Heart India

ORIGINAL ARTICLE
Year
: 2020  |  Volume : 8  |  Issue : 1  |  Page : 9--12

Evaluation of central: peripheral blood pressure ratio in patients undergoing coronary angiography: A pilot study from North India


Sharad Chandra, Gaurav Chaudhary, Varun Shankar Narain, Sudhanshu Kumar Dwivedi, Akhil Sharma 
 Department of Cardiology, King George's Medical University, Lucknow, Uttar Pradesh, India

Correspondence Address:
Dr. Gaurav Chaudhary
Department of Cardiology, King George's Medical University, Lucknow - 226 003, Uttar Pradesh
India

Abstract

Aim: The study aimed to propose the ratio of central blood pressure:peripheral blood pressure as a novel index to predict cardiovascular risk. We additionally attempted to determine the impact of beta-blocker therapy on this ratio. Materials and Methods: This was a prospective, single-centre study conducted between August 2019__ and December 2019. A total of 102 patients undergoing cath-lab procedures such as coronary angiography (CAG), percutaneous coronary intervention were studied. Central blood pressure was invasively measured from the radial artery. Peripheral blood pressure was also measured from the right arm radial artery using invasive pressure transducer. Patients were divided into two groups as follows: (i) beta-blocker group to receive beta-blocker treatment (n = 82) and (ii) nonbeta-blocker group that did not receive beta-blocker treatment (n = 20). Results: The mean age of the study participants was 55.7 ± 10.0 years. Males constituted 80 (78.4%) patients of the study population. The central:peripheral blood pressure ratios for systolic and diastolic blood pressure were 0.88 ± 0.1 and 0.93 ± 0.2 (P = 0.004), respectively. Systolic blood pressure ratios for the beta-blocker and nonbeta-blocker groups were 0.89 ± 0.1 and 0.93 ± 0.2 (P = 0.016), respectively. Similarly, diastolic blood pressure ratios for the beta-blocker and nonbeta-blocker groups were 0.84 ± 0.1 and 0.95 ± 0.1 (P = 0.770), respectively. Conclusions: This novel ratio of central:peripheral blood pressure may serve as a precursor of cardiovascular risk. This ratio may give a clue to relationship between central and peripheral blood pressure.



How to cite this article:
Chandra S, Chaudhary G, Narain VS, Dwivedi SK, Sharma A. Evaluation of central: peripheral blood pressure ratio in patients undergoing coronary angiography: A pilot study from North India.Heart India 2020;8:9-12


How to cite this URL:
Chandra S, Chaudhary G, Narain VS, Dwivedi SK, Sharma A. Evaluation of central: peripheral blood pressure ratio in patients undergoing coronary angiography: A pilot study from North India. Heart India [serial online] 2020 [cited 2020 Jun 3 ];8:9-12
Available from: http://www.heartindia.net/text.asp?2020/8/1/9/281875


Full Text



 Introduction



Over the past century, blood pressure has conventionally been measured, diagnosed, and treated through the brachial artery. However, recent technological breakthroughs have allowed routine assessment of blood pressure at the central arteries.[1] Central blood pressure directly reflects pressure on the target organs and therefore varies from peripheral blood pressure. Moreover, increased elasticity of aortic and carotid vasculatures as compared to fibrous peripheral vasculature magnifies the variability of arterial stiffness between these vasculature. Thus, central systolic blood pressure and the augmentation index – markers of arterial stiffness have emerged as more reliable predictors of adverse cardiovascular outcomes as compared to peripheral systolic blood pressure.[2],[3],[4]

In this pilot study, we propose the ratio of central:peripheral blood pressure as a novel index that may serve as a predictor of cardiovascular risk. In addition, we aimed to determine the effects of beta-blocker therapy on this ratio. To the best of our knowledge, such a ratio has not been clinically evaluated in prior studies. Furthermore, the clinical usefulness of this index is yet to be established, and several gaps regarding its use are yet to be filled. Hence, further studies to investigate potential clinical applications and contributions of this index are warranted.

 Materials and Methods



Study design and patient population

A prospective, single-center study was conducted at our tertiary-care center in North India during the study duration of August 2019 to December 2019. Patients undergoing cath-lab procedures such as coronary angiography (CAG), percutaneous coronary intervention (PCI), pacemaker implantation, balloon mitral valvotomy, or radiofrequency ablation were included in this study. Exclusion criteria were as follows: a) Severe radial spasm b) Systolic blood pressure less than 100 mm of Hg c) patient refusal to give consent. Patients were divided into two groups: (i) beta-blocker group to receive beta-blocker treatment (n = 82) and (ii) nonbeta-blocker group that did not receive beta-blocker treatment (n = 20). All patients provided written informed consent before the commencement of the study. The study was approved by the institutional ethics committee.

Central blood pressure assessment

Central aortic blood pressure was assessed invasively by using pressure transducer. Peripheral blood pressure was measured from the radial artery sheath, by connecting pressure transducer to it.

Statistical analysis

Continuous variables were expressed as mean ± standard deviation and discrete variables as percentages. Continuous variables were compared using Student's t-test. Categorical variables were compared using either the Chi-square test or Fisher's exact test. P < 0.05 was considered as statistically significant, and an adjusted odds ratio with a 95% confidence interval was used for assessment. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS; Chicago, IL, USA) program, version 15.

 Results



Baseline demographic and procedural characteristics

A total of 102 patients were enrolled in the study. The mean age was 55.7 ± 10.0 years. The study population was predominantly comprising 80 (78.4%) males. Hypertensives, diabetics, smokers, and tobacco users constituted 49 (48.0%), 33 (32.4%), 27 (26.5%), and 26 (25.5%) of the population, respectively. On clinical presentation, 29 (28.4%) patients presented with stable angina. Twenty-one (20.6%) and 11 (10.8%) patients had suffered a recent anterior wall myocardial infarction and inferior wall myocardial infarction, respectively. Twenty-four (23.5%) patients were diagnosed with non-ST-elevated myocardial infarction, and 24 (23.5%) patients were diagnosed with acute coronary syndrome. Beta-blockers were administered to 82 (80.4%) patients, whereas streptokinase was administered to 35 (34.3%) patients. Forty-seven (46.1%) and 41 (40.2%) patients underwent CAG and CAG + PCI, respectively. PCI was performed on 10 (9.0%) patients. The baseline demographic characteristics are detailed in [Table 1]. Procedural characteristics are demonstrated in [Table 2].{Table 1}{Table 2}

Blood pressure measurements and ratios

The mean systolic central and peripheral blood pressures were 129.2 ± 23.1 and 147.5 ± 28.1 mmHg (P < 0.001), respectively. The mean diastolic central and peripheral blood pressures were 79.0 ± 17.0 and 85.3 ± 17.7 mmHg (P < 0.001), respectively. The central:peripheral ratios for systolic and diastolic blood pressures were 0.88 ± 0.1 and 0.93 ± 0.2 mmHg (P = 0.004), respectively. The central and peripheral blood pressure measurements and ratios are detailed in [Table 3] and illustrated in [Figure 1].{Table 3}{Figure 1}

Blood pressure measurements in beta-blocker and nonbeta-blocker groups

Systolic central and peripheral blood pressures for the beta-blocker group (131.2 ± 21.5 and 147.9 ± 25.7 mmHg; P < 0.001) and the nonbeta-blocker group (120.7 ± 27.5 and 145.7 ± 37.3 mmHg; P < 0.001) were statistically significant. However, diastolic central and peripheral blood pressures for the beta-blocker group (80.7 ± 17.8 and 87.3 ± 18.2 mmHg; P < 0.01) did not show any statistical significance. Diastolic central and peripheral blood pressures for the nonbeta-blocker group (72.1 ± 11.5 and 77.0 ± 13.0 mmHg, P < 0.05) were statistically significant. The blood pressure measurements for the beta-blocker and nonbeta-blocker groups are outlined in [Table 4].{Table 4}

Blood pressure ratio of beta-blocker and nonbeta-blocker groups

The systolic blood pressure ratios for the beta-blocker and nonbeta-blocker groups were 0.89 ± 0.1 and 0.93 ± 0.2 (P = 0.016), respectively. Similarly, the diastolic blood pressure ratios for the beta-blocker and nonbeta-blocker groups were 0.84 ± 0.1 and 0.95 ± 0.1 (P = 0.770), respectively. The systolic and blood pressure ratios are displayed in [Figure 2].{Figure 2}

 Discussion



Blood vessels are the target organs of numerous diseases. Therefore, conditions such as arterial hypertension, diabetes mellitus, chronic renal insufficiency, atherosclerosis, and aging induce vascular changes. These insights led to the introduction of the augmentation index as a marker of arterial stiffness.[5]

Several earlier studies have evaluated the clinical applications of the augmentation in diverse populations. Matsui et al.[6] documented good reproducibility in hypertensive patients. Papaioannou et al.[7] confirmed the reproducibility of the transfer function method, a method nowadays widely used to calculate the augmentation index. Chung et al.[8] defined the diagnostic values of the augmentation index in healthy individuals. Soiza et al.[9] correlated augmentation index with increased length of stay a week after stroke and at discharge in patients with ischemic stroke.

The augmentation index displays a positive relationship with age, increasing steadily throughout the prime years of life. However, this index eventually plateaus between the ages of 50–60 years, suggestive of clinical applicability of the augmentation index in younger individuals and not the elderly.[10],[11] The second pitfall of this index is disparate results attributable to gender differences.[12],[13],[14] Our proposed index compares central blood pressure with peripheral blood pressure, thus eliminating the issue of impedance mismatch between central and peripheral vasculature.

 Conclusions



The current study was conducted with the goal of introducing a novel ratio of central:peripheral blood pressure that may serve as a precursor of cardiovascular risk. Many questions prevail regarding its clinical use, and hence, further studies are necessary.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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