Woo-In Yang

Sex Differences in Central Hemodynamics and Their Relationship to Left Ventricular Diastolic Function

OBJECTIVES This study aimed to investigate sex differences in the association between arterial stiffness and left ventricular (LV) diastolic dysfunction. BACKGROUND Heart failure with preserved ejection fraction is more common in women. Arterial stiffness has been suggested as a significant contributor to the development of heart failure. We hypothesized that the association between arterial stiffness and LV diastolic function would be stronger in women than in men. METHODS Two-dimensional, Doppler echocardiography and radial artery tonometry were performed simultaneously in 158 age-matched subjects (79 males, 79 females; mean age: 58 ± 10 years) without any structural heart disease or LV systolic dysfunction. RESULTS The peripheral blood pressure and pulse pressure (PP) were similar between sexes. However, central PP and augmentation index were significantly higher and PP amplification was significantly lower in women (1.31 vs. 1.19, p < 0.001). The associations of PP amplification with early diastolic mitral annular (Em) velocity and transmitral to mitral annular early diastolic velocity ratio (E/Em) were significant in women (r = 0.38, p = 0.001; r = -0.36, p = 0.001), whereas no significant association was found in men (r = 0.09, p = 0.428, r = -0.14, p = 0.215). Multiple regression analysis revealed that PP amplification had an independent correlation with Em velocity only in women. CONCLUSIONS Despite similar peripheral PP, the central hemodynamics reflecting arterial stiffness were different between men and women. LV diastolic function correlates significantly with the parameters representing arterial stiffness only in women. We suggest that the effects of earlier wave reflection on central pressure may contribute to greater susceptibility to heart failure with preserved LV ejection fraction in women.

Clinical outcomes of exercise-induced pulmonary hypertension in subjects with preserved left ventricular ejection fraction: implication of an increase in left ventricular filling pressure during exercise

Objective To investigate clinical outcomes of exercise-induced pulmonary hypertension (PH) and implications of an increase in left ventricular (LV) filling pressure during exercise in subjects with preserved LV ejection fraction. Design Longitudinal follow-up study. Setting Subjects who were referred for diastolic stress echocardiography. Patients and methods The ratio of transmitral and annular velocities (E/Ea) and pulmonary artery systolic pressure (PASP) at rest and during exercise were measured in 498 subjects (57±11 years; 201 male). Exercise-induced PH was defined as present if PASP ≥50 mm Hg at 50 W of exercise, and an increase in LV filling pressure during exercise was present if E/Ea ≥15 at 50 W. Main outcome measures A combination of major cardiovascular events and any cause of death. Results During a median follow-up of 41 months, there were 14 hospitalisations and four deaths. Subjects with exercise-induced PH had significantly worse clinical outcomes than those without (p=0.014). Subjects with exercise-induced PH associated with an increase in E/Ea during exercise had significantly worse outcomes than other groups (p<0.001). However, prognosis was similar between subjects with exercise-induced PH without an increase in E/Ea and those without exercise-induced PH. In subjects with exercise-induced PH, E/Ea at 50 W was an independent predictor of adverse outcomes (HR 1.37; 95% CI 1.02 to 1.83; p=0.036). Conclusions Exercise-induced PH provides prognostic information in subjects with preserved LV ejection fraction. The excess risk of exercise-induced PH is restricted to subjects with an increase in estimated LV filling pressure during exercise.

Significant invasion depth of early oral tongue cancer originated from the lateral border to predict regional metastases and prognosis

In oral tongue cancer, tumor depth is crucial for cervical lymph node metastasis. There is no standardized method to predict tumor invasion or deciding who should undergo selective neck dissection. In this study, calculated MRI invasion depth was compared with histopathologic (HP) invasion depth to find a correlation, and determine a cutoff value of invasion depth that predicts occult neck node metastasis. 50 patients, diagnosed with T1 or T2 oral tongue cancer originating from the lateral border of the tongue, underwent MRI screening and received surgical excision as primary treatment. MRI and HP invasion depths were compared and the cutoff value determined. The invasion depth to determine the presence of nodal metastasis where summation of specificity and sensitivity was greatest was 8.5mm HP, 10.5mm in T1 weighted enhanced axial image, and 11.5mm in T2 weighted MRI axial image. The relation coefficient of T2 weighted MRI invasion depth and HP depth was 0.851, and accuracy 84%, all of which showed higher correlation compared with T1 weighted enhanced axial image. HP depth was significantly correlated with survival rate. The measurement of invasion depth using MRI is a prerequisite for determining a surgical plan in early oral tongue cancer.

Clinical and echocardiographic predictors of outcomes in patients with apical hypertrophic cardiomyopathy.

Apical hypertrophic cardiomyopathy (HC) is considered to have a favorable prognosis, but recent observations have suggested less benign clinical courses. We investigated the outcomes in patients with apical HC and evaluated the predictors. All 454 patients with apical HC (316 men, age 61 ± 11 years) were recruited. Major cardiovascular events (MACE) were defined as unplanned hospitalization because of heart failure, stroke, or cardiovascular mortality. The patients were divided into 2 groups: group 1 with MACE and group 2 without MACE. During the follow-up period (43 ± 20 months), the all-cause mortality rate was 9% (39 of 454), and 110 patients (25%) had MACE. The subjects in group 1 were older and a greater proportion had diabetes, hypertension, and atrial fibrillation. On the echocardiogram, the left atrial volume index (left atrial volume index 36 ± 17 vs 31 ± 12 ml/m(2)), transmitral E velocity (65 ± 17 vs 61 ± 16 cm/s), mitral annulus Ea velocity (4.5 ± 1.4 vs 5.1 ± 1.8 cm/s), Sa velocity (5.8 ± 1.4 vs 6.6 ± 1.4 cm/s), E/Ea ratio (15 ± 5 vs 13 ± 5), and right ventricular systolic pressure (31 ± 8 vs 28 ± 7 mm Hg) were significantly different between groups 1 and 2 (p <0.05 for all). The left atrial volume index (for each 1-ml/m(2) increase, hazard ratio 1.01, 95% confidence interval 1.00 to 1.03; p = 0.047), Sa velocity (hazard ratio 0.83, 95% confidence interval 0.72 to 0.96, p = 0.014), and E/Ea ratio (hazard ratio 1.04, 95% confidence interval 1.00 to 1.09, p = 0.030) were independent predictors of a poor prognosis, along with age and the presence of diabetes or hypertension. In conclusion, the clinical outcomes of patients with apical HC were less benign in older patients and in those with hypertension or diabetes. In addition, the left atrial volume index, Sa velocity, and E/Ea ratio were predicters of a poor prognosis in patients with apical HC.

Central aortic stiffness and its association with ascending aorta dilation in subjects with a bicuspid aortic valve.

BACKGROUND Reduced elasticity and dilatation of the proximal aorta are highly prevalent in patients with bicuspid aortic valves (BAVs), even in the absence of valvular dysfunction. The aim of this study was to examine central aortic stiffness and its association with ascending aortic dilation in subjects with BAVs compared with controls. METHODS Fifty subjects with BAVs (39 men; mean age, 52 ± 14 years) without significant valve dysfunction and 50 age-matched and gender-matched controls with normal trileaflet aortic valves were studied. Aortic diameter was measured using two-dimensional echocardiography, and central hemodynamics were assessed simultaneously using radial artery tonometry. Subjects with BAVs were divided into two groups on the basis of the median value of the aortic diameter. RESULTS Subjects with BAVs had larger ascending aortic diameters (20.6 ± 4.0 vs 17.9 ± 2.4 mm/m(2), P < .001), higher augmentation indexes normalized for a heart rate of 75 beats/min (25.3 ± 9.7% vs 16.7 ± 8.6%, P < .001), higher pulse-wave velocities (7.8 ± 1.5 vs 7.2 ± 1.0 m/sec, P = .013), and lower pulse pressure amplification (1.24 ± 0.27 vs 1.35 ± 0.18, P = .022) than control subjects. The higher augmentation indexes were significant even in subjects with BAVs with relatively normal sized aortas. The diameter of the ascending aorta was correlated with augmentation index (r = 0.48, P < .001), pulse-wave velocity (r = 0.27, P = .063), and pulse pressure amplification (r = -0.46, P = .001) in subjects with BAVs. CONCLUSION Subjects with BAVs had stiffer central hemodynamics than controls with tricuspid aortic valves, even in the absence of significant aortic dilation. Central aortic stiffness was positively correlated with the degree of aortic dilation in subjects with BAV. Thus, the evaluation of central aortic stiffness could be useful for the early detection and risk stratification of aortopathy in subjects with BAVs.

Augmentation Index Association With Reactive Hyperemia as Assessed by Peripheral Arterial Tonometry in Hypertension

BACKGROUND Augmentation pressure has emerged as a surrogate marker for cardiovascular disease, and endothelial dysfunction has been proposed as related factor. However, the relationship between augmentation pressure and digital endothelial function has not yet been well defined. We investigated the relationship between augmentation pressure and digital reactive hyperemia (RH) in patients with hypertension using peripheral arterial tonometry (PAT), which is regarded as being representative of endothelial function. METHODS One hundred hypertensive patients (64 males; mean age, 49 ± 12 years) without a history of taking antihypertensive medication were enrolled in this study. RESULTS The mean augmentation pressure and augmentation index (AIx) normalized for a heart rate of 75 beats/min (AIx75) were 15 ± 8 mm Hg and 26 ± 11%, respectively. The mean RH-PAT index and log transformed PAT ratio were 2.24 ± 0.55 and 0.62 ± 0.30. There was an inverse relationship between the RH-PAT index and age, male sex, and body mass index. The log transformed PAT ratio also showed inverse relationship with age and male sex. The RH-PAT index and the log transformed PAT ratio showed no relationship with augmentation pressure or AIx75. In a multiple linear regression analysis, age, height, and central systolic BP demonstrated an independent association with augmentation pressure and AIx75. CONCLUSION In patients with hypertension, the RH-PAT index determined using PAT was not associated with augmentation pressure or AIx75. Digital vascular function may be a less important factor for pressure augmentation in patients with hypertension.

Overweight and Its Association With Aortic Pressure Wave Reflection After Exercise

BACKGROUND Obesity is associated with arterial stiffening, left ventricular (LV) hypertrophy, and diastolic dysfunction. However, there is no data regarding dynamic changes in arterial hemodynamics with exercise in overweight subjects. We hypothesized that overweight women would show a different exercise response in wave reflection compared with lean women. METHODS A total of 59 overweight and 68 lean nondiabetic women (mean age 63 ± 7 years) underwent symptom-limited supine bicycle exercise testing with simultaneous two-dimensional and Doppler echocardiography. Central hemodynamics including central aortic pressure and augmentation index (AIx) were obtained at rest and immediately after peak exercise using radial artery tonometry. RESULTS Overweight women showed a higher LV mass index (lean vs. overweight; 40.2 ± 10.2 vs. 45.3 ± 11.0 g/m(2.7), P = 0.007) and a lower early diastolic mitral annular velocity (6.3 ± 1.8 vs. 5.5 ± 1.6 cm/s, P = 0.013) than lean women. Although the two groups did not differ in peripheral and central hemodynamics including AIx (36.3 ± 11.7 vs. 36.8 ± 10.2%, P = 0.830) and AIx normalized for heart rate 75/min (AIx@75, 30.4 ± 11.5 vs. 30.1 ± 9.9%, P = 0.885) at rest, AIx (20.9 ± 11.5 vs. 27.6 ± 10.4%, P = 0.004) and AIx@75 (25.8 ± 10.2 vs. 31.6 ± 7.7%, P = 0.002) at peak exercise were significantly higher in overweight women. In simple correlation analysis, body mass index (BMI) showed significant correlations with AIx, and AIx@75 at peak exercise, whereas no relationships were found with those parameters at rest. Multiple regression analysis showed that BMI was an independent determinant of AIx@75 at peak exercise (β = 0.28, P = 0.004). CONCLUSIONS Despite similar resting peripheral and central hemodynamics, the wave reflection in overweight women after exercise differed from that in lean women. These findings suggest that being overweight is related to higher wave reflection after exercise.

Asynchronous arterial systolic expansion as a marker of vascular aging: assessment of the carotid artery with velocity vector imaging.

Objective Arterial elastic properties change with aging. Measurements of pulse wave velocity and augmentation index are useful for the evaluation of arterial stiffness. However, they likely represent only global characteristics of the arterial tree rather than local vascular alterations. The aim of this study was to evaluate whether local vascular properties assessed by velocity vector imaging differed with aging. Methods Vascular properties of carotid arteries with ages were assessed in 100 healthy volunteers (52 men) ranging from 20 to 68 years using velocity vector imaging. The peak circumferential strain and strain rate of the six segments in left common carotid arteries were analyzed and the standard deviation of the time to peak circumferential strain and strain rate of the six segments, representing the synchronicity of the arterial expansion, were calculated. Central blood pressure, augmentation index and pulse wave velocity were assessed by commercially available radial artery tonometry, the SphygmoCor system (AtCor Medical, West Ryde, Australia). A validated generalized transfer function was used to acquire the central aortic pressures and pressure waveforms. Results Pulse wave velocity, augmentation index and velocity vector imaging parameters showed significant changes with age. However, the age-related changes in pulse wave velocity, augmentation index and velocity vector imaging parameters were different. The increase in pulse wave velocity was more prominent in older individuals, whereas the changes in augmentation index and carotid strain and strain rate were evident earlier, at the age of 30 years. Unlike augmentation index, which showed little change in older individuals, the standard deviation of time to peak strain and strain rate showed a steady increase from younger to older individuals. Conclusion Asynchronous arterial expansion could be a useful discriminative marker of vascular aging independent of individuals age.

Feasibility of an automatic computer-assisted algorithm for the detection of significant coronary artery disease in patients presenting with acute chest pain

Automatic computer-assisted detection (auto-CAD) of significant coronary artery disease (CAD) in coronary computed tomography angiography (cCTA) has been shown to have relatively high accuracy. However, to date, scarce data are available regarding the performance of auto-CAD in the setting of acute chest pain. This study sought to demonstrate the feasibility of an auto-CAD algorithm for cCTA in patients presenting with acute chest pain. We retrospectively investigated 398 consecutive patients (229 male, mean age 50±21 years) who had acute chest pain and underwent cCTA between Apr 2007 and Jan 2011 in the emergency department (ED). All cCTA data were analyzed using an auto-CAD algorithm for the detection of >50% CAD on cCTA. The accuracy of auto-CAD was compared with the formal radiology report. In 380 of 398 patients (18 were excluded due to failure of data processing), per-patient analysis of auto-CAD revealed the following: sensitivity 94%, specificity 63%, positive predictive value (PPV) 76%, and negative predictive value (NPV) 89%. After the exclusion of 37 cases that were interpreted as invalid by the auto-CAD algorithm, the NPV was further increased up to 97%, considering the false-negative cases in the formal radiology report, and was confirmed by subsequent invasive angiogram during the index visit. We successfully demonstrated the high accuracy of an auto-CAD algorithm, compared with the formal radiology report, for the detection of >50% CAD on cCTA in the setting of acute chest pain. The auto-CAD algorithm can be used to facilitate the decision-making process in the ED.

Dyssynchronous Systolic Expansion of Carotid Artery in Patients with Marfan Syndrome

BACKGROUND Marfan syndrome is a multisystemic connective tissue disorder associated with a mutation affecting fibrillin-1, the main component of microfibrils. Fibrillin-1 gene mutations may affect the carotid arterial wall. The aim of this study was to investigate carotid arterial mechanics using Velocity Vector Imaging (VVI) in patients with Marfan syndrome. METHODS Forty-five patients (26 men; mean age, 39 ± 10 years) with Marfan syndrome who fulfilled the Ghent criteria and 45 gender-matched and age-matched healthy volunteers were evaluated. Transverse images of right common carotid artery proximal to the bifurcation were obtained for each subject and divided into six segments. The peak radial velocity, circumferential strain, and strain rate of the six segments were analyzed using VVI. The time to peak radial velocity (T(s)), peak circumferential strain (T(st)), and peak strain rate (T(sr)) of the six segments were calculated. Intima-media thickness was measured for each subject. RESULTS The average diameter of the common carotid artery in patients with Marfan syndrome was significantly larger than that of controls. Carotid compliance coefficients and distensibility coefficients as assessed by B-mode echocardiographic images were comparable between the two groups. In VVI analyses, averages and standard deviations of peak radial velocities, circumferential strain, and strain rates were not significantly different between the two groups. However, T(s), T(st), and T(sr) were more delayed (P < .01), and the standard deviations of T(s), T(st), and T(sr) were significantly larger in patients with Marfan syndrome (P = .01, P < .01, and P < .01, respectively), suggesting delayed and dyssynchronous arterial expansion during systole. The presence of Marfan syndrome was independently and significantly related to increased standard deviations of T(st) (β = 0.33, P < .01) and T(sr) (β = 0.44, P < .01), even after adjusting for age in multiple regression analysis. CONCLUSION In patients with Marfan syndrome, carotid arteries assessed with VVI exhibited delayed, dyssynchronous arterial expansion during systole compared with healthy controls. Arterial assessment using VVI may be useful for noninvasively quantifying vascular alterations associated with Marfan syndrome.