Flow Reserve In Hypertensive Patients Research Articles

Contrast-enhanced ultrasonography reveals a lower cortical perfusion and a decreased renal flow reserve in hypertensive patients.

Microvascular structural alteration and dysfunction is a hallmark of arterial hypertension. So far, the visualization and the quantification of renal microcirculation in humans has been hampered by the lack of non-nephrotoxic and non-invasive radiologic techniques. Contrast-enhanced ultrasonography (CEUS) is an appealing method to investigate renal microcirculation and has not been investigated in this setting. We aimed to compare renal microcirculation in normotensive (NT) and hypertensive (HT) participants using CEUS at rest and during a sympathetic stress test. We measured the renal perfusion index (PI, primary outcome), the renal resistive index (RRI), beat-to-beat systemic hemodynamics and plasma catecholamines before and during a 2-min cold pressor test (CPT) in NT and HT participants. Linear mixed model analysis was used to compare the effect of the CPT on the variables of interest. Seventy-three participants (32 HT) with normal kidney function were included. HT participants had a lower baseline PI compared with NT participants [median (interquartile range) 1476 (959-2155) arbitrary units (a.u.) vs 2062 (1438-3318) a.u., P<.001]. The CPT increased blood pressure, heart rate and catecholamines in all participants. The increase in PI observed in NT during the CPT was blunted in HT [+504 (117-920) a.u. vs +1159 (678-2352) a.u in NT, interaction P=.013]. Age, sex and body mass index did not modify these results. HT patients had a lower basal renal cortical perfusion. During the cold pressor test, HT participants had a smaller increase in the PI, suggesting that renal cortical flow reserve is impaired.

Effect of Rosuvastatin on Coronary Flow Reserve in Hypertensive Patients at Cardiovascular Risk.

BACKGROUNDIt has been unclear whether statin therapy directly improves coronary flow reserve (CFR) in hypertensive patients at cardiovascular risk, independent of lifestyle modification and antihypertensive medications.METHODSIn this double-blind, randomized controlled trial, we randomly assigned 95 hypertensive patients at cardiovascular risk to receive either rosuvastatin 10 mg or placebo for 12 months, in addition to antihypertensive therapy and lifestyle modification for hypercholesterolemia. Using Doppler echocardiography, coronary flow velocity in the distal left anterior descending artery was measured and CFR was calculated as the ratio of hyperemic to basal averaged peak diastolic flow velocity. The primary end point was change in CFR from baseline to 12 months follow-up.RESULTSLow-density lipoprotein-cholesterol was changed from 157 ± 23 to 84 ± 16 mg/dL in the rosuvastatin group (p < 0.001) and from 152 ± 19 to 144 ± 22 mg/dL in the control group (p = 0.041, but there were no significant differences between the treatment groups in the changes in C-reactive protein, high-density lipoprotein cholesterol, and blood pressures. CFR was changed from 3.03 ± 0.44 to 3.25 ± 0.49 in the rosuvastatin group (p < 0.001) and from 3.15 ± 0.54 to 3.17 ± 0.56 in the control group (p = 0.65). The primary end point of change in CFR was significantly different between the rosuvastatin group and the control group (0.216 ± 0.279 vs. 0.015 ± 0.217; p < 0.001).CONCLUSIONSCompared with lifestyle modification alone, addition of rosuvastatin significantly improved CFR in hypertensive patients at cardiovascular risk.

P5456Comparison of the Echo-derived markers of arterial stiffness to pulse wave velocity for the prediction of impaired LV function and coronary flow reserve in hypertensive patients

P5456Comparison of the Echo-derived markers of arterial stiffness to pulse wave velocity for the prediction of impaired LV function and coronary flow reserve in hypertensive patients

Impact of blood pressure control on coronary flow reserve in hypertensive patients

To investigate the impacts of blood pressure control on coronary flow reserve (CFR) in hypertensive patients. A total of 236 patients without significant coronary stenosis (defined as <50% luminal narrowing which was confirmed by coronary angiography or coronary artery CT scan) between January 2011 to July 2015 were retrospectively enrolled in this study. CFR was measured in the left anterior descending coronary artery (LAD) during adenosine triphosphate-induced hyperemia by transthoracic Doppler echocardiography. Patients were divided into hypertension group (n=173) and non-hypertension group (n=63). The hypertension patients were further divided into ideally controlled (n=31, defined as SBP <120 mmHg (1 mmHg=0.133 kPa) and DBP <80 mmHg), controlled (n=82, defined as SBP 120 to 139 mmHg and DBP <90 mmHg) and uncontrolled groups (n=60, defined as SBP≥140 mmHg and/or diastolic DBP≥90 mmHg) based on their blood pressure after systematic antihypertensive therapy and CFR values were compared among the 4 groups. Multivariate regression analyses were performed to identify the independent determinants of CFR in patients with hypertension. Compared with non-hypertension group, the CFR was significantly lower in controlled (3.27±0.71 vs. 2.87±0.56, P<0.001) and uncontrolled groups (3.27±0.71 vs. 2.61±0.71, P<0.001), but was similar in ideally controlled group (3.27±0.71 vs. 3.21±0.85, P=0.68). Furthermore, the CFR was significantly lower in uncontrolled group than that of the other two hypertension groups and was significantly lower in controlled group than that of ideally controlled group. Higher blood pressure (β=-0.17, P=0.03) and age(β=-0.02, P=0.03) were independent predictors of lower CFR in patients with hypertension. Higher blood pressure is an independent predictor of decreased CFR in patients with hypertension. Hypertensive patients with ideally controlled blood pressure have similar CFR level as patients without hypertension.

The functional state of microcirculatory vessels in patients with arterial hypertension I-II degree with different degrees of cardiovascular risk

Aim: to evaluate the main parameters of the microcirculatory blood flow and to determine its reserve capacity in patients with arterial hypertension (AH) and different degrees of cardiovascular risk (CVR).Subjects and methods. We examined 64 subjects aged 47-58 years, of which 27 were healthy volunteers and 37 patients with 1st and 2nd degree arterial hypertension, with medium, high and very high CVR (the antihypertensive therapy was cancelled for 2 weeks before the study). In all subjects laser Doppler flowmetry (LDF) with studing initial perfusion parameters, 2 constrictor and 3 dilatator tests waky perfomed. To assess the status of the tone-shaping «active» and «passive» parts of microcirculatory modulation, analysis of the amplitude and frequency spectrum of LDF- grams was carried out.Results. A significant increase in the rate of «base perfusion» in all hypertensive groups compared with the control group was found. The amplitude of respiratory oscillations was one-third higher in high and very high CVR groups in comparison with the control, the amplitude of the myogenic and neurogenic oscillations were maximal and reached significant values in very high CVR group. A reduction in constrictor response in hypertensive patients with middle and high CVR and its increase in the very high CVR group was shown during constrictor functional tests. The power of perfusion increase was reduced in response to all kinds of dilatator stimulus in hypertensive patients group.Conclusion. The findings indicate a progressive increase in the level of «base perfusion», worsening of venous congestion symptoms in hypertensive patients with the progression in CVR severity. High and very high CVR patients showed a reduction in myogenic tone of microvessels when compared with those with normotension. Dilatator functional tests showed a tendency to lower capillary blood flow reserve in hypertensive patients compared with the control group.

Функциональное состояние сосудов микроциркуляторного русла у больных артериальной гипертонией 1–2-й степени различной степени сердечно-сосудистого риска

Aim: to evaluate the main parameters of the microcirculatory blood flow and to determine its reserve capacity in patients with arterial hypertension (AH) and different degrees of cardiovascular risk (CVR).Subjects and methods. We examined 64 subjects aged 47-58 years, of which 27 were healthy volunteers and 37 patients with 1st and 2nd degree arterial hypertension, with medium, high and very high CVR (the antihypertensive therapy was cancelled for 2 weeks before the study). In all subjects laser Doppler flowmetry (LDF) with studing initial perfusion parameters, 2 constrictor and 3 dilatator tests waky perfomed. To assess the status of the tone-shaping «active» and «passive» parts of microcirculatory modulation, analysis of the amplitude and frequency spectrum of LDF- grams was carried out.Results. A significant increase in the rate of «base perfusion» in all hypertensive groups compared with the control group was found. The amplitude of respiratory oscillations was one-third higher in high and very high CVR groups in comparison with the control, the amplitude of the myogenic and neurogenic oscillations were maximal and reached significant values in very high CVR group. A reduction in constrictor response in hypertensive patients with middle and high CVR and its increase in the very high CVR group was shown during constrictor functional tests. The power of perfusion increase was reduced in response to all kinds of dilatator stimulus in hypertensive patients group.Conclusion. The findings indicate a progressive increase in the level of «base perfusion», worsening of venous congestion symptoms in hypertensive patients with the progression in CVR severity. High and very high CVR patients showed a reduction in myogenic tone of microvessels when compared with those with normotension. Dilatator functional tests showed a tendency to lower capillary blood flow reserve in hypertensive patients compared with the control group.

Fractional pulse pressure as a simple index of impaired coronary flow reserve in hypertensive patients

Fractional pulse pressure (PPf), is thought to be more directly reflect arterial stiffness than pulse pressure. Our aim was to evaluate the relationship between coronary flow reserve (CFR) and PPf in hypertensive patients with normal coronary arteries One-hundred and six consecutive hypertensive patients (aged 52.8 + 9.4 years), with indications of myocardial ischaemia with exercise electrocardiogram (EECG) and normal coronary arteries in coronary angiography. CFR was calculated noninvasively using transthoracic echo-Doppler assessment with hyperemia induced by infusion of dipyridamole at a rate of 0.56 mg/kg over 4 min. PPf was calculated as pulse pressure divided by mean arterial pressure (SBP-DBP/MAP), while diastolic function was evaluated by means of transmitral flow and tissue Doppler imaging. Hypertensive patients with low CFR ( n = 54) compared with those with normal CFR ( n = 52) exhibited significantly incresed PPf (75.2 ± 11.4 vs 64.5 ± 6.7 P < 0.001). In hypertensives with low CFR, CFR was negatively correlated with PPf ( r = −0.651, P < 0.0001). After applying multivariate linear regression analysis, age, left ventricular mass index, Em/Am, and PPf turned out to be independent predictors of CFR. Estimation of PPf by using simple sphygmomanometer blood pressure measurement is simple non-invasive index for assessment of coronary microcirculation in essential hypertensive patients with indications of myocardial ischaemia and normal coronary arteries.

A Translational Approach to Hypertensive Heart Disease

The spectrum of the cardiac complications of arterial hypertension includes heart failure (HF), sudden death, and cardiac dysrhythmias, as well as the exacerbation of coincidental diseases (ie, atherosclerosis and chronic renal disease).1 However, knowledge of the cardiac impact of chronic elevation of arterial pressure has so evolved that hypertensive heart disease (HHD) may be thought as those consequences derived from left ventricular (LV) responses to fundamental disease mechanisms triggered by mechanical overload and neurohumoral stimuli.2 For instance, the long-held views are that LV hypertrophy (LVH), as the result of cardiomyocyte growth in response to pressure overload, serves to restore heart muscle economy back to normal and to preserve LV function.3 However, a number of alterations of the cardiomyocyte and the noncardiomyocyte components of the myocardium (including apoptosis, fibrosis, and changes in the microcirculation) also develop in HHD that lead to pathological myocardial remodeling not only in the left ventricle but also the left atrium and right ventricle.2 These alterations may explain the overall risk of LVH and its associated cardiac and noncardiac complications in hypertensive patients.4 Although LVH may be detected early and accurately in hypertensive patients by electrocardiography and echocardiography, newer cardiac imaging methods and the monitoring of several circulating biomarkers hold promise as noninvasive tools for the diagnosis of myocardial remodeling. Numerous clinical studies have shown that effective long-term antihypertensive treatment may be associated with a decreased LV mass (LVM), which has been attributed to diminished risk. However, no large study (or meta-analysis) has demonstrated that diminished risk from the contemporary reduction of arterial pressure by virtue of its a priori design. Therefore, because overall risk remains unacceptably high, especially from HF, new therapeutic strategies aimed not only to decrease arterial pressure and LVM but also to repair and even prevent myocardial remodeling …

Coronary Flow Reserve in Hypertensive Patients With Hypercholesterolemia and Without Coronary Heart Disease

Coronary flow reserve (CFR) may be reduced both in arterial hypertension and in hypercholesterolemia. The aim of the study was to assess an association between CFR and levels of plasma total cholesterol (TC) in untreated arterial hypertension. We studied 54 consecutive, untreated hypertensive outpatients free of coronary heart disease. Twenty of them had normal TC and 34 high TC (>/=200 mg/dL). Standard echocardiograms and transthoracic Doppler interrogation of the distal left anterior descending artery were obtained. Coronary diastolic peak velocities were measured both at rest and after low-dose dipyridamole. The CFR was calculated as dipyridamole/resting velocities ratio. The two groups had similar age, body mass index, heart rate, and diastolic blood pressure (BP). Patients with high TC had higher systolic BP (P < .05), triglycerides (P < .02), LDL-cholesterol, and TC/HDL-cholesterol ratio (both P < .0001) than controls. Left ventricular (LV) mass index, relative wall thickness, and fractional shortening did not differ between the two groups. Coronary diastolic peak velocities were similar at rest but lower after dipyridamole in patients with high TC (P < .02). As a consequence, CFR was reduced (P < .002). In multiple linear regression analyses, adjusting for age, heart rate, systolic BP, smoking, and relative wall thickness, TC (beta = -0.338) or high LDL-cholesterol (beta = -0.301) (both P < .001) were predictors of lower CFR independently of the concomitant effect of potential confounders. In hypertensive patients free of coronary artery disease, the degree of impairment in coronary vasodilator capacity is independently associated with plasma cholesterol and LDL-cholesterol.

Association between serum uric acid levels and coronary flow reserve in hypertensive patients without concomitant risk factors

Background. Hyperuricemia is associated with hypertension, vascular disease and cardiovascular (CV) disease. However, the role of serum uric acid (SUA) level as an independent risk factor for CV and renal morbidity in hypertension remains controversial. Accordingly, we aimed to determine whether SUA levels are independently and specifically associated with coronary flow reserve (CFR) impairment in hypertensive patients. Methods. We examined 80 never treated and newly diagnosed hypertensive individuals. The hypertensive individuals were divided into two groups based on CFR values. Results. Subjects with altered CFR (<2) had significantly higher SUA levels compared with those with normal CFR (⩾2) (346.0±98.1 vs 260.7±75.6 µmol/l, p<0.0001). After adjusting for potential confounders, including age, sex, body mass index, blood pressure, lipids and creatinine, we found that SUA levels were independently associated with CFR impairment (β = −0.417, p<0.0001). We also found that SUA levels were a good predictor of low CFR at the receiver‐operating characteristic curve. Area under the curve was 76% (95% CI 0.64–0.88), and SUA levels were significantly predictive of low CFR (p<0.0001). Conclusions. These results support a role for SUA level as an independent marker of target organ damage in hypertension.

1078 Three-month Nebivolol therapy induces improvement of both left ventricular filling pressure and coronary flow reserve in hypertensive patients without coronary artery disease

1078 Three-month Nebivolol therapy induces improvement of both left ventricular filling pressure and coronary flow reserve in hypertensive patients without coronary artery disease

Long-term effects of carvedilol on coronary flow reserve in hypertensive patients

The beneficial effect of beta-blockers on the treatment of patients with essential hypertension (EH) has been demonstrated,but there is evidence of differential effects among them. We assess the effects of Talliton (Carvedilol) on coronary flow reserve (CFR) in patients with EH. 54 , II WHO hypertensive patients (28 m, 26f, mean age 47,6 years) without coronary artery disease underwent standard Doppler echocardiography. The exam was performed at baseline and after 6-week monotherapy by Talliton in a daily dose of 12.5 mg. At baseline the prevalence of left ventricular (LV) hypertrophy (LV mass index > 50 g/m powered to 2.8) was 64.6% after 6-week Talliton therapy. Blood pressure (BP) decreased in 82.4% of the patients (p < 0.01). Heart rate also significantly reduced (p < 0.01).No change could be detected in LV mass index,relative wall thickness,fractional shortening and Doppler-derived diastolic inflow indexes.LV end-diatolic internal diameter and stroke volume tended to increase (p = 0.06 and p = 0.08 respectively). After 6-week therapy , CFR increased in 88.6% of the patients (p < 0.0001). In patients with essential hypertension Talliton improves coronary flow reserve after 6-week therapy. This improvement occurs despite decrease in mean blood presuure and independently of changes in left ventricular mass.

1065-176 Role of endothelin-1 and coronary flow reserve in hypertensive patients without coronary artery disease

1065-176 Role of endothelin-1 and coronary flow reserve in hypertensive patients without coronary artery disease

383 The impact of cholesterol on coronary flow reserve in hypertensive patients without evidence of coronary heart disease

Background: It has been demonstrated that the maximal oxygen uptake (VO2max) is strictly related to functional status (NYHA Class) in patients with idiopathic dilative cardiomyopathy (IDC) and therefore represents an important clinical predictor. The VO2max is the physiological trigger to increase the coronary flow reserve (CFR). At present it is possible noninvasively evaluate the CFR by transthoracic echocardiography on left anterior descending (LAD) coronary artery. Methods: We have consecutively enrolled 26 patients (pts), 16 Male mean age 64±b12 years, all affected with IDC confirmed by normal coronary artery with angiography. Each of them underwent TTE, evaluating the standard parameters such as LVEDV, LVESV (ml), EF (%) and Stress-Echo with Dipirydamole (0,84 mg/Kg over 6 m’) evaluating the LV contractility (WMSI) and simultaneously the CFR on LAD, calculated as the maximum peak-rest diastolic flow velocity (LADDFVDp-r) ratio, using a high frequency probe in 2ˆ harmonic (7 MHz). We utilized an off axis apical approach under the guide of color-Doppler and when necessary we injected a contrast agent (Sonovue 2ml in bolus) to improve the signal-noise coronary flow ratio. All pts underwent within 24 hour the effort test (treadmill) with gas analysis evaluating particularly the VO2max (ml/kg/m’) and anaerobic threshold. We considered as clinical parameter the NYHA Class. Results: We found the following mean values: EDV = 226 ± 63ml, ESV = 144 ± 52ml, EF = 36 ± 6%, WMSIb = 1,8 ± 0,3, LADDFVr 31 ± 4cm/s, LADDFVp = 59 ± O8cm/s, CFR = 1,9 ± 0,2, VO2max = 19 ± O6, NYHA Class = 2,3 ± 0,8 The parameters that demonstrated a significance linear statistical relationship were: NYHA Class vs MVO2: r = 0,70 p = 0.002 NYHA Class vs RC: r = 0.92 p = 0.001 VO2max vs CFR: r = 0.60 p = 0.016 VO2max vs LADDFVDr: r = 0.60 p = 0.020 The feasibility of CFR study in pts affected with IDC was excellent: 27/27 pts (100%) Conclusion: The excellent relationship between the NYHA Class and VO2max and between CFR and VO2max suggest us to consider the CFR of LAD in daily practice as an important functional predictor: this, in the next future could have a relevant therapeutic and prognostic impact in pts with IDC.

Coronary flow reserve in hypertensive patients with appropriate or inappropriate left ventricular mass.

To assess the association between coronary flow reserve (CFR) and levels of left ventricular mass (LVM) exceeding the compensatory needs in arterial hypertension. DESIGN, SETTINGS AND PATIENTS: The association between the excess of LV mass and CFR was assessed in a population of 40 consecutive hypertensive outpatients free of coronary heart disease, 22 with appropriate and 17 with inappropriately high LVM (i.e. LVM exceeding 128% of the value predicted by sex, stroke work and height in m(2.7)). The CFR (the ratio between dipyridamole and basal diastolic peak velocity) of the distal left anterior descending artery was measured by transthoracic Doppler echocardiography. Patients with inappropriate LVM had similar age, body mass index (BMI), baseline blood pressure (BP) and coronary velocities, but lower LV systolic function, post-dipyridamole diastolic peak velocities (P < 0.05) and lower CFR (P < 0.002) than patients with appropriate LVM. CFR was negatively related to the extent of the excess of LVM (beta = -0.44, P < 0.005), independently of potential combined effect of age, BMI and post-dipyridamole diastolic BP. Impairment of CFR (i.e. < 2) was better discriminated by identification of clear-cut inappropriate LVM (P < 0.004) than by the presence of LV hypertrophy (i.e. LV mass index > or = 51 g/m(2.7); P = 0.057). In hypertensive patients free of coronary artery disease, the degree of reduction in CFR is associated with the excess of LVM beyond the values compensatory for individual haemodynamic load. This relation is also independent of the presence of LV hypertrophy.

746 Nebivolol therapy improves coronary flow reserve in hypertensive patients without coronary heart disease

746 Nebivolol therapy improves coronary flow reserve in hypertensive patients without coronary heart disease

Carotid intima-media thickness is correlated with impairment of coronary flow reserve in hypertensive patients without coronary artery disease.

Hypertensive individuals occasionally experience angina-like chest pain despite having angiographically normal coronary arteries, and the etiology of this phenomenon has been suggested to be associated with depressed coronary flow reserve (CFR). Carotid intima-media thickness (IMT) assessed by ultrasound is correlated with not only cerebrovascular disease but also coronary artery disease and left ventricular hypertrophy (LVH). The aim of our study was to investigate the association between CFR and carotid IMT in patients with essential hypertension. We performed transthoracic Doppler recording of diastolic coronary flow velocity in the left anterior descending coronary artery at baseline and after maximal vasodilation by adenosine triphosphate infusion in 24 normotensive subjects and 125 hypertensive patients. CFR was defined as the ratio of hyperemic to basal averaged peak coronary flow velocity. Common cardiovascular risk factors, left ventricular mass index (LVMI), relative wall thickness (RWT), and carotid IMT were evaluated. The CFR of hypertensive patients (2.55 +/- 0.52) was significantly decreased compared with that of normotensive subjects (3.15 +/- 0.45). CFR showed a significant correlation with age, systolic blood pressure, RWT, and carotid IMT. Stepwise regression analysis revealed that, among carotid IMT, LVMI and RWT, only carotid IMT was a strong and independent parameter for predicting CFR in hypertensive patients. In conclusion, B-mode ultrasound scanning of the carotid artery seemed to be of clinical value in the screening of patients with LVH and impaired microcoronary circulation. These associations may explain the links between cardiac and cerebrovascular involvements in patients with hypertension.

Evaluation of coronary flow reserve in hypertensive patients by dipyridamole transesophageal Doppler echocardiography

This study evaluates the coronary flow reserve (CFR) in hypertensive patients with and without left ventricular (LV) hypertrophy. CFR was assessed by transesophageal Doppler echocardiography in 15 normal subjects (group I), 21 hypertensive patients without LV hypertrophy (group II), and 27 hypertensive patients with LV hypertrophy (group III). All hypertensive patients were complaining of typical anginal pain and had normal coronary angiograms. The sample volume was placed at the bifurcation of the left main and left anterior descending coronary arteries. Coronary blood flow velocities were evaluated at rest, 2 minutes after dipyridamole infusion, and 2 minutes after intravenous aminophylline. The ratios of dipyridamole to rest peak diastolic and systolic velocities were considered as indexes of CFR. Peak diastolic velocity ratio was significantly lower in group III than in groups I and II (1.6 ± 0.2, 2.7 ± 0.4, and 2.1 ± 0.2, respectively; p <0.05), and it was significantly lower in group II than I (p <0.05). The peak systolic velocity ratio was significantly lower in group III than in groups I and II (1.7 ± 0.3, 2.8 ± 0.3, and 2.1 ± 0.2, respectively; p <0.05), and it was significantly lower in group II than I (p <0.05). The peak diastolic velocity ratio was inversely related to systolic blood pressure, diastolic blood pressure, and LV mass index (r = −0.48, −0.51, and −0.37 respectively) in hypertensive patients. It is concluded that CFR is significantly impaired in hypertensive patients, especially those with LV hypertrophy, compared with healthy subjects. The degree of impairment of CFR is related to LV mass index.

Evaluation of coronary flow reserve in hypertensive patients by dipyridamole transoesophageal doppler echocardiography

Evaluation of coronary flow reserve in hypertensive patients by dipyridamole transoesophageal doppler echocardiography