The Relationship between Inter-Arm Blood Pressure Difference and Coronary Artery Disease Severity Calculated by the SYNTAX Score

The Impact of the Cold Pressor Test on Inter-arm Differences in Blood Pressure

A large inter-arm difference (IAD+; ≥10mmHg between arms at rest) in blood pressure (BP) at rest is linked to cardiovascular risk, and exercise can change this difference. As mechanisms for IAD are elusive, unique physiological stimuli may provide insight towards a better understanding of this phenomenon. The cold pressor test (CPT) has a potent effect on BP and acts primarily through sympathetic nervous system (SNS) stimulation, though the effects of SNS stimulation on IAD are unknown. Therefore, the purpose of the present study was to examine the effects of the CPT on IAD. BP was monitored simultaneously using two automated, auscultatory monitors (SunTech Tango) and a non-invasive hemodynamic device (Physioflow). Participants completed a CPT test, including a 15-minute rest, three pre-test BP measurements (averaged), and a three-minute water immersion (3°C; measurements at 30-sec and 2-min). Descriptive statistics were calculated, and a repeated measures ANOVA test used to compare both the absolute and relative IAD responses. The CPT induced an average absolute increase in IAD of 4.0 mmHg at 30-sec and 6.7mmHg at 2-min across all participants (P<0.05). Differences in both the absolute and relative IAD responses to the CPT were noted between IAD- and IAD+ individuals (P<0.05). Despite a consistent HR response to the CPT between groups, stroke volume was lower in IAD+ participants at 30-sec and 2-min. Sympathetic stimulation via the CPT induced changes in both the inter-arm difference in blood pressure and hemodynamics in young, apparently-healthy individuals.

The relation between inter arm blood pressure difference and presence of cardiovascular disease: a review of current findings

Raised inter arm blood pressure difference (IABPD) is already well-known as a clinical sign of peripheral arterial diseases including aortic dissection and subclavian stenosis. However, there are several other diseases associated with high IABPD. Therefore, this study aimed to review the association between increased IABPD and the presence of lethal health conditions, the possible mechanisms behind this relationship, and its contributing risk factors. Significant IABPD has been observed in patients with atherosclerotic plaques, peripheral artery disease, coronary artery disease, and chronic kidney disease. Patients with high IABPD are also at more risk of left ventricular hypertrophy that may affect long-term cardiac function. Besides, brain injuries such as stroke, dementia, and Alzheimer's disease has been related to increased IABPD. Considering that raised IABPD is associated with multiple cardiovascular diseases and other organ damage, IABPD detection may be accurate for the early diagnosis and screening of these life-threatening diseases and help manage them better.

Elevated Interarm Systolic Blood Pressure Difference Is Positively Associated with Increased Likelihood of Coronary Artery Disease

Background

Systolic interarm differences in blood pressure have been associated with all-cause mortality and cardiovascular disease. We investigated the relationship between interarm systolic blood pressure difference and coronary artery disease.

Methods

We retrospectively analyzed data for patients undergoing coronary angiography and brachial-ankle pulse wave velocity examination during hospitalization from 2013 to 2018. Patients underwent simultaneous upper arm blood pressure measurement. Interarm systolic blood pressure difference (IASBPD) was defined as the absolute value of the difference between the right and left upper limb systolic blood pressure. Patients with IASBPD ≥10 mmHg constituted the high group, and those with IASBPD <10 mmHg constituted the normal group. We also recorded data for cardiovascular risk factors. Coronary artery disease was defined as ≥50% vessel stenosis or having undergone interventional therapy according to coronary angiography results.

Results

Compared with the normal group, the number of patients with coronary artery disease was higher in the high group (86.1% vs. 74.6%, P=0.029). Multiple logistic regression showed that IASBPD ≥10 mmHg were positively correlated with coronary artery disease (odds ratio, 2.313; 95% confidence interval, 1.086-4.509; P=0.029), and as the IASBPD value increased, the correlation also gradually increased.

Conclusions

IASBPD ≥10 mmHg was positively related to coronary artery disease and increased IASBPD values were correlated with coronary artery disease severity.

Effect of inter-arm blood pressure differences on outcomes after percutaneous coronary intervention

BACKGROUND

We investigated the effect of inter-arm blood pressure differences (IABPD) on the percutaneous coronary intervention (PCI) outcomes of patients with coronary artery diseases.

METHODS

We retrospectively reviewed the data of blood pressures measured simultaneously in the bilateral arms of 855 patients (560 males) who underwent PCI with drug-eluting stents for coronary artery diseases. IABPD was defined as the difference of blood pressure in both arms. The primary outcome was the presence of major adverse cardiac events (MACE) consisting of cardiovascular death, myocardial infarction, stroke, and ischemia-driven target vessel revascularization.

RESULTS

The mean age of the included patients was 66.2 ± 11.6 years, with a mean follow-up period of 44.5 ± 26.4 months. MACE occurred in 15.2% of patients, showing a higher rate in the higher IABPD group (≥10 mmHg) than in the lower IABPD group (<10 mmHg) (22.5% vs 14.5%, p = 0.081). The difference was induced by a higher rate of ischemia-driven target vessel revascularization (17.5% vs 8.3%, p = 0.011). The Kaplan-Meier survival analysis revealed a greater incidence of MACE in patients with a higher IABPD (log rank p = 0.054). The Cox proportional hazard analysis showed that IABPD was an independent predictor of long-term MACE (hazard ratio, 1.028; 95% confidence interval, 1.002-1.055; p = 0.037), along with age, diabetes mellitus, and number of implanted stents.

CONCLUSION

Among patients treated with PCI, the incidence of MACE was significantly higher in those with a higher IABPD (≥10 mmHg) than in those with a lower IABPD (<10 mmHg), which was mainly driven by ischemia-driven target vessel revascularization.