Elevated serum uric acid is associated with peripheral endothelial dysfunction in women

Microvascular Endothelial Function Assessed Using Peripheral Arterial Tonometry in Adolescents with Repaired Congenital Heart Disease

Atherosclerosis can develop in adult patients with congenital heart disease (CHD) and should be given attention. Endothelial function is well known as a predictor of the development of atherosclerosis but has not been well investigated in patients with repaired CHD. This study aimed to clarify the endothelial function and its relationship with clinical backgrounds and parameters in adolescents with various types of repaired CHDs. Endothelial function was evaluated using peripheral arterial tonometry (PAT). The reactive hyperemia index (RHI) was evaluated and compared between adolescents with repaired CHD and those in the control group. The relationship between the clinical background and parameters was also investigated in patients with repaired CHD. Forty-eight patients with repaired CHD (age 14.0 ± 3.3 years) and 114 healthy volunteers were included in this study. Patients with repaired CHD comprised 16 with repaired non-cyanotic CHD, 14 with repaired tetralogy of Fallot, and 18 who underwent the Fontan procedure. RHI in the repaired CHD group was significantly lower than in the control group. There was no significant correlation between the RHI and blood biochemical markers, such as uric acid, creatine, and brain natriuretic peptide levels. The RHI was significantly higher in patients taking angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) than in those not taking them. Endothelial function was impaired in adolescents with repaired CHD compared to that in the control group. Microvascular endothelial dysfunction developed even in adolescents with simple non-cyanotic CHD.

Endothelial function in healthy centenarians living in the Madonie's district (Italy)

BACKGROUND

Endothelial function declines with age and plays a critical role in cardiovascular health. Therefore, investigating endothelial function in successful aging models, such as centenarians, is of interest. Flow-mediated dilation (FMD) of the brachial artery is the gold standard for measuring endothelial function in vivo in humans. Therefore, we investigated, for the first time, the FMD of the brachial artery in a group of healthy centenarians.

METHODS

Selected as part of the ABCD project (nutrition, cardiovascular wellness, and diabetes) centenarians (aged ≥100 years) living in the municipalities of Madonie (Palermo, Italy) were compared with a younger (aged <65 years) sex-matched control group from the ABCD general cohort. FMD of the brachial artery was measured in all participants using a real-time computed video analysis system for B-mode ultrasound images. Body composition (bioimpedance), carotid intima-media thickness (IMT), and ankle-brachial index (ABI) were also measured.

RESULTS

Eleven participants (males 36.4 %; age: 101 ± 1 years) out of 28 healthy centenarians successfully cooperated with the FMD test procedures, which require remaining with the upper limb immobile for approximately 10 min. This subgroup was compared with a control group of 76 healthy and younger individuals (males 36.8 %; aged: 41 ± 14 years; P < 0.001). Centenarians exhibited better endothelial function than the control group (FMD: 12.1 ± 4.3 vs 8.6 ± 5.3 %; P < 0.05). The carotid IMT was higher in the centenarian group than in the control group (0.89 ± 0.09 vs 0.56 ± 0.18 mm; P < 0.001), whereas the ABI was comparable between the two groups.

CONCLUSIONS

This small group of centenarians demonstrated an unusually favorable endothelial function, which may contribute to their unique aging profile. Further research is needed to determine whether FMD is a valid prognostic marker for successful aging.

Gender Influence on XOR Activities and Related Pathologies: A Narrative Review

Taking into account the patient's gender is the first step towards more precise and egalitarian medicine. The gender-related divergences observed in purine catabolism and their pathological consequences are good examples of gender medicine differences. Uric acid is produced by the activity of xanthine oxidoreductase (XOR). The serum levels of both XOR activity and uric acid differ physiologically between the genders, being higher in men than in women. Their higher levels have been associated with gout and hypertension, as well as with vascular, cardiac, renal, and metabolic diseases. The present review analyzes the gender-related differences in these pathological conditions in relation to increases in the serum levels of XOR and/or uric acid and the opportunity for gender-driven pharmacological treatment.

Sex, Endothelial Cell Functions, and Peripheral Artery Disease

Peripheral artery disease (PAD) is caused by blocked arteries due to atherosclerosis and/or thrombosis which reduce blood flow to the lower limbs. It results in major morbidity, including ischemic limb, claudication, and amputation, with patients also suffering a heightened risk of heart attack, stroke, and death. Recent studies suggest women have a higher prevalence of PAD than men, and with worse outcomes after intervention. In addition to a potential unconscious bias faced by women with PAD in the health system, with underdiagnosis, and lower rates of guideline-based therapy, fundamental biological differences between men and women may be important. In this review, we highlight sexual dimorphisms in endothelial cell functions and how they may impact PAD pathophysiology in women. Understanding sex-specific mechanisms in PAD is essential for the development of new therapies and personalized care for patients with PAD.

Endothelial function measured by peripheral arterial tonometry in patients with chronic myeloid leukemia on tyrosine kinase inhibitor therapy: a pilot study

BACKGROUND

Arterial occlusive events are an emerging problem in patients with chronic myeloid leukemia (CML) receiving tyrosine kinase inhibitor (TKI) therapy. Endothelial cell damage is thought to play an important role in the development of vascular events. Measurement of the peripheral vasodilator response by peripheral arterial tonometry (PAT) has reportedly been useful in the non-invasive assessment of endothelial dysfunction. To date, no studies have assessed endothelial function using PAT in patients with CML receiving TKIs.

METHOD

We measured the reactive hyperemia index (RHI) using PAT in young patients with CML (men aged ≤ 55 years and women aged ≤ 65 years) receiving TKIs.

RESULTS

Thirty patients with CML were examined (mean age, 43.5 ± 9.8 years; men, 57%). The median RHI was 1.81. Among these patients, 16.7% and 83.3% were taking imatinib and second- or third-generation TKIs, respectively. There were no differences in the baseline characteristics between the low RHI (< 1.67, n = 10), borderline RHI (≥ 1.67 and < 2.10, n = 14), and normal RHI (≥ 2.10, n = 6) groups. Serum uric acid (UA) levels and the RHI were significantly negatively correlated (r = -0.40, p = 0.029).

CONCLUSION

One-third of young patients with CML receiving TKI therapy were classified as having a low RHI. The RHI was negatively correlated with serum UA level. Larger prospective studies are necessary to examine whether the RHI predicts cardiovascular events in such patients.

Endothelial injury and inflammation in patients with hyperuricemic nephropathy at chronic kidney disease stages 1-2 and 3-4

BACKGROUND

Endothelial injury and inflammation are the main pathological changes in hyperuricemic nephropathy (HN); however, they have not been assessed in patients in the early, middle, and late phases of HN.

AIM

To investigate endothelial injury and inflammatory conditions between patients with HN at chronic kidney disease (CKD) stages 3-4 and CKD 1-2.

METHODS

This study enrolled 80 patients (49 and 31 with HN at CKD stage 1-2 and 3-4, respectively) from the Department of Nephrology, Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine between July 2021 and January 2022. Plasma levels of heparan sulfate, endocan, oxidized low-density lipoprotein (Ox-LDL), E-selectin, soluble intercellular adhesion molecule-1 (slCAM1), interleukin (IL)-1β, and IL-6 and urine levels of lipocalin-type prostaglandin D synthase (L-PGDS), IL-1β, and IL-6 were measured using enzyme-linked immunosorbnent assay.

RESULTS

Comparison between patients with HN at CKD 1-2 and those with HN at CKD 3-4 showed that age and disease course were significant factors (P < 0.001 and P < 0.010, respectively). There were no statistical differences in sex, heart rate, body mass index, and systolic and diastolic blood pressures. The incidence of hypertension was also significant (P = 0.03). Plasma levels of heparin sulfate (P < 0.001), endocan (P = 0.034), E-selectin (P < 0.001), slCAM1 (P < 0.001), IL-1β (P = 0.006), and IL-6 (P = 0.004) and the urine levels of L-PGDS (P < 0.001), IL-1β (P = 0.003), and IL-6 (P < 0.001) were high in patients with HN at CKD 3-4 than in those with HN at CKD 1-2. The difference in plasma Ox-LDL levels was not significant (P = 0.078).

CONCLUSION

Vascular endothelial injury and inflammation were higher in patients with HN at CKD3-4 than at CKD 1-2. Plasma heparin sulfate and slCAM1 levels are synergistic factors for CKD staging in HN.

Association between Serum Uric Acid and Impaired Endothelial Function: The Circulatory Risk in Communities Study

AIMS

Higher serum uric acid (UA) may impair endothelial function. However, population-based evidence examining the association between serum UA levels and endothelial function remains to be limited. Thus, in this study, we aimed to investigate this in the general population.

METHODS

In this cross-sectional study, 1000 participants (496 males and 504 females), aged 30-79 years, free from a history of gout, have undergone both serum UA and brachial artery flow-mediated dilation (FMD) measurements. Participants were divided into four groups based on serum UA quartiles. Logistic regression models were used to calculate odds ratios (ORs) for low FMD according to the serum UA levels.

RESULTS

In total, 203 participants (138 males and 65 females) with %FMD ≤ 5.0% were identified to have endothelial dysfunction. The multivariable OR of low FMD for highest quartiles vs. lowest quartiles was 2.39 (95% confidence interval [CI]: 1.32-4.34), while OR per 1-standard deviation (SD) increment was 1.28 (95% CI: 1.04-1.56). The positive association was noted to be more evident in females (OR per 1-SD increment: 1.46; 95% CI: 1.08-1.96) than in males and confined to individuals not using antihypertensive medications. The ORs per 1-SD increment were 1.01 (95% CI: 0.68-1.50) among individuals using antihypertensive medications and 1.43 (95% CI: 1.12-1.81) among individuals not using antihypertensive medications.

CONCLUSION

Higher serum UA was positively associated with the prevalence of endothelial dysfunction in samples of the general Japanese population and that positive association was confined to individuals not using antihypertensive medications.

Uric Acid Expression in Carotid Atherosclerotic Plaque and Serum Uric Acid Are Associated With Cerebrovascular Events

BACKGROUND

Uric acid (UA) concentration within carotid plaque and its association with cerebrovascular events have not been detected or quantified. Systemically, serum UA is a marker of inflammation and risk factor for atherosclerosis. However, its association with carotid plaque instability and stroke pathogenesis remains unclear. In patients undergoing carotid endarterectomy, we aimed to determine whether UA is present differentially in symptomatic versus asymptomatic carotid plaques and whether serum UA is associated with cerebrovascular symptoms (stroke, transient ischemic attack, or amaurosis fugax).

METHODS

Carotid atherosclerotic plaques were collected during carotid endarterectomy. The presence of UA was assessed using Gomori methenamine silver staining as well as anti-UA immunohistochemical staining and its quantity measured using an enzymatic colorimetric assay. Clinical information was obtained through a retrospective review of data.

RESULTS

UA was more commonly detected in symptomatic (n=23) compared with asymptomatic (n=9) carotid plaques by Gomori methenamine silver (20 [86.9%] versus 2 [22.2%]; P=0.001) and anti-UA immunohistochemistry (16 [69.5%] versus 1 [11.1%]; P=0.004). UA concentration was higher in symptomatic rather than asymptomatic plaques (25.1 [9.5] versus 17.9 [3.8] µg/g; P=0.021). Before carotid endarterectomy, serum UA levels were higher in symptomatic (n=341) compared with asymptomatic (n=146) patients (5.9 [interquartile range, 4.6-6.9] mg/dL versus 5.2 [interquartile range, 4.6-6.2] mg/dL; P=0.009).

CONCLUSIONS

The current study supports a potential role of UA as a potential tissue participant and a systemic biomarker in the pathogenesis of carotid atherosclerosis. UA may provide a mechanistic explanation for plaque instability and subsequent ischemic cerebrovascular events.

Increased risk of modality failure with higher serum uric acid level in continuous ambulatory peritoneal dialysis patients: a prospective cohort study

BACKGROUND

Peritoneal dialysis (PD) is one of the most important kidney replacement therapies for patients with end-stage kidney disease (ESKD). PD technique failure can lead to an escalated cost and increased infectious and cardiovascular risk, up and including to death. The accumulation of uric acid (UA) was associated with adverse outcomes in ESKD patients. However, the relationship between serum UA and technique failure is little explored.

METHODS

Here, a total of 266 continuous ambulatory peritoneal dialysis (CAPD) patients (age, 41.8 ± 12.6 years; 125 males) were enrolled and followed up for 31.7 months. Serum UA levels were examined at baseline and each visit. Subjects were divided into three groups according to their baseline serum UA concentrations. Multivariable Cox regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of PD technique failure.

RESULTS

The level of serum UA increased gradually as time prolonged. During the follow-up period, 77 (28.9%) patients occurred PD technique failure, of which 56 (21.1%) transferred to hemodialysis (HD) and 21 (7.9%) died. Compared to the lowest UA tertile, after adjusting for potential confounders, HRs of technique failure in tertile 2 and tertile 3 were 1.82 (95% CI: 0.95-3.49) and 2.03 (95% CI: 1.05-3.92), respectively, and p for trend was 0.043. Adjusted HRs of all-cause technique failure, transferring to HD and mortality with each 1 mg/dL increase in serum UA were 1.20 (95% CI: 1.03-1.40, p = 0.019), 1.22 (95% CI: 1.01-1.48, p = 0.039), and 1.25 (95% CI: 0.94-1.67, p = 0.128), respectively.

CONCLUSION

Higher serum UA level predicted higher risk of technique failure in CAPD patients.

CTRP3 protects against uric acid-induced endothelial injury by inhibiting inflammation and oxidase stress in rats

Hyperuricemia, which contributes to vascular endothelial damage, plays a key role in multiple cardiovascular diseases. This study was designed to investigate whether C1q/tumor necrosis factor (TNF)-related protein 3 (CTRP3) has a protective effect on endothelial damage induced by uric acid and its underlying mechanisms. Animal models of hyperuricemia were established in Sprague-Dawley (SD) rats through the consumption of 10% fructose water for 12 weeks. Then, the rats were given a single injection of Ad-CTRP3 or Ad-GFP. The animal experiments were ended two weeks later. In vitro, human umbilical vein endothelial cells (HUVECs) were first infected with Ad-CTRP3 or Ad-GFP. Then, the cells were stimulated with 10 mg/dL uric acid for 48 h after pretreatment with or without a Toll-like receptor 4 (TLR4)-specific inhibitor. Hyperuricemic rats showed disorganized intimal structures, increased endothelial apoptosis rates, increased inflammatory responses and oxidative stress, which were accompanied by reduced CTRP3 and elevated TLR4 protein levels in the thoracic aorta. In contrast, CTRP3 overexpression decreased TLR4 protein levels and ameliorated inflammatory responses and oxidative stress, thereby improving the morphology and apoptosis of the aortic endothelium in rats with hyperuricemia. Similarly, CTRP3 overexpression decreased TLR4-mediated inflammation, reduced oxidative stress, and rescued endothelial damage induced by uric acid in HUVECs. In conclusion, CTRP3 ameliorates uric acid-induced inflammation and oxidative stress, which in turn protects against endothelial injury, possibly by inhibiting TLR4-mediated inflammation and downregulating oxidative stress.

Viral Endothelial Dysfunction: A Unifying Mechanism for COVID-19

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible virus with significant global impact, morbidity, and mortality. The SARS-CoV-2 virus may result in widespread organ manifestations including acute respiratory distress syndrome, acute renal failure, thromboembolism, and myocarditis. Virus-induced endothelial injury may cause endothelial activation, increased permeability, inflammation, and immune response and cytokine storm. Endothelial dysfunction is a systemic disorder that is a precursor of atherosclerotic vascular disease that is associated with cardiovascular risk factors and is highly prevalent in patients with atherosclerotic cardiovascular and peripheral disease. Several studies have associated various viral infections including SARS-CoV-2 infection with inflammation, endothelial dysfunction, and subsequent innate immune response and cytokine storm. Noninvasive monitoring of endothelial function and identification of high-risk patients who may require specific therapies may have the potential to improve morbidity and mortality associated with subsequent inflammation, cytokine storm, and multiorgan involvement.

Gout-induced endothelial impairment: The role of SREBP2 transactivation of YAP

Gout is a multifaceted inflammatory disease involving vascular impairments induced by hyperuricemia. Experiments using human umbilical vein endothelial cells treated with uric acid (UA), monosodium urate (MSU), or serum from gout patients showed increased expression of pro-inflammatory genes (ie, VCAM1, ICAM1, CYR61, CCNA1, and E2F1) with attendant increase in monocyte adhesion. Mechanistically, UA- or MSU-induced SREBP2 expression and its transcriptional activity. RNA sequencing analysis and real-time PCR showed the induction of YAP signaling and pro-inflammatory pathways in HUVECs transfected with adenovirus-SREBP2. The SREBP2 knockdown by siRNA partially abolished UA- or MSU-induced YAP activity, pro-inflammatory gene expression, and monocytes adhesion. Vascular intima from transgenic mice overexpressing SREBP2 in endothelium or mice with hyperuricemia exhibited activated YAP signaling and increased expression of pro-inflammatory genes. Betulin, an SREBP pharmacological inhibitor, attenuated the UA-, MSU-, or gout serum-induced endothelial cell inflammation and dysfunction. In the human study, endothelial cell function, assessed by EndoPAT, was negatively correlated with serum UA level among gouty patients and healthy controls. Collectively, UA or MSU causes endothelial dysfunction via SREBP2 transactivation of YAP. Betulin inhibition of SREBP2 may restrain gout-induced endothelial dysfunction.

Association between Serum Uric Acid and Pre-hypertension and Hypertension among Chinese Adults

Fundamento

O ácido úrico (AU), produto final do metabolismo dos nucleotídeos das purinas, participa dos processos de doenças metabólicas e cardiovasculares. Evidências experimentais sugerem que o ácido úrico é um mediador importante na resposta fisiológica ao aumento da pressão arterial.

Objetivo

Avaliar a associação entre os níveis séricos de AU e pré-hipertensão e hipertensão em uma população chinesa.

Métodos

Conduziu-se um estudo transversal entre março e setembro de 2017, e 1.138 participantes com idades entre 35 e 75 anos foram incluídos neste estudo, onde 223 normotensos, 316 pré-hipertensos e 599 hipertensos foram selecionados para avaliar a associação entre níveis séricos de AU e hipertensão. Considerou-se um valor de p<0,05 estatisticamente significativo.

Resultados

Os níveis séricos de AU foram significativamente maiores no grupo pré-hipertensão e hipertensão em comparação com o grupo controle em toda a população (p<0,05 para todos). A análise quantitativa das características indicou níveis séricos de AU (2,92±0,81, 3,06±0,85, 3,22±0,98 mg/d) linearmente aumentados em mulheres normotensas, pré-hipertensas e hipertensas, com um valor de p de 0,008. Os níveis séricos de AU nos quartis correlacionaram-se positivamente com a PAD (p<0,05), principalmente em mulheres. Após o ajuste para idade, sexo, índice de massa corporal (IMC), glicose (GLI), colesterol total (CT), triglicerídeos (TG), colesterol HDL (lipoproteína de alta densidade), as razões de chances ( odds ratios — ORs) e intervalos de confiança (IC) de 95% da pré-hipertensão, dos níveis séricos de AU mais baixos (referentes) aos mais altos foram 1,718 (1,028–2,872), 1,018 (0,627–1,654) e 1,738 (1,003–3,010). Além disso, o segundo quartil dos níveis séricos de AU esteve significativamente associado à hipertensão, com uma OR (IC 95%) de 2,036 (1,256–3,298).

Conclusões

O presente estudo sugere que níveis séricos mais elevados de AU estão positivamente associados à pré-hipertensão e hipertensão entre adultos chineses.

Relationship between peripheral arterial reactive hyperemia and the index of myocardial resistance in patients undergoing invasive coronary angiography

BACKGROUND

Coronary microvascular dysfunction is a powerful prognostic factor in patients with coronary artery disease. We investigated the role of reactive digital hyperemia peripheral arterial tonometry (RH-PAT) as a non-invasive tool to identify patients with impaired coronary microvasculature.

METHODS

Patients undergoing elective coronary angiography were consecutively assessed for peripheral microvascular endothelial function before coronary angiography: both the Reactive Hyperemic Index (RHI) and the Framingham reactive hyperemic index (Endoscore) were measured. During coronary angiography, the Index of microvascular resistance (IMR) was measured in all patients, and an IMR value > 25 identified patients with coronary microvascular impairment.

RESULTS

A total of 47 patients with chronic coronary syndromes candidate to coronary angiography were included. Those with coronary microvascular impairment (n = 18 [38%]) presented with significantly lower RHI (1.68 ± 0.38 vs. 1.94 ± 0.93, p = 0.04) and Endoscore 0.50 ± 0.23 vs. 0.64 ± 0.23, p = 0.04) values as compared with patients with preserved coronary microvasculature. A significant relationship was observed between IMR with both RHI (r = 0.35, p = 0.02) and Endoscore (r = 0.34, p = 0.02). At the multivariable analysis, RHI and Endoscore were the only independent predictors of an IMR > 25.

CONCLUSIONS

Our study demonstrates that digital reactive hyperemia indexes are lower in patients with high IMR values, suggesting a role for RH-PAT as non-invasive tool for identifying patients with coronary microvascular impairment.

Vascular Aging Detected by Peripheral Endothelial Dysfunction Is Associated With ECG-Derived Physiological Aging

Background An artificial intelligence algorithm that detects age using the 12-lead ECG has been suggested to signal "physiologic age." This study aimed to investigate the association of peripheral microvascular endothelial function (PMEF) as an index of vascular aging, with accelerated physiologic aging gauged by ECG-derived artificial intelligence-estimated age. Methods and Results This study included 531 patients who underwent ECG and a noninvasive PMEF assessment using reactive hyperemia peripheral arterial tonometry. Abnormal PMEF was defined as reactive hyperemia peripheral arterial tonometry index ≤2.0. Accelerated or delayed physiologic aging was calculated by the Δ age (ECG-derived artificial intelligence-estimated age minus chronological age), and the association between Δ age and PMEF as well as its impact on composite major adverse cardiovascular events were investigated. Δ age was higher in patients with abnormal PMEF than in patients with normal PMEF (2.3±7.8 versus 0.5±7.7 years; P=0.01). Reactive hyperemia peripheral arterial tonometry index was negatively associated with Δ age after adjustment for cardiovascular risk factors (standardized β coefficient, -0.08; P=0.048). The highest quartile of Δ age was associated with an increased risk of major adverse cardiovascular events compared with the first quartile of Δ age in patients with abnormal PMEF, even after adjustment for cardiovascular risk factors (hazard ratio, 4.72; 95% CI, 1.24-17.91; P=0.02). Conclusions Vascular aging detected by endothelial function is associated with accelerated physiologic aging, as assessed by the artificial intelligence-ECG Δ age. Patients with endothelial dysfunction and the highest quartile of accelerated physiologic aging have a marked increase in risk for cardiovascular events.

Harnessing hyperuricemia to atherosclerosis and understanding its mechanistic dependence

Atherosclerosis is regarded as the disease of the arterial vasculature. The main characteristics of atherosclerosis are the abnormal accumulation of lipids, increased inflammatory cells, matrix deposits, and proliferation of smooth muscle cells. Diabetes mellitus, obesity, and hyperlipidemia are the most studied risk factors of atherosclerosis. One least studied risk factor is the uric acid (UA), a high UA in circulation is interlinked with many pathological processes. Several epidemiological studies suggest elevated UA levels as an essential biomarker in the forecast of several cardiovascular diseases. Available evidence claims that UA upholds the atherosclerosis process via disturbing lipid metabolism, reducing the nitric oxide synthesis in endothelial cells, promoting the proliferation of vascular smooth muscle cells, and overwhelms inflammation. In endothelial dysfunction and coronary artery lesions, UA is considered as an independent predictor. The updated studies on the involvement of hyperuricemia in atherosclerosis prove that treatment with xanthine oxidase (XO) inhibitors not just benefits the treatment of hyperuricemia but also reduces the burden of atherosclerosis to a greater extent. In this review, we highlight how the hyperuricemia affects vascular integrity, causes atherosclerosis, and the mechanism of action of XO inhibitors on atherosclerosis.

Secondary Raynaud's phenomenon is associated with microvascular peripheral endothelial dysfunction

Previous studies in patients with Raynaud's phenomenon (RP) have found an association between microvascular abnormalities assessed by nail fold capillaroscopy and macrovascular peripheral endothelial dysfunction (PED), but the association between RP and nitric oxide related (NO) microvascular PED is not yet established. We performed a retrospective cross-sectional analysis of patients who were referred to Mayo Clinic between 2006 and 2014 for routine cardiovascular evaluation and who underwent evaluation of Reactive Hyperemia Peripheral Arterial Tonometry (index <2 consistent with PED). Identification of the presence of RP was determined by retrospective chart review. Six hundred sixty six individuals were included in this study (mean age 51.9 ± 13.5 years, 411 (61.3%) women), 637 (95.1%) individuals did not have RP (control group), and 29 (4.3%) had secondary RP. Only 4 patients had primary RP and were thus excluded from the final analyses. In a multivariate analysis adjusting for age, sex, smoking status, and use of statins we found a significant association between secondary RP and microvascular PED in all patients (Odds ratio: 2.45; 95% confidence interval 1.13-5.34; P = 0.0236) that remained significant in women after stratifying by sex. Secondary RP is associated with microvascular PED, detected using a non-invasive NO-dependent method. Early detection of microvascular PED could help in identifying individuals with secondary RP who are at risk for developing connective tissue disease as well as CVD.

Incremental Prognostic Impact of Peripheral Microvascular Endothelial Dysfunction on the Development of Ischemic Stroke

Background

Peripheral microvascular endothelial dysfunction (PMED) has been linked to an increased risk of cardiovascular events, but there is a lack of information characterizing the predictive value of PMED for future risk of ischemic stroke (IS).

Methods and Results

This retrospective observational cohort study enrolled 637 patients who underwent non‐invasive microvascular endothelial function assessment using reactive hyperemia peripheral arterial tonometry. Reactive hyperemia peripheral arterial tonometry index ≤2 was defined as PMED. Of 280 patients with PMED, 12 (4.3%) patients developed IS, compared with only 4 (1.1%) of 357 patients without PMED during a median follow‐up of 5.3 years. Patients with PMED had lower IS‐free survival compared with patients without PMED (log‐rank P=0.03). Cox proportional hazard ratio (HR) analyses showed that PMED predicted the incidence of IS, with a HR of 3.43, 95% CI, 1.10–10.63 (P=0.03); adjusted HR of 3.70, 95% CI, 1.18–11.59 (P=0.02) after adjusting for sex, smoking history, and atrial fibrillation; adjusted HR of 3.45, 95% CI, 1.11–10.72 (P=0.03) after adjusting for CHA₂DS₂‐VASc score; adjusted HR of 5.70, 95% CI, 1.40–23.29 (P=0.02) after adjusting for revised Framingham Stroke Risk Score. Reactive hyperemia peripheral arterial tonometry index improved discrimination of risk for IS after adding reactive hyperemia peripheral arterial tonometry index to CHA₂DS₂‐VASc score and revised Framingham Stroke Risk Score.

Conclusions

PMED was associated with a >3‐fold increased risk of IS. These findings underscore the concept of the systemic nature of endothelial dysfunction, which could act as a potential marker to predict future risk of IS.