Study of central aortic blood pressure in hypertensive patients & its relation with blood pressure-lowering drugs

Background & objectives: In clinical settings, peripheral blood pressure (PBP) is measured routinely. It is thought that central blood pressure (CBP) which reflects aortic BP, may be more predictive of outcomes in specific populations. Hence, this study was carried out to measure CBP in patients with hypertension and to see the effect of antihypertensive drugs on CBP. Methods: This cross-sectional study was conducted on 134 hypertensive patients and 134 normotensive healthy individuals as controls. Peripheral BPs and CBPs were measured of all patients and controls. The data were correlated and the effect of antihypertensive drugs on CBP was also evaluated. Results: Of the 134 hypertensive patients, 44 (32.84%) were newly diagnosed and the rest 90 (67.16%) had a history of hypertension and were on treatment. Of these 90 patients on treatment, 37 (41.11%) had uncontrolled peripheral BP and 53 (58.89%) had normal peripheral BP. Of the 134 hypertensive patients, 45 (33.58%) had controlled CBP. In 90 patients, who were on antihypertensive treatment, 45 (50%) had controlled CBP and 45 (50%) had uncontrolled CBP. Patients on calcium channel blockers (CCBs) had better control of CBP. Interpretation & conclusions: Hypertension is diagnosed mainly by measuring peripheral BP. CBP, which correlates better with the incidence of cardiovascular events, is not routinely measured. Patients with a history of hypertension and on treatment had normal office peripheral BP, but a few of them had high CBP and may require modification in treatment for control of CBP. Control of CBP was better in patients taking CCB.

Central blood pressure and vascular stiffness in Mexican population / Presión central aórtica y rigidez vascular en mexicanos

Abstract Introduction: Central blood pressure (CBP) is considered a measure of prognostic value for cardiovascular risk. In turn, the aortic pulse wave velocity (PWVAo) and augmentation index (Aix) have been related to arterial stiffness and cardiovascular risk. Controversies exist regarding the reference values in different ethnic groups, ages, and anthropometrics. The objective of this study is to evaluate the CBP and arterial stiffness parameters in a Mexican population by age, gender, and anthropometry. Methods: Between 2015 and 2016, 1009 apparently healthy subjects were recruited in the Instituto Nacional de Cardiología Ignacio Chávez. Using the Arteriograph (TensioMed) equipment with an oscillometric technique, CBP, central pulse pressure (cPP), PWVAo, and Aix were acquired. All results were automatically obtained by computer software version 3.0.0.4. Results: Female sex was prevalent (72%), mean age was 47 ± 12 years; 26% had normal weight, 43% were overweight, and 30% had obesity. The reference values were higher than those reported in other populations. PWVAo and Aix were always found to be higher in females. A central-brachial pressure gradient was observed in < 40 years with lower CBP. Body mass index (BMI) presented a direct and positive correlation with CBP (p < 0.001); however, PWVAo and Aix were not modified. Conclusion: CBP, cPP, PWVAo, and Aix parameters should be considered based on age, gender, and BMI. In Mexican population, CBP and cPP values were higher compared with other previously reported values, especially in women, the elderly, and obese. PWVAo and Aix are higher in older women; however, they are not modified by BMI.

Resumen Introducción: La presión central aórtica (PCA) se considera una medida del valor pronóstico. A su vez, la velocidad de la onda del pulso aórtico (VOPA) y el índice de aumento (IA) se han relacionado con la rigidez arterial y riesgo cardiovascular. Existen controversias sobre los valores de referencia en diferentes grupos. El objetivo de este estudio es evaluar estos parámetros en una población mexicana por edad, género y antropometría. Métodos: Entre 2015 y 2016 se reclutaron 1,009 sujetos aparentemente sanos en el Instituto Nacional de Cardiología Ignacio Chávez. Usando el equipo de Arteriograph (TensioMed) con técnica oscilométrica, se adquirieron: PCA, presión de pulso central, VOPA e IA. Todos los resultados fueron obtenidos automáticamente. Resultados: El sexo femenino fue prevalente (72%), edad de 47 ± 12 años; 26% con peso normal, 43% con sobrepeso y 30% con obesidad. Todos los valores fueron superiores a los reportados en otras poblaciones. VOPA e IA siempre fueron más altos en mujeres. Se observó un gradiente de presión central-braquial en < 40 años, con menor PCA. El IMC presentó una correlación directa y positiva con la PCA (p < 0,001), sin embargo, VOPA e IA no se modificaron. Conclusión: Los parámetros de PCA, VOPA e IA deben considerarse en función de edad, género e IMC. En una población mexicana, los valores de PCA fueron más altos en comparación con informados previamente (Europa y Asia), especialmente en mujeres, ancianos y obesos. VOPA e IA son más altos en mujeres mayores; sin embargo, no son modificados por el IMC.

Interpretation of the Results of Arterial Stiffness Tests / 대한내과학회지

Cardiovascular disease is the leading cause of morbidity and mortality worldwide. Early detection of subclinical atherosclerosis is important for reduction of cardiovascular risk. However, the current diagnostic strategy, which focuses on traditional risk factors or the use of risk scoring, is unsatisfactory. Arterial walls thicken and stiffen with age, a process known as arteriosclerosis. There is a close interaction between arterial stiffness and atherosclerosis. Increased luminal pressure and shear stress caused by arterial stiffening result in endothelial dysfunction, accelerate the formation of atheromas, and stimulate excessive collagen production and deposition in the arterial wall. Carotid intima-media thickness (CIMT) has been shown to predict cardiovascular risk in many large studies. However, there is controversy regarding the value of CIMT for prediction of cardiovascular risk because of differences in study design, specifically with respect to CIMT measurements. Pulse wave velocity (PWV) is the most widely used measure of arterial stiffness; measurement of PWV is simple, non-invasive, and reproducible. Many clinical studies and meta-analyses have shown that PWV has predictive value in cardiovascular disease beyond traditional risk factors, both in the general population and in patients with various diseases. Brachial pressure has been a poor surrogate for aortic pressure for more than 50 years. However, recent studies have shown a closer relationship between central blood pressure and intermediate cardiovascular phenotypes or cardiovascular target organ damage, compared to the respective relationships with brachial blood pressure. Considering the non-invasiveness and ability to collect multiple types of clinical data, measurement of CIMT, PWV, and central blood pressure may be useful to identify patients at high risk for development of cardiovascular disease.

Circulating microparticles and central blood pressure according to antihypertensive strategy

OBJECTIVES: This prospective, randomized, open-label study aimed to compare the effects of antihypertensive treatment based on amlodipine or hydrochlorothiazide on the circulating microparticles and central blood pressure values of hypertensive patients. METHODS: The effects of treatments on circulating microparticles were assessed during monotherapy and after the consecutive addition of valsartan and rosuvastatin followed by the withdrawal of rosuvastatin. Each treatment period lasted for 30 days. Central blood pressure and pulse wave velocity were measured at the end of each period. Endothelial, monocyte, and platelet circulating microparticles were determined by flow cytometry. Central blood pressure values and pulse wave velocity were recorded at the end of each treatment period. RESULTS: No differences in brachial blood pressure were observed between the treatment groups throughout the study. Although similar central blood pressure values were observed during monotherapy, lower systolic and diastolic central blood pressure values and early and late blood pressure peaks were observed in the amlodipine arm after the addition of valsartan alone or combined with rosuvastatin. Hydrochlorothiazide-based therapy was associated with a lower number of endothelial microparticles throughout the study, whereas a higher number of platelet microparticles was observed after rosuvastatin withdrawal in the amlodipine arm. CONCLUSIONS: Despite similar brachial blood pressure values between groups throughout the study, exposure to amlodipine was associated with lower central blood pressure values after combination with valsartan, indicating a beneficial interaction. Differences between circulating microparticles were modest and were mainly influenced by rosuvastatin withdrawal in the amlodipine arm.

Impact of coronary artery disease on augmentation index as measured by estimated central blood pressure: A case control study in Asian Indians

Aims We compared various components of blood pressure and arterial stiffness of healthy control with those of coronary artery disease (CAD) patients using BP+ machine™. Methods In this prospective, case-control study, total 585 individuals of both the genders were enrolled. The study population consisted of 277 controls (healthy siblings of diseased subjects not having CAD – group A) and 308 CAD patients (group B). Age and sex adjusted regression and receiver operative curve (ROC) analysis was performed to assess the strength of association of these parameters. Results We found that mean systolic blood pressure (SBP) (137.14 ± 22.49 vs. 129.26 ± 19.86), central systolic blood pressure (CSBP) (130.78 ± 21.89 vs. 117.53 ± 17.98), augmentation index (AI) (108.55 ± 44.98 vs. 49.38 ± 21.03) and pulse rate variability (98.82 ± 231.09 vs. 82.86 ± 208.77) were significantly (p < 0.05) higher in CAD population as compared to healthy counterparts. Left ventricular contractibility as measured by dP/dt was significantly lower in CAD patients. All these parameters were significantly abnormal in CAD as compared to healthy control population irrespective of the gender of the patient except for SBP in females. Both – odds ratio (1.108; 95% CI: 1.081–1.135; p < 0.0001) and ROC analysis (AUC: 0.937; 95% CI: 0.919–0.956; p < 0.0001) showed AI as the strongest predictor of CAD, closely followed by CSBP. Conclusion Central aortic blood pressure parameters such as AI and CSBP measured noninvasively with BP+ machine could be the effective predictors of CAD in Asian Indians.

Influence of central aortic and pulse pressure in coronary Artery Disease / 实用医学杂志

Objective To investigate the influence of central aortic pressure and pulse pressure in coronary Artery. Methods The research involed 173 patients who were suspected coronary heart disease (CHD) in the Fifth People′s Hospital of Chengdu city. The patients were divided into non-coronary disease and coronary disease groups. Patients were divided into one- vessel, two- vessels and three-vessels in coronary disease groups. The data were analyzed by using spass 17.0 software. Results SBP-C,DBP-C and PP-C had statistical significance compared with non-coronary disease (P < 0.05).SBP-C and PP-C had significant difference between single-branch and multiple-branch group(P < 0.05).Logistic multivariate analysis indicated that SBP-C [P = 0.019,OR = 1.207, 95%CI(1.032,1.412)]and PP-C [P = 0.023, OR = 1.166,95%CI (1.021,1.332)] had significant correlation. Conclusion Compared with non-coronary, SBP-C and PP-C were higher, while DBP-C was lower. The higher SBP-C and PP-C are,the worse coronary artery is. SBP-C and PP-C are predispose risk factors for multiple-vessels coronary disease.

Nitroglycerin reduces augmentation index and central blood pressure independent of effects on cardiac preload / 药物分析学报

Objective To determine whether reduction In central pressure augmentation and central systolic blood pressure by nitroglycerine (NTG) results from effects on pre-lead or is due to arterial dilation. Methods We compared effects of NTG with these of lower body negative pressure (LBNP). Hemodyunmic measurements were made at rest, during LBNP (10, 20 and 30 mmHg, each for 15 min) and after NTG (10, 30 and 100μg/min, each dose for 15 min) in ten healthy volunteers. Cardiac pre-lead, stroke volume and cardiac output were assessed by echacardiography. Central pressure an mnentation and central systolic pressure were obtained by radial tonometry using a transfer function. Results LBNP (20 mmHg) and NTG (30μg/min) reduced pre-lead (as measured by the peak velocity of the S wave in the superior vena eava) to a similar degree [by (26. 8 ± 3.8) % and (23.9 ± 3. 4) %, respectively]. Compared to LBNP, NTG reduced systemic vascular resistance [by (32. 9 ± 7.5) %, p< 0. 01], decreased peripheral and central pressure augmentation [by (20. 8 ± 3. 4)% units and (12. 9±2. 9)% units, respectively, each P< 0. 01]. Conclusion These results suggest that a reduction in pre-load does not explain reduction in pressure augmentation and central systolic blood pressure by NTG and that these effects are mediated through arterial dilation.

Nitroglycerin reduces augmentation index and central blood pressure independent of effects on cardiac preload / 西安交通大学学报·英文版

Objective: To determine whether reduction in central pressure augmentation and central systolic blood pressure by nitroglycerine (NTG) results from effects on pre-load or is due to arterial dilation. Methods: We compared effects of NTG with those of lower body negative pressure (LBNP). Hemodynamic measurements were made at rest, during LBNP (10, 20 and 30 mmHg, each for 15 min) and after NTG (10, 30 and 100 μg/min, each dose for 15 min) in ten healthy volunteers. Cardiac pre-load, stroke volume and cardiac output were assessed by echocardiography. Central pressure augmentation and central systolic pressure were obtained by radial tonometry using a transfer function. Results: LBNP (20 mmHg) and NTG (30 μg/min) reduced pre-load (as measured by the peak velocity of the S wave in the superior vena cava) to a similar degree [by (26.8 ± 3.8)% and (23.9 ± 3.4)%, respectively]. Compared to LBNP, NTG reduced systemic vascular resistance [by (32.9± 7.5)%, P<0.01], decreased peripheral and central pressure augmentation [by (20.8 ± 3.4)% units and (12.9 ± 2.9)% units, respectively, each P<0.01]. Conclusion: These results suggest that a reduction in pre-load does not explain reduction in pressure augmentation and central systolic blood pressure by NTG and that these effects are mediated through arterial dilation.