Peripheral Microangiopathy in Patients with Precapillary Pulmonary Hypertension: Correlation with Cardiac Function and Patients' Functional Capacity. Study Design and Rationale

Asymmetric dimethylarginine correlates with worsening peripheral microangiopathy in systemic sclerosis

BACKGROUND

Systemic sclerosis (SSc) is a connective tissue disease characterized primarily by micro-angiopathy and endothelial dysfunction which stimulate a fibrotic process. Asymmetric dimethylarginine (ADMA) is an endogenous nitric oxide (NO) inhibitor and represents a novel biomarker for vascular dysfunction. Nailfold video capillaroscopy (NVC) represents a non-invasive and reliable technique for the evaluation of microvasculopathy in SSc.

OBJECTIVES

The aim of this study was to examine the possible association between ADMA and microvascular involvement in patients with SSc.

METHODS

This was a cross-sectional study including consecutive SSc patients attending the Scleroderma Outpatient Clinic. ADMA was measured in serum samples using a commercial enzyme immunoassay. Participants underwent NVC with qualitative and semi-quantitative assessment and all NVC parameters were measured in the distal row of each finger. The findings were classified in one of the three qualitative NVC patterns: early, active, and late.

RESULTS

Eighty-one (92,6 % women) SSc individuals with mean age 55.44 ± 13.4 years were included in this analysis. Within-groups comparisons revealed a trend between higher ADMA levels and progressive micro-vasculopathy (1,29 [2,1] vs 1,57 [1,95] vs 2,41 [3,87]; for early, active and late patterns respectively, p = 0.039). Furthermore, ADMA concentration was significantly associated with the number of capillaries/mm (r = -0.235; p = 0.035).

CONCLUSIONS

Serum ADMA levels were significantly associated with advancing stages of microcirculatory abnormalities suggesting that ADMA may have a role in promoting microvascular endothelial dysfunction in SSc individuals.

Nailfold Videocapillaroscopy for the Evaluation of Peripheral Microangiopathy in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic and refractory autoimmune joint disease that affects multiple organs. Several methods have been applied for the study of microvascular endothelial dysfunction, which is considered an important component of vascular disease in RA. Implementation of nailfold videocapillaroscopy (NVC) represents a viable choice, as the skin is an easily accessible window for the non-invasive, real-time assessment of subtle microcirculation abnormalities. Although NVC is routinely used in the rheumatology field, especially for the diagnostic workout of Raynaud’s phenomenon, accumulating evidence suggests a role in the evaluation of systemic vasculopathy associated with autoimmune rheumatic disorders. The current paper aims to provide an overview of NVC as a valuable clinical aid for the assessment of peripheral microcirculation in RA. Previous studies characterizing the capillaroscopic pattern in RA are summarized, along with associations with disease-related characteristics. Most available reports have mainly focused on the descriptions of non-specific morphological alterations that may reflect endothelial injury over the course of the disease. Still, the exact pattern of structural and functional capillaroscopic alterations and their clinical significance in RA remains a subject of ongoing research.

Peripheral microcirculatory abnormalities are associated with cardiovascular risk in systemic sclerosis: a nailfold video capillaroscopy study

INTRODUCTION

Microvascular dysfunction is the key element in the pathogenesis of systemic sclerosis (SSc), whereas the contribution of large and medium size vessel abnormalities is yet to be established. The aim of the present study is to assess the association between micro- and macrovascular function by utilizing a broad spectrum of assessments of vascular performance.

METHODS

We included consecutive, consenting SSc patients who underwent nailfold video capillaroscopy (NVC) for microcirculation evaluation. Peripheral and central systolic and diastolic blood pressure, carotid intima-media thickness (cIMT), aortic augmentation index (AIx) corrected for a heart rate of 75 beats per minute (AIx-75), and carotid-femoral pulse wave velocity (PWV) were also performed to assess macrovascular function. Cardiovascular risk disease (CVD) algorithms were also calculated and included in the analysis.

RESULTS

A total of 81 patients (6 males) were studied with mean age 55.44 ± 13.40 years. Reduced capillary density was inversely correlated with arterial stiffness (Alx-75) and augmentation pressure (r =  - 0.262, p = 0.018, and r =  - 0.249, p = 0.025 respectively). Alx was significantly lower in the early compared to late pattern (28.24 ± 11.75 vs 35.63 ± 10.47, p = 0.036). A significant trend was found among NVC patterns with Alx-75 values being higher with the progression of microangiopathy towards the "late" group (26.36 ± 10.90 vs 30.81 ± 11.59 vs 35.21 ± 7.90, p = 0.027 for trend). Similarly, Framingham risk score and Atherosclerotic Cardiovascular Disease score were progressively higher across the worsening NVC patterns (4.10 ± 4.13 vs 2.99 ± 2.72 vs 6.36 ± 5.65, p = 0.023, and 6.99 ± 7.18 vs 5.63 ± 4.41 vs 12.09 ± 9.90, p = 0.019, respectively, for trends). Finally, QRISK3 (10-year cardiovascular disease risk) and ASCVD (Atherosclerotic Cardiovascular Disease) scores were inversely correlated with the number of capillaries (r =  - 0.231, p = 0.048, and r =  - 0.260, p = 0.038 respectively).

CONCLUSION

These data suggest that CVD risk scores and macrovascular parameters are strongly correlated with microvasculopathy in patients with SSc. Key Points • Microangiopathy is the hallmark of SSc, but the relationship between subclinical atherosclerosis and small vessel disease remains unknown. • Arterial stiffening and CVD risk scores are positively associated with the degree of progression of peripheral microvasculopathy assessed with NVC. • The results of the study suggest an association between NVC abnormalities and higher CVD risk in SSc patients.

Nailfold videocapillaroscopic changes in patients with pulmonary arterial hypertension associated with connective tissue diseases

Pulmonary arterial hypertension (PAH) represents one of the most devastating complications in connective tissue diseases (CTDs). The aim of this study was to investigate the presence of peripheral microangiopathy in patients with PAH associated with CTDs (CTD-PAH) by exploring nailfold videocapillaroscopic (NVC) changes and identify possible associations of NVC characteristics with markers of disease severity. Α cross-sectional study was performed in 18 CTD-PAH patients [13 PAH due to systemic sclerosis (SSc-PAH) and 5 with other types of CTD-PAH], 14 patients with SSc without PAH (SSc-non-PAH) and 20 healthy controls. NVC quantitative and qualitative parameters were evaluated using Optilia Digital Capillaroscope. To ensure inter-observer repeatability, capillaroscopic images were reviewed by two independent investigators. When compared to healthy controls, patients with CTD-PAH (77.8% women, mean age 65.9 years) presented reduced capillary density (6.5 ± 1.6 loops/mm vs. 9.7 ± 0.7 loops/mm, p < 0.001) and increased capillary loop width (23.3 ± 10.1 μm vs. 11.2 ± 2.5 μm, p < 0.001). SSc-PAH patients presented lower capillary density in comparison with other CTD-PAH patients and SSc-non-PAH subjects and abnormal and disorganized capillaries compared to controls. Patients with other CTD-PAH had also reduced capillary density and increased loop diameter compared to controls. A significant linear correlation was identified between capillary density and estimated glomerular filtration rate in the total CTD-PAH population (r = 0.63, p = 0.007). In SSc-PAH group, capillary loop diameter was positively correlated to cardiac index (r = 0.61, p = 0.02). Significant NVC microvascular changes were detected in patients with various types of CTD-PAH, suggesting an impaired peripheral microcirculation parallel to pulmonary vasculopathy.

Peripheral microangiopathy in Eisenmenger syndrome: A nailfold video capillaroscopy study

BACKGROUND

Eisenmenger syndrome (ES) comprises a severe phenotype of pulmonary arterial hypertension characterized by angiopathy of the lung circulation. The aim of the present study was to demonstrate the presence of systemic microvascular abnormalities in patients with ES using nailfold video-capillaroscopy (NVC) and to identify potential correlations of nailfold capillaroscopic characteristics with non-invasive markers of systemic organ function.

METHODS

Α cross-sectional NVC study was performed in 17 consecutive patients with ES and 17 healthy controls matched for age and sex. NVC quantitative (capillary density, capillary dimensions, haemorrhages, thrombi, shape abnormalities) and qualitative (normal, non-specific or scleroderma pattern) parameters were evaluated.

RESULTS

Patients with ES [median age 40 (18-65) years, 11 women] presented reduced capillary density [8.8 (7.2-10.2) loops/mm vs. 9.9 (8.3-10.9) loops/mm, p = .004] and increased loop width [15.9 (10.3-21.7) μm vs. 12.3 (7.6-15.2) μm, p < .001], while they had significantly more abnormal capillaries than healthy controls [2.5 (0.9-5.4) abnormal loops/mm vs. 1.0 (0.0-1.7) abnormal loops/mm, p < .001]. NVC shape abnormalities in ES were positively correlated with NT-proBNP (r = 0.52, p = .03) and were negatively associated with estimated glomerular filtration rate (r = -0.60, p = .02). Additionally, capillary loop diameter was positively correlated with increased haemoglobin levels (r = 0.55, p = .03) and negatively correlated with reduced peripheral oxygen saturation (r = - 0.56, p = .02).

CONCLUSIONS

This study supports the hypothesis of peripheral microvascular involvement in ES parallel to pulmonary microangiopathy detected by NVC. Further longitudinal studies are needed to confirm our preliminary results.

Non-Invasive Assessment of Endothelial Dysfunction in Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is characterised by an increased pressure in the pulmonary arterial circulation, resulting in the elevation of pulmonary vascular resistance. Pulmonary endothelial dysfunction and inflammation, triggered by shear stress and hypoxia, constitute the hallmarks of pulmonary vasculopathy by promoting endothelial and smooth muscle cells proliferation, vasoconstriction, and thrombosis. While research was predominantly focused on pulmonary vasculature, the investigation of peripheral endothelial damage in different vascular beds has attracted the interest over the last years. As a result, effective non-invasive methods that can assess the endothelial function and the architectural integrity have been utilized for the evaluation of pulmonary and peripheral vasculature. Non-invasive plethysmography, pulmonary flow reserve, nailfold videocapillaroscopy, near-infrared spectroscopy, and imaging techniques such as magnetic resonance angiography and perfusion imaging coupled by a number of biomarkers can be used for the assessment of peripheral vascular function in PAH individuals. In this review, we summarise and critically approach the current evidence of more systemic derangement of vascular function in PAH defined by novel, non-invasive methods employed for functional and morphological assessment of endothelium and microcirculation.

Peripheral microangiopathy in precapillary pulmonary hypertension: a nailfold video capillaroscopy prospective study

Background

Although pulmonary vascular bed has been the main subject of research for many years in pulmonary hypertension (PH), interest has recently started to divert towards the possibility of a co-existing peripheral microangiopathy. The aim of the current study was to investigate the presence of nailfold video-capillaroscopic (NVC) structural changes in patients with precapillary PH and to identify possible associations of NVC measurements with markers of disease severity.

Methods

Α prospective case–control study was performed in 28 consecutive patients with precapillary PH [14 with idiopathic pulmonary arterial hypertension (IPAH) and 14 with chronic thromboembolic pulmonary hypertension (CTEPH)] and 30 healthy controls. NVC quantitative and qualitative parameters were evaluated using Optilia Digital Capillaroscope. To ensure inter-observer repeatability capillaroscopic images were reviewed by two independent investigators. For multiple comparisons among continuous variables, one-way ANOVA or the Kruskal–Wallis test were used. Differences between the groups were tested with post-hoc analysis with adjustment for multiple comparisons (Bonferroni test).

Results

Both IPAH (71.4% were women, mean age 53.1 ± 13.4 years) and CTEPH (64.3% women, mean age 60.9 ± 14.4 years) groups presented reduced capillary density compared to healthy controls (8.4 ± 1.2 loops/mm and 8.0 ± 1.2 loops/mm vs. 9.7 ± 0.81 loops/mm, p < 0.001) and increased loop width (15.7 ± 3.9 μm and 15.8 ± 1.9 μm vs. 11.5 ± 2.3 μm, p < 0.001). More than half of patients with IPAH presented microhaemorrhages on capillary nailfold, while increased shape abnormalities in capillary morphology and more capillary thrombi per linear mm were detected in patients with CTEPH compared to patients with IPAH and healthy controls. All PH patients presented a non-specific NVC pattern compared to controls (p < 0.001).

Conclusion

The findings of the study reveal a degree of significant peripheral microvascular alterations in patients with IPAH and CTEPH, suggesting a generalized impairment of peripheral microvasculature in pulmonary vascular disease.