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

Risk of Heart Disease in Patients With Amputation: A Nationwide Cohort Study in South Korea

BACKGROUND

Amputation confers disabilities upon patients and is linked to substantial morbidity and death attributed to heart disease. While some studies have focused on traumatic amputees in veterans, few studies have focused on traumatic amputees within the general population. Therefore, the present study aimed to assess the risk of heart disease in patients with traumatic amputation with disability within the general population using a large-scale nationwide population-based cohort.

METHODS AND RESULTS

We used data from the Korean National Health Insurance System. A total of 22 950 participants with amputation were selected with 1:3 age, sex-matched controls between 2010 and 2018. We used Cox proportional hazard models to calculate the risk of myocardial infarction, heart failure, and atrial fibrillation among amputees. Participants with amputation had a higher risk of myocardial infarction (adjusted hazard ratio [aHR], 1.30 [95% CI, 1.14-1.47]), heart failure (aHR, 1.27 [95% CI, 1.17-1.38]), and atrial fibrillation (aHR, 1.17 [95% CI, 1.03-1.33]). The risks of myocardial infarction and heart failure were further increased by the presence of disability (aHR, 1.43 [95% CI, 1.04-1.95]; and aHR, 1.38 [95% CI, 1.13-1.67], respectively).

CONCLUSIONS

We demonstrate an increased risk of myocardial infarction, heart failure, and atrial fibrillation among individuals with amputation, and the risk further increased in those with disabilities. Clinicians should pay attention to the increased risk for heart disease in patients with amputation.

Association of arterial stiffness and heart failure with preserved ejection fraction in the elderly population - results from the CARLA study

Arterial stiffness has been suspected as a cause of left ventricular diastolic dysfunction and may thereby contribute to the development of heart failure with preserved ejection fraction (HFpEF). However, this association is derived from a small number of studies and application of outdated criteria to diagnose HFpEF. This study aimed to investigate the association of arterial stiffness measured by the augmentation index (AIx) and criteria for diagnosing HFpEF according to the recommended HFA-PEFF score. Our analysis based on data from the first follow-up of the CARdiovascular Disease, Living and Ageing in Halle study. The current analysis included participants with available information about comorbidities and risk factors for HFpEF, parameters for calculation of the HFA-PEFF and noninvasive AIx estimated by applanation tonometry. The association of AIx and HFA-PEFF was investigated through descriptive and inductive statistics. A total of 767 participants were included in the analysis. AIx was associated with E/e', left ventricular wall thickness (LVWT), relative wall thickness, left ventricular mass index (LVMI) and NT-proBNP but not with e' or left atrial volume index. However, after adjustment for confounders, only LVMI and LVWT remained associated with AIx. Males with a high AIx had a 3.2-fold higher likelihood of HFpEF than those with a low AIx. In contrast, that association was not present in females. In summary, AIx is associated with the morphological domain of the HFA-PEFF score represented by LVMI and LVWT. Higher values of AIx are associated with a higher likelihood for HFpEF in elderly males but not in females.

Effects of hormone replacement therapy on endothelial function, arterial stiffness and myocardial deformation in women with Turner syndrome

OBJECTIVES

Turner syndrome (TS) is associated with increased cardiovascular risk. We investigated whether hormone replacement therapy (HRT) affects endothelial function, arterial stiffness and myocardial deformation in women with TS.

METHODS

Twenty-five women with TS were studied in the estrogen phase of the HRT and two months after discontinuation of HRT. The following measurements were made: flow-mediated dilation (FMD) of the brachial artery, pulse wave velocity (PWV-Complior) and central systolic blood pressure (cSBP), carotid intima-media thickness (cIMT), aortic (Ao) elastic indexes - namely Ao strain, distensibility, stiffness index and pressure strain modulus (Ep) - and left ventricular (LV) global longitudinal strain (GLS) using speckle-tracking echocardiography. Ten healthy female of similar age and BMI served as a control group.

RESULTS

Compared to controls, women with TS on HRT had higher PWV (9.1 ± 2.4 vs. 7.5 ± 0.5 m/s), cSBP (130 ± 15 vs. 121 ± 6 mmHg), cIMT (0.66 ± 0.06 vs. 0.55 ± 0.05 mm), aortic stiffness index, Ep and LA strain, and lower FMD (7.2 ± 4 vs. 10.5 ± 2.3%), Ao strain, Ao distensibility and GLS (-18.8 ± 2.7 vs. -21.9 ± 1.5%) (P < 0.05 for all comparisons). Two months after discontinuation of HRT, all women increased FMD (11.7 ± 6 vs. 7.2 ± 4%) and reduced PWV (7.8 ± 1.7 vs. 9.1 ± 2.4 m/s) and cSBP (123 ± 14 vs. 130 ± 15 mmHg). There were no statistically significant changes in BMI, cIMT and GLS (P > 0.05 for all comparisons). The percentage decrease of cSBP was associated with the percentage decrease of PWV (r = 0.54) and reversely related with the percentage increase of FMD (r = -0.57; P < 0.05 for all comparisons).

CONCLUSIONS

HRT in women with TS may deteriorate endothelial function contributing to increased arterial stiffness and central arterial blood pressure.

Increased Arterial Stiffness Is Associated With Reduced Diastolic Function in Youth With Obesity and Type 2 Diabetes

Background: Increased arterial stiffness is associated with diastolic dysfunction in adults. Data in youth are lacking, so we examined the impact of arterial stiffness on diastolic function in youth. Methods: We obtained diastolic function and augmentation index, pulse wave velocity, brachial artery distensibility, and carotid stiffness on 612 youth [10-24 years, 65% female, 38% normal weight, 36% obese, and 26% with type 2 diabetes mellitus (T2DM)]. Participants were classified as compliant (C) vs. stiff (S) arteries based on seven arterial stiffness parameters [Global Stiffness Index (GSI), S = GSI > 4). Mean differences in covariates were evaluated by Student's t-tests. A stepwise regression analysis was performed to determine if GSI was an independent predictor of diastolic function. Results: Lower diastolic function and more adverse cardiovascular disease (CVD) risk factors were present in the S group (n = 67) than the C group (n = 545) (p < 0.001). Covariates that were associated with diastolic dysfunction were higher GSI, male sex, higher body mass index (BMI), and systolic blood pressure (SBP) z-score (R ² = 0.18 to 0.25; p ≤ 0.05). Conclusion: Adverse diastolic function is seen in youth with increased arterial stiffness independent of CVD risk factors. Interventions to improve arterial stiffness prior to clinical onset of diastolic dysfunction are needed to prevent development of heart failure.

Hemodynamic Determinants of Age Versus Left Ventricular Diastolic Function Relations Across the Full Adult Age Range

The relative contribution of loading conditions at different ages across the full adult lifespan to decreases in left ventricular (LV) diastolic function is unclear. Using central arterial pressure and aortic velocity and diameter measurements in the outflow tract, we determined the contribution of systemic vascular resistance, compression wave pressures (characteristic impedance [Zc]×aortic flow [Q], [P Q×Zc ]) and backward wave pressures (Pb) to LV diastolic function (echocardiography) in a community sample across the full adult lifespan (n=605). Starting from early adulthood, stepwise age-related increases in LV filling pressures (E/e’) and decreases in myocardial relaxation (e’) were noted ( P <0.0001). Before 50 years of age, before when P Q×Zc positively correlates with age, Pb, but not systemic vascular resistance was independently associated with LV mass index ( P <0.002), E/e’ ( P <0.002), and e’ ( P <0.05). Moreover, in those over 50 years of age, when P Q×Zc positively correlates with age, again Pb, but neither P QxZc nor systemic vascular resistance was independently associated with LV mass index ( P <0.01), E/e’ ( P <0.001), and e’ ( P <0.001). The contribution of Pb to age-related decreases in LV diastolic function was as strong in those younger as compared with older than 50 years of age and poorly indexed by brachial BP. In conclusion, a striking age-related deterioration in LV diastolic function begins at an early adult age and Pb is the dominant hemodynamic factor that accounts for this relationship. Age-related increases in Pb in young adults contribute as much to functional abnormalities ultimately responsible for LV diastolic dysfunction in hypertension as at an older age, effects poorly indexed by brachial BP.

Effects of Smoking Cessation with Nicotine Replacement Therapy on Vascular Endothelial Function, Arterial Stiffness, and Inflammation Response in Healthy Smokers

The effects of nicotine replacement therapy (NRT)-aided smoking cessation on vascular function are not fully clarified. We investigated 100 healthy smokers who were motivated to quit and received NRT for a 3-month period. Vascular endothelial function (measured by reactive hyperemia-peripheral arterial tonometry [RH-PAT]), arterial stiffness (measured by augmentation index [AI] and brachial-ankle pulse wave velocity [baPWV]), and systemic inflammation markers (including serum soluble intercellular adhesion molecule-1 [sICAM-1] and interleukin-1β [IL-1β]) were assessed at baseline and 3 and 12 months of follow-up. After 3 months of intervention, endothelial function, arterial stiffness, and inflammatory markers significantly improved (RH-PAT increased, AI and baPWV decreased, sICAM-1 and IL-1β decreased, all P < .05) for the participants who abstained from smoking completely, but for those who did not abstained completely, RH-PAT, AI, baPWV, and IL-1β remained unchanged. At 12 months follow-up, endothelial function (RH-PAT), arterial stiffness (AI and baPWV), and inflammatory markers (sICAM-1 and IL-1β) were further improved in participants who abstained from smoking (P < .001), while the above parameters deteriorated in continued smokers (P < .05). In conclusion, vascular dysfunction can be reversible after NRT-aided smoking cessation in healthy smokers and vascular function could be further damaged if they continue smoking.

The role of ventricular-arterial coupling in cardiac disease and heart failure: assessment, clinical implications and therapeutic interventions. A consensus document of the European Society of Cardiology Working Group on Aorta & Peripheral Vascular Diseases, European Association of Cardiovascular Imaging, and Heart Failure Association

Ventricular-arterial coupling (VAC) plays a major role in the physiology of cardiac and aortic mechanics, as well as in the pathophysiology of cardiac disease. VAC assessment possesses independent diagnostic and prognostic value and may be used to refine riskstratification and monitor therapeutic interventions. Traditionally, VAC is assessed by the non-invasive measurement of the ratio of arterial (Ea) to ventricular end-systolic elastance (Ees). With disease progression, both Ea and Ees may become abnormal and the Ea/Ees ratio may approximate its normal values. Therefore, the measurement of each component of this ratio or of novel more sensitive markers of myocardial (e.g. global longitudinal strain) and arterial function (e.g. pulse wave velocity) may better characterize VAC. In valvular heart disease, systemic arterial compliance and valvulo-arterial impedance have an established diagnostic and prognostic value and may monitor the effects of valve replacement on vascular and cardiac function. Treatment guided to improve VAC through improvement of both or each one of its components may delay incidence of heart failure and possibly improve prognosis in heart failure. In this consensus document, we describe the pathophysiology, the methods of assessment as well as the clinical implications of VAC in cardiac diseases and heart failure. Finally, we focus on interventions that may improve VAC and thus modify prognosis.

Pulsatile Hemodynamics Are Associated With Exercise Capacity in Patients With Exertional Dyspnea and Preserved Left Ventricular Ejection Fraction

BACKGROUND

Pulsatile hemodynamics are associated with left ventricular filling pressures and diastolic dysfunction. We investigated their relationship with maximum workload and peak oxygen uptake (peak VO2) in patients with exertional dyspnea and preserved left ventricular ejection fraction (LVEF).

METHODS

Radial waveforms from tonometry were processed with a transfer function, pulse wave analysis and wave separation analysis, yielding central aortic pressures and measures of forward (amplitude of forward wave-Pf) and reflected waves (augmentation index-AIx, augmentation pressure-AP, amplitude of backward wave-Pb) and their ratio (reflection magnitude). Aortic pulse wave velocity (aoPWV) was estimated with a validated formula from single-point waveforms. Ergospirometry for assessment of exercise capacity was performed on a bicycle ergometer, using a ramp protocol.

RESULTS

Sixty-six patients were included (43 females; mean age 66 years; 83% hypertensives; mean body mass index 28.3 kg/m2). Mean peak VO2 was 17.0 ml/min/kg, mean achieved maximum workload 104.5 watts (80.9% of a reference population). Maximum workload and peak VO2 showed significant inverse relationships with AIx, AP, Pb, and aoPWV (r = -0.26 to -0.57). In multiple adjusted regression models, brachial and aortic pulse pressure, AP, Pf, Pb, and aoPWV were significant independent predictors of maximum workload, whereas AP, AIx75, Pf, Pb, and aoPWV were independently related to peak VO2.

CONCLUSIONS

Pulsatile hemodynamics are independently associated with objective measures of exercise capacity in patients with normal LVEF.

Relationship between Fragmented QRS Complex and Aortic Stiffness in Chronic Hemodialysis Patients

OBJECTIVE

This study aimed to evaluate the correlation between fragmented QRS complex (fQRS), aortic stiffness, and diastolic dysfunction in hemodialysis patients.

SUBJECTS AND METHODS

A sample of 56 patients who received hemodialysis treatment was stratified into 2 groups according to their electrocardiography (ECG) patterns with or without fQRS. Baseline characteristics and laboratory parameters of patients were documented. Conventional echocardiographic and Doppler echocardiographic procedures were performed in all patients. The mean early (Em) diastolic and late (Am) diastolic myocardial velocities were calculated. These tests were performed before dialysis. The Student t test, Mann-Whitney U test, χ2 test, Spearman correlation, and multivariate linear regression analysis were used to analyze parameters where appropriate.

RESULTS

Of the 56 patients under hemodialysis, fQRS in ECG was detected in 26 (46.4%). Echocardiographic evaluation showed that deceleration time (237.57 ± 40.10 ms; p = 0.030), isovolumic relaxation time (126.84 ± 15.62 ms; p < 0.001), early (E)/late (A) ventricular filling velocity (E/A) ratio (1.15 ± 0.40; p ≤ 0.001), and aortic stiffness index value (9.62 ± 4.53; p = 0.016) exhibited a statistical increase in hemodialysis patients with fQRS compared to patients without fQRS. E (58.23 ± 19.96 m/s; p = 0.004), and Em (5.96 ± 2.08 cm/s; p = 0.023) velocity levels were significantly lower in hemodialysis patients with fQRS than patients without fQRS. Aortic stiffness closely correlated with diastolic dysfunction (deceleration time r = 0.273, p = 0.042; isovolumic relaxation time r = 0.497, p < 0.001; E/A ratio r = -0.449, p = 0.001). On multivariate linear regression analysis, fQRS and aortic stiffness were independently associated in hemodialysis patients (β = 0.321, p = 0.049).

CONCLUSIONS

Increased aortic stiffness and left ventricular systolic dysfunction were observed more frequently in hemodialysis patients with fQRS than in patients without fQRS. fQRS is an important determinant of aortic stiffness in hemodialysis patients.

Cardiac Diastolic Dysfunction is Associated With Aortic Wave Reflection, but Not Stiffness in a Predominantly Young-to-Middle-Aged Community Sample

BACKGROUND

Whether the impact of backward wave pressures (Pbs) on left ventricular (LV) diastolic dysfunction (DD) antedates the effects of aortic stiffness is uncertain. We compared the relative contribution of various aortic hemodynamic parameters to preclinical DD in a predominantly young-to-middle-aged community-based sample.

METHODS

In 524 randomly selected participants of African ancestry (mean age = 46.8±18.4 years), we assessed central aortic pulse pressure (PPc), forward wave pressure (Pf), Pb, augmented pressure (Pa), the time-to-wave reflection (Rt), and aortic pulse wave velocity (PWV) using applanation tonometry (SphygmoCor software). LV mass index (LVMI), early to late transmitral velocity (E/A), and E/velocity of myocardial tissue lengthening (E/e') were determined using echocardiography.

RESULTS

Independent of age, sex, mean arterial pressure, body mass index, diabetes mellitus and/or HbA1c > 6.1%, regular smoking, regular alcohol intake, treatment for hypertension, pulse rate, and LVMI; PPc (P < 0.002), Pb (P < 0.0005), Pa (P < 0.002), and Pf (P < 0.02), but not Rt or PWV were independently associated with E/e' (but not with E/A). With adjustments for confounders, PPc (P < 0.005), Pb (P < 0.002), and Pa (P < 0.001), but not Pf, Rt, or PWV were independently associated with E/e' ≥ 12 (moderate-to-severe DD, n = 69). The independent relations between PPc and E/e' or moderate-to-severe DD were not affected by adjustments for PWV, Pf, or Rt, but were abolished with adjustments for Pb.

CONCLUSIONS

In a predominantly young-to-middle-aged community sample, the impact of Pbs on LV DD antedates the effects of aortic stiffness, the time-to-wave reflection, or Pfs.

Vascular Physiology according to Clinical Scenario in Patients with Acute Heart Failure: Evaluation using the Cardio-Ankle Vascular Index

Increased aortic stiffness may be an important cause of acute heart failure (AHF). Clinical scenario (CS), which classifies the pathophysiology of AHF based on the initial systolic blood pressure (sBP), was proposed to provide the most appropriate therapy for AHF patients. In CS, elevated aortic stiffness, vascular failure, has been considered as a feature of patients categorized as CS1 (sBP > 140 mmHg at initial presentation). However, whether elevated aortic stiffness, vascular failure, is present in such patients has not been fully elucidated. Therefore, we assessed aortic stiffness in AHF patients using the cardio-ankle vascular index (CAVI), which is considered to be independent of instantaneous blood pressure. Sixty-four consecutive AHF patients (mean age, 70.6 ± 12.8 years; 39 men) were classified with CS, based on their initial sBP: CS1: sBP > 140 mmHg (n = 29); CS2: sBP 100-140 mmHg (n = 22); and CS3: sBP < 100 mmHg (n = 13). There were significant group differences in CAVI (CS1 vs. CS2 vs. CS3: 9.7 ± 1.4 vs. 8.4 ± 1.7 vs. 8.3 ± 1.7, p = 0.006, analysis of variance). CAVI was significantly higher in CS1 than in CS2 (p = 0.02) and CS3 (p = 0.04). CAVI did not significantly correlate with sBP at the time of measurement of CAVI (r = 0.24 and p = 0.06). Aortic stiffness assessed using blood pressure-independent methodology apparently increased in CS1 AHF patients. We conclude that vascular failure is a feature of CS1 AHF initiation.

Relations of Central Hemodynamics and Aortic Stiffness with Left Ventricular Structure and Function: The Framingham Heart Study

Background

The differing relations of steady and pulsatile components of central hemodynamics and aortic stiffness with cardiac dimensions and function have not been fully elucidated.

Methods and Results

Central hemodynamics and carotid‐femoral pulse wave velocity (CFPWV, a measure of aortic stiffness) were measured by arterial tonometry in 5799 participants of the Framingham Heart Study (mean age 51 years, 54% women) and related to echocardiographic left ventricular (LV) dimensions and systolic and diastolic function using multivariable‐adjusted partial Pearson correlations. Mean arterial pressure (MAP, steady component of central blood pressure) was associated positively with LV wall thickness (r=0.168; P<0.0001) but showed only a weak direct association with LV diastolic dimension (r=0.035, P=0.006). Central pulse pressure (pulsatile component of central blood pressure) showed a direct correlation with both LV diastolic dimension and LV wall thickness (r=0.08 and 0.044, both P<0.0001 in multivariable models that included MAP). CFPWV was not associated with LV structure (all P≥0.27) in MAP‐adjusted models). Both MAP and CFPWV were associated inversely with LV diastolic function (E′; r=−0.140 and −0.153, respectively; both P<0.0001), and these associations persisted after additional adjustment for LV mass and central pulse pressure (r=−0.142 and −0.108, both P<0.0001). MAP and CFPWV were not associated with LV fractional shortening (P≥0.10), whereas central pulse pressure was positively related (r=0.064, P<0.0001).

Conclusions

Pulsatile and steady components of central pressure are conjointly yet variably related to LV structure. CFPWV is related to LV diastolic function but not to systolic function. Additional studies are warranted to confirm these observations.

Insulin resistance and acute glucose changes determine arterial elastic properties and coronary flow reserve in dysglycaemic and first-degree relatives of diabetic patients

BACKGROUND

Insulin resistance is linked to endothelial dysfunction. We investigated whether first-degree relatives of type-2 diabetes patients (FDR) present differences in vascular function at baseline and during postprandial hyperglycemia compared to dysglycaemic or normoglycaemic subjects.

METHODS

We studied 40 FDR with normal oral glucose test (OGTT), 40 subjects with abnormal OGTT (dysglycaemic) and 20 subjects with normal OGTT without parental history of diabetes (normoglycaemic) with similar clinical characteristics. Glucose, insulin, pulse wave velocity (PWV), central systolic blood pressure (cSBP) and augmentation index (AI) were measured at 0, 30, 60, 90 and 120min during OGTT. Coronary flow reserve (CFR) was assessed using Doppler echocardiography at 0 and 120min after OGTT. Insulin sensitivity was evaluated using Matsuda and insulin sensitivity index (ISI).

RESULTS

FDR and dysglycaemics had higher fasting insulin, reduced ISI, Matsuda index as well as reduced CFR (2.54 ± 0.5 vs. 2.45 ± 0.3 vs. 2.74 ± 0.5), increased PWV, (8.9 ± 1.1 vs. 10.3 ± 2.4vs. 8.0 ± 1.5 m/sec), AI (23.8 ± 13.6 vs. 26.5 ± 14.4vs.17.7  ±  14%) and cSBP than normoglycaemics (p < 0.05 for all comparisons). During OGTT, AI was similarly reduced in both normoglycaemic and FDR (p < 0.05) at peak insulin levels (60 min) though FDR had 2-fold higher insulin than normoglycaemics. AI was increased in dysglycaemics after peak glucose levels, at 120 min (p < 0.05). CFR was reduced by 10% and 15% at 120min in FDR and dysglycaemic respectively, while remained unchanged in normoglycaemics (p < 0.05). The percent reduction of CFR was related with the percent increase of glucose levels, ISI and Matsuda index(p < 0.05).

CONCLUSION

First-degree relatives and dysglycaemic patients have impaired arterial and coronary microcirculatory function. Insulin resistance determines acute vascular responses during postprandial hyperglycemia. CLINICALTRIALS.

GOV IDENTIFIER

NCT02244736.

Cardiovascular risk analysis by means of pulse morphology and clustering methodologies

The purpose of this study was the development of a clustering methodology to deal with arterial pressure waveform (APW) parameters to be used in the cardiovascular risk assessment. One hundred sixteen subjects were monitored and divided into two groups. The first one (23 hypertensive subjects) was analyzed using APW and biochemical parameters, while the remaining 93 healthy subjects were only evaluated through APW parameters. The expectation maximization (EM) and k-means algorithms were used in the cluster analysis, and the risk scores (the Framingham Risk Score (FRS), the Systematic COronary Risk Evaluation (SCORE) project, the Assessing cardiovascular risk using Scottish Intercollegiate Guidelines Network (ASSIGN) and the PROspective Cardiovascular Münster (PROCAM)), commonly used in clinical practice were selected to the cluster risk validation. The result from the clustering risk analysis showed a very significant correlation with ASSIGN (r=0.582, p<0.01) and a significant correlation with FRS (r=0.458, p<0.05). The results from the comparison of both groups also allowed to identify the cluster with higher cardiovascular risk in the healthy group. These results give new insights to explore this methodology in future scoring trials.

Early contribution of arterial wave reflection to left ventricular relaxation abnormalities in a community-dwelling population of normotensive and untreated hypertensive men and women

We examined the contribution of arterial wave reflection to early abnormalities in left ventricular relaxation, whether this association was modified by gender or hypertension, and the role of reflected wave timing and amplitude. We studied a cohort of normotensive and untreated essential hypertensive Taiwanese participants (675 men, 601 women, mean age 52 years). Doppler flow and applanation tonometry were performed to assess carotid-femoral pulse wave velocity (PWV) and augmentation index (AI). Diastolic parameters including transmitral E/A, E-deceleration time, and left atrial diameter were measured by echocardiography. In multivariate models predicting E/A, women were more likely to have lower E/A than men (β −0.08, p<.001). AI was significantly associated with lower E/A in both men (β −0.09, p=0.005) and women (β −0.12, p<.001) independent of PWV. Inclusion of AI in the overall model reduced the gender difference in E/A by 61% and rendered it non-significant. There was a significant interaction between AI and hypertension (p=0.02). The inverse association between AI and E/A was significant only in normotensive men and women, and only for the amplitude but not timing of the reflected wave. In conclusion, the contribution of wave reflection to left ventricular diastolic dysfunction was independent of arterial stiffness, more pronounced in normotensive individuals, and explained a significant portion of the gender difference in diastolic function.

Increased wave reflection and ejection duration in women with chest pain and nonobstructive coronary artery disease: ancillary study from the Women's Ischemia Syndrome Evaluation

OBJECTIVE

Wave reflections augment central aortic SBP and increase systolic pressure time integral (SPTI) thereby increasing left ventricular (LV) afterload and myocardial oxygen (MVO2) demand. When increased, such changes may contribute to myocardial ischemia and angina pectoris, especially when aortic diastolic time is decreased and myocardial perfusion pressure jeopardized. Accordingly, we examined pulse wave reflection characteristics and diastolic timing in a subgroup of women with chest pain (Women's Ischemia Syndrome Evaluation, WISE) and no obstructive coronary artery disease (CAD).

METHODS

Radial artery BP waveforms were recorded by applanation tonometry, and aortic BP waveforms derived. Data from WISE participants were compared with data from asymptomatic women (reference group) without chest pain matched for age, height, BMI, mean arterial BP, and heart rate.

RESULTS

Compared with the reference group, WISE participants had higher aortic SBP and pulse BP and ejection duration. These differences were associated with increased augmentation index and reflected pressure wave systolic duration. These modifications in wave reflection characteristics were associated with increased SPTI and wasted LV energy (Ew) and a decrease in pulse pressure amplification, myocardial viability ratio, and diastolic pressure time fraction.

CONCLUSION

WISE participants with no obstructive CAD have changes in systolic wave reflections and diastolic timing that increase LV afterload, MVO2 demand, and Ew with the potential to reduce coronary artery perfusion. These alterations in cardiovascular function contribute to an undesirable mismatch in the MVO2 supply/demand that promotes ischemia and chest pain and may contribute to, or increase the severity of, future adverse cardiovascular events.

Brachial artery tonometry and the Popeye phenomenon: explanation of anomalies in generating central from upper limb pressure waveforms

BACKGROUND

Noninvasive applanation tonometry studies of the brachial and radial artery pressure waves show that the arterial pulse is substantially amplified between the brachial and radial sites. Brachial tonometry waveforms have also been used to calibrate carotid tonometry waves as a measure of central pressure in major clinical trials. These trials assume identity of mean and of DBP in calculation of central (carotid) SBP. None of these trials showed superiority of central over brachial pressure in predicting outcome, but all showed equivalence of SBP and pulse pressure at brachial and carotid sites!

METHOD

We tested this method by measuring pressure waves at brachial, radial and carotid sites by applanation tonometry in 100 patients, with attention to any subtle difference between brachial and radial waveforms, and with both calibrated to cuff SBP and DBP.

RESULTS

The results confirmed no proximal and strong distal amplification in the arm. However, this was accompanied by blunting of the brachial compared with radial waveform with brachial pressure 2.7 mmHg higher during most of the cardiac cycle. Form factor of the ensemble-averaged brachial wave [39.1 standard deviation (SD) 4.9%] was similar to the carotid (40.2 SD 4.1%) but different to the radial wave (34.8 SD 3.7%; P < 0.01).

CONCLUSIONS

All findings were explained by inability to applanate the brachial artery, and resulting systematic error in generating brachial waveforms. In estimation of central pressure with applanation tonometry, the radial pressure wave, which can be accurately applanated, should be used, and calibrated to the brachial cuff.

Endothelial dysfunction, arterial stiffness, and heart failure

Outcomes for heart failure (HF) patients remain suboptimal. No known therapy improves mortality in acute HF and HF with preserved ejection fraction; the most recent HF trial results have been negative or neutral. Improvement in surrogate markers has not necessarily translated into better outcomes. To translate breakthroughs with potential therapies into clinical benefit, a better understanding of the pathophysiology establishing the foundation of benefit is necessary. Vascular function plays a central role in the development and progression of HF. Endothelial function and nitric oxide availability affect myocardial function, systemic and pulmonary hemodynamics, and coronary and renal circulation. Arterial stiffness modulates ventricular loading conditions and diastolic function, key components of HF with preserved ejection. Endothelial function and arterial stiffness may therefore serve as important physiological targets for new HF therapies and facilitate patient selection for improved application of existing agents.

Pulsatile hemodynamics and clinical outcomes in acute heart failure

BACKGROUND

The role of pulsatile hemodynamics in the management of patients with acute heart failure syndrome (AHFS) remains to be elucidated. We investigated the changes of the pulsatile hemodynamics along the hospital course of AHFS in relation to short-term outcomes.

METHODS

A total of 80 AHFS patients (73.2 ± 14.1 years, 82.5% men) were enrolled and followed up for up to 6 months after discharge. Measures of the pulsatile hemodynamics including brachial and central systolic blood pressure (SBP) and pulse (PP) pressure, carotid-femoral pulse wave velocity (cf-PWV), carotid augmentation index (cAI and cAI(75)) and carotid augmented pressure (cAP) were obtained within 24 h of admission, before discharge, and 2 weeks after discharge.

RESULTS

During a follow-up of 174 ± 32 days (16-183 days), 29 patients experienced events including rehospitalization for heart failure, nonfatal myocardial infarction, nonfatal stroke, and mortality. Predischarge brachial and central PP, and cAP, and postdischarge brachial and central SBP and PP, cAP, and cf-PWV were significantly lower in patients without events than those with events. Predischarge central PP (hazard ratio per 1-s.d. and 95% confidence interval: 1.62 (1.12-2.34)) and cAP (1.47 (1.05-2.05)) predicted events independent of age and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels. Similarly, postdischarge brachial and central SBP and PP, cAP, and cf-PWV were also significant independent predictors.

CONCLUSION

Suboptimal recovery of the perturbations of the pulsatile hemodynamics in patients hospitalized due to AHFS may relate to adverse short-term outcomes and warrant aggressive treatment.

The combined effect of hypertension and smoking on arterial stiffness

Arterial stiffness plays a critical role in the function of the cardiovascular system as it represents the coupling of the left ventricle and arterial tree. Increased arterial stiffness is associated with a number of cardiovascular complications. Increased stiffness occurs with age and with the development of chronic conditions (e.g., hypertension) and the presence of vascular risk factors (e.g., smoking). Measuring arterial stiffness is increasingly gaining popularity as a method of assessing cardiovascular health and treatment efficacy. The purpose of this review was to assess the combined effect of hypertension and smoking on arterial stiffness. A systematic review of the literature revealed four relevant studies; hypertension and smoking were found to be independent detrimental factors for raising arterial stiffness, and combined they raise arterial stiffness more than either solitary factor. However, a need was identified for future studies to determine the extent to which smoking cessation therapy combined with the appropriate anti-hypertensive medication can lead to stabilization or even reversal of arterial stiffness.

Elevated augmentation index derived from peripheral arterial tonometry is associated with abnormal ventricular-vascular coupling

BACKGROUND

Although typically derived from the contour of arterial pressure waveform, augmentation index (AIx) may also be derived from the digital pulse volume waveform using finger plethysmography (peripheral arterial tonometry, PAT). Little is known regarding the physiologic correlates of AIx derived from PAT. In this study, we investigated the relation of PAT-AIx with measures of ventricular-vascular coupling.

METHODS

Pulse volume waves were measured via PAT and used to derive AIx. Using 2-dimensional echocardiography, effective arterial elastance index (EaI) was estimated as end-systolic pressure/stroke volume index. Left ventricular (LV) end-systolic elastance index (E(LV)I) was calculated as end-systolic pressure/end-systolic volume index. Ventricular-vascular coupling ratio was defined as EaI/E(LV)I.

RESULTS

Given the bi-directional nature of ventricular-vascular uncoupling as measured by echocardiography, patients were separated into three groups: low EaI/E(LV)I (<0.6, n = 21), optimal EaI/E(LV)I (mean 0.6-1.2, n = 16) and high EaI/E(LV)I (>1.2, n = 10). Adjusting for potential confounders (age, mean arterial pressure, height and heart rate), patients with optimal EaI/E(LV)I had lower AIx (1 +/- 4%, P<0.05) compared to those with low EaI/E(LV)I (13 +/- 4%) and high EaI/E(LV)I (19 +/- 5%).

CONCLUSIONS

Abnormal ventricular-vascular coupling, arising from either increased effective arterial elastance or increased ventricular elastance, is associated with increased AIx as measured by PAT. Additional research is needed to examine other vascular correlates of PAT-AIx.

Assessing individual cardiac risk using extra-cardiac arterial imaging

Cardiovascular disease is the leading cause of death globally. Cardiovascular risk factors predict the risk of cardiovascular events in populations but have limitations in predicting individual risk. Emerging technologies that non-invasively measure carotid intima media thickness, aortic pressure and brachial artery reactivity may be useful in identifying the vulnerable patient who may benefit from more aggressive preventive therapy. These tests vary between each other in their reproducibility, cost, required operator skill, availability and patient preparation. However, all require further validation for clinical use as screening tests for cardiovascular disease.

Arterial Wave Reflections During the Menstrual Cycle of Healthy Women

Increased wave reflection is an independent factor associated with cardiovascular diseases, risk, and mortality. The influence of the menstrual cycle on wave reflections and particularly on the reproducibility of their measurement has never been examined. The aim of the present study was to examine the reproducibility and variability of wave reflection indices in premenopausal healthy women during their menstrual cycle. Thirty-two women were examined at 3 phases of their menstrual cycle: days 1 to 2 (menstrual phase), days 6 to 14 (late follicular), and days 4 to 7 after ovulation (early luteal phase). Applanation tonometry of the radial artery and aortic pulse wave analysis were performed for the calculation of augmentation pressure, augmentation index, and timing of reflected waves. Reproducibility of these measures was evaluated by intraclass correlation coefficient and Bland-Altman analysis, whereas ANOVA was performed to assess their variability during the menstrual cycle. The SD of augmentation index differences between repeated measurements within the menstrual cycle ranged from 7.6% to 9.9%. Bland-Altman analysis indicated no evidence of systemic bias and no trend for the reproducibility of measurements to vary with their underlying mean value. Intraclass correlation coefficient indicated a moderate reproducibility of augmentation index and augmentation pressure (>0.80) and a rather low reproducibility for timing of reflected waves (0.43). Mean augmentation pressure, augmentation index, and timing of reflected waves did not vary significantly during the menstrual cycle (ANOVA). Measurement of wave reflections at the same phase of the menstrual cycle or statistical adjustment could be suggested for optimal study design and data interpretation.

Augmentation index relates to progression of aortic disease in adults with Marfan syndrome

BACKGROUND

Noninvasive applanation tonometry (APT) is useful to assess aortic stiffness and pulse wave reflection. Moreover, APT can predict outcome in many conditions such as arterial hypertension. In this study, we test whether APT measurements relate to progression of aortic disease in Marfan syndrome (MFS).

METHODS

We performed APT in 50 consecutive, medically treated adults with MFS (19 men and 31 women aged 32 +/- 13 years), who had not undergone previous cardiovascular surgery. During 22 +/- 16 months of follow-up, 26 of these patients developed progression of aortic disease, which we defined as progression of aortic root diameters >or=5 mm/annum (18 individuals), aortic surgery >or=3 months after APT (seven individuals), or onset of acute aortic dissection any time after APT (one individual).

RESULTS

Univariate Cox regression analysis suggested an association of aortic disease progression with age (P = 0.001), total cholesterol levels (P = 0.04), aortic root diameter (P = 0.007), descending aorta diameter (P = 0.01), aortic root ratio (P = 0.02), and augmentation index (AIx@HR75; P < 0.006). Multivariate Cox regression analysis confirmed an independent impact on aortic disease progression exclusively for baseline aortic root diameters (hazard ratio = 1.347; 95% confidence interval (CI) 1.104-1.643; P = 0.003) and AIx@HR75 (hazard ratio = 1.246; 95% CI 1.029-1.508; P = 0.02). In addition, Kaplan-Meier survival curve analysis illustrated significantly lower rates of aortic root disease progression both with lower AIx@HR75 (P = 0.025) and with lower pulse wave velocity (PWV) values (P = 0.027).

CONCLUSIONS

We provide evidence that APT parameters relate to aortic disease progression in medically treated patients with MFS. We believe that APT has a potential to improve risk stratification in the clinical management of MFS patients.

Radial augmentation index unmasks premature coronary artery disease in younger males

OBJECTIVE

The augmentation index, a marker of arterial wave reflection, is considered to indicate cardiovascular risk burden, particularly in younger persons. We assessed whether the easily obtainable radial augmentation index (rAIx) is superior to systolic blood pressure (SBP) or pulse pressure (PP) in detecting atherosclerotic vascular disease at an early age.

METHODS

We determined rAIx by applanation tonometry, SBP and PP in 152 male patients with or without invasively documented coronary artery disease (CAD). Ejection fraction (EF) was visually estimated by echocardiography or left ventricular angiography.

RESULTS

In younger patients (age < or =60 years, EF > or =30%), rAIx was significantly higher in patients with CAD (79.8+/-13.5%, n=31) compared with patients without CAD (68.5+/-22.0%, n=21; P = 0.04), whereas SBP (121+/-16 vs. 131+/-18 mmHg, P=0.04) and PP (48.7+/-9.4 vs. 56.3+/-12.1 mmHg, P=0.01) were even lower in patients with CAD compared with patients without CAD. In patients aged < or =60 years, rAIx was highest when EF was less than 30% (90.0+/-9.2%) compared with patients with EF 30-54% (80.7+/-11.5%) or EF > or =55% (72.1+/-20.4%, P=0.01). In contrast, in patients above 60 years of age, rAIx, SBP or PP did not differ between patients with or without CAD and the rAIx tended to be lowest in patients with severely reduced EF (P=0.07).

CONCLUSION

We conclude that premature vascular disease in younger patients with CAD is reflected only by an elevated rAIx, and not by SBP or PP. The rAIx is not suited to distinguish between older patients with high or low cardiovascular risk. Age seems to influence the interplay between rAIx and systolic heart function.