Raynaud's phenomenon and digital ischaemia--pharmacologic approach and alternative treatment options.

The primary goal of therapy is to reduce the frequency and intensity of Raynaud's attacks and to minimize the related morbidity rather than to cure the underlying condition. Treatment strategies depend on whether Raynaud's phenomenon (RP) is primary or secondary. All patients should be instructed about general measures to maintain body warmth and to avoid triggers of RP attacks. Pharmacologic intervention can be useful for patients with severe and frequent RP episodes that impair the patient's quality of life. Calcium channel blockers are currently the most prescribed and studied medications for this purpose. There has been limited evidence for the efficacy of alpha-1-adrenergic receptor antagonists, angiotensin receptor blockers, topical nitrates or fluoxetine to treat RP. The intravenously administered prostacyclin analogue iloprost can reduce the frequency and severity of RP attacks and is considered a second-line therapy in patients with markedly impaired quality of life, critical digital ischaemia and skin ulcers who are at risk for substantial tissue loss and amputation. Phosphodiesterase inhibitors (e.g., sildenafil) can also improve RP symptoms and ulcer healing whereas endothelin-1 receptor antagonists (e.g., bosentan) are mainly considered treatment options in secondary prevention for patients with digital skin ulcers related to systemic sclerosis. However, their use in clinical practice has been limited by their high cost. Antiplatelet therapy with low-dose aspirin is recommended for all patients who suffer from secondary RP due to ischaemia caused by structural vessel damage. Anticoagulant therapy can be considered during the acute phase of digital ischaemia in patients with suspected vascular occlusive disease attributed to the occurrence of new thromboses. In patients with critical digital ischaemia, consideration should be given to hospitalisation, optimisation of medical treatment in accordance with the underlying disease and evaluation for a secondary, possibly reversible process that is causing or aggravating the clinical symptoms.

Raynaud’s phenomenon - assessment and differential diagnoses.

Raynaud’s phenomenon (RP) is characterised by paroxysmal reversible episodes of vasospasm, usually involving peripheral small vessels of the fingers or toes and resulting in a triple-colour change starting with pallor and followed by cyanosis and erythema. Attacks are typically triggered by cold or emotional stress. The diagnosis of RP can be made on the basis of the patient’s clinical symptoms. Primary RP occurs without underlying disease and is considered a benign condition. A normal erythrocyte sedimentation rate, negative testing for antinuclear antibodies, normal nailfold capillaries and the absence of structural micro- or macrovascular damage and other diseases lead to the diagnosis of primary RP. Digital photoplethysmography and pulse contour analysis can be used as an additional tool to exclude structural macro- or microvascular disease. In contrast, secondary RP is associated with other diseases, mainly connective tissue diseases such as systemic sclerosis. If there is a suspicion of secondary RP, a thorough laboratory and vascular assessment is required to make the diagnosis of underlying disease. Acrocyanosis and erythromelalgia are additional functional vascular disorders that can be easily distinguished when patients are carefully assessed for their history and clinical symptoms.

Thrombophilia and risk of VTE recurrence according to the age at the time of first VTE manifestation.

BACKGROUND: Whether screening for thrombophilia is useful for patients after a first episode of venous thromboembolism (VTE) is a controversial issue. However, the impact of thrombophilia on the risk of recurrence may vary depending on the patient's age at the time of the first VTE. PATIENTS AND METHODS: Of 1221 VTE patients (42 % males) registered in the MAISTHRO (MAin-ISar-THROmbosis) registry, 261 experienced VTE recurrence during a 5-year follow-up after the discontinuation of anticoagulant therapy. RESULTS: Thrombophilia was more common among patients with VTE recurrence than those without (58.6 % vs. 50.3 %; p = 0.017). Stratifying patients by the age at the time of their initial VTE, Cox proportional hazards analyses adjusted for age, sex and the presence or absence of established risk factors revealed a heterozygous prothrombin (PT) G20210A mutation (hazard ratio (HR) 2.65; 95 %-confidence interval (CI) 1.71 - 4.12; p < 0.001), homozygosity/double heterozygosity for the factor V Leiden and/or PT mutation (HR 2.35; 95 %-CI 1.09 - 5.07, p = 0.030), and an antithrombin deficiency (HR 2.12; 95 %-CI 1.12 - 4.10; p = 0.021) to predict recurrent VTE in patients aged 40 years or older, whereas lupus anticoagulants (HR 3.05; 95%-CI 1.40 - 6.66; p = 0.005) increased the risk of recurrence in younger patients. Subgroup analyses revealed an increased risk of recurrence for a heterozygous factor V Leiden mutation only in young females without hormonal treatment whereas the predictive value of a heterozygous PT mutation was restricted to males over the age of 40 years. CONCLUSIONS: Our data do not support a preference of younger patients for thrombophilia testing after a first venous thromboembolic event.

Prevalence of thrombophilia according to age at the first manifestation of venous thromboembolism: results from the MAISTHRO registry.

Thrombophilia is a well-established risk factor for a venous thromboembolic event (VTE), and it has been proposed that hereditary thrombophilia may substantially contribute to the development of VTE in young patients. We aimed to analyse the prevalence of thrombophilia with special regard to the age of VTE manifestation. The study cohort consisted of 1490 patients (58% females) with a median age 43 years at the time of their first VTE. At least one thrombophilic disorder was identified in 50·1% of patients. The probability of detecting a hereditary thrombophilia declined significantly with advancing age (from 49·3% in patients aged 20 years and younger to 21·9% in patients over the age of 70 years; P < 0·001). This may be primarily attributed to the decreasing frequencies of the F5 R506Q (factor V Leiden) mutation and deficiencies of protein C or protein S with older age at the time of the initial VTE event. Moreover, thrombophilia was more prevalent in unprovoked compared with risk-associated VTE (57·7% vs. 47·7%; P = 0·001). The decline in the prevalence of hereditary thrombophilia with older ages supports the use of a selected thrombophilia screening strategy dependent on age and the presence or absence of additional VTE risk factors.

Are patients with thrombophilia and previous venous thromboembolism at higher risk to arterial thrombosis?

INTRODUCTION: Whether thrombophilic disorders, which are established risk factors for venous thromboembolism (VTE), also increase the risk of arterial thrombosis is still unknown. MATERIALS AND METHODS: We analyzed data from 1081 consecutive patients (649 F/432 M, 16-93 years of age) with previous VTE registered in the MAISTHRO (MAin-ISar-THROmbosis) database with regard to arterial thrombotic events and contributing risk factors. Screening for thrombophilia included testing for factor V Leiden and prothrombin G20210A mutation, antiphospholipid antibodies and activities of factor VIII, protein C, protein S and antithrombin. RESULTS: Of the entire study cohort, 40 patients (3.7%) had a prior myocardial infarction (MI), and 41 (3.8%) suffered a stroke. Other arterial thrombotic events were rare. Elevated factor VIII levels were more prevalent in MI patients than in controls (44.4 vs. 25.9%, p=0.044), but after adjusting for the traditional cardiovascular risk factors, this relationship was no longer significant. We observed a higher rate of lupus anticoagulant in MI patients with an adjusted odds ratio of 3.3 (95%CI 0.84-12.8, p=0.090). No difference in any other tested thrombophilia was observed in patients with MI or stroke relative to those without. CONCLUSION: The cumulative incidence of arterial thrombotic events in VTE patients is low, and the inherited thrombophilias do not seem to substantially increase the risk of arterial thrombosis.

Etiology and VTE risk factor distribution in patients with inferior vena cava thrombosis.

INTRODUCTION: Inferior vena cava (IVC) thrombosis is a rare event and data detailing the underlying etiology are scarce. MATERIALS AND METHODS: Therefore, we reviewed all available cases of IVC thrombosis consecutively registered in the MAISTHRO (MAin-ISar-THROmbosis) database and described the prevalence of VTE risk factors and other conditions contributing to IVC thrombosis development. RESULTS: 53 patients (35 F, 18 M) with IVC thrombosis aged 12 to 79 years were identified. 40 patients (75.5%) developed thrombosis under the age of 45. Local problems, such as IVC anomalies or external venous compression, contributed to the development of thrombosis in 12 cases (22.6%). Lupus anticoagulants (10.9 vs. 2.3%, p=0.013) and malignoma (17.0 vs. 6.4%, p=0.023) were more prevalent in IVC thrombosis patients compared to 265 age and sex matched controls with isolated lower extremity DVT. No difference was identified with regard to inherited thrombophilia or other known VTE risk factors. Symptomatic pulmonary embolism (PE) occurred in 32.1% of IVC thrombosis patients compared to 15.2% of controls (p=0.005). CONCLUSIONS: Local problems such as IVC anomalies and external venous compression, malignancy and the presence of lupus anticoagulants contribute to the risk of IVC thrombosis. The risk of symptomatic pulmonary embolism in the acute setting is high.

Acquired protein C and protein S deficiency in HIV-infected patients.

Infection with human immunodeficiency virus (HIV) may lead to hemostatic imbalances. Forty-nine consecutive patients with acute opportunistic infections were screened for thrombophilic parameters. A follow-up investigation was performed after 10 +/- 8 weeks in 26 patients. In acutely ill patients, the incidence of protein S deficiency was 67% (33/49) and of protein C deficiency 25% (12/49), while at the follow-up visit the incidences were 54% (14/26) and 8% (2/26), respectively. Protein S and protein C levels increased significantly from initial to follow-up visit (p < 0.05). Lupus anticoagulants were not detected and anticardiolipin IgG antibodies were present in 11.4% (5/44). Three patients presented with deep venous thrombosis on admission; in two, protein S or protein C deficiency was observed. In conclusion, an acquired protein S and protein C deficiency often develop in patients with HIV and acute illness; this may be reversible after treatment for opportunistic infections.

Necessity and risks of arterial blood sampling in healthy volunteer studies.

Arterial blood sampling is necessary when drugs such as the fast-acting opioid analgesic remifentanil exhibit relevant differences between arterial and venous blood concentrations. Arterial cannulation is generally considered to be clinically safe and has thus become a standard procedure in pharmacokinetic-pharmacodynamic assessments. However, rare cases of arterial occlusions have to be considered in risk-benefit assessments of arterial sampling in pharmacokinetic studies, especially when including healthy volunteers. In an actual case, arterial occlusion requiring surgical repair was caused by a factor V Leiden thrombophilia associated genetic variant F5 1691G>A (rs6025) and aggravated by a hypoplastic radial artery. Neither risk factor had been identified prior to enrolment by routine laboratory tests such as the prothrombin time (international normalized ratio), partial thromboplastin time and the clinical Allen's test of arterial function. Re-assessment of the necessity of arterial sampling showed that none of the potential alternatives, target concentrations of computerized infusions or venous concentrations during non-steady-state and steady-state conditions could provide the arterial concentrations. Relying on venous concentrations may result in erroneous pharmacodynamic parameters. Accurate pharmacokinetic-pharmacodynamic studies relying on precisely measured blood concentrations require serial sampling techniques during both steady-state and non-steady-state conditions. However, as illustrated by the presented case, incidents involving the generally safe procedure of arterial sampling are possible, although rare. To further minimize the risks, screening of subjects for prothrombotic risks and careful assessment of the suitability of the artery should be considered in pharmacokinetic studies requiring arterial cannulation.