of catheterization associated with long term major adverse cardiovascular events. We enrolled 334 consecutive patients undergoing cardiac catheterization and assessed thrombogenicity by thrombelastography. Patients were followed up to 3 years. The primary endpoint was a composite of cardiovascular death, myocardial infarction, and ischemic stroke and the secondary endpoint was occurrence of the primary endpoint or recurrent ischemic events requiring hospitalization. Patients with primary and secondary endpoint occurrence had higher CPP (83 ± 20 vs. 60 ± 18mmHg, p < 0.0001; 70 ± 21 vs. 59 ± 18mmHg, p < 0.0001, respectively) and TIP-FCS (68.5 ± 5.8 vs. 65.5 ± 5.0mm, p = 0.008; 67.4 ± 5.9 vs. 65.2 ± 4.8mm, p = 0.001, respectively). CPP >60mmHg and TIP-FCS >69mm were both independent predictors of primary endpoint occurrence (p = 0.0001 and p = 0.02, respectively). ROC analysis for CPP and TIP-FCS showed a C-statistic of 0.81 (p < 0.0001) and 0.68 (p = 0.007) for the primary endpoint, respectively. Patients with CPP >60mmHg had higher TIP-FCS (66.8 ± 5.1 vs. 64.8 ± 5.0mm, p < 0.001) and primary and secondary endpoint occurrence (13 vs. 1.1%, p < 0.0001 and 31.8 vs. 14.4%, p = 0.0002, respectively). CPP >60mmHg + TIP-FCS > 69mm was associated with a markedly increased risk of primary endpoint occurrence [HR (95% CI) 5.4(2.3-12.5), p = 0.0001]. High CPP and thrombogenicity are interrelated; each are independently associated with increased cardiovascular risk; and simultaneous presence markedly enhances risk. The mechanistic link between CPP and thrombogenicity deserves further study.

Ascending to descending aortic pulse pressure amplification in children.

A peripheral pulse pressure (PP) is larger than a central PP (PP amplification). The phenomenon has been examined in adult, but not in children. Fifty-four patients with a normal aorta were enrolled. The ascending and descending aorta pressure waveforms were recorded by a pressure sensor-mounted catheter. The difference of the PP, which was defined as the PP in the descending aorta minus that in the ascending aorta and the ratio of the PP, which was defined as the ratio of the descending to the ascending aortic PP, was examined as the index of the PP amplification. The patient's age was 6.2 ± 3.0 years. The difference of the PP was 4.5 ± 2.7 mmHg and had a significant positive relationship with the mean blood pressure (r = 0.46, P = 0.0005) and the age (r = 0.36, P = 0.009). The ratio of the PP was 1.14 ± 0.08 and had a significant positive relationship with the mean blood pressure (r = 0.42, P = 0.002) and the age (r = 0.29, P = 0.04). The PP amplification is observed even in children. The degree of the PP amplification increases with age during childhood contrary to the relationship in adults.

Comparison of Different Invasive Hemodynamic Measurements as a Prediction Tool for Mortality after Transcatheter Aortic Valve Replacement in Men: A Retrospective Observational Study.

IntroductionHemodynamic measurements can assess for paravalvular aortic regurgitation after transcatheter aortic valve replacement (TAVR). This study compared the utility of different invasive hemodynamic measures in providing prognostic information.MethodsThis retrospective observational study of TAVR patients at a Veterans Hospital assessed aortic regurgitation index, diastolic delta, pulse pressure, and heart rate adjusted diastolic delta obtained at valve implantation. The primary outcome was total mortality.ResultsOverall, 151 patients underwent TAVR. Immediately after implantation, mean aortic regurgitation index was 31 ± 8.6, mean diastolic delta was 38 ± 9.8 mmHg, mean pulse pressure was 67 ± 18 mmHg, and mean heart rate adjusted diastolic delta was 47 ± 14.3 mmHg/beats per minute. Two percent of patients had ≥ moderate paravalvular aortic regurgitation by postoperative transthoracic echocardiography. Total mortality was 15.2% at a mean follow-up of 12.7 ± 9.2 months. Aortic regurgitation index <25 vs. ≥25, diastolic delta <19 vs. ≥19 mmHg, and pulse pressure >60 vs. ≤60 mmHg were not associated with total mortality. However, total mortality was 50% for heart rate adjusted diastolic delta <25 mmHg/beats per minute vs. 12.6% for heart rate adjusted diastolic delta ≥25 mmHg/beats per minute (p = 0.017). In a multivariate Cox regression analysis, heart rate adjusted diastolic delta <25 mmHg/beats per minute vs. heart rate adjusted diastolic delta ≥25 mmHg/beats per minute was associated with total mortality (hazard ratio 9.4, 95% confidence interval 2.0–44, p = 0.004).ConclusionsAmong a cohort of TAVR patients, the only invasive hemodynamic test independently associated with total mortality was heart rate adjusted diastolic delta.

Hypertensive Cardiovascular Risk: Pulsatile Hemodynamics, Gender, and Therapeutic Implications.

In recent years, the predictive value of 2 pulsatile parameters has been extensively studied in hypertension: aortic stiffness and pulse pressure (PP) amplification. Aortic stiffness is an index of aortic rigidity and PP-amplification is the ratio between central and brachial PP, an indirect evaluation of wave reflections. Both are safe, independent, noninvasive predictors of overall and cardiovascular risk. Our purpose is to determine the validity of these parameters in 2 different circumstances: gender and therapeutic implications. Studies have shown that whereas steady mean arterial pressure is significantly higher in men than in women, pulsatile pressure largely predominates in women, mostly in older age and as a consequence of short stature. Gender differences require more extensive investigation due to the disparities of dose-response ranging among populations and the contribution of ethnic factors, frequently based on individual origin. Many questions have yet to be resolved. First, the prognosis of antihypertensive therapy is largely based on blood pressure reduction but also requires evaluation of arterial rigidity and wave reflections to achieve adequate therapeutic "de-stiffening." The most effective approach appears to be the combination of angiotensin- and calcium-channel blockade, in certain cases associated with diuretic compounds. Second, antialdosterone drugs can be useful, but it is their antifibrotic more than their antihypertensive effect that appears effective. Third, prevention of comorbidities, such as those associating hypertension, diabetes, and/or kidney damage, should become primary targets for drug treatment.

Greater Aortic Hemodynamic Responses to Muscle Metaboreflex Activation In Older Adults with Prediabetes than Diabetes

PURPOSE: Wave reflection measures (augmentation pressure [AP] and index [AIx]) are similarly increased in adults with type 2 diabetes (T2D) and prediabetes (PRET2D) suggesting high cardiovascular risk. An exaggerated blood pressure (BP) response to muscle metaboreflex activation induced via post-exercise muscle ischemia (PEMI) following isometric handgrip exercise has been reported in patients with T2D. The purpose of this study was to examine the wave reflection responses to PEMI in adults with PRET2D and T2D. METHODS: Aortic hemodynamics were obtained using pulse wave analysis at rest and during PEMI following isometric handgrip at 30% of maximal voluntary contraction in adults (age, 59.7 ± 6.3 y) with PRET2D (n= 12) and T2D (n= 12). RESULTS: Vascular parameters were similar at rest. Aortic systolic BP (PRET2D Δ42 ± 13 mmHg vs. T2D Δ31 ± 10 mmHg, P < 0.001 for both), pulse pressure (PRET2D Δ22± 9 mmHg vs. T2D Δ13 ± 10 mmHg, P < 0.001 and P < 0.01, respectively) and AP (PRET2D Δ13 ± 5 mmHg vs. T2D Δ9 ± 5 mmHg, P < 0.001 for both) responses to PEMI were greater (P < 0.05) in PRET2D compared with T2D patients. The aortic diastolic BP, AIx, AIx adjusted at 75 bpm, and time to reflection responses to PEMI were similar in PRET2D and T2D. CONCLUSIONS: Our findings show that aortic hemodynamic responses to exercise-related metabolites are exaggerated in PRET2D. These findings suggest that an increased left ventricular afterload during muscle metaboreflex activation may contribute to augment cardiovascular risk in adults with PRET2D.

Assessment of Early Cardiovascular Risk in Children and Adolescents with Essential Hypertension.

The aim of our study was to investigate some early markers of hypertensive target organ damage in hypertensive children and adolescents, and to detect those showing most prominent clinical significance. We included 100 children with essential hypertension (EH) and 50 age-matched healthy control children, and evaluated left ventricular mass (LVM), intima-media thickness in the carotid arteries (IMT), pulse wave velocity (PWV), microalbuminuria, biochemical parameters and some adipokines. Statistically significant differences between the 2 groups were observed for HDL-cholesterol, LDL-cholesterol, triglycerides, insulin, uric acid, glucose, apolipoprotein A1, and total adiponectin. The mean values of IMT, PWV and LVM were greater in hypertensive children, but only the differences in IMT and LVM were statistically significant. In addition, hypertensive children showed significantly higher values of AoSP (aortic systolic pressure), AoPP (aortic pulse pressure) and AIx@75 (augmentation index corrected for heart rate of 75 b.p.m.). Metabolic syndrome was diagnosed in 31% of hypertensive children. A significant number of children with EH have early target organ changes as well as other risk factors, including metabolic syndrome, especially obese ones. However, IMT, LVM and some parameters of arterial stiffness have been found to be early markers in both obese and non-obese hypertensives. In addition, adipokines and coagulation factors seem to be important in obese hypertensives.

Model-Based Blind System Identification Approach to Estimation of Central Aortic Blood Pressure Waveform From Noninvasive Diametric Circulatory Signals

This paper presents a model-based blind system identification approach to estimation of central aortic blood pressure (BP) waveform from noninvasive diametric circulatory signals. First, we developed a mathematical model to reproduce the relationship between central aortic BP waveform and a class of noninvasive circulatory signals at diametric locations by combining models to represent wave propagation in the artery, arterial pressure–volume relationship, and mechanics of the measurement instrument. Second, we formulated the problem of estimating central aortic BP waveform from noninvasive diametric circulatory signals into a blind system identification problem. Third, we performed identifiability analysis to show that the mathematical model could be identified and its parameters determined up to an unknown scale. Finally, we illustrated the feasibility of the approach by applying it to estimate central aortic BP waveform from two diametric pulse volume recording (PVR) signals. Experimental results from ten human subjects showed that the proposed approach could estimate central aortic BP waveform accurately: the average root-mean-squared error (RMSE) associated with the central aortic BP waveform was 4.1 mm Hg (amounting to 4.5% of the underlying mean BP) while the average errors associated with central aortic systolic pressure (SP) and pulse pressure (PP) were 2.4 mm Hg and 2.0 mm Hg (amounting to 2.5% and 2.1% of the underlying mean BP). The proposed approach may contribute to the improved monitoring of cardiovascular (CV) health by enabling estimation of central aortic BP waveform from conveniently measurable diametric circulatory signals.

The value of diastolic flow reversal in the descending thoracic aorta as a determinant of invasively measured aortic pulse pressure.

Although the diastolic flow reversal of the descending aorta has been recognized in patients with aortic regurgitation, its generation without this condition is still unknown. This study was performed to investigate whether flow patterns of the descending thoracic aorta, as measured by echocardiography, can represent invasively measured aortic pulse pressure (APP). A total of 100 patients (age, 62.3±11.0years; men, 62.0%) undergoing invasive coronary angiography (ICA) was analyzed. APP was measured at ascending thoracic aorta using pigtail catheter before ICA. Flow in the descending thoracic aorta was assessed using pulse wave Doppler echocardiography, and R/F ratio was defined as reverse peak velocity (R)/forward peak velocity (F). Eighty patients (80.0%) had obstructive coronary artery disease (CAD) (≥50% stenosis of one or more epicardial coronary arteries) in ICA. APP and R/F ratio were significantly higher in patients with obstructive CAD than those without (P<.05 for each). Both R/F ratio (β=0.379, P<.001) and APP (β=0.255, P<.001) were positively correlated with age. In simple linear regression analysis, there was a significant positive correlation between R/F ratio and APP (β=0.266, P<.001). This correlation remained significant even after controlling for potential confounders including age, gender, E/e', and left atrial volume index in multiple linear regression analysis (β=0.193, P=.036). R/F ratio may be independently associated with APP in patients undergoing ICA.

Respiratory variation in peak aortic velocity accurately predicts fluid responsiveness in children undergoing neurosurgery under general anesthesia.

The determination of fluid responsiveness in the critically ill child is of vital importance, more so as fluid overload becomes increasingly associated with worse outcomes. Dynamic markers of volume responsiveness have shown some promise in the pediatric population, but more research is needed before they can be adopted for widespread use. Our aim was to investigate effectiveness of respiratory variation in peak aortic velocity and pulse pressure variation to predict fluid responsiveness, and determine their optimal cutoff values. We performed aprospective, observational study at a single tertiary care pediatric center. Twenty-one children with normal cardiorespiratory status undergoing general anesthesia for neurosurgery were enrolled. Respiratory variation in peak aortic velocity (ΔVpeak ao) was measured both before and after volume expansion using a bedside ultrasound device. Pulse pressure variation (PPV) value was obtained from the bedside monitor. All patients received a 10ml/kg fluid bolus as volume expansion, and were qualified as responders if stroke volume increased >15% as a result. Utility of ΔVpeak ao and PPV and to predict responsiveness to volume expansion was investigated. A baseline ΔVpeak ao value of greater than or equal to 12.3% best predicted a positive response to volume expansion, with a sensitivity of 77%, specificity of 89% and area under receiver operating characteristic curve of 0.90. PPV failed to demonstrate utility in this patient population. Respiratory variation in peak aortic velocity is a promising marker for optimization of perioperative fluid therapy in the pediatric population and can be accurately measured using bedside ultrasonography. More research is needed to evaluate the lack of effectiveness of pulse pressure variation for this purpose.

Contributions of aortic pulse wave velocity and backward wave pressure to variations in left ventricular mass are independent of each other

Aortic pulse wave velocity (PWV) and backward waves, as determined from wave separation analysis, predict cardiovascular events beyond brachial blood pressure. However, the extent to which these aortic hemodynamic variables contribute independent of each other is uncertain. In 749 randomly selected participants of African ancestry, we therefore assessed the extent to which relationships between aortic PWV or backward wave pressures (Pb) (and hence central aortic pulse pressure [PPc]) and left ventricular mass index (LVMI) occur independent of each other. Aortic PWV, PPc, forward wave pressure (Pf), and Pb were determined using radial applanation tonometry and SphygmoCor software and LVMI using echocardiography; 44.5% of participants had an increased left ventricular mass indexed to height1.7. With adjustments for age, brachial systolic blood pressure or PP, and additional confounders, PPc and Pb, but not Pf, were independently related to LVMI and left ventricular hypertrophy (LVH) in both men and women. However, PWV was independently associated with LVMI in women (partial r = 0.16, P < .001), but not in men (partial r = 0.03), and PWV was independently associated with LVH in women (P < .05), but not in men (P = .07). With PWV and Pb included in the same multivariate regression models, PWV (partial r = 0.14, P < .005) and Pb (partial r = 0.10, P < .05) contributed to a similar extent to variations in LVMI in women. In addition, with PWV and Pb included in the same multivariate regression models, PWV (P < .05) and Pb (P < .02) contributed to LVH in women. In conclusion, aortic PWV and Pb (and hence pulse pressure) although both associated with LVMI and LVH produce effects which are independent of each other.

Noninvasive evaluation of varying pulse pressures in vivo using brachial sphymomanometry, applanation tonometry, and Pulse Wave Ultrasound Manometry

The routine assessment and monitoring of hypertension may benefit from the evaluation of arterial pulse pressure (PP) at more central locations (e.g. the aorta) rather solely at the brachial artery. Pulse Wave Ultrasound Manometry (PWUM) was previously developed by our group to provide direct, noninvasive aortic PP measurements using ultrasound elasticity imaging. Using PWUM, radial applanation tonometry, and brachial sphygmomanometry, this study investigated the feasibility of noninvasively obtaining direct PP measurements at multiple arterial locations in normotensive, pre-hypertensive, and hypertensive human subjects. Two-way ANOVA indicated a significantly higher aortic PP in the hypertensive subjects, while radial and brachial PP were not significantly different among the subject groups. No strong correlation (r2 < 0.45) was observed between aortic and radial/brachial PP in normal and pre-hypertensive subjects, suggesting that increases in PP throughout the arterial tree may not be uniform in relatively compliant arteries. However, there was a relatively strong positive correlation between aortic PP and both radial and brachial PP in hypertensive subjects (r2 = 0.68 and 0.87, respectively). PWUM provides a low-cost, non-invasive, and direct means of measuring the pulse pressure in large central arteries such as the aorta. When used in conjunction with peripheral measurement devices, PWUM allows for the routine screening of hypertension and monitoring of BP-lowering drugs based on the PP from multiple arterial sites.

Effects of Sacubitril/Valsartan Versus Olmesartan on Central Hemodynamics in the Elderly With Systolic Hypertension: The PARAMETER Study.

Effective treatment of systolic hypertension in elderly patients remains a major therapeutic challenge. A multicenter, double-blind, randomized controlled trial with sacubitril/valsartan (LCZ696), a first-in-class angiotensin receptor neprilysin inhibitor, was conducted to determine its effects versus olmesartan (angiotensin receptor blocker) on central aortic pressures, in elderly patients (aged ≥60 years) with systolic hypertension and pulse pressure >60 mm Hg, indicative of arterial stiffness. Patients (n=454; mean age, 67.7 years; mean seated systolic blood pressure, 158.6 mm Hg; mean seated pulse pressure, 69.7 mm Hg) were randomized to receive once-daily sacubitril/valsartan 200 mg or olmesartan 20 mg, force titrated to double the initial doses after 4 weeks, before primary assessment at 12 weeks. The study extended double-blind treatment for 12 to 52 weeks, during which amlodipine (2.5-5 mg) and subsequently hydrochlorothiazide (6.25-25 mg) were added-on for patients not achieving blood pressure target (<140/90). At week 12, sacubitril/valsartan reduced central aortic systolic pressure (primary assessment) greater than olmesartan by -3.7 mm Hg (P=0.010), further corroborated by secondary assessments at week 12 (central aortic pulse pressure, -2.4 mm Hg, P<0.012; mean 24-hour ambulatory brachial systolic blood pressure and central aortic systolic pressure, -4.1 mm Hg and -3.6 mm Hg, respectively, both P<0.001). Differences in 24-hour ambulatory pressures were pronounced during sleep. After 52 weeks, blood pressure parameters were similar between treatments (P<0.002); however, more patients required add-on antihypertensive therapy with olmesartan (47%) versus sacubitril/valsartan (32%; P<0.002). Both treatments were equally well tolerated. The PARAMETER study (Prospective Comparison of Angiotensin Receptor Neprilysin Inhibitor With Angiotensin Receptor Blocker Measuring Arterial Stiffness in the Elderly), for the first time, demonstrated superiority of sacubitril/valsartan versus olmesartan in reducing clinic and ambulatory central aortic and brachial pressures in elderly patients with systolic hypertension and stiff arteries.

Loss of pulse pressure amplification between the ascending and descending aorta in patients after an aortic arch repair.

One of the most important problems in patients with an aortic coarctation after an aortic arch repair is future cardiovascular disease. We previously reported the enhancement of the aortic pressure wave reflection in patients and hypothesized that the enhancement was caused by a new pressure wave reflection generated from the repaired site. To prove the hypothesis, we analyzed the pressure waveform in the ascending and descending aorta and examined their pulse pressure (PP) amplification. Fifteen patients after an aortic arch repair without a recoarctation were enrolled. The ascending and descending aorta pressure waveforms were recorded by a pressure sensor mounted catheter. The pressures were compared with those of age-matched controls. The patient's age was 7.3 ± 2.7 years, and they underwent the aortic arch repair at 30.1 ± 29.0 days. The ascending aorta SBP (106.1 ± 12.7 mmHg) was higher than in the control patients (97.9 ± 14.3) (P = 0.015). The PP at the ascending aorta in the patients (41.3 ± 7.8) was wider than that in the controls (36.4 ± 5.0) (P = 0.010). There was no difference concerning the PP at the descending aorta between the patients (41.0 ± 7.7) and controls (40.5 ± 6.5). The difference in the PP between the descending and ascending aorta (PP at the descending aorta - PP at the ascending aorta) in the patients was -0.3 ± 1.7 and 5.1 ± 2.9 in the controls (P < 0.0001). The ascending aortic PP was augmented in the patients after the aortic arch repair. It could be one of the causes of future cardiovascular disease.

Time to the peak of the aortic forward wave determines the impact of aortic backward wave and pulse pressure on left ventricular mass.

To determine the degree to which an extended time to the peak of the aortic forward wave or early wave reflection time enhance associations between aortic backward wave pressure and hence central aortic pulse pressure (PPc) and left ventricular mass index (LVMI). In 701 adult participants from a community sample either receiving no antihypertensive therapy or receiving low-dose thiazide diuretic monotherapy for at least a year (the major therapy employed), we assessed aortic haemodynamics (SphygmoCor software and wave separation analysis; AtCor Medical, West Ryder, New South Wales, Australia) and LVMI (echocardiography). An interaction between time to the peak of the aortic forward wave and aortic backward wave pressure was independently associated with aortic augmented pressure (P < 0.01), PPc (P < 0.005), LVMI (P < 0.01), and LV hypertrophy (LVH; P = 0.01). The time to the peak of the aortic forward wave-aortic backward wave pressure interaction translated into a stepwise increase in the independent association between aortic backward wave pressure and aortic augmented pressure or PPc across quartiles of time to the peak of the aortic forward wave (P < 0.05 to < 0.0001 for comparison of slopes of relations). Furthermore, the time to the peak of the aortic forward wave-aortic backward wave pressure interaction translated into an increase in the independent association between PPc or aortic backward wave pressure and LVMI (P < 0.05 to < 0.001 for comparison of slopes and strength of relations) or LVH (P < 0.05 for comparisons of odds ratios), but not between forward wave pressures and LVMI or LVH across quartiles of time to the peak of the aortic forward wave. A markedly better ability of aortic backward wave pressure and PPc, but not forward wave pressures to detect LVH was noted in the highest as compared with the first three quartiles of time to the peak of the aortic forward wave (P < 0.05). In contrast, reflection time failed to influence the impact of aortic backward wave pressure or PPc on LVMI. Time to the peak of the aortic forward wave, but not early wave reflection markedly influences the impact of aortic backward wave pressure and hence aortic pulse pressure on LVMI and LVH in adults.

Left Atrial Mechanical Function and Aortic Stiffness in Middle-aged Patients with the First Episode of Atrial Fibrillation.

Background:In the early stages of atrial remodeling, aortic stiffness might be an indication of an atrial myopathy, in particular, atrial fibrosis. This study aimed to investigate the association between left atrial (LA) mechanical function, assessed by two-dimensional speckle tracking echocardiography, and aortic stiffness in middle-aged patients with the first episode of nonvalvular atrial fibrillation (AF).Methods:This prospective study included 34 consecutive patients with the first episode of AF, who were admitted to Kartal Koşuyolu Research and Training Hospital between May 2013 and October 2015, and 31 age- and gender-matched healthy controls. During the 1st month (mostly in the first 2 weeks) following their first admission, 34 patients underwent the first pulse wave measurements. Then, 21 patients were recalled for their second pulse wave measurement at 11.8 ± 6.0 months following their initial admission. Echocardiographic and pulse wave findings were compared between these 34 patients and 31 healthy controls. We also compared the pulse wave and echocardiographic findings between the first and second measurements in 21 patients.Results:Pulse wave analysis showed no significant differences between the AF patients and healthy controls with respect to PWV (10.2 ± 2.5 m/s vs. 9.7 ± 2.1 m/s; P = 0.370), augmentation pressure (9.6 ± 7.4 mmHg vs. 9.1 ± 5.7 mmHg; P = 0.740), and aortic pulse pressure (AoPP; 40.4 ± 14.0 mmHg vs. 42.1 ± 7.6 mmHg, P = 0.550). The first LA positive peak of strain was inversely related to the augmentation pressure (r = −0.30; P = 0.02) and aortic systolic pressure (r = −0.26, P = 0.04). Comparison between the two consecutive pulse wave measurements in 21 patients showed similar results, except for AoPP. In 21 patients, the AoPP at the second measurement (45.1 ± 14.1 mmHg) showed a significant increase compared with AoPP at the first measurement (39.0 ± 10.6 mmHg, P = 0.028), which was also higher than that of healthy controls (42.1 ± 7.6 mmHg, P = 0.000).Conclusion:The association between aortic stiffness with reduced atrial strain and the key role of AoPP in the development of AF should be considered when treating nonvalvular AF patients with normal LA sizes.

Determining arterial wave transit time from a single aortic pressure pulse in rats: vascular impulse response analysis

Arterial wave transit time (τw) in the lower body circulation is an effective biomarker of cardiovascular risk that substantially affects systolic workload imposed on the heart. This study evaluated a method for determining τw from the vascular impulse response on the basis of the measured aortic pressure and an assumed triangular flow (Qtri). The base of the unknown Qtri was constructed with a duration set equal to ejection time. The timing of the peak triangle was derived using a fourth-order derivative of the pressure waveform. Values of τws obtained using Qtri were compared with those obtained from the measure aortic flow wave (Qm). Healthy rats (n = 27), rats with chronic kidney disease (CKD; n = 22), and rats with type 1 (n = 22) or type 2 (n = 11) diabetes were analyzed. The cardiovascular conditions in the CKD rats and both diabetic groups were characterized by a decrease in τws. The following significant relation was observed (P < 0.0001): τwtriQ = −1.5709 + 1.0604 × τwmQ (r2 = 0.9641). Our finding indicates that aortic impulse response can be an effective method for the estimation of arterial τw by using a single pressure recording together with the assumed Qtri.

Gender Difference in the Association between Aortic Pulse Pressure and Left Ventricular Filling Pressure in the Elderly: An Invasive Hemodynamic Study

BackgroundThis study was conducted to determine the association between aortic pulse pressure (APP) and left ventricular (LV) filling pressure in the elderly of both genders. MethodsA total of 211 stable elderly subjects (age ≥65 years, mean age 72.1 ± 5.2 years, 53.6% women) who underwent invasive coronary angiography (ICA) for the evaluation of coronary artery disease (CAD) were prospectively investigated. APP was measured in the ascending aorta using a pigtail catheter immediately before ICA. E/e′, reflecting LV filling pressure, was assessed by transthoracic echocardiography. ResultsThere were positive linear correlations between APP and E/e′ in both genders, but the correlation power was stronger in women than in men (r = 0.402, P < .001 vs r = 0.208, P = .040). The significance of this association between APP and E/e′ remained after controlling for potential confounders in multiple linear regression analysis in women (β = 0.359, P < .001), but not in men (r = 0.139, P = .108). ConclusionsInvasively measured APP is independently associated with E/e′ in elderly women, but not in elderly men undergoing ICA. Aortic stiffness may be a potential mechanism for more prevalent LV diastolic dysfunction and heart failure with preserved ejection fraction in elderly women.

In silico analysis of the anti-hypertensive drugs impact on myocardial oxygen balance.

Hypertension is a very common pathology, and its clinical treatment largely relies on different drugs. Some of these drugs exhibit specific protective functions in addition to those resulting from blood pressure reduction. In this work, we study the impact of commonly used anti-hypertensive drugs (RAAS, [Formula: see text] and calcium channel blockers) on myocardial oxygen supply-consumption balance, which plays a crucial role in type 2 myocardial infarction. To this aim, 42 wash-out hypertensive patients were selected, a number of measured data were used to set a validated multi-scale cardiovascular model to subject-specific conditions, and the administration of different drugs was suitably simulated. Our results ascribe the well-known major cardioprotective efficiency of [Formula: see text] blockers compared to other drugs to a positive change of myocardial oxygen balance due to the concomitant: (1) reduction in aortic systolic, diastolic and pulse pressures, (2) decrease in left ventricular work, diastolic cavity pressure and oxygen consumption, (3) increase in coronary flow and (4) ejection efficiency improvement. RAAS blockers share several positive outcomes with [Formula: see text] blockers, although to a reduced extent. In contrast, calcium channel blockers seem to induce some potentially negative effects on the myocardial oxygen balance.

GENETIC POLYMORPHISM OF THE INFLAMMATORY CYTOKINE GENES AND ARTERIAL WALL PROPERTIES IN HYPERTENSIVE PATIENTS

Objective. To elucidate the association between polymorphic markers of the genes of C-reactive protein (CRP), interleukin 10 (IL10), interleukin 6 (IL6), lymphotoxin alpha (LTA) and tumor necrosis factor (TNFA) and changes of arterial stiffness in hypertensive patients. Design and methods. The study included 130 patients with hypertension (HTN) (64 (49,3%) men and 66 (50,7%) women), average age 63,7 ± 12,87 years. The intima-media thickness was measured by the method proposed by P. Pignolli. The arterial stiffness was assessed by the carotidfemoral and carotid-radial pulse wave velocity (PWV). Central aortic pulse pressure (PP) was calculated using pulse contour analysis. Results. An association of polymorphic markers of A (-3872)G, G (-2667)C, A (-5237) G CRP gene, G (-1082)A gene IL10, C (-174)G gene IL6, and A (-308)G gene TNFA with pulse wave velocity, PP in the aorta, the presence of atherosclerotic plaques of carotid arteries was found. Among patients with aortic PP &gt; 50 mmHg the frequency of AA genotype carriers of polymorphic marker C804A LTA gene was higher (p = 0,037). Carriers AA genotype had a significantly greater carotid-femoral PWV as compared with native CC genotype (13,4 and 11,9 m/s, p = 0,042) and higher PP in the aorta. Also, higher PP and aortic PWV were found in carriers of GG genotype of A (252)G LTA gene. Among patients with the presence of atherosclerotic plaques of carotid arteries the frequency of AA genotype of the G (-3014)A CRP gene was higher (p = 0,031). Conclusion. Thus, we have shown that CRP gene polymorphism is associated with the development of carotid atherosclerosis and increased central PP, while lymphotoxin alpha gene polymorphism is associated with the increase in arterial stiffness in high risk hypertensive patients. Our data confirm the involvement of pro-inflammatory cytokines in the development of atherosclerosis and endothelial dysfunction.

High-frequency operation of a pulsatile VAD - a simulation study.

Ventricular assist devices (VADs) are mechanical blood pumps that are clinically used to treat severe heart failure. Pulsatile VADs (pVADs) were initially used, but are today in most cases replaced by turbodynamic VADs (tVADs). The major concern with the pVADs is their size, which prohibits full pump body implantation for a majority of patients. A reduction of the necessary stroke volume can be achieved by increasing the stroke frequency, while maintaining the same level of support capability. This reduction in stroke volume in turn offers the possibility to reduce the pump's overall dimensions. We simulated a human cardiovascular system (CVS) supported by a pVAD with three different stroke rates that were equal, two- or threefold the heart rate (HR). The pVAD was additionally synchronized to the HR for better control over the hemodynamics and the ventricular unloading. The simulation results with a HR of 90 bpm showed that a pVAD stroke volume can be reduced by 71%, while maintaining an aortic pulse pressure (PP) of 30 mm Hg, avoiding suction events, reducing the ventricular stroke work (SW) and allowing the aortic valve to open. A reduction by 67% offers the additional possibility to tune the interaction between the pVAD and the CVS. These findings allow a major reduction of the pVAD's body size, while allowing the physician to tune the pVAD according to the patient's needs.