Increased Intracranial Arterial Pulsatility and Microvascular Brain Damage in Pseudoxanthoma Elasticum

BACKGROUND AND PURPOSE

Carotid siphon calcification might contribute to the high prevalence of cerebrovascular disease in pseudoxanthoma elasticum through increased arterial flow pulsatility. This study aimed to compare intracranial artery flow pulsatility, brain volumes, and small-vessel disease markers between patients with pseudoxanthoma elasticum and controls and the association between arterial calcification and pulsatility in pseudoxanthoma elasticum.

MATERIALS AND METHODS

Fifty patients with pseudoxanthoma elasticum and 40 age- and sex-matched controls underwent 3T MR imaging, including 2D phase-contrast acquisitions for flow pulsatility in the assessment of ICA and MCA and FLAIR acquisitions for brain volumes, white matter lesions, and infarctions. All patients with pseudoxanthoma elasticum underwent CT scanning to measure siphon calcification. Flow pulsatility (2D phase-contrast), brain volumes, white matter lesions, and infarctions (3D T1 and 3D T2 FLAIR) were compared between patients and controls. The association between siphon calcification and pulsatility in pseudoxanthoma elasticum was tested with linear regression models.

RESULTS

Patients with pseudoxanthoma elasticum (mean age, 57 [SD, 12] years; 24 men) had significantly higher pulsatility indexes (1.05; range, 0.94-1.21 versus 0.94; range, 0.82-1.04; P = .02), lower mean GM volumes (597 [SD, 53] mL versus 632 [SD, 53] mL; P < .01), more white matter lesions (2.6; range, 0.5-7.5 versus 1.1; range, 0.5-2.4) mL; P = .05), and more lacunar infarctions (64 versus 8, P = .04) than controls (mean age, 58 [SD, 11] years; 20 men). Carotid siphon calcification was associated with higher pulsatility indexes in patients with pseudoxanthoma elasticum (β = 0.10; 95% CI, 0.01-0.18).

CONCLUSIONS

Patients with pseudoxanthoma elasticum have increased intracranial artery flow pulsatility and measures of small-vessel disease. Carotid siphon calcification might underlie the high prevalence of cerebrovascular disease in pseudoxanthoma elasticum.

Plasma lipids in Pseudoxanthoma Elasticum (PXE) patients: A comparative study with population-based reference values and Non-PXE controls

Background and aims

- Pseudoxanthoma elasticum (PXE) is a rare genetic disease caused by pathogenic mutations in the ABCC6 gene, resulting in low values of inorganic pyrophosphate (PPi). While low PPi is thought to contribute to arterial calcification, it remains unclear whether this fully explains premature calcification in PXE. It has been hypothesized that the ABCC6 gene could be related to dyslipidemia, which could contribute to vascular calcification seen in PXE. The aim of this study is to evaluate the relation between PXE and plasma lipid concentrations in a large cohort of PXE patients compared with reference values for the general population and compared with non-PXE controls.

Methods

- The plasma concentrations of total cholesterol, HDL-cholesterol, tiglycerides, and LDL-cholesterol of 312 PXE patients were compared to age- and sex-matched modeled data of the general Dutch population. Differences in median lipid levels were compared with Mann-Whitney-U test. Secondly, plasma lipid concentrations of 44 PXE patients were compared to 44 not-genetically related relatives (spouses or friends), with linear models adjusted for age, sex and BMI.

Results

- Total cholesterol in PXE patients was 5.6 [IQR 4.6-6.4] mmol/L versus 5.3 [IQR 4.7-6.0] mmol/L (p < 0.01) in the general population; triglycerides were 1.1 [IQR 0.9-1.7] mmol/L versus 1.0 [0.7-1.4] mmol/L (p < 0.01); HDL-c was 1.4 [IQR 1.2-1.7] mmol/L versus 1.5 [IQR 1.2-1.8] mmol/L (p = 0.03) and LDL-c was 3.3 [IQR 2.7-4.1] mmol/L versus 3.2 [IQR 2.7-3.8] mmol/L (p = 0.01). In the patient control analysis with 44 pairs and age, sex and BMI adjusted, comparison with the non-PXE controls only triglycerides were significantly different (mean difference: 0.38 (0.13-0.63)).

Conclusion

-The lipid profiles of PXE patients are marginally different from the general population or compared to a matched control group, but the differences are unlikely to be clinically relevant. It is therefore unlikely that plasma lipids contribute to the premature vascular calcifications in PXE patients.

Bruch's Membrane Calcification in Pseudoxanthoma Elasticum: Comparing Histopathology and Clinical Imaging

Purpose

To investigate the histology of Bruch's membrane (BM) calcification in pseudoxanthoma elasticum (PXE) and correlate this to clinical retinal imaging.

Design

Experimental study with clinicopathological correlation.

Subjects and Controls

Six postmortem eyes from 4 PXE patients and 1 comparison eye from an anonymous donor without PXE. One of the eyes had a multimodal clinical image set for comparison.

Methods

Calcification was labeled with OsteSense 680RD, a fluorescent dye specific for hydroxyapatite, and visualized with confocal microscopy. Scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy (SEM-EDX) and time-of-flight secondary ion mass spectrometry (TOF-SIMs) were used to analyze the elemental and ionic composition of different anatomical locations. Findings on cadaver tissues were compared with clinical imaging of 1 PXE patient.

Main Outcome Measures

The characteristics and topographical distribution of hydroxyapatite in BM in eyes with PXE were compared with the clinical manifestations of the disease.

Results

Analyses of whole-mount and sectioned PXE eyes revealed an extensive, confluent OsteoSense labeling in the central and midperipheral BM, transitioning to a speckled labeling in the midperiphery. These areas corresponded to hyperreflective and isoreflective zones on clinical imaging. Scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy and TOF-SIMs analyses identified these calcifications as hydroxyapatite in BM of PXE eyes. The confluent fluorescent appearance originates from heavily calcified fibrous structures of both the collagen and the elastic layers of BM. Calcification was also detected in an aged comparison eye, but this was markedly different from PXE eyes and presented as small snowflake-like deposits in the posterior pole.

Conclusions

Pseudoxanthoma elasticum eyes show extensive hydroxyapatite deposition in the inner and outer collagenous and elastic BM layers in the macula with a gradual change toward the midperiphery, which seems to correlate with the clinical phenotype. The snowflake-like calcification in BM of an aged comparison eye differed markedly from the extensive calcification in PXE.

Financial Disclosures

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Rationale for a New Low-Dose Triple Single Pill Combination for the Treatment of Hypertension

Two recent large trials showed the potential of single pill combinations (SPCs) with ≥3 low-dose components among people with hypertension who were untreated or receiving monotherapy. In both trials, these 'hypertension polypills' were superior to usual care, achieving >80% BP control without increasing withdrawal due to side effects. However, there are no such products available for prescribers. To address this unmet need, George Medicines developed GMRx2 with telmisartan/amlodipine/indapamide in three strengths (mg): 10/1.25/0.625, 20/2.5/1.25; 40/5/2.5. Two pivotal trials are ongoing to support FDA submission for the treatment of hypertension, including initial treatment. These assess efficacy and safety of GMRx2 compared to: placebo, and each of the three possible dual combinations. Regulatory submissions are planned for 2024, with the aim of providing access to GMRx2 in developed and developing regions. Wider implementation of GMRx2-based treatment strategies will be guided by further research to inform access and appropriate scale up.

The effects of etidronate on brain calcifications in Fahr's disease or syndrome: rationale and design of the randomised, placebo-controlled, double-blind CALCIFADE trial

BACKGROUND

Fahr's disease and syndrome are rare disorders leading to calcification of the small arteries in the basal ganglia of the brain, resulting in a wide range of symptoms comprising cognitive decline, movement disorders and neuropsychiatric symptoms. No disease-modifying therapies are available. Studies have shown the potential of treatment of ectopic vascular calcifications with bisphosphonates. This paper describes the rationale and design of the CALCIFADE trial which evaluates the effects of etidronate in patients with Fahr's disease or syndrome.

METHODS

The CALCIFADE trial is a randomised, placebo-controlled, double-blind trial which evaluates the effects of etidronate 20 mg/kg during 12 months follow-up in patients aged ≥ 18 years with Fahr's disease or syndrome. Etidronate and placebo will be administered in capsules daily for two weeks on followed by ten weeks off. The study will be conducted at the outpatient clinic of the University Medical Center Utrecht, the Netherlands. The primary endpoint is the change in cognitive functioning after 12 months of treatment. Secondary endpoints are the change in mobility, neuropsychiatric symptoms, volume of brain calcifications, dependence in activities of daily living, and quality of life.

RESULTS

Patient recruitment started in April 2023. Results are expected in 2026 and will be disseminated through peer-reviewed journals as well as presentations at national and international conferences.

CONCLUSIONS

Fahr's disease and syndrome are slowly progressive disorders with a negative impact on a variety of health outcomes. Etidronate might be a new promising treatment for patients with Fahr's disease or syndrome.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05662111. Registered 22 December 2022, https://clinicaltrials.gov/ct2/show/NCT01585402 .

Intracranial arteriosclerosis and the risk of dementia: A population-based cohort study

BACKGROUND

The impact of intracranial arteriosclerosis on dementia remains largely unclear.

METHODS

In 2339 stroke-free and dementia-free participants (52.2% women, mean age 69.5 years) from the general population, we assessed intracranial carotid artery calcification (ICAC) and vertebrobasilar artery calcification (VBAC) as proxy for arteriosclerosis. Associations with dementia were assessed using Cox models. In addition, indirect effects through cerebral small vessel disease (cSVD) and subcortical brain structure volumes were assessed using causal mediation analyses.

RESULTS

During a median of 13.4 years (25th-75th percentiles 9.9-14.5) of follow-up, 282 participants developed dementia. Both ICAC presence (hazard ratio [HR]: 1.53, 95% confidence interval [CI]: 1.00-2.32]) and volume (HR per standard deviation: 1.19, 95% CI: 1.01-1.40) increased dementia risk. For VBAC, severe calcifications increased dementia risk (HR for third vs first volume tertile: 1.89, 95% CI: 1.00-3.59). These effects were mediated partly through increased cSVD (percentage mediated for ICAC: 13% and VBAC: 24%).

DISCUSSION

Intracranial arteriosclerosis increases the risk of dementia.

Do pseudoxanthoma elasticum patients have higher prevalence of kidney stones on computed tomography compared to hospital controls?

BACKGROUND

Pseudoxanthoma elasticum (PXE) is an autosomal recessive disease characterized by diminished inorganic plasma pyrophosphate (PPi), a strong calcification inhibitor. In addition to more typical calcification of skin, retina and arterial wall a diminished plasma PPi could lead to other ectopic calcification, such as formation of kidney stones.

OBJECTIVE

To compare the prevalence of kidney stones between PXE patients and hospital controls on computed tomography (CT).

METHOD

Low-dose CT images of PXE patients and controls were assessed by one radiologist, who was blinded for the diagnosis PXE. The number of kidney stones, and the size of the largest stone was recorded. Odds ratios (ORs) for having kidney stone were calculated using multivariable adjusted logistic regression.

RESULTS

Our study comprised 273 PXE patients and 125 controls. The mean age of PXE patients was 51.5 ± 15.9 years compared to 54.9 ± 14.2 in the control group (p = 0.04) and PXE patients more often were women (63 vs. 50%, p = 0.013). The prevalence of kidney stones on CT was similar: 6.9% in PXE patients, compared to 5.6% in controls (p = 0.6). In the multivariate analysis adjusting for age and sex, there was no significantly higher odds for PXE patients on having stones, compared to controls: OR 1.48 (95% CI 0.62-3.96).

CONCLUSION

There is no significant difference in the prevalence of incidental kidney stones on CT in PXE patients versus controls.

Validation of spot urine in estimating 24-h urinary sodium, potassium and sodium-to-potassium ratio during three different sodium diets in healthy adults

PURPOSE

To evaluate the validity of spot urine assay methods in estimating the 24-h urinary sodium, potassium and sodium-to-potassium ratio during three different sodium diets.

MATERIALS AND METHODS

Twelve healthy volunteers were asked to adhere to 3 dietary sodium targets (3.3-5.0g/day,<3.3 g/day and >5.0 g/day) for three consecutive weeks and to measure salt excretion daily in spot urine samples using a self-monitoring device. On day 7 of each week, 24-h urine was collected to compare measured with estimated 24-h salt excretion (by the Kawasaki, Tanaka and INTERSALT equations).

RESULTS

Correlation coefficients relating measured and estimated 24-h sodium excretion were low and not significant for Kawasaki and INTERSALT and moderate for the Tanaka equation (τ 0.56-0.64,p<.05). Bland-Altman plots showed considerable differences between estimated and measured sodium excretion across all salt diets. Over 40% of the participants showed an absolute difference between measured and estimated 24-h sodium of more than 1000 mg/day. The correlation coefficients between 24-h and spot Na/K ratio were 0.67, 0.94 and 0.85(p<.05), and mean differences were 0.59, 0.06 and 0.48 for the intermediate, low and high sodium diets, respectively.

CONCLUSION

These findings do not support estimation of individual 24-h salt excretion from spot urine by the Kawasaki, Tanaka, or INTERSALT formula. Plain language summaryAccurate monitoring of salt intake is essential to improve BP control. At present, measurement of sodium and potassium excretion in multiple non-consecutive 24-h urinary collections is considered the gold standard for measuring dietary sodium intake. However, this method is burdensome, time-consuming and error prone.Therefore, we assessed and compared the validity of three formula-based approaches to estimate 24-h urinary sodium and potassium excretion and the Na/K ratio from spot urine samples measured by a self-monitoring device under three different sodium diets using 24-h urine collections as the reference.We conclude that use of three commonly used equations that estimate 24-h urinary sodium and potassium excretion result in substantial bias, poor precision and poor accuracy and are therefore not recommended. The Na/K ratio based on multiple casual urine samples may be a useful, low-burden, low-cost alternative method to 24-h urine collection for monitoring daily salt intake.

Stepwise treatment of uncontrolled HyperTensioN (Stepwise-HTN): Study design of a cluster randomised controlled trial in primary care

BACKGROUND

Uncontrolled hypertension is a major health problem, and a key risk factor for cardiovascular disease. Most patients are detected and managed in primary care, but approximately 50% remains uncontrolled. Our aim is to assess whether a guided stepwise work-up management strategy for patients with uncontrolled hypertension in primary care would result in better blood pressure control in these patients compared to usual care.

METHODS

A cluster randomised controlled trial aiming at randomizing 40 general practices to either "a protocolised stepwise work-up" or to "usual care". Uncontrolled hypertension is defined as an office blood pressure (BP) >140/90 mmHg while being prescribed three or more antihypertensive drugs simultaneously from different therapeutic classes for three or more months in an adequate dose. In the intervention arm, patients with uncontrolled hypertension will receive the stepwise approach, consisting of (i) excluding a white coat effect, (ii) re-evaluation of lifestyle, (iii) re-evaluation of drug adherence, (iv) optimalisation of antihypertensive treatment and (v) referral if the office BP is still >140/90 mmHg. The control group receives usual care in a regular program for cardiovascular risk management. The primary outcome is the absolute difference in the mean 24-h systolic BP between intervention and control arm after 8 months. Secondary outcomes include differences in the percentage of patients achieving a controlled BP, and time to reach a controlled BP.

CONCLUSION

If stepwise treatment of uncontrolled hypertension is proven effective, the strategy could be implemented by blending the approach to the cardiovascular risk management already applied in general practice. Trial registration NTR7304, https://www.trialregister.nl/trial/7099.

Plasma Level of Pyrophosphate Is Low in Pseudoxanthoma Elasticum Owing to Mutations in the ABCC6 Gene, but It Does Not Correlate with ABCC6 Genotype

BACKGROUND

Pseudoxanthoma elasticum (PXE), a monogenic disorder resulting in calcification affecting the skin, eyes and peripheral arteries, is caused by mutations in the ABCC6 gene, and is associated with low plasma inorganic pyrophosphate (PP_i). It is unknown how ABCC6 genotype affects plasma PP_i.

METHODS

We studied the association of ABCC6 genotype (192 patients with biallelic pathogenic ABCC6 mutations) and PP_i levels, and its association with the severity of arterial and ophthalmological phenotypes. ABCC6 variants were classified as truncating or non-truncating, and three groups of the 192 patients were formed: those with truncating mutations on both chromosomes (n = 121), those with two non-truncating mutations (n = 10), and a group who had one truncating and one non-truncating ABCC6 mutation (n = 61). The hypothesis formulated before this study was that there was a negative association between PP_i level and disease severity.

RESULTS

Our findings confirm low PP_i in PXE compared with healthy controls (0.53 ± 0.15 vs. 1.13 ± 0.29 µM, p < 0.01). The PP_i of patients correlated with increasing age (β: 0.05 µM, 95% CI: 0.03-0.06 per 10 years) and was higher in females (0.55 ± 0.17 vs. 0.51 ± 0.13 µM in males, p = 0.03). However, no association between PP_i and PXE phenotypes was found. When adjusted for age and sex, no association between PP_i and ABCC6 genotype was found.

CONCLUSIONS

Our data suggest that the relationship between ABCC6 mutations and reduced plasma PP_i may not be as direct as previously thought. PP_i levels varied widely, even in patients with the same ABCC6 mutations, further suggesting a lack of direct correlation between them, even though the ABCC6 protein-mediated pathway is responsible for ~60% of this metabolite in the circulation. We discuss potential factors that may perturb the expected associations between ABCC6 genotype and PP_i and between PP_i and disease severity. Our findings support the argument that predictions of pathogenicity made on the basis of mutations (or on the structure of the mutated protein) could be misleading.

Peripheral Interventions in Patients with Pseudoxanthoma Elasticum (PXE)

OBJECTIVE

Pseudoxanthoma elasticum (PXE) is an autosomal recessive metabolic disorder that may be associated with a high prevalence of peripheral artery disease (PAD) and related symptoms. However, the evidence supporting this association is weak, as only small cohort studies are available. Furthermore, limited data are available on the outcome of lower limb peripheral arterial interventions (PAI) in patients with PXE. It was the aim of this study to clarify the prevalence of PAD, and the occurrence and outcome of PAI in patients with PXE.

METHODS

This was a retrospective review of prospectively collected data from the Dutch Expertise Centre for PXE database. Clinical data of consecutive patients with a definitive diagnosis of PXE were examined. The primary endpoint was the prevalence of PAD (defined as an ankle brachial index of < 0.9). The secondary endpoint was to report an overview of PAI and target lesion revascularisations.

RESULTS

In 285 PXE patients (median age 58 years), 50.9% of patients (n = 145) met the criteria for PAD. Seventeen patients underwent a PAI, mostly for intermittent claudication, at a median age of 51 years. The incidence of PAI was 2.25 per 1 000 patient years in patients with PAD and PXE. A total of 58 interventions was recorded, of which 35 were target lesion revascularisations in nine patients. Twenty one revascularisations were performed within a year following the primary intervention, in 16 cases due to an acute occlusion.

CONCLUSION

Within a well phenotyped and large PXE cohort, the diagnosis of PAD was prevalent in one in two patients. The observed rate of peripheral interventions was low, while the re-intervention rate was unfavourable after endovascular or bypass surgical procedures, with over half of these re-interventions indicated within a year.

Clinical characteristics do not reliably identify non-adherence in patients with uncontrolled hypertension

PURPOSE

Chemical adherence testing is a reliable method to assess adherence to antihypertensive drugs. However, it is expensive and has limited availability in clinical practice. To reduce the number and costs of chemical adherence tests, we aimed to develop and validate a clinical screening tool to identify patients with a low probability of non-adherence in patients with uncontrolled hypertension.

MATERIALS AND METHODS

In 495 patients with uncontrolled hypertension referred to the University Medical Centre Utrecht (UMCU), the Netherlands, a penalised logistic regression model including seven pre-specified easy-to-measure clinical variables was derived to estimate the probability of non-adherence. Non-adherence was defined as not detecting at least one of the prescribed antihypertensive drugs in plasma or urine. Model performance and test characteristics were evaluated in 240 patients with uncontrolled hypertension referred to the Heartlands Hospital, United Kingdom.

RESULTS

Prevalence of non-adherence to antihypertensive drugs was 19% in the UMCU and 44% in the Heartlands Hospital population. After recalibration of the model's intercept, predicted probabilities agreed well with observed frequencies. The c-statistic of the model was 0.63 (95%CI 0.53-0.72). Predicted probability cut-off values of 15%-22.5% prevented testing in 5%-15% of the patients, carrying sensitivities between 97% (64-100) and 90% (80-95), and negative predictive values between 74% (10-99) and 70% (50-85).

CONCLUSION

The combination of seven clinical variables is not sufficient to reliably discriminate adherent from non-adherent individuals to safely reduce the number of chemical adherence tests. This emphasises the complex nature of non-adherence behaviour and thus the need for objective chemical adherence tests in patients with uncontrolled hypertension.

Arterial calcification over time in pseudoxanthoma elasticum: a repeated measurements study

Background

Pseudoxanthoma elasticum (PXE) is a rare genetic disorder, characterized by progressive systemic arterial calcification and an elevated cardiovascular disease risk. Although arterial calcification is an established risk factor of cardiovascular morbidity and mortality, insights into its artery-specific changes over time in PXE remain lacking.

Objectives

To assess artery-specific changes in arterial calcification over time in PXE and to investigate the associations of cardiovascular risk factors with these changes.

Methods

We prospectively included 311 PXE patients (mean age 53.1 years, 185 [59.5%] females). During a median follow-up of 3.7 (25th–75th percentiles 1.3–4.2) years patients underwent 472 full-body, non-contrast computed tomography (CT) scans (maximum of 6 CTs per patient) to quantify the volume (μL) of intracranial carotid artery calcification (ICAC), extracranial carotid artery calcification (ECAC), coronary artery calcification (CAC), aortic calcification (AoC), iliac artery calcification (IAC), and leg artery calcification (LAC) and total body calcification (sum of all arteries). We calculated absolute yearly change (follow-up volume × baseline volume / time difference) and relative yearly change (absolute change divided by baseline volume × 100%) in calcification. The correlations amongst arteries in absolute and relative calcification change were assessed using Spearman's correlation coefficients. Risk factors for change in arterial calcification were assessed using linear mixed models (including age as time variable and with all risk factors entered simultaneously into models).

Results

Calcification volume change ranged from 3% to 12% increase per year, with a total body calcification progression of 11% per year. The correlations amongst arteries in absolute and relative yearly progression of calcification were only weak to moderate (correlation coefficients ranged from 0.23 between CAC and ECAC to 0.38 between CAC and LAC). Hypertension was markedly associated with increased AoC (multiplicative change in calcification per 5 years of age 1.46 [95% CI 1.13–1.89]). Moreover, the strongest predictor of ICAC change was ever smoking (1.23 [95% CI 1.03–1.46]) and of ECAC change was hypercholesterolemia (1.21 [95% CI 1.02–1.43]).

Conclusions

Arterial calcification volume progressed with 11% per year in PXE, with considerable variation between and only moderate correlation amongst arteries. Moreover, we found several modifiable, artery-specific risk factors for the progression of calcification. Although both PXE and risk factor presence are considered systemic in nature, our findings highlight that considerable differences exist between arteries in susceptibility to calcification. As such, our results provide important insights into the mechanisms underlying arterial calcification in PXE, which might be used for more targeted treatment and prevention.

Funding Acknowledgement

Type of funding sources: None.

Patients with pseudoxanthoma elasticum (PXE) do not have dyslipidemia

Background

Pseudoxanthoma elasticum (PXE) is a rare genetic disease caused by low inorganic pyrophosphate and is characterized by medial arterial calcification, leading to peripheral arterial disease and ischemic cerebral disease. Animal studies and small human studies have reported an association between PXE and dyslipidemia and therefore suggest that atherosclerosis is a second pathway contributing to cardiovascular disease in PXE patients. The association between PXE and dyslipidemia was however not consistent across these studies and there are several biological hypotheses proposed where the affected gene in PXE (ABCC6) could affect the cholesterol pathway: ABCC might influence HMA-CoA reductase – and increase total cholesterol and LDL-c – on one hand, but there is also evidence that points toward influence of ABCC6 on the reversed cholesterol pathway, influencing HDL-c. This study is important to analyze if PXE subjects, from the larges PXE cohort in the world, indeed do have a different a different lipid profile compared to well matched controls.

Purpose

To evaluate whether PXE patients have a different lipid profile compared to non-PXE patients.

Methods

A cross-sectional patient-control study was done at the Dutch Expertise Center for PXE in the University Medical Center Utrecht. Patients were all diagnosed conform the Plomp cirteria. The control population consisted of acquaintances of PXE patients, excluding first and second-degree relatives. Total cholesterol, LDL-c, HDL-c and triglycerides were assessed in both patients and controls and if lipid-lowering treatment (LLT) was used pre-treatment levels were calculated using known effects of LLT on lipids.

To eliminate the imbalances between patients and controls, we used Coursened Exact Matching (CEM), to investigate the effect of PXE on lipids.

Results

The study population included 323 PXE patients and 57 controls. Their characteristics are displayed in Figure 1.

After CEM 186 patients (weighted means: age 57.8±9.9 years, 58% females, BMI 25.5±2.9 kg/m2) and 52 controls (age 57.3±43.1 years, 58% females, BMI 25.5±17 kg/m2) were left for analyses. The univariate, weighted regression analysis of the effect of having PXE on lipid profile shows that the differences in lipids between patients and controls were 0.22 mmol/L for total cholesterol (p=0.299), 0.15 mmol/L for LDL-c (p=0.524), 0.07 mmol/L for HDL-c (p=0.314) and 0.10 mmol/L for triglycerides (p=0.433).

A sensitivity analysis where only the crude values of untreated subjects were included in the analysis showed that LDL-c was sginficantly lower in PXE-patients. Probably due to the fact that only the very healthy PXE patients were included.

Conclusion

There are no differences in levels of total cholesterol, LDL-c, HDL-c, and triglycerides between PXE patients and matched controls.

Funding Acknowledgement

Type of funding sources: None.

Smartphone Application-Assisted Home Blood Pressure Monitoring Compared With Office and Ambulatory Blood Pressure Monitoring in Patients With Hypertension: the AMUSE-BP Study

The development of automated, smartphone application (app)-assisted home blood pressure monitoring (HBPM) allows for standardized measurement of blood pressure (BP) at home. The aim of this study was to evaluate the (diagnostic) agreement between app-assisted HBPM, automated office BP (OBP), and the reference standard 24-hour ambulatory BP monitoring (ABPM).

The effect of endovascular baroreflex amplification on central sympathetic nerve circuits and cerebral blood flow in patients with resistant hypertension: A functional MRI study

BACKGROUND

Endovascular baroreflex amplification (EVBA) by implantation of the MobiusHD is hypothesized to lower blood pressure by decreasing sympathetic activity through the mechanism of the baroreflex. In the present exploratory study we investigated the impact of MobiusHD implantation on central sympathetic nerve circuits and cerebral blood flow (CBF) in patients with resistant hypertension.

MATERIALS AND METHODS

In thirteen patients, we performed blood oxygenation level-dependent functional magnetic resonance imaging (BOLD fMRI) at rest and during Valsalva maneuvers, before and 3 months after EVBA. Data were analyzed using a whole-brain approach and a brainstem-specific analysis. CBF was assessed using arterial spin labeling MRI.

RESULTS

Resting-state fMRI analysis did not reveal significant differences in functional connectivity at 3 months after EVBA. For the Valsalva maneuver data, the whole-brain fMRI analysis revealed significantly increased activation in the posterior and anterior cingulate, the insular cortex, the precuneus, the left thalamus and the anterior cerebellum. The brainstem-specific fMRI analysis showed a significant increase in BOLD activity in the right midbrain 3 months after EVBA. Mean gray matter CBF (partial volume corrected) decreased significantly from 48.9 (9.9) ml/100 gr/min at baseline to 43.4 (13.0) ml/100 gr/min (p = 0.02) at 3 months.

CONCLUSIONS

This first fMRI pilot study in patients with resistant hypertension treated with EVBA showed a significant increase in BOLD activity during the Valsalva maneuver in brain regions related to sympathetic activity. No notable signal intensity changes were observed in brain areas involved in the baroreflex circuit. Future randomized controlled studies are needed to investigate whether the observed changes are directly caused by EVBA.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov, identifier: NCT02827032.

Hypertensive response to exercise in adult patients with repaired aortic coarctation

OBJECTIVE

The clinical and prognostic implications of a hypertensive response to exercise after repair of coarctation of the aorta (CoA) remain controversial. We aimed to determine the prevalence of a hypertensive response to exercise, identify factors associated with peak exercise systolic blood pressure (SBP) and explore the association of peak exercise SBP with resting blood pressure and cardiovascular events during follow-up.

METHODS

From the Dutch national CONgenital CORvitia (CONCOR) registry, adults with repaired CoA who underwent exercise stress testing were included. A hypertensive response to exercise was defined as a peak exercise SBP ≥210 mm Hg in men and ≥190 mm Hg in women. Cardiovascular events consisted of coronary artery disease, stroke, aortic complications and cardiovascular death.

RESULTS

Of the original cohort of 920 adults with repaired CoA, 675 patients (median age 24 years (range 16-72 years)) underwent exercise stress testing. Of these, 299 patients (44%) had a hypertensive response to exercise. Mean follow-up duration was 10.1 years. Male sex, absence of a bicuspid aortic valve and elevated resting SBP were independently associated with increased peak exercise SBP. Peak exercise SBP was positively predictive of office SBP (β=0.11, p<0.001) and 24-hour SBP (β=0.05, p=0.03) at follow-up, despite correction for baseline SBP. During follow-up, 100 patients (15%) developed at least 1 cardiovascular event. Peak exercise SBP was not significantly associated with the occurrence of cardiovascular events (HR 0.994 (95% CI 0.987 to 1.001), p=0.11).

CONCLUSIONS

A hypertensive response to exercise was present in nearly half of the patients in this large, prospective cohort of adults with repaired CoA. Risk factors for increased peak exercise SBP were male sex, absence of a bicuspid aortic valve and elevated resting SBP. Increased peak exercise SBP independently predicted hypertension at follow-up. These results support close follow-up of patients with a hypertensive response to exercise to ensure timely diagnosis and treatment of future hypertension.

Treatment of arterial calcification in patients with chronic limb threatening ischemia with etidronate: protocol of an investigator-initiated multicenter, double blind, placebo-controlled, randomized clinical trial

Background

Pathologic studies have shown that in patients with critical limb threatening ischaemia (CLTI) medial arterial calcifications are frequently found and may be responsible for aggravating the disease. These extensive calcifitcations are found not only in arteries of the leg but also in the coronary arteries and the aorta. The progression of these calcifications is fast and they stiffen the vessel wall and may thus increase the cardiovascular risk.

Reduction of progression of calcification may not only reduce the burden of CLTI but may also reduce the high residual cardiovascular risk. Medial calcifications have been halted by etidronate in other trials. Its potential to reduce the burden from peripheral vascular disease in CLTI and residual cardiovascular risk remains to be established.

Methods

This is an investigator-initiated multicenter, double blind, placebo-controlled, randomized trial comparing the effects of etidronate versus placebo in patients with CLTI.

Subjects will be randomized to either treatment with etidronate for 12 months (cyclical 20 mg/kg for 2 weeks on and 10 weeks off) orally or placebo for 12 months (in a similar routine).

The primary endpoint is the change in arterial calcification as quantified by CT-scan.

Secondary endpoints are the number of amputations above and below the ankle, mortality, number of vascular interventions and quality of life.

Discussion

Up to now, the inert end stage of vascular disease in patients with CLTI, has been considered calcification of vessel walls. We believe there is reason to reverse causation and hypothesize that calcification causes vascular disease. This reversal can be proven in a clinical trial if halting the calcification process improves the outcome of the patient. Therefore we use etidronate, a bisphosphate that has proven to stop the calcification in several rare monogenetic calcifying diseases. We aim to perform this mechanistic proof-of-concept study hopefully leading to a clinical outcome study later on.

The relation between urinary sodium and potassium excretion and risk of cardiovascular events and mortality in patients with cardiovascular disease

Background

Most evidence on the relationship between sodium and potassium intake and cardiovascular disease originated from general population studies. This study aimed to evaluate the relation between estimated 24-hour sodium and potassium urinary excretion and the risk of recurrent vascular events and mortality in patients with vascular disease.

Methods

7561 patients with vascular disease enrolled in the UCC-SMART cohort (1996–2015) were included. Twenty-four hour sodium and potassium urinary excretion were estimated (Kawasaki formulae) from morning urine samples. Cox proportional hazard models with restricted cubic splines were used to evaluate the relation between estimated urinary salt excretion and major adverse cardiovascular events (MACE; including myocardial infarction, stroke, cardiovascular mortality) and all-cause mortality.

Results

After a median follow-up of 7.4 years (interquartile range: 4.1–11.0), the relations between estimated 24-hour sodium urinary excretion and outcomes were J-shaped with nadirs of 4.59 gram/day for recurrent MACE and 4.97 gram/day for all-cause mortality. The relation between sodium-to-potassium excretion ratio and outcomes were also J-shaped with nadirs of 2.71 for recurrent MACE and 2.60 for all-cause mortality. Higher potassium urinary excretion was related to an increased risk of both recurrent MACE (HR 1.25 per gram potassium excretion per day; 95%CI 1.13–1.39) and all cause-mortality (HR 1.13 per gram potassium excretion per day; 95%CI 1.03–1.25).

Conclusions

In patients with established vascular disease, lower and higher sodium intake were associated with higher risk of recurrent MACE and all-cause mortality. Higher estimated 24-hour potassium urinary excretion was associated with a higher risk of recurrent MACE and all-cause mortality.

Treatment of Resistant Hypertension With Endovascular Baroreflex Amplification: 3-Year Results From the CALM-FIM Study

OBJECTIVES

The aim of this study was to evaluate the long-term (3-year) safety and effectiveness of endovascular baroreflex amplification (EVBA) from both the European and American CALM-FIM cohorts.

BACKGROUND

The CALM-FIM study demonstrated that EVBA in patients with resistant hypertension significantly lowered blood pressure (BP) with an acceptable safety profile during 6-month follow-up.

METHODS

The CALM-FIM studies were prospective, nonrandomized, first-in-human studies that enrolled patients with resistant hypertension (office systolic BP ≥160 mm Hg and mean 24-hour ambulatory BP ≥130/80 mm Hg despite a stable regimen of ≥3 antihypertensive medications, including a diuretic agent). The incidence of (serious) adverse events and changes in BP, heart rate, and prescribed antihypertensive medication up to 3 years after implantation were determined.

RESULTS

The Mobius device was implanted in 47 patients (30 in Europe, 17 in the United States; mean age 54 years, 23 women). Five serious adverse events (hypotension, n = 2; hypertension, n = 1; vascular access complications, n = 2) and 2 transient ischemic attacks occurred within 30 days postprocedure. Two strokes and 1 transient ischemic attack occurred more than 2 years postimplantation. Mean office BP at baseline was 181 ± 17/107 ± 16 mm Hg and decreased by 25/12 mm Hg (95% CI: 17-33/8-17 mm Hg) at 6 months and 30/12 mm Hg (95% CI: 21-38/8-17 mm Hg) at 3 years. Mean 24-hour ambulatory BP at baseline was 166 ± 16/98 ± 15 mm Hg and decreased by 20/11 mm Hg (95% CI: 14-25/8-15 mm Hg) at 6 months.

CONCLUSIONS

EVBA with the MobiusHD was effective in reducing BP at 3-year follow-up and appears to have an acceptable safety profile in patients with uncomplicated implantation, although data from randomized sham-controlled trials are needed to further evaluate the risk-benefit profile. (Controlling and Lowering Blood Pressure With the MobiusHD™ [CALM-FIM_EUR], NCT01911897; Controlling and Lowering Blood Pressure With the MobiusHD™ [CALM-FIM_US], NCT01831895).

Nonadherence in Hypertension: How to Develop and Implement Chemical Adherence Testing

Nonadherence to antihypertensive medication is common, especially in those with apparent treatment-resistant hypertension (true treatment-resistant hypertension requires exclusion of nonadherence), and its routine detection is supported by clinical guidelines. Chemical adherence testing is a reliable and valid method to detect adherence, yet methods are unstandardized and are not ubiquitous. This article describes the principles of chemical adherence testing for hypertensive patients and provides a set of recommendations for centers wishing to develop the test. We recommend testing should be done in either of two instances: (1) in those who have resistant hypertension or (2) in those on 2 antihypertensives who have a less than 10 mm Hg drop in systolic blood pressure on addition of the second antihypertensive medication. Furthermore, we recommend that verbal consent is secured before undertaking the test, and the results should be discussed with the patient. Based on medications prescribed in United Kingdom, European Union, and United States, we list top 20 to 24 drugs that cover >95% of hypertension prescriptions which may be included in the testing panel. Information required to identify these medications on mass spectrometry platforms is likewise provided. We discuss issues related to ethics, sample collection, transport, stability, urine versus blood samples, qualitative versus quantitative testing, pharmacokinetics, instrumentation, validation, quality assurance, and gaps in knowledge. We consider how to best present, interpret, and discuss chemical adherence test results with the patient. In summary, this guidance should help clinicians and their laboratories in the development of chemical adherence testing of prescribed antihypertensive drugs.

Endovascular baroreflex amplification and the effect on sympathetic nerve activity in patients with resistant hypertension: A proof-of-principle study

BACKGROUND

First in human studies suggest that endovascular baroreflex amplification (EVBA) lowers blood pressure (BP). To explore potential mechanisms for BP reduction, this study examines the effects of EVBA on muscle sympathetic nerve activity (MSNA) and baroreceptor sensitivity (BRS).

METHODS

In a single-center sub-study of the CALM-DIEM study (Controlling And Lowering blood pressure with the MobiusHD-Defining Efficacy Markers), 14 patients with resistant hypertension were treated with EVBA. Microneurography and non-invasive continuous BP measurements were performed at baseline and three months after MobiusHD implantation. The primary outcome was change in MSNA. Secondary outcomes were change in baroreflex sensitivity (BRS), cardiovascular responses to a sympathetic stimulus, BP, heart rate (HR) and heart rate variability (HRV).

RESULTS

The primary endpoint was obtained in 10 of 14 patients enrolled in the sub-study. MSNA burst frequency and burst incidence decreased in 6 of 10 patients: mean change -4.1 bursts/min (95% confidence interval -12.2 to 4.0) and -3.8 bursts/100 heartbeats (-15.2 to 7.7). MSNA spike frequency and spike count decreased in 8 of 10 patients: mean change -2.8 spikes/sec (-7.3 to 1.8) and -3.0 spikes/heartbeat (-6.1 to 0.1). Change in MSNA and BP were not correlated. Office BP decreased by -14/-6 mmHg (-27 to -2/-15 to 3). We observed a trend towards decreased HR (-5 bpm, -10 to 1) and increased total power HRV (623 msec2, 78 to 1168). In contrast, BRS and cardiovascular responses remained unchanged after EVBA.

CONCLUSIONS

In this proof-of-principle study, EVBA did not significantly decrease MSNA in patients with resistant hypertension. EVBA did not impair baroreflex function.

TRIAL REGISTRATION

Clinical trial registration at NCT02827032.

Vascular uptake on 18F-sodium fluoride positron emission tomography: precursor of vascular calcification?

BACKGROUND

Microcalcifications cannot be identified with the present resolution of CT; however, 18F-sodium fluoride (18F-NaF) positron emission tomography (PET) imaging has been proposed for non-invasive identification of microcalcification. The primary objective of this study was to assess whether 18F-NaF activity can assess the presence and predict the progression of CT detectable vascular calcification.

METHODS AND RESULTS

The data of two longitudinal studies in which patients received a 18F-NaF PET-CT at baseline and after 6 months or 1-year follow-up were used. The target to background ratio (TBR) was measured on PET at baseline and CT calcification was quantified in the femoral arteries at baseline and follow-up. 128 patients were included. A higher TBR at baseline was associated with higher calcification mass at baseline and calcification progression (β = 1.006 [1.005-1.007] and β = 1.002 [1.002-1.003] in the studies with 6 months and 1-year follow-up, respectively). In areas without calcification at baseline and where calcification developed at follow-up, the TBR was .11-.13 (P < .001) higher compared to areas where no calcification developed.

CONCLUSION

The activity of 18F-NaF is related to the amount of calcification and calcification progression. In areas where calcification formation occurred, the TBR was slightly but significantly higher.

Pulsatility Attenuation along the Carotid Siphon in Pseudoxanthoma Elasticum

We compared velocity pulsatility, distensibility, and pulsatility attenuation along the intracranial ICA and MCA between 50 patients with pseudoxanthoma elasticum and 40 controls. Patients with pseudoxanthoma elasticum had higher pulsatility and lower distensibility at all measured locations, except for a similar distensibility at C4. The pulsatility attenuation over the siphon was similar between patients with pseudoxanthoma elasticum and controls. This finding suggests that other disease mechanisms are the main contributors to increased intracranial pulsatility in pseudoxanthoma elasticum.

Therapeutic inertia in the management of hypertension in primary care

BACKGROUND

Therapeutic inertia is considered to be an obstacle to effective blood pressure (BP) control.

AIMS

To identify patient characteristics associated with therapeutic inertia in patients with hypertension managed in primary care and to assess reasons not to intensify therapy.

METHODS

A Dutch cohort study was conducted using electronic health record data of patients registered in the Julius General Practitioners' Network (n = 530 564). Patients with a diagnosis of hypertension, SBP at least 140 and/or DBP at least 90 mmHg, and one or two BP-lowering drug(s) were included. Therapeutic inertia was defined as not undertaking therapeutic action in follow-up despite uncontrolled BP. Multivariable logistic regression was used to identify characteristics associated with inertia. Furthermore, an exploratory survey was performed in which general practitioners of 114 patients were asked for reasons not to intensify treatment.

RESULTS

We identified 6400 (10% of all patients with hypertension) uncontrolled patients on one or two BP-lowering drugs. Therapeutic inertia was 87%, similar in men and women. Older age, lower systolic, diastolic and near-target SBP, and diabetes were positively associated, while renal insufficiency and heart failure were inversely related to inertia. General practitioners did not intensify therapy because they first, considered office BP measurements as nonrepresentative (27%); second, waited for next BP readings (21%); third, wanted to optimize lifestyle first (19%). Eleven percent of patients explicitly did not want to change treatment.

CONCLUSION

Therapeutic inertia is common in primary care patients with uncontrolled hypertension. Older age, and closer to target BP, but also concurrent diabetes were associated with inertia.

Apparent treatment resistant hypertension and the risk of recurrent cardiovascular events and mortality in patients with established vascular disease

AIM

To quantify the relation between apparent treatment resistant hypertension (aTRH) and the risk of recurrent major adverse cardiovascular events (MACE including stroke, myocardial infarction and vascular death) and mortality in patients with stable vascular disease.

METHODS

7455 hypertensive patients with symptomatic vascular disease were included from the ongoing UCC-SMART cohort between 1996 and 2019. aTRH was defined as an office blood pressure ≥140/90 mmHg despite treatment with ≥3 antihypertensive drugs including a diuretic. Cox proportional hazard models were used to quantify the relation between aTRH and the risk of recurrent MACE and all-cause mortality. In addition, survival for patients with aTRH was assessed, taking competing risk of non-vascular mortality into account.

RESULTS

A total of 1557 MACE and 1882 deaths occurred during a median follow-up of 9.0 years (interquartile range 4.8-13.1 years). Compared to patients with non-aTRH, the 614 patients (8%) with aTRH were at increased risk of cardiovascular mortality (HR 1.27; 95% CI 1.03-1.56) and death from any cause (HR 1.25; 95% CI 1.07-1.45) but not recurrent MACE (HR 1.13; 95% CI 0.95-1.34). At the age of 50 years, patients with aTRH after a first cardiovascular event on average had a 6.4 year shorter median life expectancy free of recurrent MACE than patients with non-aTRH.

CONCLUSION

In hypertensive patients with clinically manifest vascular disease, aTRH is related to a higher risk of vascular death and death from any cause. Moreover, patients with aTRH after a first cardiovascular event have a 6.4 year shorter median life expectancy free of recurrent cardiovascular disease.

Genotype-phenotype correlation in pseudoxanthoma elasticum

BACKGROUND AND AIMS

Pseudoxanthoma elasticum (PXE) is caused by variants in the ABCC6 gene. It results in calcification in the skin, peripheral arteries and the eyes, but has considerable phenotypic variability. We investigated the association between the ABCC6 genotype and calcification and clinical phenotypes in these different organs.

METHODS

ABCC6 sequencing was performed in 289 PXE patients. Genotypes were grouped as two truncating, mixed, or two non-truncating variants. Arterial calcification mass was quantified on whole body, low dose CT scans; and peripheral arterial disease was measured with the ankle brachial index after treadmill test. The presence of pseudoxanthoma in the skin was systematically scored. Ophthalmological phenotypes were the length of angioid streaks as a measure of Bruchs membrane calcification, the presence of choroidal neovascularizations, severity of macular atrophy and visual acuity. Regression models were built to test the age and sex adjusted genotype-phenotype association.

RESULTS

158 patients (median age 51 years) had two truncating variants, 96 (median age 54 years) a mixed genotype, 18 (median age 47 years) had two non-truncating variants. The mixed genotype was associated with lower peripheral (β: 0.39, 95%CI:-0.62;-0.17) and total (β: 0.28, 95%CI:-0.47;-0.10) arterial calcification mass scores, and lower prevalence of choroidal neovascularizations (OR: 0.41 95%CI:0.20; 0.83) compared to two truncating variants. No association with pseudoxanthomas was found.

CONCLUSIONS

PXE patients with a mixed genotype have less severe arterial and ophthalmological phenotypes than patients with two truncating variants in the ABCC6 gene. Research into environmental and genetic modifiers might provide further insights into the unexplained phenotypic variability.

The Natural History of Bruch’s Membrane Calcification in Pseudoxanthoma Elasticum

Purpose

To describe the natural history of Bruch’s membrane (BM) calcification in patients with pseudoxanthoma elasticum (PXE).

Design

Retrospective cohort study.

Participants

Both eyes of 120 PXE patients younger than 50 years, 78 of whom had follow-up imaging after more than 1 year.

Methods

All patients underwent multimodal imaging, including color fundus photography, near-infrared reflectance (NIR) imaging, and late phase indocyanine green angiography (ICGA). We determined the distance from the optic disc to the central and temporal border of peau d’orange on NIR, expressed in horizontal optic disc diameter (ODD). The length of the longest angioid streak was classified into 5 zones.

Main Outcome Measures

Age-specific changes of peau d’orange, angioid streaks, and ICGA hypofluorescence as surrogate markers for the extent of BM calcification.

Results

In cross-sectional analysis, longer angioid streaks were associated with increasing age (P < 0.001 for trend). The temporal border of peau d’orange showed a weak association with increasing age (β = 0.02; 95% confidence interval [CI], 0.00–0.04), whereas the central border showed a strong association (β = 0.12; 95% CI, 0.09–0.15). Longitudinal analysis revealed a median shift of the central border to the periphery of 0.08 ODD per year (interquartile range [IQR], 0.00–0.17; P < 0.001). This shift was more pronounced in patients younger than 20 years (0.12 ODD per year [IQR, 0.08–0.28]) than in patients older than 40 years (0.07 ODD per year [IQR, –0.05 to 0.15]). The temporal border did not shift during follow-up (P = 0.69). New or growing angioid streaks were detected in 39 of 156 eyes (25%). The hypofluorescent area on ICGA was visible only in the fourth or fifth decade and correlated with longer angioid streaks.

Conclusions

In PXE patients, the speckled BM calcification slowly confluences during life. The location of the temporal border of peau d’orange remains rather constant, whereas the central border shifts to the periphery. This suggests the presence of a predetermined area for BM calcification. A larger ICGA hypofluorescent area correlates with older age and longer angioid streaks, which implies that it depends on the degree of BM calcification.

Intracranial Arterial Calcification: Prevalence, Risk Factors, and Consequences: JACC Review Topic of the Week

Intracranial large and small arterial calcifications are a common incidental finding on computed tomography imaging in the general population. Here we provide an overview of the published reports on prevalence of intracranial arterial calcifications on computed tomography imaging and histopathology in relation to risk factors and clinical outcomes. We performed a systematic search in Medline, with a search filter using synonyms for computed tomography scanning, (histo)pathology, different intracranial arterial beds, and calcification. We found that intracranial calcifications are a frequent finding in all arterial beds with the highest prevalence in the intracranial internal carotid artery. In general, prevalence increases with age. Longitudinal studies on calcification progression and intervention studies are warranted to investigate the possible causal role of calcification on clinical outcomes. This might open up new therapeutic directions in stroke and dementia prevention and the maintenance of the healthy brain.

Adrenalectomy for Primary Aldosteronism: Significant Variability in Work-Up Strategies and Low Guideline Adherence in Worldwide Daily Clinical Practice

BACKGROUND

Various diagnostic tests are available to establish the primary aldosteronism (PA) diagnosis and to determine the disease laterality. Combined with the controversies in the literature, unawareness of guidelines and technical demands and high costs of some of these diagnostics, this could lead to significant differences in work-up strategies worldwide. Therefore, we investigated the work-up before surgery for PA in daily clinical practice within a multicenter study.

METHODS

Patients who underwent unilateral adrenalectomy for PA within 16 centers in Europe, Canada, Australia and the USA between 2010 and 2016 were included. We did not exclude patients based on the performed diagnostic tests during work-up to make our data representative for current clinical practice. Adherence to the Endocrine Society Guideline and variables associated with not performing adrenal venous sampling (AVS) were analyzed.

RESULTS

In total, 435 patients were eligible. An aldosterone-to-renin ratio, confirmatory test, computed tomography (CT), magnetic resonance imaging and AVS were performed in 82.9%, 32.9%, 86.9%, 17.0% and 65.3% of patients, respectively. A complete work-up, as recommended by the guideline, was performed in 13.1% of patients. Bilateral disease or normal adrenal anatomy on CT (OR 16.19; CI 3.50-74.99), smaller tumor size on CT (OR 0.06; CI 0.04-0.08) and presence of hypokalemia (OR 2.00; CI 1.19-3.32) were independently associated with performing AVS.

CONCLUSIONS

This study is the first to examine the daily clinical practice work-up of PA within a worldwide cohort of surgical patients. The results demonstrate significant variability in work-up strategies and low adherence to The Endocrine Society guideline.

Applicability of Blood Pressure-Lowering Drug Trials to Real-World Patients With Cardiovascular Disease

This study aimed to assess applicability of blood pressure-lowering drug trials to real-world secondary preventive care. We applied the eligibility criteria of the landmark blood pressure-lowering drug trials (EUROPA, PEACE, HOPE-peripheral arterial disease [PAD], PRoFESS, and PROGRESS) to patients with coronary artery disease (CAD; n=5155), peripheral arterial disease (PAD; n=1487), and cerebrovascular disease (n=2515) participating in the UCC-SMART cohort. Baseline differences according to trial eligibility were assessed. Differences in risk of all-cause mortality and a composite of cardiovascular death, myocardial infarction, and stroke (major adverse cardiovascular event) were calculated using Cox proportional hazard models, adjusted for age, sex, and cardiovascular risk factors. Seventy-five percent of UCC-SMART patients with CAD would have been eligible for EUROPA, 84% for PEACE, 59% of patients with PAD for HOPE-PAD, 17% of patients with cerebrovascular disease for PRoFESS, and 100% for PROGRESS. Eligible patients were older (average difference ranging 1.4-14.6 years across trials). Eligible patients with CAD were at lower risk of major adverse cardiovascular event after adjustment for age, sex, and cardiovascular risk factors in PEACE (hazard ratio, 0.65 [95% CI, 0.53-0.79]) and of mortality in both EUROPA (hazard ratio, 0.72 [95% CI, 0.62-0.82]) and PEACE (0.63 [95% CI, 0.51-0.78]). Adjusted mortality and major adverse cardiovascular event risks were not different between eligible and ineligible patients with PAD and cerebrovascular disease in HOPE-PAD, PRoFESS, and PROGRESS. The majority of real-world patients with CAD, PAD, or cerebrovascular disease would be eligible for landmark trials on blood pressure-lowering drugs. Patients with CAD ineligible for the EUROPA and PEACE trials are at higher adjusted mortality and major adverse cardiovascular event risks, which may limit applicability of their results to ineligible patients.

Trends in blood pressure-related outcomes after adrenalectomy in patients with primary aldosteronism: A systematic review

BACKGROUND

Decrease in blood pressure (BP) is the major goal of adrenalectomy for primary aldosteronism. Nevertheless, the optimal timing to assess these outcomes and the needed duration of follow-up are uncertain. We systematically reviewed the literature regarding trends in BP-related outcomes during follow-up after adrenalectomy.

METHODS

A systematic literature search of medical literature from PubMed, Embase and the Cochrane Library regarding BP-related outcomes (i.e. cure of hypertension rates, BP and antihypertensives) was performed. The Quality In Prognosis Studies risk of bias tool was used.

RESULTS

Of the 2057 identified records, 13 articles met the inclusion criteria. Overall study quality was low. In multiple studies, the biggest decrease in BP was shown within the first month(s) after adrenalectomy and afterwards BP often remained stable during long-term follow-up.

CONCLUSIONS

Based on the available studies one might suggest that long follow-up is unnecessary, since outcomes seem to stabilize within the first months.

Osteoarthritis in Pseudoxanthoma Elasticum Patients: An Explorative Imaging Study

Pseudoxanthoma elasticum (PXE) is a systemic disease affecting the skin, eyes, and cardiovascular system of patients. Cardiovascular disease is associated with osteoarthritis (OA), which is the most common cause of joint pain. There is a lack of systematic investigations on joint manifestations in PXE in the literature. In this explorative study, we aimed to investigate whether patients with PXE are more at risk for developing osseous signs of OA. Patients with PXE and hospital controls with whole-body low-dose CT examinations available were included. OA was assessed using the OsteoArthritis Computed Tomography (OACT)-score, which is a 4-point Likert scale, in the acromioclavicular (AC), glenohumeral (GH), facet, hip, knee, and ankle joints. Additionally, intervertebral disc degeneration was scored. Data were analyzed using ordinal logistic regression adjusted for age, body mass index (BMI), and smoking status. In total, 106 PXE patients (age 56 (48-64), 42% males, BMI 25.3 (22.7-28.2)) and 87 hospital controls (age 55 (43-67), 46% males, BMI 26.0 (22.5-29.2)) were included. PXE patients were more likely to have a higher OA score for the AC joints (OR 2.00 (1.12-3.61)), tibiofemoral joint (OR 2.63 (1.40-5.07)), and patellofemoral joint (2.22 (1.18-4.24)). For the other joints, the prevalence and severity of OA did not differ significantly. This study suggests that patients with PXE are more likely to have structural OA of the knee and AC joints, which needs clinical confirmation in larger groups and further investigation into the mechanism.

The Extent of Angioid Streaks Correlates With Macular Degeneration in Pseudoxanthoma Elasticum

PURPOSE

To investigate whether the extent of Bruch's membrane calcification is associated with choroidal neovascularization (CNV) and macular atrophy in patients with pseudoxanthoma elasticum (PXE) by using the extent of angioid streaks as a surrogate marker for the degree of Bruch's membrane calcification.

DESIGN

Retrospective cross-sectional study.

METHODS

We investigated 301 patients with PXE (median age, 52 years; range, 9-79 years) in a tertiary referral center. For both eyes, we graded the extent of angioid streaks, that is, their distance from the optic disc, into 5 groups. Imaging was systematically assessed for signs of CNV and macular atrophy. Associations between the extent of angioid streaks and CNV or macular atrophy were investigated using regression analysis.

RESULTS

CNV was present in 148 patients (49%) and retinal atrophy in 71 patients (24%). The extent of angioid streaks was associated with older age (P for trend = 1.92 × 10^-15) and a higher prevalence of CNV and/or macular atrophy (P for trend = 4.22 × 10^-10 and P for trend = 5.17 × 10^-6, respectively). In addition, the extent of angioid streaks was associated with the presence of CNV when adjusted for age and sex (odds ratio, 1.9; 95% confidence interval, 1.3-2.9) and with more severe macular atrophy (proportional odds ratio, 2.3; 95% confidence interval, 1.5-3.6).

CONCLUSIONS

In patients with PXE, longer angioid streaks are associated with an increased risk of CNV and macular atrophy, even after adjustment for age. These findings are relevant when counseling PXE patients on their visual prognosis.

Plasma Trough Concentrations of Antihypertensive Drugs for the Assessment of Treatment Adherence: A Meta-Analysis

Supplemental Digital Content is available in the text.

Biochemical drug screening by liquid chromatography-tandem mass spectrometry in plasma is an accurate method for the quantification of plasma concentrations of antihypertensive medications in patients with hypertension. Trough concentrations could possibly be used as drug-specific cutoff values in the biochemical assessment of (non-)adherence. We performed a literature review and meta-analysis of pharmacokinetic studies to determine plasma trough concentrations of amlodipine, hydrochlorothiazide, and valsartan. PubMed was searched for pharmacokinetic studies up to September 2020. Eligible studies reported steady-state mean trough concentration and their variance. Pooled trough concentrations were estimated using a three-level random effects meta-analytic model. Moderator analyses were performed to explore sources of heterogeneity. One thousand three hundred eighteen potentially relevant articles were identified of which 45 were eligible for inclusion. The pooled mean trough concentration was 9.2 ng/mL (95% CI, 7.5–10.8) for amlodipine, 41.0 ng/mL (95% CI, 17.4–64.7) for hydrochlorothiazide, and 352.9 ng/mL (95% CI, 243.5–462.3) for valsartan. Substantial heterogeneity was present for all 3 pooled estimates. Moderator analyses identified dosage as a significant moderator for the pooled trough concentration of amlodipine (β₁=0.9; P<0.05), mean age, and mean body weight for the mean trough concentration of hydrochlorothiazide (β₁=2.2, P<0.05, respectively, β₁=−4.0, P<0.05) and no significant moderators for valsartan. Plasma trough concentrations of amlodipine, hydrochlorothiazide, and valsartan, measured with liquid chromatography-tandem mass spectrometry, are highly heterogeneous over the different studies. Use of the pooled trough concentration as a cutoff in the biochemical assessment of adherence can result in inaccurate diagnosis of (non-)adherence, which may seriously harm the patient-physician relationship, and is therefore not recommended.

Plasma trough concentrations of antihypertensive drugs for the assessment of treatment adherence: a meta-analysis

Background

Non-adherence to antihypertensive drugs is an important behavioral contributor to poor blood pressure control and is associated with increased risk of cardiovascular disease, hospitalization and increased healthcare costs. Biochemical drug screening in plasma is an accurate method for the detection of non-adherence. When performed qualitatively (present/not present) this method may lead to overestimation of adherence to drugs with long half-lives. Detection of non-adherence may be improved by performing it quantitatively (measurement of exact concentrations) making use of reliable, drug-specific cut-off values based on exposure parameters in plasma.

Purpose

To perform a literature review and meta-analysis of pharmacokinetic studies to determine plasma population trough concentrations of three frequently prescribed antihypertensive drugs with different pharmacological properties; amlodipine, hydrochlorothiazide and valsartan. These population trough concentrations could possibly be used as drug-specific cut-off values for the diagnosis of (non-)adherence.

Methods

PubMed was searched for pharmacokinetic studies regarding amlodipine, hydrochlorothiazide and valsartan up to December 2019. Eligible studies reported steady-state mean trough concentration estimates and their variance measured in healthy subjects or in patients with hypertension without hepatic or renal failure. Pooled trough concentrations were estimated using a DerSimonian and Laird random-effect approach. To take dependency between mean trough concentrations into account a multilevel meta-analysis was performed. Meta-regression was used to explore sources of heterogeneity identified by the I2 statistic.

Results

The literature search identified 1154 potentially relevant articles of which 44 were eligible for inclusion; 23 for amlodipine, 10 for hydrochlorothiazide and 11 for valsartan. The overall pooled mean trough concentration estimate was 9.3 ng/ml (95% confidence interval: 8.4–10.2) for amlodipine, 29.4 ng/ml (24.4–43.3) for hydrochlorothiazide and 355.4 ng/ml (294.1–416.6) for valsartan (figure 1A-C). Substantial heterogeneity was present for all three pooled estimates (I2 &gt;90%). Based on meta-regression 33.3%, 20.3% and 8.2% of the heterogeneity between the studies can be explained by differences in dose for amlodipine, hydrochlorothiazide and valsartan, respectively.

Conclusions

Plasma trough concentrations of amlodipine, hydrochlorothiazide and valsartan are highly heterogeneous over the different study populations. This heterogeneity is caused, at least in part, by differences in drug dose. Use of the pooled trough concentration mean estimate as a cut-off in the biochemical assessment of adherence can result in inaccurate diagnosis of (non-)adherence and should therefore be implemented with caution. Future research might focus on combining drug specific pharmacokinetics with individual patient characteristics to predict personalized trough concentrations.

Figure 1

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): UMC Utrecht

Apparent resistant hypertension and the risk of recurrent cardiovascular events and mortality after a first manifestation of vascular disease

Background

Previous studies have shown that patients with resistant hypertension carry a higher risk of developing cardiovascular disease than patients with non-resistant hypertension. However, little is known about the prognosis of apparent resistant hypertension in patients with symptomatic vascular disease.

Purpose

The aim of this study was to examine the relation between different stages of hypertension and the risk of recurrent cardiovascular events and mortality in a cohort of hypertensive patients with symptomatic vascular disease.

Methods

Hypertensive patients (n=7280) with symptomatic vascular disease (cerebrovascular disease, coronary heart disease, peripheral artery disease or abdominal aortic aneurysm) were included from the ongoing SMART cohort between 1996 and 2018. Patients were classified into three groups according to baseline office blood pressure (BP): controlled (BP &lt;140/90 mmHg and a hypertension diagnosis or on 1 to 3 antihypertensive drugs), uncontrolled (BP ≥140/90 mmHg on ≤2 drugs) and apparent resistant (BP ≥140/90 mmHg despite treatment with three or more antihypertensive drugs including a diuretic or treatment with four or more antihypertensive medications irrespective of BP status). Cox proportional hazard models were used to quantify the relation between the different stages of hypertension and the risk of recurrent major adverse cardiovascular events (MACE including stroke, myocardial infarction and vascular death) and death from any cause. Models were adjusted for age, sex, current smoking, body mass index, renal function and diabetes. In addition, survival according to the different stages of hypertension was plotted, taking competing risk of non-vascular mortality into account by using the Fine and Gray method.

Results

In total 3123 patients (43%) had controlled hypertension, 3354 patients (46%) had uncontrolled hypertension and 803 (11%) had apparent resistant hypertension. A total of 1498 MACE and 1762 deaths occurred in 64,469 person-years (median follow-up of 8.6 years, IQR 4.6–12.7 years). Compared to patients with controlled hypertension patients with apparent resistant hypertension were at increased risk of recurrent MACE (HR 1.32; 95% CI 1.11–1.58) and death from any cause (HR 1.46; 95% CI 1.25–1.72). At the age of 60 years, patients with apparent resistant hypertension after a first cardiovascular event on average had a recurrent cardiovascular event 10 years earlier than patients with controlled or uncontrolled hypertension (Figure 1).

Conclusions

Irrespective of age at first cardiovascular event, apparent resistant hypertension is related to a higher risk of recurrent vascular events and death from any cause. These findings support the need for greater efforts toward improving blood pressure control and treatment of other cardiovascular risk factors among patients with apparent resistant hypertension.

Figure 1

Funding Acknowledgement

Type of funding source: Private hospital(s). Main funding source(s): UMC Utrecht

External applicability of blood pressure-lowering drug trials to real-world patients with manifest cardiovascular disease

Background

Randomised controlled trials (RCTs) are the main source of evidence for clinical treatment guidelines. However, there are concerns that strict eligibility criteria for participant selection may limit applicability of trial results to real-world patients.

Purpose

To assess the applicability of blood pressure-lowering drug trials in real-world secondary preventive care in stable coronary artery disease, peripheral artery disease and cerebrovascular disease.

Methods

Eligibility criteria from the largest guideline-informing RCTs on blood pressure-lowering drugs, the EUROPA, PEACE, HOPE-PAD, PRoFESS and PROGRESS trials, were applied to three subcohorts within the UCC-SMART study with coronary artery disease (n=5155), peripheral artery disease (n=1487) and cerebrovascular disease (n=2515). Baseline differences between would-be trial eligible and ineligible patients were estimated. Differences in all-cause mortality and a composite major adverse cardiovascular event (MACE) outcome of cardiovascular death, myocardial infarction and stroke were calculated and adjusted for age, sex and cardiovascular risk factors using Cox proportional hazard models.

Results

Seventy-five percent of UCC-SMART patients with the appropriate cardiovascular disease were eligible for EUROPA, 84% for PEACE, 59% for HOPE-PAD, 17% for PRoFESS and 100% for PROGRESS. Across trials, the main reasons for UCC-SMART patients' ineligibility were age younger than 50 or 55 years and cardiovascular history. On average, eligible patients were older (range 1.4–14.6 years across trials). Incidence rates for all-cause mortality and MACE were higher for trial eligible patients (Figure 1). After adjustment for age and sex, EUROPA and PEACE eligible patients had a lower risk of mortality (EUROPA: hazard ratio (HR) 0.68 95% confidence interval (CI) 0.59–0.77, PEACE: HR 0.52 95% CI 0.43–0.64) and MACE (EUROPA: HR 0.88 95% CI 0.76–1.01, PEACE: 0.56 95% CI 0.46–0.69), while differences between HOPE-PAD and PRoFESS eligible and ineligible patients were not statistically significant.

Conclusion

The results from the landmark trials on blood pressure-lowering drugs, specifically RAASi, in patients with peripheral artery and cerebrovascular disease are widely applicable to real-world patient populations. Although the majority of coronary artery disease patients is eligible for the EUROPA and PEACE trial, the results of these trials should be applied to trial ineligible patients with caution.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): UMC Utrecht

The effect of etidronate on choroidal neovascular activity in patients with pseudoxanthoma elasticum

Aim

To assess the effect of the bisphosphonate etidronate on choroidal neovascular (CNV) activity in patients with pseudoxanthoma elasticum (PXE).

Methods

This is an ancillary study in a single center, randomized, double-blind placebo-controlled trial (RCT) in which 74 patients with PXE were assigned to either one-year etidronate or placebo treatment. Spectral domain optical coherence tomography (SD-OCT) imaging and color fundus photography were performed every three months for one year and were systematically assessed on signs of CNV activity.

Results

In the etidronate group, 11 (30%) of the patients had CNV activity at baseline, compared to 25 (67%) of the patients in the placebo group (P = 0.005). The proportion of eyes with CNV activity during the study ranged from 18–33% in the etidronate group and 42–56% in the placebo group and no significant difference in improvement or worsening of CNV activity was found (P = 0.168). Using a generalized mixed model for repeated measures, there was a protective effect of etidronate in crude analysis (RR 0.86, 95% CI 0.75–0.98) that disappeared when adjusting for baseline CNV activity (RR 0.97, 95% CI 0.84–1.13).

Conclusion

In this post-hoc RCT analysis we did not observe a protecting or deteriorating effect of etidronate on CNV activity in patients with PXE after adjustment for baseline CNV.

New diagnostic and treatment strategies in renal artery stenosis: a promising pursuit or disappointment foretold?

Clinical management of renal artery stenosis has seen a major shift, after randomised clinical trials have shown no group benefit of endovascular intervention relative to optimal medical control. However, the inclusion criteria of these trials have been criticised for focusing on a subset of patients with atherosclerotic renal artery stenosis where intervention was unlikely to be beneficial. Moreover, new imaging and computational techniques have become available, which have the potential to improve identification of patients that will respond to interventional treatment. This review addresses the challenges associated with clinical decision making in patients with renal artery stenosis. Opportunities for novel diagnostic techniques to improve patient selection are discussed, along with ongoing Dutch studies and network initiatives that investigate these strategies.

Increased Elastin Degradation in Pseudoxanthoma Elasticum Is Associated with Peripheral Arterial Disease Independent of Calcification

Pseudoxanthoma elasticum (PXE) results in extensive fragmentation and calcification of elastin fibers in the peripheral arteries, which results in peripheral arterial disease (PAD). Current research focuses on the role of calcifications in the pathogenesis of PXE. Elastin degradation and calcification are shown to interact and may amplify each other. This study aims to compare plasma desmosines, a measure of elastin degradation, between PXE patients and controls and to investigate the association between desmosines and (1) arterial calcification, (2) PAD, and (3) PAD independent of arterial calcification in PXE. Plasma desmosines were quantified with liquid chromatography-tandem mass spectrometry in 93 PXE patients and 72 controls. In PXE patients, arterial calcification mass was quantified on CT scans. The ankle brachial index (ABI) after treadmill test was used to analyze PAD, defined as ABI < 0.9, and the Fontaine classification was used to distinguish symptomatic and asymptomatic PAD. Regression models were built to test the association between desmosines and arterial calcification and arterial functioning in PXE. PXE patients had higher desmosines than controls (350 (290–410) ng/L vs. 320 (280–360) ng/L, p = 0.02). After adjustment for age, sex, body mass index, smoking, type 2 diabetes mellitus, and pulmonary abnormalities, desmosines were associated with worse ABI (β (95%CI): −68 (−132; −3) ng/L), more PAD (β (95%CI): 40 (7; 73) ng/L), and higher Fontaine classification (β (95%CI): 30 (6; 53) ng/L), but not with arterial calcification mass. Lower ABI was associated with higher desmosines, independent from arterial calcification mass (β (95%CI): −0.71(−1.39; −0.01)). Elastin degradation is accelerated in PXE patients compared to controls. The association between desmosines and ABI emphasizes the role of elastin degradation in PAD in PXE. Our results suggest that both elastin degradation and arterial calcification independently contribute to PAD in PXE.

Is arterial stiffness in the carotid artery associated with choroidal thinning in patients with pseudoxanthoma elasticum or controls?

PURPOSE

Patients with pseudoxanthoma elasticum (PXE) develop calcification of Bruch's membrane (BM) and choroidal thinning, as well as calcification of intracranial arteries, leading to arterial stiffness. We investigated whether arterial stiffness is associated with choroidal thinning in PXE patients, besides the presumed effect of BM calcification.

METHODS

Cross-sectional study with 75 PXE patients and 40 controls. Macular choroidal thickness was measured using optical coherence tomography scans. Functional magnetic resonance imaging was used to calculate the pulsatility index (PI) of the carotid siphon as a measure of arterial stiffness. Associations between PI and choroidal thickness were investigated using linear mixed effects models adjusted for age and ocular axial length. Furthermore, we investigated choroidal thickness in relation to the presence of retinal pigment epithelium (RPE) atrophy, its topographical distribution and age.

RESULTS

Median age was 58 years (IQR 53-66) in PXE patients and 62 years (IQR 56-67) in controls (p = 0.08). Pseudoxanthoma elasticum (PXE) patients had a thinner choroid than controls (138 μm versus 248 μm, p < 0.01). No association was observed between PI and choroidal thickness in PXE patients (β = -1.6, 95% CI -59.4 to 54.5) nor in controls (β =-47.6, 95% CI -129.7 to 31.9). In PXE patients, RPE atrophy was associated with a thinner choroid (p < 0.01). Also, the nasal choroid was thinner than the temporal choroid, and choroidal thickness already decreased with age in PXE eyes without RPE atrophy.

CONCLUSION

There was no independent association between measures of arterial stiffness and choroidal thinning in PXE patients and controls. Probably, changes in BM lead to choroidal thinning in PXE.

A Reflectivity Measure to Quantify Bruch's Membrane Calcification in Patients with Pseudoxanthoma Elasticum Using Optical Coherence Tomography

Purpose

Progressive calcification of Bruch's membrane (BM) causes considerable visual morbidity in patients with pseudoxanthoma elasticum (PXE). Since calcification is hyperreflective on optical coherence tomography (OCT), our aim was to measure BM calcification with OCT imaging.

Methods

Case-control study with 45 patients with PXE under 40 years (range, 11-39) and 25 controls (range, 14-39). Spectralis HRA-OCT imaging consisted of seven macular B-scans with 250-µm spacing. Retinal segmentation was performed with the IOWA Reference Algorithms. MATLAB was used to extract and average z-axis reflectivity profiles. Layer reflectivities were normalized to the ganglion cell and inner plexiform layers. Both median and peak layer reflectivities were compared between patients with PXE and controls. The discriminative value of the retinal pigment epithelium (RPE)-BM peak reflectivity was analyzed using receiver operating characteristic analysis.

Results

The reflectivity profile of patients with PXE differed from controls in the outer retinal layers. The normalized median RPE-BM reflectivity was 41.1 (interquartile range [IQR], 26.3-51.9) in patients with PXE, compared with 22.5 (IQR, 19.3-29.5) in controls (P = 2.09 × 10^-3). The normalized RPE-BM peak reflectivity was higher in patients with PXE (67.5; IQR, 42.1-84.2) than in controls (32.7; IQR, 25.7-38.9; P = 2.43 × 10^-5) and had a high discriminative value with an area under the curve of 0.85 (95% confidence interval, 0.76-0.95). In patients with PXE under 40 years, increasing age did not have a statistically significant effect on the RPE-BM peak reflectivity (patients under 20 years: 44.2 [IQR, 40.5-74.6]; 20-30 years: 66.0 [IQR, 45.1-83.8]; 30-40 years: 70.8 [IQR, 49.0-88.0], P = 0.47).

Conclusions

BM calcification can be measured as increased RPE-BM reflectivity in young patients with PXE and has a high discriminative value.

Translational Relevance

In patients with PXE, the OCT reflectivity of Bruch's membrane may be the first biomarker for Bruch's membrane calcification and a valuable ophthalmologic endpoint in clinical trials.

Intimal and medial calcification in relation to cardiovascular risk factors

Purpose

To assess specific risk factors and biomarkers associated with intimal arterial calcification (IAC) and medial arterial calcification (MAC).

Methods

We conducted a cross-sectional study in patients with or at risk of vascular disease from the SMART study(n = 520) and the DCS cohort(n = 198). Non-contrast computed tomography scanning of the lower extremities was performed and calcification in the femoral and crural arteries was scored as absent, predominant IAC, predominant MAC or indistinguishable. Multinomial regression models were used to assess the associations between cardiovascular risk factors and calcification patterns. Biomarkers for inflammation, calcification and vitamin K status were measured in a subset of patients with IAC(n = 151) and MAC(n = 151).

Results

Femoral calcification was found in 77% of the participants, of whom 38% had IAC, 28% had MAC and 11% were scored as indistinguishable. The absolute agreement between the femoral and crural arteries was high(69%). Higher age, male sex, statin use and history of coronary artery disease were associated with higher prevalences of femoral IAC and MAC compared to absence of calcification. Smoking and low ankle-brachial-index (ABI) were associated with higher prevalence of IAC and high ABI was associated with less IAC. Compared to patients with IAC, patients with MAC more often had diabetes, have a high ABI and were less often smokers. Inactive Matrix-Gla Protein was associated with increased MAC prevalence, while osteonectin was associated with decreased risk of MAC, compared to IAC.

Conclusions

When femoral calcification is present, the majority of the patients have IAC or MAC throughout the lower extremity, which have different associated risk factor profiles.