Reduced aortic distensibility and coronary flow velocity reserve in diabetes mellitus patients with a negative coronary angiogram

Alterations in Coronary Resistance Artery Network Geometry in Diabetes and the Role of Tenascin C

Background

Geometrical alterations in the coronary resistance artery network and the potential involvement of Tenascin C (TNC) extracellular matrix protein were investigated in diabetic and control mice.

Methods

Diabetes was induced by streptozotocin (STZ) injections (n = 7-11 animals in each group) in Tenascin C KO (TNC KO) mice and their Wild type (A/J) littermates. After 16-18 weeks the heart was removed and the whole subsurface network of the left coronary artery was prepared (down to branches of 40 μ m outer diameter), in situ pressure-perfused and studied using video-microscopy. Outer and inner diameters, wall thicknesses and bifurcation angles were measured on whole network pictures reconstructed into collages at 1.7 μ m pixel resolutions.

Results

Diabetes induced abnormal morphological alterations including trifurcations, sharp bends of larger branches, and branches directed retrogradely (p < 0.001 by the χ 2 test). Networks of TNC KO mice tended to form early divisions producing parallelly running larger branches (p < 0.001 by the χ 2 probe). Networks of coronary resistance arteries were substantially more abundant in 100-180 μ m components, appearing in 2-5 mm flow distance from orifice in diabetes. This was accompanied by thickening of the wall of larger arterioles ( > 220 μ m) and thinning of the wall of smaller (100-140 μ m) arterioles (p < 0.001). Blood flow should cover larger distances in diabetic networks, but interestingly STZ-induced diabetes did not generate further geometrical changes in TNC KO mice.

Conclusions

Diabetes promotes hypertrophic and hypotrophic vascular remodeling and induces vasculogenesis at well defined, specific positions of the coronary vasculature. TNC plays a pivotal role in the formation of coronary network geometry, and TNC deletion causes parallel fragmentation preventing diabetes-induced abnormal vascular morphologies.

The diagnosis and prognosis of coronary microvascular disease using PET/CT

OBJECTIVE

This study aimed to evaluate the diagnostic and prognostic value of 13N-NH3·H2O positron emission tomography combined with computed tomography (PET/CT) for non-obstructive coronary microvascular disease (CMVD).

METHODS

A retrospective analysis was conducted on 70 patients with clinically suspected non-obstructive CMVD (35 males, 35 females) between March 2017 and August 2019. The average age of the patients was 53.32±7.82 years. The patients underwent 13N-NH3·H2O PET/CT and were divided into two groups based on diagnostic criteria: a CMVD group and a non-CMVD group. They were then followed up for 180-1,095 days. Data were analyzed using an χ 2 test, the logistic regression model, the multiple linear regression model, the Kaplan-Meier method, the Cox proportional hazards regression model, and a receiver operating characteristic (ROC) curve.

RESULTS

(1) The incidence of cardiovascular family history and a high calcification score (11-400) was higher in the CMVD group than in the non-CMVD group (58.8% vs. 20.8% and 29.4% vs. 5.7%, respectively; P <  0.05 for all), stress myocardial blood flow (MBF) and coronary flow reserve (CFR) values were lower in the CMVD group than in the non-CMVD group (2.280±0.693 vs. 3.641±1.365 and 2.142±0.339 vs. 3.700±1.123, respectively), and calcification score was higher in the CMVD group than in the non-CMVD group (110.18±165.07 vs. 13.21±41.68, respectively; P <  0.05 for all). Gender and diabetes were risk factors for stress MBF reduction (β= 1.287 and β= -0.636, respectively), calcification score and hypertension were risk factors for CFR reduction (β= -0.004 and β= -0.654, respectively), and hypertension, family history, and calcification score were risk factors in the CMVD group (OR = 7.323, OR = 5.108, OR = 1.012, respectively; P <  0.05 for all). (2) The prognosis of patients with CFR <  2.5 was worse than that of patients with CFR≥2.5 (x2 value: 27.404, P <  0.001). The risk of adverse cardiovascular events in diabetic patients was also increased (β= 0.328, P <  0.001). When CFR was set to 2.595, the prognostic sensitivity was 94% and the specificity was 80%.

CONCLUSION

The technology of 13N-NH3·H2O PET/CT can be used for the diagnosis and prognosis of non-obstructive CMVD. Cardiovascular risk factors are related to the occurrence and prognosis of CMVD.

Recurrence of atrial fibrillation after pulmonary vein isolation in dependence of arterial stiffness

Background

Arterial stiffness (AS) has emerged as a strong predictor of cardiovascular (CV) diseases. Although increased AS has been described as a predictor of atrial fibrillation (AF), its role as a risk marker for AF recurrence has not yet been elucidated.

Methods

Patients with AF who underwent pulmonary vein isolation (PVI) were included in this study. Presence of AS was evaluated by measuring aortic distensibility (AD) of the descending aorta by transoesophageal echocardiography.

Results

In total, 151 patients (mean ± standard deviation (SD) age 71.9 ± 9.8 years) were enrolled and followed for a median duration of 21 months (interquartile range 15.0–31.0). During follow-up, AF recurred in 94 (62.3%) patients. AF recurrence was seen more frequently in patients with permanent AF (27% vs 46%, p = 0.03) and in those who had undergone prior PVI (9% vs 23%, p = 0.02). AD was significantly reduced in patients with AF recurrence (mean ± SD 2.6 ± 2.3 vs 1.5 ± 0.7 × 10⁻³ mm Hg⁻¹, p < 0.0001), as well as left atrial volume index (LAVI) (mean ± SD 29 ± 12 vs 44 ± 15 ml/m², p < 0.0001). Multivariable analysis revealed LAVI (odds ratio (OR) 2.9, 95% confidence interval (CI) 1.2–3.4) and AS (OR 3.6, 95% CI 2.8–4.1) as independent risk factors of AF recurrence.

Conclusion

Increased AS and left atrial size were independent predictors of AF recurrence after PVI. AD as surrogate marker of AS seemed to reflect the overall CV risk. In addition, AD was significantly correlated with left atrial size, which suggests that increased AS leads to atrial remodelling and thus to AF recurrence.

Trial registration

German registry for clinical studies (DRKS), DRKS00019007.

Supplementary Information

The online version of this article (10.1007/s12471-021-01644-w) contains supplementary material, which is available to authorized users.

Diabetes mellitus deteriorates left ventricular deformation in acromegaly-analysis from the three-dimensional speckle-tracking echocardiographic MAGYAR-Path study

Acromegaly and diabetes mellitus (DM) separately are associated with cardiovascular alterations and modified left ventricular (LV) deformation, which can be quantitatively assessed by three-dimensional speckle-tracking echocardiography (3DSTE). The present study aimed to assess the relationship between LV deformation and twist in the presence of DM in acromegaly. Thirty-seven acromegaly patients were involved in the study, but due to insufficient image quality 13 have to be excluded from analysis. Therefore, the present study comprised 24 acromegaly patients, from which 5 had DM. Their data was compared to 35 age- and gender matched healthy controls. Complete two-dimensional Doppler echocardiography extended with 3DSTE were performed in all patients and controls. Only non-diabetic acromegaly cases had increased global and mean segmental LV radial strain, diabetic acromegaly patients had similar LV radial strain as compared to that of healthy subjects. Other LV strain parameters did not show any difference between diabetic and non-diabetic acromegaly patients. While LV basal rotation was similar among the groups, LV apical rotation was reduced in both diabetic and non-diabetic patients as compared to healthy subjects. However, diabetic acromegaly patients had tendentiously higher values. The ratio of absence of LV twist called as LV rigid body rotation was similar between the groups examined. Diabetes mellitus deteriorates left ventricular deformation in acromegaly.

Abdominal aorta diameter as a novel marker of diabetes incidence risk in elderly women

The prevalence of diabetes mellitus is increasing worldwide, including the nation of Poland. The aim of this prospective and observational study was to determine risk factors and the predictors of diabetes incidence in elderly women, and to calculate the diabetes incidence ratio in this population. Two-hundred women, aged 65–74, who were non-diabetic at baseline in 2012 were followed for 6.5 years. All women were checked for incident diabetes. In non-diabetic subjects, diagnostic procedures for diabetes were performed according to Poland’s Diabetes recommendations. Between April 2012 and September 2018, 25 women developed diabetes and the next 11 cases were diagnosed based on FPG or oral glucose tolerance test. Women with incident diabetes had significantly higher baseline FPG, triglycerides (TG), TG/HDL cholesterol ratio and visceral adiposity index (VAI) score, and lower abdominal aorta diameter (AAD), HDL cholesterol and eGFR. In the Cox proportional hazard regression analysis, only AAD < 18 mm and VAI score ≥ 3.8 were independently associated with diabetes risk, hazard ratio (HR) 2.47 (95% confidence interval 1.21–5.02), P = 0.013 and HR 2.83 (1.35–5.94), P = 0.006 respectively. In the backward stepwise regression analysis including all variables, diabetes incidence could be predicted from a linear combination of the independent variables: AAD < 18 mm (P = 0.002), VAI score ≥ 3.8 (P < 0.001) and FPG ≥ 5.6 mmol/L (P = 0.011). The calculated incidence of diabetes was 2769.2 new cases/100,000 persons per year. AAD below 18 mm seem to be a novel, independent marker of diabetes risk in elderly women, and AAD assessment during routine abdomen ultrasound may be helpful in identifying females at early elderliness with high risk of diabetes incidence.

Fiber-reinforced computational model of the aortic root incorporating thoracic aorta and coronary structures

Cardiovascular diseases are still the leading causes of death in the developed world. The decline in the mortality associated with circulatory system diseases is accredited to development of new diagnostic and prognostic tools. It is well known that there is an inter relationship between the aortic valve impairment and pathologies of the aorta and coronary vessels. However, due to the limitations of the current tools, the possible link is not fully elucidated. Following our previous model of the aortic root including the coronaries, in this study, we have further developed the global aspect of the model by incorporating the anatomical structure of the thoracic aorta. This model is different from all the previous studies in the sense that inclusion of the coronary structures and thoracic aorta into the natural aortic valve introduces the notion of globality into the model enabling us to explore the possible link between the regional pathologies. The developed model was first validated using the available data in the literature under physiological conditions. Then, to provide a support for the possible association between the localized cardiovascular pathologies and global variations in hemodynamic conditions, we simulated the model for two pathological conditions including moderate and severe aortic valve stenoses. The findings revealed that malformations of the aortic valve are associated with development of low wall shear stress regions and helical blood flow in thoracic aorta that are considered major contributors to aortic pathologies.

3D physiological model of the aortic valve incorporating small coronary arteries

The diseases of the coronary arteries and the aortic root are still the leading causes of mortality and morbidity worldwide. In this study, a 3D global fluid-structure interaction of the aortic root with inclusion of anatomically inspired small coronary arteries using the finite element method is presented. This innovative model allows to study the impact and interaction of root biomechanics on coronary hemodynamics and brings a new understanding to small coronary vessels hemodynamics. For the first time, the velocity profiles and shear stresses are reported in distal coronary arteries as a result of the aortic flow conditions in a global fluid-structure interaction model.

The impact of the aortic valve impairment on the distant coronary arteries hemodynamics: a fluid-structure interaction study

Atherosclerosis is still the leading cause of death in the developed world. Although its initiation and progression is a complex multifactorial process, it is well known that blood flow-induced wall shear stress (WSS) is an important factor involved in early atherosclerotic plaque initiation. In recent clinical studies, it was established that the regional pathologies of the aortic valve can be involved in the formation of atherosclerotic plaques. However, the impact of hemodynamic effects is not yet fully elucidated for disease initiation and progression. In this study, our developed 3D global fluid-structure interaction model of the aortic root incorporating coronary arteries is used to investigate the possible interaction between coronary arteries and aortic valve pathologies. The coronary hemodynamics was examined and quantified for different degrees of aortic stenosis varying from nonexistent to severe. For the simulated healthy model, the calculated WSS varied between 0.41 and 1.34 Pa which is in the atheroprotective range. However, for moderate and severe aortic stenoses, wide regions of the coronary structures, especially the proximal sections around the first bifurcation, were exposed to lower values of WSS and therefore they were prone to atherosclerosis even in the case of healthy coronary arteries.

Diabetes mellitus and coronary microvascular function in asymptomatic patients with severe aortic stenosis and nonobstructed coronary arteries

BACKGROUND AND AIM

Coronary flow reserve is impaired in asymptomatic patients with aortic stenosis and has a prognostic value. We investigated whether the type II diabetes mellitus additionally impairs microvascular circulation assessed by coronary flow reserve in patients with asymptomatic severe aortic stenosis, normal left ventricular ejection fraction and nonobstructed coronary arteries.

METHODS

A total of 128 patients, mean age of 66.35 ± 10.51 (58.6% males), with severe aortic stenosis and normal left ventricular ejection fraction were enrolled in this study. Patients with diabetes mellitus, those who were treated for diabetes mellitus or had documentation confirming the diagnosis of diabetes mellitus, were considered. All patients underwent coronary angiography and had no obstructive coronary disease (defined as having no stenosis >50% in diameter), standard transthoracic Doppler-echocardiographic study and adenosine stress transthoracic echocardiography for coronary flow reserve measurement.

RESULTS

Diabetes mellitus was present in 26 patients (20.31%). There was no significant difference in aortic stenosis severity between diabetic and non-diabetic patients [aortic valve area (0.81 ± 0.18 vs 0.85 ± 0.15 cm(2)) and Vmax (4.20 ± 0.57 vs 4.21 ± 0.48 m/s)]. Mean coronary flow reserve in diabetic patients was 1.98 ± 0.48, while mean coronary flow reserve in non-diabetic patients was 2.64 ± 0.54 (p < 0.01). Diabetes mellitus was independent predictor of coronary flow reserve [B = -0.636, 95% confidence interval (-0.916 to -0.368), p < 0.001].

CONCLUSION

Diabetes mellitus additionally impairs coronary microvascular function in asymptomatic patients with severe aortic stenosis and nonobstructed coronary arteries.

Impaired Coronary and Renal Vascular Function in Spontaneously Type 2 Diabetic Leptin-Deficient Mice

BACKGROUND

Type 2 diabetes is associated with macro- and microvascular complications in man. Microvascular dysfunction affects both cardiac and renal function and is now recognized as a main driver of cardiovascular mortality and morbidity. However, progression of microvascular dysfunction in experimental models is often obscured by macrovascular pathology and consequently demanding to study. The obese type 2 diabetic leptin-deficient (ob/ob) mouse lacks macrovascular complications, i.e. occlusive atherosclerotic disease, and may therefore be a potential model for microvascular dysfunction. The present study aimed to test the hypothesis that these mice with an insulin resistant phenotype might display microvascular dysfunction in both coronary and renal vascular beds.

METHODS AND RESULTS

In this study we used non-invasive Doppler ultrasound imaging to characterize microvascular dysfunction during the progression of diabetes in ob/ob mice. Impaired coronary flow velocity reserve was observed in the ob/ob mice at 16 and 21 weeks of age compared to lean controls. In addition, renal resistivity index as well as pulsatility index was higher in the ob/ob mice at 21 weeks compared to lean controls. Moreover, plasma L-arginine was lower in ob/ob mice, while asymmetric dimethylarginine was unaltered. Furthermore, a decrease in renal vascular density was observed in the ob/ob mice.

CONCLUSION

In parallel to previously described metabolic disturbances, the leptin-deficient ob/ob mice also display cardiac and renal microvascular dysfunction. This model may therefore be suitable for translational, mechanistic and interventional studies to improve the understanding of microvascular complications in type 2 diabetes.

The association between aortic distensibility and coronary flow reserve in newly diagnosed diabetic patients

INTRODUCTION

Aortic distensibility (AD) is an important parameter affecting coronary hemodynamics. Coronary flow velocity reserve (CFVR) is a reliable marker of coronary endothelial function in diabetic patients. The aim of this study was to investigate the association between AD and CFVR in newly diagnosed diabetic patients.

METHOD

We studied 77 patients with newly diagnosed diabetes mellitus (DM) and 30 age- and sex-matched healthy control subjects. CFVR was calculated as the hyperemic to resting coronary diastolic velocities ratio by using transthoracic echocardiography. Pulse pressure (PP) and AD were calculated.

RESULTS

Fasting blood glucose, HbA1c and PP were significantly higher in patients with diabetes (P < 0.001, P < 0.001 and P = 0.009, respectively). Other clinical and demographical characteristics, laboratory findings and echocardiographic findings were similar in both groups (P > 0.05, for all). The measurement of CFVR and AD in patients with diabetes were significantly lower compared with the controls (P < 0.001 and P = 0.001, respectively). CFVR was significantly negatively correlated with age, body mass index, HbA1c, systolic blood pressure, and PP, while significantly positively correlated with AD (P < 0.05, for all). Multivariate regression analysis showed that only AD (β = 0.485, P < 0.0001) and HbA1c (β = -0.362, P < 0.0001) were independently associated with CFVR. The cutoff value of AD obtained by the receiver operator characteristic (ROC) curve analysis was 2.44 for the prediction of impaired CFVR.

CONCLUSION

Aortic distensibility and HbA1c were independently associated with CFVR. The decrease in AD may be used as a marker of impaired coronary microcirculation in asymptomatic diabetic patients.

Selective up-regulation of arginase-1 in coronary arteries of diabetic patients

Coronary artery disease (CAD) remains the leading cause of death in the Western societies. Diabetes mellitus (DM) is one of the highly prevalent diseases, which remarkably accelerates the development of CAD. Experimental evidence indicates that decreased bioavailability of coronary endothelial nitric oxide (NO) contributes to the development of CAD in DM. There are recent studies showing that a selective impairment of NO synthesis occurs in coronary arteries of DM patients, which is mainly due to the limited availability of endothelial NO synthase (eNOS) precursor, l-arginine. Importantly, these studies demonstrated that DM, independent of the presence of CAD, leads to selective up-regulation of arginase-1. Arginase-1 seems to play an important role in limiting l-arginine availability in the close proximity of eNOS in vessels of DM patients. This brief review examines recent clinical studies demonstrating the pathological role of vascular arginase-1 in human diabetes. Whether arginase-1, which is crucial in the synthesis of various fundamental polyamines in the body, will represent a potent therapeutic target for prevention of DM-associated CAD is still debated.

Does cardiovascular phenotype explain the association between diabetes and incident heart failure? The Strong Heart Study

BACKGROUND AND AIMS

Diabetes remains a predictor of incident heart failure (HF), independent of intercurrent myocardial infarction (MI) and concomitant risk factors. Initial cardiovascular (CV) characteristics, associated with incident heart failure (HF) might explain the association of diabetes with incident HF.

METHODS AND RESULTS

Participants to the 2nd Strong Heart Study exam, without prevalent HF or coronary heart disease, or glomerular filtration rate <30 mL/min/1.73 m(2), were analyzed (n = 2757, 1777 women, 1278 diabetic). Cox regression of incident HF (follow-up 8.91 ± 2.76 years) included incident MI censored as a competing risk event. Acute MI occurred in 96 diabetic (7%) and 84 non-diabetic participants (6%, p = ns). HF occurred in 156 diabetic (12%) and in 68 non-diabetic participants (5%; OR = 2.89, p < 0.001). After accounting for competing MI and controlling for age, gender, BMI, systolic blood pressure, smoking habit, plasma cholesterol, antihypertensive treatment, heart rate, fibrinogen and C-reactive protein, incident HF was predicted by greater LV mass index, larger left atrium, lower systolic function, greater left atrial systolic force and urinary albumin/creatinine excretion. Risk of HF was reduced with more rapid LV relaxation and anti-hypertensive therapy. Diabetes increases hazard of HF by 66% (0.02 < p < 0.001). The effect of diabetes could be explained by the level of HbA1c.

CONCLUSIONS

Incident HF occurs more frequently in diabetes, independent of intercurrent MI, abnormal LV geometry, subclinical systolic dysfunction and indicators of less rapid LV relaxation, and is influenced by poor metabolic control. Identification of CV phenotype at high-risk for HF in diabetes should be advised.

Arginase inhibition restores in vivo coronary microvascular function in type 2 diabetic rats

Nitric oxide (NO) is crucial for maintaining normal endothelial function and vascular integrity. Increased arginase activity in diabetes might compete with NO synthase (NOS) for their common substrate arginine, resulting in diminished production of NO. The aim of this study was to evaluate coronary microvascular function in type 2 diabetic Goto-Kakizaki (GK) rats using in vivo coronary flow velocity reserve (CFVR) and the effect of arginase inhibition to restore vascular function. Different groups of GK and Wistar rats were given vehicle, the arginase inhibitor Nω-hydroxy-nor-l-arginine (nor-NOHA), l-arginine, and the NOS inhibitor NG-monomethyl -l-arginine (l-NMMA). GK rats had impaired CFVR compared with Wistar rats (1.31 ± 0.09 vs. 1.87 ± 0.05, P < 0.001). CFVR was restored by nor-NOHA treatment compared with vehicle in GK rats (1.71 ± 0.13 vs. 1.23 ± 0.12, P < 0.05) but remained unchanged in Wistar rats (1.88 ± 0.10 vs. 1.79 ± 0.16). The beneficial effect of nor-NOHA in GK rats was abolished after NOS inhibition. CFVR was not affected by arginine compared with vehicle. Arginase II expression was increased in the aorta and myocardium from GK rats compared with Wistar rats. Citrulline-to-ornithine and citrulline-to-arginine ratios measured in plasma increased significantly more in GK rats than in Wistar rats after nor-NOHA treatment, suggesting a shift of arginine utilization from arginase to NOS. In conclusion, coronary artery microvascular function is impaired in the type 2 diabetic GK rat. Treatment with nor-NOHA restores the microvascular function by a mechanism related to increased utilization of arginine by NOS and increased NO availability.

Echocardiographic evaluation and clinical implications of aortic stiffness and coronary flow reserve and their relation

The normal human aorta is not a stiff tube but is characterized by elastic properties with a buffering Windkessel function. Aortic stiffening may cause an increase in aortic pulse pressure, left ventricular load, and ultimately left ventricular hypertrophy. This, together with the decreased diastolic transmyocardial pressure gradient interacts with coronary flow and flow reserve. In recent studies, significant correlations between coronary flow reserve and aortic stiffness have been demonstrated in different patient populations. The aim of the present review is to describe the current echocardiographic modalities to measure aortic stiffness and coronary flow reserve and to overview our knowledge about the relationship between aortic stiffness and coronary flow reserve.

Diminished coronary flow velocity reserve and aortic distensibility in elderly patients with chest pain and negative coronary angiograms

BACKGROUND AND AIMS

Aging is a dominant process that alters vascular stiffness, endothelial function and coronary flow regulation. The objective of our work was to assess simultaneously the elastic properties of the descending aorta and coronary flow velocity reserve (CFR) during the same transesophageal echocardiography (TEE) in elderly patients.

METHODS

The following patients with normal epicardial coronary arteries were compared: 30 subjects under 55 years of age (group 1) and 17 patients over 55 years (group 2). A complete TEE examination was carried out in all patients, and the following aortic elastic properties were calculated from aortic diameter and blood pressure data: aortic elastic modulus [E(p)] and Young's circumferential static elastic modulus [E(s)]. Doppler evaluation of left anterior descending coronary flow velocity was performed in resting conditions and after administration of 0.56 mg/Kg dipyridamole over 4 min. Peak coronary flow velocities were measured at the 6th minute at maximum vasodilation. CFR was estimated as the ratio of hyperemic to basal peak diastolic coronary flow velocities.

RESULTS

Peak hyperemic diastolic coronary flow velocities were significantly decreased (139.1+/-35.6 cm/s vs 105.7+/-39.7 cm/s, p<0.01) in patients >55 years. CFR was decreased (2.67+/-1.05 vs 2.13+/-0.56, p<0.05), whereas E(p) (in 103 mmHg, 0.59+/-0.49 vs 0.94+/-0.65, p<0.05) and E(s) (in 103 mmHg, 5.70+/-4.30 vs 8.47+/-5.14, p<0.05) were increased in patients >55 years. A correlation was found between CFR and E(p) (r=-0.20, p<0.05).

CONCLUSIONS

CFR and aortic distensibility are altered in elderly patients. There is a relationship between these functional parameters.

Comparison of coronary flow velocity reserve and aortic distensibility in diabetic versus non-diabetic patients with and without aortic atherosclerosis

Coronary flow velocity reserve (CFR) and aortic distensibility are altered both in diabetes and in the presence of aortic atherosclerosis (AA). Transoesophageal echocardiography has been demonstrated to be a suitable method for simultaneous evaluation of these functional parameters. In the present study no significant difference could be observed in CFR and aortic distensibility in diabetic patients compared to non-diabetic subjects with or without AA.

Reduction of coronary flow reserve in patients with increased aortic stiffness

Aortic stiffness is thought to affect coronary blood flow, but little is known about its influence on coronary flow reserve (CFR). The objective of the present study was to investigate the relationship between aortic stiffness and CFR in matched patients with and without increased aortic stiffness. Stress transoesophageal echocardiography (TEE) as the CFR measurement and coronary angiography were performed in all cases. Increased aortic stiffness was defined if elastic modulus Ep > 680 mmHg. The following patient populations free of coronary artery disease were compared: 36 subjects with normal aortic distensibility and 19 age-, sex-, and risk factor-matched patients with increased aortic stiffness. CFR was significantly reduced in patients with increased aortic stiffness as compared with cases with normal aortic distensibility (2.64 ± 1.16 vs. 2.12 ± 0.58, p <0.01). Hyperaemic diastolic flow velocities were reduced in patients with increased aortic stiffness (129.5 ± 36.6 cm/s vs. 102.1 ± 39.8 cm/s, p <0.05). Negative correlations were found between Ep and hyperaemic diastolic coronary flow velocity (r = –0.41, p < 0.01) and CFR (r = –0.21, p < 0.05). CFR is reduced in patients with increased aortic stiffness and negative correlations exist between these functional parameters.

Simultaneous echocardiographic evaluation of coronary flow velocity reserve and aortic distensibility indices in hypertension

The coronary flow velocity reserve (CFVR), a measure of endothelial function in coronary circulation, can be measured semi-invasively in the left anterior descending coronary artery by using stress transesophageal echocardiography (TEE). During the same stress TEE, aortic distensibility indices (elastic modulus [E(p)] and Young's circumferential static elastic modulus [E(s)]) can be assessed. The purpose of the present study was to examine whether stress TEE is valuable method for parallel evaluation of CFVR, E(p), and E(s) in patients with hypertension. A total of 38 patients with chest pain but with a negative coronary angiogram were enrolled into the present study, which included examination of the presence or absence of hypertension. Significant coronary stenosis was considered present in the event of a luminal diameter reduction of >50% on use of the "worst view method." Patients with significant coronary or valvular heart disease, atrial fibrillation, heart failure, unstable angina pectoris, acute myocardial infarction, or diabetes mellitus were excluded from the study. Stress TEE was performed in each case to evaluate CFVR, E(p), and E(s). Coronary flow velocity reserve and diastolic coronary flow velocities measured at peak stress were decreased in hypertensive patients as compared with normotensive subjects. E(p) and E(s) were significantly increased in hypertensive patients. In conclusion, it can be stated that Stress TEE is a useful tool for the simultaneous evaluation of the CFVR, E(p), and E(s) in hypertension. The CFVR and aortic distensibility are decreased in hypertension.