Antihypertensive Medication Use and Its Effects on Blood Pressure and Haemodynamics in a Tri-ethnic Population Cohort: Southall and Brent Revisited (SABRE)

Objectives:We characterised differences in BP control and use of antihypertensive medications in European (EA), South Asian (SA) and African-Caribbean (AC) people with hypertension and investigated the potential role of type 2 diabetes (T2DM), reduced arterial compliance (Ca), and antihypertensive medication use in any differences.Methods:Analysis was restricted to individuals with hypertension [age range 59–85 years; N = 852 (EA = 328, SA = 356, and AC =168)]. Questionnaires, anthropometry, BP measurements, echocardiography, and fasting blood assays were performed. BP control was classified according to UK guidelines operating at the time of the study. Data were analysed using generalised structural equation models, multivariable regression and treatment effect models.Results:SA and AC people were more likely to receive treatment for high BP and received a greater average number of antihypertensive agents, but despite this a smaller proportion of SA and AC achieved control of BP to target [age and sex adjusted odds ratio (95% confidence interval) = 0.52 (0.38, 0.72) and 0.64 (0.43, 0.96), respectively]. Differences in BP control were partially attenuated by controlling for the higher prevalence of T2DM and reduced Ca in SA and AC. There was little difference in choice of antihypertensive agent by ethnicity and no evidence that differences in efficacy of antihypertensive regimens contributed to ethnic differences in BP control.Conclusions:T2DM and more adverse arterial stiffness are important factors in the poorer BP control in SA and AC people. More effort is required to achieve better control of BP, particularly in UK ethnic minorities.

Vascular Responses to Simulated Breath-Hold Diving Involving Multiple Reflexes

Breath-hold diving evokes a complex cardiovascular response. The degrees of hypertension induced by the diving reflex are substantial and accentuated by the underwater swimming. This condition provides a circulatory challenge to properly buffer and cushion cardiac pulsations. We determined hemodynamic changes during the diving maneuver. A total of 20 healthy young adults were studied. Hemodynamics were measured during exercise on a cycle ergometer, apnea, face immersion in cold water (trigeminal stimulation), and simulated breath-hold diving. Dynamic arterial compliance (measured by changes in carotid artery diameter via ultrasound divided by changes in carotid blood pressure as assessed by arterial tonometry) increased with simulated diving compared with rest (p=0.007) and was elevated compared with exercise and apnea alone (p<0.01). A significant increase in heart rate was observed with exercise, apnea, and facial immersion when compared with rest (p<0.001). However, simulated diving brought the heart rate down to resting levels. Cardiac output increased with all conditions (p<0.001), with an attenuated response during simulated diving compared with exercise and facial immersion (p<0.05). Mean blood pressure was elevated during all conditions (p<0.001), with a further elevation observed during simulated diving compared with exercise (p<0.001), apnea (p=0.016), and facial immersion (p<0.001). Total peripheral resistance was decreased during exercise and facial immersion compared with rest (p<0.001) but was increased during simulated diving compared with exercise (p<0.001), apnea (p=0.008), and facial immersion (p=0.003). We concluded that central artery compliance is augmented during simulated breath-hold diving to help buffer cardiac pulsations.

Association between serum placental growth factor and vascular endothelial function in hyprtensive disorders complicating pregnancy

Hypertensive disorders complicating pregnancy (HDCP) is a systemic disease among pregnant women. Therefore, the prevention and prediction of hypertension during pregnancy are critical. This study aimed to clarify whether the vascular endothelial function of women with gestational hypertension was linked to placental growth factor. A total of 200 pregnant women were enrolled in our study and subsequently divided into two groups: the HDCP group and the normal pregnancy controls. The levels of serum placental growth factor, as well as plasma endothelin-1 and nitric oxide, between the two groups were measured. In addition, the endothelial function indexes, including pressure-strain elasticity coefficient (EP), the common carotid stiffness index (β), arterial compliance, single-point pulsed-wave velocity, and augment index (AI) of bilateral common carotid arteries, were compared between the HDCP and control groups using the echo tracking technique. In our study, the level of placental growth factor in the HDCP group was significantly lower than the control group. Furthermore, our results clarified that endothelin-1 increased while nitric oxide decreased in the HDCP group compared with the control group. On the other hand, we found that EP, β, pulsed-wave velocity and augment index values were significantly higher in the HDCP group than in the control group (P < 0.001). However, the value of arterial compliance was significantly decreased in patients of the HDCP group compared with the control group (P < 0.001). In conclusion, the association between serum placental growth factor and vascular endothelial function in HDCP could serve as a more accurate predictive factor of pregnant hypertension.

45 Experience of 5 years of balloon pulmonary angioplasty in a single centre: safety and short-term results

Aims Balloon pulmonary angioplasty (BPA) has recently been developed as a treatment strategy for chronic thromboembolic pulmonary hypertension (CTEPH) but efficacy and technical safety have to be established. We examine the effects of BPA on patients with inoperable disease or residual pulmonary hypertension (PH) after pulmonary endarterectomy (PEA). Methods and results From 2015 to 2020 we enrolled symptomatic inoperable CTEPH patients and patients with residual PH after PEA. At baseline and 3 months after last BPA session patients underwent clinical evaluation, 6-min walking distance (6MWD), and right heart catheterization. Friedman test with Bonferroni post-hoc pairwise analysis was used. Fifty patients [male 42%, median age 68 (51–74) years, 42 inoperable, and 8 with residual PH after PEA] were treated for a total of 156 sessions (median 2 sessions/patient); during each session we treated 2.3 (2.2–2.7) vessels. Results are shown in the Table. Forty-nine patients were treated with medical therapy before BPA (19 with combination therapy). Five pulmonary artery dissection and two haemoptysis with clinical impairment were documented during the procedures; 37 patients had lung injury (radiographic opacity with/without haemoptysis and/or hypoxaemia), none had renal dysfunction, 7 patients had access site complications. Seven patients died during follow-up (none within 30 days from the procedure) because of sepsis (1), heart failure (1), cancer (2), arrhythmic storm (2), and sudden death in patients with severe coronary atherosclerosis (1). Conclusions BPA is a safe and effective treatment able to improve symptoms and haemodynamic profile. 45 Table 16MWD, six minute walking distanceCI, cardiac index; mPAP, mean pulmonary arterial pressure; PAC, pulmonary arterial compliance; PVR, pulmonary vascular resistance; RAP, right atrial pressure; SvO2, mixed venous oxygen saturation; WHO-FC, World Health Organization functional class.

Cardiac Remodeling and Disease Progression in Patients With Repaired Coarctation of Aorta and Aortic Stenosis

Background: Valvulo-arterial impedance (Zva) is used for assessment of left ventricular (LV) global pressure load in patients with aortic stenosis (AS) and impaired arterial compliance. Because patients with repaired coarctation of aorta (COA) have impaired arterial compliance, we hypothesized that COA patients with greater than or equal to moderate AS (AS-COA group) will have higher Zva, symptomatic progression, and cardiovascular events, as compared to non-COA patients with similar AS severity (AS group). Methods: Propensity matching (1:1) of 71 AS-COA and 71 AS patients based on age, sex, body mass index, and aortic valve mean gradient (cohort 1). Of 172 patients, 117 patients (AS-COA [n=62]; AS [n=55]) underwent aortic valve replacement, cohort 2. Cohort 1 was used to assess the relationship between preoperative Zva, cardiac remodeling, and symptomatic progression, while cohort 2 was used to assess the relationship between postoperative Zva, LV mass index regression (reduction in LV mass index after aortic valve replacement), and cardiovascular events. Results: The AS-COA group had higher Zva (4.2±0.6 versus 3.5±0.4 mm Hg/mL·m 2 , P <0.001), more advanced cardiac remodeling, and higher 5-year incidence of symptomatic progression (85% versus 51%, P <0.001). Preoperative Zva was independently associated with cardiac remodeling (r=0.66, P <0.001) and symptomatic progression (hazard ratio, 1.06 [1.02–1.10], per mm Hg/mL·m 2 increase in Zva). The AS-COA group had higher postoperative Zva (3.3±0.5 versus 2.4±0.4 mm Hg/mL·m 2 , P <0.001), less robust LV mass index regression at 1-year post–aortic valve replacement, and higher 5-year incidence of cardiovascular events. Postoperative Zva was independently associated with LV mass index regression (r=−0.46, P <0.001) and cardiovascular events (hazard ratio, 1.06 [1.02–1.10], per mm Hg/mL·m 2 increase in Zva). Conclusions: Adults with AS-COA had higher LV global pressure load, cardiac remodeling, symptomatic progression, and cardiovascular events as compared to non-COA patients with similar severity of AS. Zva can identify patients at risk for adverse outcomes, and perhaps should be used for risk stratification with regards to timing of aortic valve replacement.

Stress and the Cardiovascular System

<p>The research reported in this thesis is primarily concerned with systemic arterial pulse transit time (PTT) which is of physiological significance because it is the most appropriate indicator of arterial compliance, the primary determinant of cardiac load, PTT acceleration or deceleration being associated with an increase or decrease in cardiac load respectively. Initially, PTT was investigated in the context of active/passive coping. Obrist, et al., (1978) proposed that active coping is generated by tasks of moderate difficulty and is characterized by large, sustained cardiac accelerations. Interbeat interval (IBI) was measured as the reference response for active/passive coping. The assumption is that active coping is the behavioural state which provides the link between psychological stress and hypertension. However, contemporary cardiovascular physiologists put more emphasis on arterial compliance than IBI because it is not only significant in essential hypertension, but is also a critical determinant of circulation efficiency in health and disease. In Experiment 1 men and women completed mental arithmetic, problem solving, reaction time and personal tempo (voluntary button pressing). Acceleratory and deceleratory PTT changes were found during all tasks; IBI changes were predominantly acceleratory and their magnitude was determined by task difficulty. In Experiment 2 subjects completed problem solving tasks at two levels of difficulty. The results confirmed that unexplained directional variability characterized PTT changes and acceleration characterized IBI changes. It was hypothesized that subject state could be a determinant of PTT response direction. In Experiment 3 the State-Trait Anxiety Inventory, the Stress Arousal Checklist, the Eysenck Personality Inventory and the Jenkins Activity Survey were administered before problem solving at three levels of difficulty and personal tempo were completed. PTT directional variability was not accounted for by any of the measures used. IBI changes were again acceleratory and their magnitude was determined by task difficulty. Two extensions of the active/passive coping hypothesis were proposed: 1) that task difficulty and magnitude of IBI change are related along a continuum of behavioural coping; 2) that task type, not difficulty, determines the frequency of IBI acceleration. The effect of task contingency on IBI change was identified as requiring more detailed investigation. It was further hypothesized that relative subject state as measured by a change in resting IBI (Malmo, 1959) could predict the direction of PTT change during task. In Experiment 4 subjects completed all tasks from Experiment 3 in both parts of an extended experimental session. Half the subjects ingested caffeine. IBI decelerated during baseline from part 1 to part 2 and deceleratory PTT changes dominated task responding in part 2. However, a caffeine-induced deceleration in IBI across baselines was not associated with deceleratory PTT change, and directional variability continued to characterize PTT changes. In order to eliminate the directional variability of PTT changes during tasks a further experiment was undertaken which manipulated relative behavioural state prior to task by informing subjects on their first attendance at the laboratory that they would be required to perform a demanding problem solving task on their fifth attendance. From sessions 1 to 4 subjects attended the laboratory for short rest periods only during which cardiovascular activity was recorded. On the fifth session subjects also completed a task. In that experiment (Experiment 5), IBI acceleration over multiple session baselines in anticipation of a task was associated with uniformly acceleratory PTT changes during tasks, supporting the hypothesis that subject initial state is an important determinant of the direction of PTT change, and hence in whether cardiac load increases or decreases under stress.</p>

Stress and the Cardiovascular System

<p>The research reported in this thesis is primarily concerned with systemic arterial pulse transit time (PTT) which is of physiological significance because it is the most appropriate indicator of arterial compliance, the primary determinant of cardiac load, PTT acceleration or deceleration being associated with an increase or decrease in cardiac load respectively. Initially, PTT was investigated in the context of active/passive coping. Obrist, et al., (1978) proposed that active coping is generated by tasks of moderate difficulty and is characterized by large, sustained cardiac accelerations. Interbeat interval (IBI) was measured as the reference response for active/passive coping. The assumption is that active coping is the behavioural state which provides the link between psychological stress and hypertension. However, contemporary cardiovascular physiologists put more emphasis on arterial compliance than IBI because it is not only significant in essential hypertension, but is also a critical determinant of circulation efficiency in health and disease. In Experiment 1 men and women completed mental arithmetic, problem solving, reaction time and personal tempo (voluntary button pressing). Acceleratory and deceleratory PTT changes were found during all tasks; IBI changes were predominantly acceleratory and their magnitude was determined by task difficulty. In Experiment 2 subjects completed problem solving tasks at two levels of difficulty. The results confirmed that unexplained directional variability characterized PTT changes and acceleration characterized IBI changes. It was hypothesized that subject state could be a determinant of PTT response direction. In Experiment 3 the State-Trait Anxiety Inventory, the Stress Arousal Checklist, the Eysenck Personality Inventory and the Jenkins Activity Survey were administered before problem solving at three levels of difficulty and personal tempo were completed. PTT directional variability was not accounted for by any of the measures used. IBI changes were again acceleratory and their magnitude was determined by task difficulty. Two extensions of the active/passive coping hypothesis were proposed: 1) that task difficulty and magnitude of IBI change are related along a continuum of behavioural coping; 2) that task type, not difficulty, determines the frequency of IBI acceleration. The effect of task contingency on IBI change was identified as requiring more detailed investigation. It was further hypothesized that relative subject state as measured by a change in resting IBI (Malmo, 1959) could predict the direction of PTT change during task. In Experiment 4 subjects completed all tasks from Experiment 3 in both parts of an extended experimental session. Half the subjects ingested caffeine. IBI decelerated during baseline from part 1 to part 2 and deceleratory PTT changes dominated task responding in part 2. However, a caffeine-induced deceleration in IBI across baselines was not associated with deceleratory PTT change, and directional variability continued to characterize PTT changes. In order to eliminate the directional variability of PTT changes during tasks a further experiment was undertaken which manipulated relative behavioural state prior to task by informing subjects on their first attendance at the laboratory that they would be required to perform a demanding problem solving task on their fifth attendance. From sessions 1 to 4 subjects attended the laboratory for short rest periods only during which cardiovascular activity was recorded. On the fifth session subjects also completed a task. In that experiment (Experiment 5), IBI acceleration over multiple session baselines in anticipation of a task was associated with uniformly acceleratory PTT changes during tasks, supporting the hypothesis that subject initial state is an important determinant of the direction of PTT change, and hence in whether cardiac load increases or decreases under stress.</p>