Etidronate halts systemic arterial calcification in pseudoxanthoma elasticum.

BACKGROUND AND AIMS: In pseudoxanthoma elasticum (PXE), low levels of inorganic pyrophosphate result in extensive arterial calcification. Recently, the treatment of ectopic mineralization in the PXE (TEMP) trial showed that one year of treatment with etidronate halts progression of femoral artery calcification in PXE patients. The aim of this study was to test the efficacy of etidronate on calcification in different vascular beds. METHODS: In this prespecified post-hoc analysis of the TEMP trial, arterial calcification mass was quantified in the carotid siphon, common carotid artery, thoracic and abdominal aorta, coronary arteries, iliac arteries, and the femoropopliteal and crural arteries using CT at baseline and after one year of etidronate treatment or placebo. In addition, a total arterial calcification score was calculated. The difference in calcification progression was compared between the etidronate and placebo group. RESULTS: 74 PXE patients were enrolled and randomized. Etidronate significantly halted progression of calcification in all vascular beds except for the coronary arteries. For the total arterial calcification score, the median absolute increase in mass score was -63.6 (-438.4-42.2) vs. 113.7 (9.4-377.1) (p < 0.01) and the median relative increase was -2.4% (-10.3-3.8) vs. 6.3% (0.2-15.8) (p < 0.01) in the etidronate and placebo arm, respectively. CONCLUSIONS: Etidronate treatment halts systemic arterial calcification in PXE. Further research must assess the long term safety and efficacy of etidronate on clinical outcomes in PXE.

The prevalence of pseudoxanthoma elasticum: Revised estimations based on genotyping in a high vascular risk cohort.

BACKGROUND: Pseudoxanthoma elasticum (PXE), an autosomal recessive systemic calcification disorder, is caused by mutations in the ABCC6-gene and associated with severe visual impairment and peripheral arterial disease. Given the progress in development of a therapy for PXE, more precise estimations of its prevalence are warranted. METHODS: We genotyped the four most common ABCC6 mutations (c.3421C > T, c.4182delG, c.3775delT, c.2787+1G > T), together accounting for half of all ABCC6 mutations identified in PXE patients from the Dutch population, in a Dutch high vascular risk cohort (n = 7893). The obtained allele frequencies were used to estimate the prevalence of PXE using the Hardy-Weinberg equilibrium. RESULTS: The carrier frequency of ABCC6 was 0.60% for c.3421C > T, 0.17% for c.4182delG, 0.05% for c.3775delT and 0.03% for c.2787+1G > T. The prevalence of PXE based upon the allele frequencies of these four mutations was estimated as 1 per 56,000 (95%CI 1 per 35,000-97,000). CONCLUSION: The prevalence of PXE is at least 1 per 56,000 meaning that there would be at least 307 affected individuals in the Netherlands that may benefit from a potential upcoming treatment. Since this estimate is based on mutations together accounting for half of all ABCC6 mutations identified among PXE patients, the actual prevalence will probably be higher.

The amount of calcifications in pseudoxanthoma elasticum patients is underestimated in computed tomographic imaging; a post-mortem correlation of histological and computed tomographic findings in two cases.

OBJECTIVES: Pseudoxanthoma elasticum (PXE) is a rare genetic disorder, characterised by elastic fibre degeneration and calcifications in multiple organ systems. Computed tomography (CT) imaging is a potential method to monitor disease progression in PXE patients; however, this method has not been validated. The aim of this study was to correlate histological and computed tomographic findings in PXE patients to investigate the ability of CT scanning to detect these alterations. METHODS: Post mortem total body CT scans were obtained from two PXE patients (a 69-year-old male and 77-year-old female). Autopsy was performed, and 38 tissue samples of the first and 45 tissue samples of the second patient were extensively investigated histologically. The findings were compared with the CT scans. RESULTS: Degenerated and calcified elastic fibres and calcifications were histologically found in the skin, subcutaneous fat, heart, arteries and pleura and around the oesophagus. On CT imaging only the intradermal alterations of the skin and the larger vascular calcifications were detected. The smaller PXE-related abnormalities were not visible on CT. CONCLUSIONS: With CT imaging vascular calcifications and skin alterations can be monitored in PXE patients. However, many of the subtle PXE-related abnormalities found in other organ systems during the autopsy were not visualised by CT scans. Furthermore, we extended the current knowledge on the disease location of PXE with subcutaneous, oesophageal and pleural lesions. TEACHING POINTS: • CT can be used to monitor gross vascular calcifications in PXE patients. • Many subtle PXE-related abnormalities are not visualised by CT scans. • PXE-related alterations can also be found in oesophagus, pleura and subcutaneous fat.

Etidronate for Prevention of Ectopic Mineralization in Patients With Pseudoxanthoma Elasticum.

BACKGROUND: In pseudoxanthoma elasticum (PXE), low pyrophosphate levels may cause ectopic mineralization, leading to skin changes, visual impairment, and peripheral arterial disease. OBJECTIVES: The authors hypothesized that etidronate, a pyrophosphate analog, might reduce ectopic mineralization in PXE. METHODS: In the Treatment of Ectopic Mineralization in Pseudoxanthoma Elasticum trial, adults with PXE and leg arterial calcifications (n = 74) were randomly assigned to etidronate or placebo (cyclical 20 mg/kg for 2 weeks every 12 weeks). The primary outcome was ectopic mineralization, quantified with 18fluoride positron emission tomography scans as femoral arterial wall target-to-background ratios (TBRfemoral). Secondary outcomes were computed tomography arterial calcification and ophthalmological changes. Safety outcomes were bone density, serum calcium, and phosphate. RESULTS: During 12 months of follow-up, the TBRfemoral increased 6% (interquartile range [IQR]: -12% to 25%) in the etidronate group and 7% (IQR: -9% to 32%) in the placebo group (p = 0.465). Arterial calcification decreased 4% (IQR: -11% to 7%) in the etidronate group and increased 8% (IQR: -1% to 20%) in the placebo group (p = 0.001). Etidronate treatment was associated with significantly fewer subretinal neovascularization events (1 vs. 9, p = 0.007). Bone density decreased 4% ± 12% in the etidronate group and 6% ± 9% in the placebo group (p = 0.374). Hypocalcemia (<2.20 mmol/l) occurred in 3 versus 1 patient (8.1% vs. 2.7%, p = 0.304). Eighteen patients (48.6%) treated with etidronate, compared with 0 patients treated with placebo (p < 0.001), experienced hyperphosphatemia (>1.5 mmol/l) and recovered spontaneously. CONCLUSIONS: In patients with PXE, etidronate reduced arterial calcification and subretinal neovascularization events but did not lower femoral 18fluoride sodium positron emission tomography activity compared with placebo, without important safety issues. (Treatment of Ectopic Mineralization in Pseudoxanthoma elasticum; NTR5180).

Arterial stiffening and thickening in patients with pseudoxanthoma elasticum.

BACKGROUND AND AIMS: Patients with pseudoxanthoma elasticum (PXE), a monogenetic calcification disease, are at high vascular risk. Although the precise arterial phenotype remains unestablished, it is hypothesized that PXE predominantly affects the medial arterial layer leading to arterial stiffening. We aimed to test this hypothesis by measuring arterial wall characteristics in PXE and comparisons with the general population and diabetes mellitus type 2 (DM2), a condition typically associated with mixed intimal and medial arterial disease. METHODS: Extensive arterial wall characterization was performed in 203 PXE patients involving intima-media thickness (IMT), pulse wave velocity (PWV) and pulse pressure (PP) measurements. IMT and PWV in PXE were compared with the general population using age, sex and mean arterial pressure corrected values for each PXE patient. IMT and PP were compared between PXE and DM2 independently of sex, age and systolic blood pressure, using data of DM2 patients (n = 1033) from the Second Manifestations of ARTerial disease (SMART) cohort. RESULTS: PXE patients had significantly higher IMT (mean difference 0.09 mm; 95% CI 0.07-0.12 mm) and PWV (mean difference 2.5 m/s; 95% CI 1.9-3.0 m/s) compared to the general population. IMT in PXE was lower compared to DM2 (0.72 mm; 95% CI 0.68-0.75 mm vs. 0.85 mm; 95% CI 0.83-0.87 mm, p-value<0.01), whereas PP in PXE was higher compared to DM2 (60 mmHg; 95% CI 59-62 vs. 57 mmHg; 95% CI 57-58 mmHg, p-value<0.01). CONCLUSIONS: PXE patients have thicker arterial walls than the general population, but thinner arterial walls than DM2 patients at similar age. Arterial stiffening is more pronounced in PXE patients compared to DM2 patients.

Inter-arm systolic blood pressure differences, relations with future vascular events and mortality in patients with and without manifest vascular disease.

BACKGROUND: Inter-arm systolic blood pressure difference (SBPD) is an easily obtained patient characteristic which relates to vascular disease. We aimed to identify determinants of large inter-arm SBPD and to investigate the relation between inter-arm SBPD and vascular events in patients with and without manifest vascular disease. METHODS: In a cohort of 7344 patients with manifest vascular disease or vascular risk factors alone enrolled in the Second Manifestations of ARTerial disease (SMART) study, single bilateral non-simultaneous blood pressure measurements were performed. Logistic and Cox regression was used to identify determinants of large inter-arm SBPD (≥15mmHg) and to investigate the relation between inter-arm SBPD and vascular events (composite of non-fatal myocardial infarction, stroke, and vascular mortality) and all-cause mortality. RESULTS: In all patients the median inter-arm SBPD was 7mmHg (IQR 3-11) and 1182 (16%) patients had inter-arm SBPD ≥15mmHg. Higher age, higher systolic blood pressure, diabetes mellitus, peripheral artery disease, carotid artery stenosis, higher carotid intima-media thickness, and lower ankle-brachial indices were related to large inter-arm SBPD (≥15mmHg). Each 5mmHg increase in inter-arm SBPD was related to a 12% higher risk of vascular events in patients without manifest vascular disease (HR 1.12; 95% CI 1.00-1.27), whereas no relation was apparent in patients with manifest vascular disease (HR 0.98; 95% CI 0.93-1.04, interaction p-value 0.036). Inter-arm SBPD was not related to all-cause mortality (HR 1.05; 95% CI 0.93-1.19). CONCLUSIONS: Inter-arm SBPD relates to a higher risk of vascular events in patients without manifest vascular disease, whereas this relation is not apparent in patients with manifest vascular disease.

Cerebral disease in a nationwide Dutch pseudoxanthoma elasticum cohort with a systematic review of the literature.

BACKGROUND: Pseudoxanthoma elasticum (PXE) is a monogenetic disease with progressive calcification of arteries and potential risk of stroke. To gain insights in the cerebral involvement in PXE, we evaluated prevalence and determinants of cerebral disease in our PXE cohort and performed a systematic review of literature. METHODS: Systematic history taking concerning cerebral disorders was performed in our PXE cohort. Cardiovascular risk factors were compared between PXE patients with and without cerebral disease. Additionally, Pubmed, Embase, the Cochrane Library and PsycINFO were systematically reviewed for studies published up to August 2016 about cerebral disease in PXE. RESULTS: Of the 178 PXE patients 31 (17%) had cerebral disease including ischemic stroke (n=15, 8%) or transient ischemic attack (n=13, 7%). The cerebral disease group was older (61±12 vs. 52±15years, adjusted p=0.004) and had less favorable profiles of traditional cardiovascular risk factors regarding the use of lipid lowering medication (61% vs. 31%, adjusted p=0.037) and levels of HDL-cholesterol (1.4±0.3 vs. 1.6±0.4mmol/L, adjusted p=0.005). One prospective cohort study reporting an incidence rate of ischemic stroke of 477/100,000/year and two cross-sectional studies with a reported prevalence of ischemic stroke of 14% and 0% were identified. Furthermore, 53 unique cases of cerebral disease in PXE including ischemic stroke (n=16) and transient ischemic attack (n=7) were reported. CONCLUSIONS: Physicians and patients should be aware of the prevalent occurrence of cerebrovascular disease in PXE, which further stresses the importance of strict cardiovascular risk management in these patients.

Prevalence and severity of arterial calcifications in pseudoxanthoma elasticum (PXE) compared to hospital controls. Novel insights into the vascular phenotype of PXE.

BACKGROUND AND AIMS: Pseudoxanthoma elasticum (PXE) is a monogenetic disorder with progressive calcifications of the skin, the Bruch's membrane in the eyes and the arterial wall. Vascular disease is considered to be very prevalent, but the whole-body distribution of arterial calcifications in PXE is unknown. We aimed to systematically investigate arterial calcifications in PXE. METHODS: We included 104 PXE patients from the Dutch PXE cohort and 93 hospital controls. All subjects underwent full-body low-dose CT scans without contrast. To investigate the prevalence and severity of arterial calcification per arterial location, CT scans were scored using a reproducible semi-quantitative scale with four calcification categories (interobserver kappa 0.54-0.99). RESULTS: PXE patients (38/104 males) were 54 ± 13 years and controls (45/93 males) 54 ± 16 years old. Arterial calcifications were significantly more common in PXE patients in the intracranial internal carotid artery (75% vs. 44%), the arteries of the arms (20% vs. 3%), the femoral-popliteal arteries (74% vs. 44%) and the subpopliteal arteries (84% vs. 38%). In these arteries, calcification scores also indicated more severe calcification. No significant differences in prevalence of arterial calcification were observed in other arterial beds such as the coronary arteries (45% vs. 43%, p = 0.776), the carotid arteries (52% vs. 46%, p = 0.476) and the abdominal aorta (71% vs. 63%, p = 0.287). Analyses using patients younger than 55 years only, showed similar differences in prevalence of arterial calcifications between PXE patients and controls, with most pronounced calcifications in the arteries of the lower legs (67% vs. 8%). Similar patterns were observed in those without concomitant diabetes or renal dysfunction. CONCLUSIONS: In PXE, a vascular phenotype can be identified with a distribution of arterial calcifications that is clearly distinct from hospital controls and involves arterial calcifications in the legs, the intracranial internal carotid arteries and the arteries of the arms.

Bisphosphonates for cardiovascular risk reduction: A systematic review and meta-analysis.

BACKGROUND AND AIMS: Bisphosphonates might be effective in reducing cardiovascular events due to their ability to reduce calcification in arterial walls. We aimed to investigate the effects of treatment with bisphosphonates on the prevention of atherosclerotic processes and cardiovascular disease. METHODS: Pubmed, Embase and the Cochrane Library were systematically reviewed by two independent investigators for randomized controlled studies published up to January 2016, in which the effect of bisphosphonates on arterial wall disease, cardiovascular events, cardiovascular mortality or all-cause mortality were reported. There was no restriction for the type of population used in the trials. Random-effects models were used to calculate the pooled estimates. RESULTS: 61 trials reporting the effects of bisphosphonates on the outcomes of interest were included. Bisphosphonates had beneficial effects on arterial wall disease regarding arterial calcification (pooled mean percentage difference of 2 trials -11.52 (95% CI -16.51 to -6.52, p < 0.01, I(2) 13%), but not on arterial stiffness (pooled mean percentage difference of 2 trials -2.82; 95% CI -10.71-5.07; p = 0.48, I(2) 59%). No effect of bisphosphonate treatment on cardiovascular events was found (pooled RR of 20 trials 1.03; 95% CI 0.91-1.17, I(2) 16%), while a lower risk for cardiovascular mortality was observed in patients treated with bisphosphonates (pooled RR of 10 trials 0.81; 95% CI 0.64-1.02; I(2) 0%) although not statistically significant. Patients treated with bisphosphonates had a reduced risk of all-cause mortality (pooled RR of 48 trials 0.90; 95% CI 0.84-0.98; I(2) 53%). CONCLUSIONS: In this systematic review and meta-analysis it is shown that bisphosphonates reduce arterial wall calcification but have no effect on arterial stiffness or on cardiovascular events. Bisphosphonates tend to reduce the risk of cardiovascular mortality and reduce all-cause mortality in various patient groups, including osteoporosis and cancer patients.

The relation between HbA1c and cardiovascular events in patients with type 2 diabetes with and without vascular disease.

OBJECTIVE: Poor glycemic control is related to vascular events in patients with type 2 diabetes, but the presence of vascular disease might influence this relation. We evaluated the relation between glycemic control (HbA1c level) and new cardiovascular events and mortality in patients with type 2 diabetes, with and without vascular disease. RESEARCH DESIGN AND METHODS: In a cohort of 1,687 patients with type 2 diabetes enrolled in the Second Manifestations of Arterial Disease (SMART) study, the continuous relation between HbA1c and cardiovascular events (composite of myocardial infarction, stroke, and vascular mortality) and all-cause mortality was evaluated with Cox proportional hazard analyses stratified for the presence of vascular disease. RESULTS: During a median follow-up time of 6.1 years (interquartile range 3.1-9.5 years), a new cardiovascular event developed in 293 patients and 340 patients died. In all patients, the hazard ratio (HR) of the relation between HbA1c level and cardiovascular events was 1.06 (95% CI 0.97-1.17). A 1 percentage point higher HbA1c level was related to a 27% higher risk of a cardiovascular event in patients with type 2 diabetes without vascular disease (HR 1.27 [95% CI 1.06-1.51]), but not in patients with vascular disease (HR 1.03 [95% CI 0.93-1.15], P for interaction = 0.195). A 1 percentage point higher HbA1c level was related to a 16% higher risk of death (HR 1.16 [95% CI 1.06-1.28]) in patients with vascular disease and a nonsignificant 13% higher risk of all-cause mortality (HR 1.13 [95% CI 0.97-1.31]) in patients without vascular disease. CONCLUSIONS: In patients with type 2 diabetes, there is a modest, but not statistically significant, relation between HbA1c level and cardiovascular events, and, as there was no statistically significant interaction, this relation was not different for patients with or without clinical manifestation of vascular disease.

Mortality after cardiac surgery in patients with liver cirrhosis classified by the Child-Pugh score.

Liver cirrhosis is a known risk factor for postoperative mortality in patients undergoing cardiac surgery. Clinical assessment of liver cirrhosis using the widely accepted Child-Pugh (CP) score is thus vital for evaluation of surgical options and perioperative care. However, detailed mortality rates as a consequence of liver cirrhosis are unclear. This review aimed to stratify the risk of short-term (<30 days) and overall (up to 10 years) mortality after cardiac surgery in patients with liver cirrhosis, classified by the CP score. Thus, PubMed, Embase, CINAHL and the Cochrane Library were systematically reviewed by two independent investigators for studies published up to February 2014, in which mortality in cirrhotic patients, classified by the CP classification, undergoing cardiac surgery was evaluated postoperatively. A total of 993 articles were identified. After critical appraisal of 21 articles, 19 were selected for final analysis. Weighted short-term mortality of cirrhotic patients undergoing cardiac surgery was 19.3% [95% confidence interval (CI): 16.4-22.5%]. Across the different CP groups, short-term mortality appeared to be 9.0% (95% CI: 6.6-12.2%), 37.7% (95% CI: 30.8-44.3%) and 52.0% (95% CI: 33.5-70.0%) in Groups A, B and C, respectively. Weighted overall mortality within 1 year was 42.0% (95% CI: 36.0-48.3%) in all cirrhotic patients. Subdivided in groups, overall mortality within that 1 year was 27.2% (95% CI: 20.9-34.7%), 66.2% (95% CI: 54.3-76.3%) and 78.9% (95% CI: 56.1-92.1%) in Groups A, B and C, respectively. In conclusion, short-term mortality is considerably increased in patients with liver cirrhosis CP class B and C. Overall mortality is significantly high in all classes of liver cirrhosis.

Abnormally high failure rate for femoral angioplasty in patients with pseudoxanthoma elasticum.

Pseudoxanthoma elasticum (PXE) is an inherited disease characterized by skin lesions, central blindness, and progressive peripheral occlusive disease. Severe claudication is a frequent symptom for which angioplasty represents a possible therapeutic avenue. We report the outcomes of four patients with PXE treated by angioplasty and stenting of the superficial femoral artery in two centers. These patients exhibited an abnormal failure rate for angioplasty and stenting of the superficial femoral artery, suggesting an as yet unknown susceptibility in such patients. In the absence of further evidence, we do not recommend arterial angioplasty with stenting as a primary surgical approach in PXE patients with femoral artery lesions.

[Hypersomnia: a diagnostic problem]. / Overmatige slaperigheid: een diagnostisch dilemma.

Hypersomnia is a frequently occurring problem. When taking a medical history it is important to distinguish between fatigue and sleepiness. We present a 14-year-old girl with narcolepsy and a 59-year-old man with idiopathic hypersomnia. Features that are typical of narcolepsy are cataplexy and weight gain. Features that are typical of both narcolepsy and idiopathic hypersomnia are daytime naps, insomnia, sleep paralysis and hypnagogic hallucinations. Additional testing in patients with hypersomnia should include a polysomnography in order to exclude other sleeping disorders, and a mean sleep latency test. Practice shows that both patients with narcolepsy and those with idiopathic hypersomnia benefit from treatment with stimulating drugs such as modafinil.

Screening for frailty in primary care: a systematic review of the psychometric properties of the frailty index in community-dwelling older people.

BACKGROUND: To better accommodate for the complex care needs of frail, older people, general practitioners must be capable of easily identifying frailty in daily clinical practice, for example, by using the frailty index (FI). To explore whether the FI is a valid and adequate screening instrument for primary care, we conducted a systematic review of its psychometric properties. METHODS: We searched the Cochrane, PubMed and Embase databases and included original studies focusing on the criterion validity, construct validity and responsiveness of the FI when applied in community-dwelling older people. We evaluated the quality of the studies included using the Quality in Prognosis Studies (QUIPS) tool. This systematic review was conducted based on the PRISMA statement. RESULTS: Of the twenty studies identified, eighteen reported on FIs derived from research data, one reported upon an FI derived from an administrative database of home-care clients, and one reported upon an FI derived from routine primary care data. In general, the FI showed good criterion and construct validity but lacked studies on responsiveness. When compared with studies that used data gathered for research purposes, there are indications that the FI mean score and range might be different in datasets using routine primary care data; however, this finding needs further investigation. CONCLUSIONS: Our results suggest that the FI is a valid frailty screening instrument. However, further research using routine Electronic Medical Record data is necessary to investigate whether the psychometric properties of the FI are generalizable to a primary care setting and to facilitate its interpretation and implementation in daily clinical practice. TRIAL REGISTRATION: PROSPERO systematic review register number: CRD42013003737.

Identifying frailty: do the Frailty Index and Groningen Frailty Indicator cover different clinical perspectives? a cross-sectional study.

BACKGROUND: Early identification of frailty is important for proactive primary care. Currently, however, there is no consensus on which measure to use. Therefore, we examined whether a Frailty Index (FI), based on ICPC-coded primary care data, and the Groningen Frailty Indicator (GFI) questionnaire identify the same older people as frail. METHODS: We conducted a cross-sectional, observational study of 1,580 patients aged ≥ 60 years in a Dutch primary care center. Patients received a GFI questionnaire and were surveyed on their baseline characteristics. Frailty-screening software calculated their FI score. The GFI and FI scores were compared as continuous and dichotomised measures. RESULTS: FI data were available for 1549 patients (98%). 663 patients (42%) returned their GFI questionnaire. Complete GFI and FI scores were available for 638 patients (40.4%), mean age 73.4 years, 52.8% female. There was a positive correlation between the GFI and the FI (Pearson's correlation coefficient 0.544). Using dichotomised scores, 84.3% of patients with a low FI score also had a low GFI score. In patients with a high FI score, 55.1% also had a high GFI score. A continuous FI score accurately predicted a dichotomised GFI score (AUC 0.78, 95% CI 0.74 to 0.82). Being widowed or divorced was an independent predictor of both a high GFI score in patients with a low FI score, and a high FI score in patients with a low GFI score. CONCLUSIONS: The FI and the GFI moderately overlap in identifying frailty in community-dwelling older patients. To provide optimal proactive primary care, we suggest an initial FI screening in routine healthcare data, followed by a GFI questionnaire for patients with a high FI score or otherwise at high risk as the preferred two-step frailty screening process in primary care.