Aortic Elastic Properties in Patients With Hypertensive Response to Exercise

Exercise blood pressure and cardiovascular disease risk: a systematic review and meta-analysis of cross-sectional studies

BACKGROUND

A hypertensive response to exercise (HRE) is associated with cardiovascular disease and high blood pressure (BP). A poor cardiovascular risk factor profile may underlie these associations, although this has not been systematically elucidated. Via systematic review and meta-analysis, we aimed to assess the relationship between exercise BP and cardiovascular risk factors, and determine if cardiovascular risk is higher in those with an HRE vs. no-HRE across different study populations (including those with/without high BP at rest).

METHODS

Three online databases were searched for cross-sectional studies reporting data on exercise BP, an HRE and cardiovascular risk factors (including arterial structure, lipid, metabolic, inflammatory and kidney function markers). Random-effects meta-analyses and meta-regression were used to calculate pooled correlations between exercise BP and each risk factor and pooled mean differences between those with/without an HRE.

RESULTS

Thirty-eight studies (38 295 participants, aged 50 ± 3years; 78% male) were included. Exercise SBP was associated with arterial, lipid and kidney function risk markers (P < 0.05). Those with an HRE had greater aortic stiffness (+0.80 ± 0.35 m/s), total (+0.14 ± 0.03 mmol/l) and low-density lipoprotein (+0.12 ± 0.03 mmol/l) cholesterol, triglycerides (+0.24 ± 0.04 mmol/l), glucose (+0.15 ± 0.05 mmol/l), white blood cell count (+0.49 ± 0.16 mmol/l) and albumin-to-creatinine ratio (standardized mean difference: +0.97 ± 0.34), and lower flow-mediated dilation (-4.13 ± 1.02%) and high-density lipoprotein cholesterol (-0.04 ± 0.01 mmol/l) vs. those with no-HRE (P < 0.05 all). Results were broadly similar across study populations.

CONCLUSION

Exercise SBP is associated with multiple cardiovascular risk factors, which appear worse in those with an HRE vs. no-HRE. As results were similar across population groups, an HRE should be considered an important indicator of cardiovascular risk.

Exercise blood pressure and cardiac structure: A systematic review and meta-analysis of cross-sectional studies

OBJECTIVES

A hypertensive response to exercise (HRE) is associated with cardiovascular disease and high blood pressure (BP). Sub-clinical changes to cardiac structure may underlie these associations, although this has not been systematically determined. Via systematic review and meta-analysis, we aimed to (1) assess the relationship between exercise BP and cardiac structure, and (2) determine if cardiac structure is altered in those with an HRE, across various study populations (including those with/without high BP at rest).

DESIGN AND METHODS

Three online databases were searched for cross-sectional studies reporting exercise BP, HRE and cardiac structural variables. Random-effects meta-analyses and meta-regressions were used to calculate pooled correlations between exercise BP and cardiac structure, and pooled mean differences and relative risk between those with/without an HRE.

RESULTS

Forty-nine studies, (n=23,707 total; aged 44±4 years; 63% male) were included. Exercise systolic BP was associated with increased left ventricular (LV) mass, LV mass index, relative wall thickness, posterior wall thickness and interventricular septal thickness (p<0.05 all). Those with an HRE had higher risk of LV hypertrophy (relative risk: 2.6 [1.85-3.70]), increased LV mass (47±7g), LV mass index (7±2g/m²), relative wall thickness (0.02±0.005), posterior wall thickness (0.78±0.20mm), interventricular septal thickness (0.78±0.17mm) and left atrial diameter (2±0.52mm) vs. those without an HRE (p<0.05 all). Results were broadly similar between studies with different population characteristics.

CONCLUSIONS

Exercise systolic BP is associated with cardiac structure, and those with an HRE show evidence towards adverse remodelling. Results were similar across different study populations, highlighting the hypertension-related cardiovascular risk associated with an HRE.

Vascular-ventricular coupling during exercise is not affected by exaggerated blood pressures in endurance-trained athletes

This study sought to examine whether cardiovascular performance during exercise, assessed using the vascular-ventricular coupling index (VVC), was affected by exaggerated blood pressure (EBP) responses in endurance-trained athletes. Subjects were middle-aged endurance-trained men and women. Blood pressure measurements and left ventricular echocardiography were performed in a semiupright position at rest and during steady-state cycling at workloads that elicited 100–110 beats/min ( stage 1) and 130–140 beats/min ( stage 2). These data were used to calculate effective arterial elastance index ( EaI), left ventricular end-systolic elastance index ( ELVI), and their ratio (VVC). Additional measurements of left ventricular volumes and function (i.e., stroke volume, cardiac output, and longitudinal strain) and indirect assessments of peripheral vascular function (i.e., total arterial compliance and peripheral vascular resistance) were examined. Fourteen subjects with EBP (EBP+, 50% men) and 14 sex-matched subjects without EBP (EBP−) participated, with results presented as EBP+ versus EBP−. EaI and ELVI increased from rest to exercise while VVC decreased, but only ELVI was different between groups at stage 1 [7.6 (1.8) vs. 6.4 (1.0) mmHg·ml−1·m−2, P = 0.045] and stage 2 [10.3 (1.6) vs. 8.0 (1.7) mmHg·ml−1·m−2, P < 0.001]. Additional comparisons revealed no group difference in the contribution of the Frank-Starling mechanism or left ventricular and peripheral vascular function during exercise. The cardiovascular adjustment to exercise in athletes with EBP is achieved through a matched increase in both EaI and ELVI, and the absence of between-group differences in left ventricular or peripheral vascular function suggests that other factors may contribute to the EBP response.

NEW & NOTEWORTHY Cardiovascular performance during submaximal exercise, assessed using vascular-ventricular coupling, is unaffected by exaggerated blood pressure (EBP) responses in endurance-trained athletes. The underlying mechanisms of EBP in athletes remain unknown as changes in left ventricular and peripheral vascular function during exercise were similar in athletes with and without EBP.

Blood pressure response to exercise in young athletes aged 10 to 18 years

The aim of the study was to determine arterial blood pressure response to exercise in young athletes. The study group comprised 711 young athletes (457 boys, 254 girls) aged 10 to 18 years (mean 13.41 ± 3.12 years) who had been training for an average of 7.62 ± 4.2 h per week for an average of 4.01 ± 2.5 years. Participants with elevated arterial blood pressure above the 90th percentile at rest were excluded from investigation. A symptom-limited, multistage exercise test to exhaustion was performed using a Monark cycle ergometer. Arterial blood pressure was measured with an aneroid manometer in the third minute of each stage of the test. Mean systolic arterial blood pressure during peak exercise was significantly higher in boys than in girls: 183.21 ± 27.97 mm Hg and 170.97 ± 21.4 mm Hg, respectively (p = 0.03). Multivariate linear regression analysis showed that age and workload had significant effects on arterial blood pressure during the test. Systolic arterial blood pressure during the exercise can be described with the following equations: boys, SBPex (mm Hg) = -1.92 × age (years) + 0.55 × workload (W) + 120.84; girls, SBPex (mm Hg) = -0.88 × age (years) + 0.48 × workload (W) + 111.22. The study results describe reference values of arterial blood pressure during the exercise test. The presented equations and figures can help to assess whether the arterial blood pressure at each stage of the exercise test exceeds the normal range or not.

Evaluation of aortic elastic properties in patients with exaggerated systolic blood pressure response to exercise testing

We aimed to evaluate the aortic elastic properties in subjects with hypertensive response to exercise stress test (HRE). Sixty-six patients were divided into two groups (33 patients in HRE group and 33 patients in normotensive group). Baseline demographic characteristics were similar. The mean aortic stiffness index (ASI) was significantly higher (p=0.001) whereas aortic distensibility (AD) was significantly lower (p=0.029) in patients suggesting HRE. The C-reactive protein levels of patients with HRE was higher in the HRE group (p=0.03). AD was significantly correlated with age (r=-0.406, p<0.001), pre-test systolic blood presure (SBP) (r=-0.427, p<0.001), peak exercise SBP (r=-0.307, p=0.01), peak exercise diastolic blood presure (DBP) (r=-0.315, p=0.008), and recovery time (3 min) SBP (r=-0.497, p=0.004). Age (β=-0.506, p=0.003) and peak DBP (β=-0.322, p=0.049) were independent predictors of decreased AD. In conclusion, we found a deterioration in arterial elastic properties in patients with HRE.

Exaggerated exercise blood pressure response is related to tissue Doppler imaging estimated diastolic dysfunction in the early stages of hypertension

We investigated the plausible interrelationship of exaggerated blood pressure response (EBPR) during exercise with left ventricular (LV) diastolic dysfunction, both associated with adverse cardiovascular outcomes, in the early stages of essential hypertension (EH). Sixty-five consecutive patients (aged 54 years, 56 males) with stage I to II EH underwent 24-hour ambulatory blood pressure (BP) recording and treadmill exercise testing and were classified as subjects with (n = 21) and without EBPR (n = 44) based on the systolic BP elevation at peak exercise (>/=210 mm Hg for men and >/=190 mm Hg for women). LV diastolic function was estimated by pulsed tissue Doppler imaging (TDI), averaging diastolic mitral annular velocities (Em, Am) from four separate sites (LV lateral, septal, anterior, and inferior wall). Hypertensives with EBPR, compared with those without EBPR, exhibited increased 24-hour pulse pressure by 4.8 mm Hg (P < .05) and significantly lower values of Em/Am ratio by 0.07 (P < .05). Univariate logistic regression analysis revealed that only 24-hour pulse pressure (odds ratio [OR] = 1.069; P = .043) and Em/Am (OR = 0.041; P = .049) were independent predictors of EBPR. Hypertensives with EBPR compared to their counterparts without EBPR are characterized by more pronounced LV diastolic dysfunction - assessed by TDI. Moreover, the increased pulsatile load seems to be a common denominator of these hypertension-linked states.

Aortic stiffness: current understanding and future directions

The aorta stiffens with aging, a process that is accelerated by arterial hypertension. Decreased arterial compliance is one of the earliest detectable manifestations of adverse structural and functional changes within the vessel wall. The use of different imaging techniques optimized for assessment of vascular elasticity and quantification of luminal and vessel wall parameters allows for a comprehensive and detailed view of the vascular system. In addition, several studies have also documented the prognostic importance of arterial stiffness (AS) in various populations as an independent predictor of cardiovascular morbidity and all-cause mortality. Measurement of AS by applanation tonometry with pulse-wave velocity has been the gold-standard method and is well-validated in large populations as a strong predictor of adverse cardiovascular outcomes. Because aortic stiffness depends on the prevailing blood pressure, effective antihypertensive treatment is expected to reduce it in proportion to the blood pressure reduction. Nevertheless, drugs lowering blood pressure might differ in their effects on structure and function of the arterial walls. This review paper not only will discuss the current understanding and clinical significance of AS but also will review the effects of various pharmacological and nonpharmacological interventions that can be used to preserve the favorable profile of a more compliant and less stiff aorta.

Association between exaggerated blood pressure response to exercise and serum asymmetric dimethylarginine levels

BACKGROUND

The exaggerated blood pressure response to exercise (EBPR) is an independent predictor of hypertension. Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide inhibitor and higher plasma levels of ADMA are related to increased cardiovascular risk. The aim of this study is to identify the relationship between ADMA and EBPR.

METHODS AND RESULTS

A total of 66 patients (36 with EBPR and 30 as controls) were enrolled in the study. EBPR is defined as blood pressure (BP) measurements > or =200/100 mmHg during the treadmill test. All the subjects underwent 24-h ambulatory BP monitoring. L-arginine and ADMA levels were measured using a high performance lipid chromatography technique. The serum ADMA levels were increased in the EBPR group compared to the healthy controls (4.0+/-1.4 vs 2.6+/-1.1 micromol/L respectively, P=0.001), but L-arginine levels were similar in the 2 groups (P=0.19). The serum ADMA levels were detected as an independent predictor of EBPR (odds ratio 2.28; 95% confidence interval 1.22-4.24; P=0.002).

CONCLUSIONS

Serum ADMA levels might play a role in EBPR to exercise.

Value of ventricular stiffness index and ventriculoarterial interaction in patients with nonischemic dilated cardiomyopathy

BACKGROUND

Whether echo-Doppler-derived index of ventricular elastance or ventriculoarterial interaction can reliably reflect circulatory efficiency in various conditions was investigated in the present study and whether they can be helpful in predicting exercise capacity in patients with dilated cardiomyopathy (DCM).

METHODS AND RESULTS

The 25 patients with DCM, 25 age- and gender-matched hypertensive patients, and 25 marathon runners underwent symptom-limited graded supine bicycle exercise echocardiography after resting echo-Doppler evaluation. Echo-Doppler-derived left ventricular (LV) diastolic elastance index (Ed), ventricular-vascular coupling index (10 x Ea/Ees), based on arterial elastance index (Ea) to LV end-systolic elastance index (Ees), and hemodynamic parameters were measured during rest and exercise. DCM patients had lower Ees, higher Ed and Ea/Ees with blunted exercise responses of Ees than the other groups, and the hypertensive patients had lower Ees and DeltaEes compared with the marathon runners. Resting Ed, Ea/Ees, and total stiffness index (10 x Ed x Ea/Ees) correlated with exercise duration independent of age and gender. A stiffness index of 0.8 could reliably predict impaired exercise capacity.

CONCLUSIONS

Echo-derived elastance is predictive of exercise capacity in patients with DCM.

Antihypertensive therapy and central hemodynamics in women with hypertensive disorders in pregnancy

OBJECTIVE

To estimate the changes in central hemodynamics features of pregnant women presenting with hypertensive disorders and to analyze the effects of standard antihypertensive treatment on maternal central hemodynamics.

METHODS

Applanation tonometry was used to record the radial artery pulse waveform in 80 women presenting with preeclampsia or gestational hypertension and 80 normotensive controls matched for gestational age. In each case, an averaged aortic waveform was derived and analyzed to calculate augmentation pressure and augmentation index at heart rate 75 beats per minute (bpm).

RESULTS

In women with preeclampsia and gestational hypertension, both augmentation pressure (P<.001 and P<.05, respectively) and augmentation index at heart rate 75 bpm (P<.001 and P<.001, respectively) were significantly higher than in controls. Augmentation pressure and augmentation index at heart rate 75 bpm were significantly higher in early- compared with late-onset preeclampsia (P<.001) and in severe compared with mild preeclampsia (P<.001). Antihypertensive therapy with alpha methyldopa resulted in a significant fall in both augmentation pressure and augmentation index at heart rate 75 bpm in preeclampsia (P<.001) but not in gestational hypertension.

CONCLUSION

Arterial stiffness is increased in women with hypertensive disorders of pregnancy compared with normotensive controls. In preeclampsia, vascular stiffness was significantly improved by antihypertensive treatment with alpha methyldopa, but remained higher than in normotensive controls.

Impact of aortic arch stiffness on recurrence of stroke in patients with acute ischemic stroke

BACKGROUND

Aortic arch plaques are associated with increased risk of stroke recurrence. The atherosclerotic process also affects aortic stiffness. The purpose of the present study was to evaluate aortic arch stiffness by transesophageal echocardiography (TEE) and its effect on recurrence of stroke.

METHODS AND RESULTS

TEE was performed in 201 patients with stroke and the aortic stiffness parameter beta was measured as an expression of the elasticity of the aortic arch wall. Patients were followed during a median follow-up period of 459 days with the endpoint as stroke recurrence. There were 21 cases of stroke recurrence (10%) during the follow-up period and the stiffness parameter beta was significantly higher in those cases (16.8+/-4.6 vs 12.5+/-3.3 [no recurrence], p<0.01). Cox multivariate hazard analysis revealed that stiffness parameter beta was the only independent predictor for stroke recurrence (hazard ratio 1.683, p<0.01). Kaplan-Meier survival analysis revealed that stiffness parameter beta effectively risk stratified patients for stoke recurrence. Furthermore, in 3 groups based on the value of beta, the 3rd tertile had the highest stroke recurrent risk (relative risk 5.473, p<0.01).

CONCLUSIONS

The value of beta in the aortic arch, assessed by TEE, may be a sensitive indicator of stroke recurrence.