Brachial artery constriction during brachial artery reactivity testing predicts major adverse clinical outcomes in women with suspected myocardial ischemia: results from the NHLBI-sponsored women's ischemia Syndrome Evaluation (WISE) Study

Endothelial dysfunction predicts bleeding and cardiovascular death in acute coronary syndrome

BACKGROUNDS

Recently, there has been increasing awareness that bleeding may lead to adverse outcomes. Endothelial dysfunction is associated with increased risk of cardiovascular and bleeding events. This study aimed to investigate the association of endothelial dysfunction with major bleeding and specific causes of death in addition to major adverse cardiovascular events in patients with acute coronary syndrome.

METHODS

This single-centre retrospective observational study was conducted at a tertiary-care hospital; patients with acute coronary syndrome were included between June 2010 and November 2014 (median follow-up, 6.1 years). The reactive hyperaemia index was assessed before their discharge; reactive hyperaemia index <1.67 was defined as endothelial dysfunction. The main outcomes were the incidence of major bleeding, all-cause death, cardiovascular death, non-cardiovascular death, resuscitated cardiac arrest, non-fatal myocardial infarction, non-fatal stroke, and hospitalisation for heart failure.

RESULTS

Among the included 674 patients with acute coronary syndrome, 264 (39.2%) had endothelial dysfunction. Multivariable Cox-hazard analyses revealed an independent predictive value of endothelial dysfunction for major bleeding (hazard ratio 2.29, 95% confidence interval 1.17-4.48, P = 0.016) and major adverse cardiovascular events (hazard ratio 2.04, 95% confidence interval 1.43-2.89, P < 0.001). The endothelial dysfunction group patients had a 2.5-fold greater risk of cardiovascular death; however, no association was found with non-cardiovascular death.

CONCLUSION

Endothelial dysfunction assessed using reactive hyperaemia index predicted future major cardiovascular event as well as major bleeding and cardiovascular death in patients with acute coronary syndrome.

Total brachial artery reactivity and first time incident coronary heart disease events in a longitudinal cohort study: The multi-ethnic study of atherosclerosis

Background

Brachial artery reactivity (BAR) is usually determined as the maximum brachial artery diameter (BAD) following release of an occluding pressure cuff compared to a BAD before cuff inflation. BAD early after cuff deflation can also serve as baseline for estimating total brachial artery reactivity (TBAR). We investigate whether TBAR is associated with first time coronary heart disease events.

Methods

Participants of the Multi-Ethnic Study of Atherosclerosis (n = 5499) consisting of whites, African-Americans, Chinese and Hispanics were followed longitudinally for a mean of 12.5 years. Brachial artery ultrasound was performed following five minutes of cuff occlusion at the forearm. TBAR was estimated from BAD following cuff release as the difference between maximum and minimum brachial artery diameters divided by the minimum diameter multiplied by 100%. TBAR was added to multivariable Cox proportional hazards models with Framingham risk factors as predictors and time to first coronary heart disease event as outcome.

Results

Average TBAR was 9.7% (9.7 SD). Mean age was 61.7 years, 50.9% women. Increased TBAR was associated with lower risk of CHD events with a hazard rate of 0.78 per SD increase (95% C.I. 0.67, 0.91; p = 0.001). A TBAR below the median of 7.87% (Inter Quartile Range: 4.16%, 13.0%) was associated with a 31% lower risk of coronary heart disease event (Hazard Ratio: 0.69; 95% C.I.: 0.55, 0.87).

Conclusion

TBAR is an independent predictor of first time coronary heart disease events and is exclusively measured after release of a blood pressure occlusion cuff.

Mental stress peripheral vascular reactivity is elevated in women with coronary vascular dysfunction: Results from the NHLBI-sponsored Cardiac Autonomic Nervous System (CANS) study

BACKGROUND

Women with chest pain, ischemia, and no obstructive coronary artery disease often have coronary vascular dysfunction (CVaD). Peripheral vascular reactivity to mental stress may contribute mechanistic understanding of stress-induced ischemia in women with CVaD.

METHODS

62 women (41 CVaD and 21 controls) underwent mental stress testing (MST) with anger recall, mental arithmetic, and forehead cold pressor (COP) challenge. Emotional arousal was measured (Likert scale). Reactive hyperemia index (RHI) was calculated before and after MST by peripheral arterial tonometry (PAT). Stress PAT ratio (SPR) of pulse amplitude during stress to rest was obtained to measure vasoconstriction. Wilcoxson rank sum test was used for analysis.

RESULTS

Mean age of CVaD and control groups was 58±9 and 55±10years (p=0.73). Baseline RHI correlated with coronary endothelial function (r=0.36, p=0.03) and inversely with RHI change post-MST (r=-0.51, p<0.001). During MST, 10% of controls reported chest pain vs. 41% of CVaD subjects (p=0.01). RHI did not change significantly after MST in either group. CVaD subjects had lower SPR vs. controls during mental arithmetic (0.54 [0.15, 1.46] vs. 0.67 [0.36, 1.8], p=0.039), not evident in the other tasks. Vasoconstriction inversely correlated with anxiety (r=-3.4, p=0.03), frustration (r=-0.37, p=0.02), and feeling challenged (r=-0.37, p=0.02) in CVaD but not controls.

CONCLUSIONS

Mental stress peripheral vascular reactivity is elevated in women with CVaD compared to controls. Elevated vascular reactivity may be one contributor to stress-induced chest pain in CVaD. Interventions that modulate vasoconstrictive responses may be of benefit and should be tested in clinical trials in women with CVaD.

Menopausal symptoms and cardiovascular disease mortality in the Women's Ischemia Syndrome Evaluation (WISE)

OBJECTIVE

Studies have linked vasomotor symptoms (VMS) to markers of cardiovascular disease (CVD) risk, yet few have considered clinical cardiovascular events. Data suggest that associations may depend upon the age that symptoms occur. We examined associations between VMS and cardiovascular events and endothelial function, considering age of symptom onset.

METHODS

The Women's Ischemia Syndrome Evaluation enrolled women referred for coronary angiography for suspected myocardial ischemia. A total of 254 women aged more than 50 years, postmenopausal, with both ovaries, not taking hormone therapy underwent a baseline evaluation, were followed annually (median = 6.0 y), and the National Death Index was searched to ascertain CVD mortality (median = 9.3 y). A subset of participants underwent brachial artery ultrasound for flow-mediated dilation (FMD). Receiver-operating curve analysis was used to determine vasomotor symptom groups (symptoms beginning < age 42 [early onset], beginning ≥42 [later onset], never) which were examined in relation to cardiovascular events and FMD in Cox proportional hazard and linear regression models.

RESULTS

Women reporting early onset VMS (HR = 3.35, 95% CI = 1.23-7.86, P = 0.005) and women who never had VMS (HR = 2.17, 95% CI = 1.02-4.62, P = 0.05) had higher CVD mortality than women with later onset symptoms (multivariable models). Women with early onset VMS had lower FMD than women with later onset symptoms (b = -4.31, SE = 2.10, P = 0.04, multivariable).

CONCLUSIONS

Women with signs and symptoms of ischemia who had VMS beginning early in midlife had higher CVD mortality and reduced endothelial function relative to women with later onset symptoms. Future research should evaluate the vascular phenotype of women with early midlife VMS.

Prognostic Value of Flow-Mediated Vasodilation in Brachial Artery and Fingertip Artery for Cardiovascular Events: A Systematic Review and Meta-Analysis

BACKGROUND

Endothelial dysfunction plays a pivotal role in cardiovascular disease progression, and is associated with adverse events. The purpose of this systematic review and meta-analysis was to investigate the prognostic magnitude of noninvasive peripheral endothelial function tests, brachial artery flow-mediated dilation (FMD), and reactive hyperemia--peripheral arterial tonometry (RH-PAT) for future cardiovascular events.

METHODS AND RESULTS

Databases of MEDLINE, EMBASE, and the Cochrane Library were systematically searched. Clinical studies reporting the predictive value of FMD or RH-PAT for cardiovascular events were identified. Two authors selected studies and extracted data independently. Pooled effects were calculated as risk ratio (RR) for continuous value of FMD and natural logarithm of RH-PAT index (Ln_RHI) using random-effects models. Thirty-five FMD studies of 17 280 participants and 6 RH-PAT studies of 1602 participants were included in the meta-analysis. Both endothelial function tests significantly predicted cardiovascular events (adjusted relative risk [95% CI]: 1% increase in FMD 0.88 [0.84-0.91], P<0.001, 0.1 increase in Ln_RHI 0.79 [0.71-0.87], P<0.001). There was significant heterogeneity in the magnitude of the association across studies. The magnitude of the prognostic value in cardiovascular disease subjects was comparable between these 2 methods; a 1 SD worsening in endothelial function was associated with doubled cardiovascular risk.

CONCLUSIONS

Noninvasive peripheral endothelial function tests, FMD and RH-PAT, significantly predicted cardiovascular events, with similar prognostic magnitude. Further research is required to determine whether the prognostic values of these 2 methods are independent of each other and whether an endothelial function-guided strategy can provide benefit in improving cardiovascular outcomes.

Assessment and prognosis of peripheral artery measures of vascular function

The endothelium plays a crucial role in the regulation of vascular homeostasis. Our understanding of its role in health and disease has increased dramatically since the pivotal discovery of nitric oxide more than 30 years ago. Clinical researchers utilized emerging technologies to study the vasodilator properties of the endothelium in both the coronary and peripheral circulation. Early studies established the methodologies and were able to demonstrate attenuated endothelium-dependent vasodilation in response to atherosclerosis and its risk factors. A variety of interventions can modulate endothelial function. More recent studies have established that some of these measures are independent predictors of cardiovascular outcomes. As such, peripheral measures of endothelial function are now established surrogate markers of vascular risk and have become important markers for clinical research. In this review, we will discuss a variety of measures of peripheral artery function to assess both conduit and resistance vessel function in humans.