Transcatheter Mitral Valve-in-Ring Implantation.

Failed surgical mitral valve repair using an annuloplasty ring has traditionally been treated with surgical valve replacement or repair1. For patients at high risk for repeat open heart surgery, placement of a trans-catheter aortic valve (i.e., TAVI valve) within the mitral ring (i.e., Mitral-Valve-in-Ring, MViR) has emerged as a novel alternative treatment strategy2-5 . We describe our experience of a failed mitral valve repair that was successfully treated with a TAVI valve delivered via the trans-septal approach, and summarise the data relating to this emerging treatment strategy.

Assessment of clinical occupational dose reduction effect of a new interventional cardiology shield for radial access combined with a scatter reducing drape.

OBJECTIVES: To assess the occupational dose reduction effect of a new interventional cardiology shield for radial access combined with a scatter reducing drape. BACKGROUND: Transradial access for catheterization has been shown to increase occupational radiation dose. Current shielding techniques are primarily based on the femoral access. This article looks at the clinical occupational combined dose reduction effect of a commercially available shield and drape which is specific to access type. METHODS: The evaluation took place in a busy interventional cardiology laboratory, with a single plane 30×40 cm flat panel detector (Siemens Artis Zee, Germany). Radiation exposure to staff was measured using electronic personal dosimeters (Unfors RaysafeAB, Sweden) placed at the collar. Patient radiation exposure was assessed using screening time and dose area product per case. Both staff and patient radiation exposure were monitored for a number of case types and operators before, during, and after deployment of the new shield and drapes. RESULTS: The cardiologists' overall median collar badge reading per case reduced from 15.4 µSv per case without the shield/drape combination to 7.3 µSv per case with the shield drape combination in situ (P<0.001). The radiographers badge reading was reduced from 4.2 µSv per case without to 2.5 µSv per case with the shield drape combination in situ (P<0.001). There was no statistical difference in the cardiac technician's badge reading. Patient's dose area product was not significantly affected by the placement of the shield and drape combination. CONCLUSIONS: The shield/drape combination can significantly reduce operator exposure in a cardiac catheterization laboratory.

Experience of a high-risk aortic valve clinic in Ireland.

BACKGROUND: The advent of transcatheter aortic valve implantation (TAVI) has broadened the management options for severe aortic stenosis. The indications for TAVI are narrow. Selecting those that will benefit most from this intervention warrants careful consideration and input from cardiologists, anaesthetists and cardiac surgeons familiar with TAVI and surgical aortic valve replacement (SAVR). AIMS: The aims of this paper were to assess the feasibility of establishing a high-risk aortic clinic in Ireland, and report stratification of the referred group into those suitable for SAVR, TAVI and conservative management. METHODS: Patient data was prospectively collected by a dedicated clinical nurse specialist. ANOVA was used to assess variance in means between groups. Analyses were performed using IBM SPSS v20 (Armonk, NY: IBM Corp.). RESULTS: A total of 105 patients were assessed. Eighty-five patients were deemed suitable for TAVI, 9 (10.5 %) died awaiting the procedure and a further 6 (7 %) declined intervention. Eleven (10.5 %) underwent conventional SAVR, 1 (0.9 %) a balloon valvuloplasty, 4 (3.8 %) entered surveillance and 4 (3.8 %) were declined treatment. CONCLUSIONS: Establishment of a high-risk aortic clinic is feasible in the Irish context. The advent of TAVI has reduced the proportion of patients denied intervention to a minority. Despite being considered high risk, a number of patients were suitable candidates for SAVR. Measuring frailty continues to provide a challenge; a TAVI-specific frailty assessment tool would be advantageous to patient stratification.

Glycoprotein IIb/IIIa antagonists--from bench to practice.

The central role played by the alphaIIb beta3 receptor in platelet aggregation, and hence in platelet thrombosis, has led to the development of a number of parenteral and oral glycoprotein (GP) IIb/IIIa inhibitors for use in cardiovascular disease states, such as acute coronary syndromes and stroke. The predominant effect of these agents is to inhibit platelet aggregation, although studies of alphaIIb beta3 receptor function and various GP IIb/IIIa inhibitors have demonstrated the potential for these agents to produce effects on other aspects of platelet function, in addition to non-platelet effects. Overall, clinical studies have demonstrated an impressive beneficial effect for parenteral agents in reducing ischemic complications following percutaneous intervention, and a more modest beneficial effect in the treatment of patients with acute coronary syndromes. Trials with oral GP IIb/IIIa inhibitors in similar patient populations have demonstrated toxicity, manifested by an increased mortality in treated patients. Increased understanding of molecular aspects of both alphaIIb beta3 receptor function and the effects of GP IIb/IIIa inhibition may help explain some of the inconsistency in recently reported clinical studies with parenteral agents, and the frank toxicity of oral agents. Such studies may also hold the key to the development of newer agents with enhanced therapeutic benefit.

Angioplasty and stenting in acute coronary syndromes: who, when, how, and why.

PTCA and stenting now form an integral part of therapy for acute coronary syndromes and are important in achieving the optimal clinical outcome.

Platelet glycoprotein IIb/IIIa receptor antagonists.

The molecular understanding of platelet function, together with an appreciation of the role of platelet thrombus in the pathogenesis of acute coronary syndromes (ACS) and abrupt vessel closure following coronary intervention, lead to the development of the class of agents now referred to as platelet glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitors. Currently three parenteral GP IIb/IIIa inhibitors are licensed for use in patients undergoing coronary intervention or as empirical therapy in non-ST elevation ACS (unstable angina and non-Q wave myocardial infarction). Clinical trials using these agents in patients undergoing coronary interventions have demonstrated a consistent reduction in ischaemic end points at 30 days that is sustained during long-term follow-up. Similar benefits have been found in patients with ACS who are managed medically or who proceed to revacularization. Studies using prolonged platelet inhibition using oral GP IIb/IIIa inhibitors in patients following coronary intervention or with ACS have produced disappointing results. Further investigation with existing and newer oral agents are ongoing. The use of GP IIb/IIIa inhibitors in combination with fibrinolytic agents for optimal reperfusion in patients with acute ST-elevation myocardial infarction (MI) is an active area of interest. Angiographic outcomes with this approach have been encouraging and clinical outcome data are awaited. Beyond efficacy, GP IIb/IIIa inhibitors have proven to be safe for clinical use. Haemorrhagic complications and thrombocytopenia are the most common adverse events, though infrequent. Unresolved issues regarding drug dosing, monitoring of effect, duration of therapy, head-to-head comparisons of agents, and use of adjunctive therapies are the subject of ongoing studies.

Usefulness of abciximab for treatment of early coronary artery stent thrombosis.

The clinical and angiographic outcomes of 10 patients who received abciximab as part of their therapy for early stent thrombosis was compared with 25 patients (using historical controls) who received conventional therapy. Although the angiographic outcome and the incidence of myocardial infarction in both groups was similar, there were no deaths or referral for emergency coronary bypass surgery in the abciximab-treated group versus 3 deaths and 10 referrals for emergency bypass surgery in the conventionally treated group.

Lung findings on high-resolution computed tomography in idiopathic ankylosing spondylitis--correlation with clinical findings, pulmonary function testing and plain radiography.

Previous studies on the association of ankylosing spondylitis and abnormalities of the lung parenchyma have been based largely on plain radiography and pulmonary function testing. This study, although uncontrolled, is the first to use high-resolution computed tomography to examine the entire lung parenchyma in ankylosing spondylitis patients, and to correlate the findings with clinical assessment, plain radiography and pulmonary function testing. The study population comprised 26 patients meeting the New York criteria for idiopathic ankylosing spondylitis who attended the out-patient department at our institution. High-resolution computed tomography examination revealed abnormalities in 19 patients (70%): these included interstitial lung disease (n = 4), bronchiectasis (n = 6), emphysema (n = 4), apical fibrosis (n = 2), mycetoma (n = 1) and non-specific interstitial lung disease (n = 12). Plain radiography was abnormal in only four patients and failed to identify any patient with interstitial lung disease. All patients with interstitial lung disease on high-resolution computed tomography had respiratory symptoms and three of the four had evidence of a restrictive process on pulmonary function testing. This study raises, for the first time, the possible association between interstitial lung disease and ankylosing spondylitis, and highlights the use of high-resolution computed tomography in detecting such disease in ankylosing spondylitis patients.

Plain radiographs and thoracic high-resolution CT in patients with ankylosing spondylitis.

OBJECTIVE: The aims of this study were to identify the spectrum of abnormalities seen on high-resolution CT in patients with ankylosing spondylitis and to compare our findings with reports of plain film pulmonary manifestations of the disease. SUBJECTS AND METHODS: We prospectively studied 26 patients with documented ankylosing spondylitis. All patients underwent plain chest radiography (posteroanterior and lateral views), thoracic helical CT, high-resolution CT, and pulmonary function tests. RESULTS: High-resolution CT revealed abnormalities in 18 patients (69%), whereas plain chest radiography revealed abnormalities in four patients (15%). The most common abnormalities seen on CT were interstitial lung disease (ILD) (n = 4), bronchial wall thickening and bronchiectasis (n = 6), paraseptal emphysema (n = 3), mediastinal lymphadenopathy (n = 3), tracheal dilatation (n = 2), and apical fibrosis (n = 2). CONCLUSION: This study, which describes high-resolution CT findings in patients with ankylosing spondylitis, reveals a spectrum of abnormalities unlike those described in previous reports in which researchers used plain chest radiographs as the sole imaging technique. In addition to apical fibrosis, high-resolution CT revealed nonapical ILD, bronchiectasis, paraseptal emphysema, and tracheobronchomegaly. Of these new findings, we believe that identification of ILD is the most important. We suggest that nonapical ILD should be actively sought as an explanation for pulmonary symptoms developing in patients with ankylosing spondylitis. High-resolution CT should form an integral part of such workup.

Innervation of the tylotrich-touch dome complexes in rat skin: changing patterns during postnatal development.

The tylotrich-touch dome complexes of the rat were studied in detail at thoracic level, with two objectives: to follow the pattern of innervation of the individual complexes from birth to maturity and to determine the extent of overlap of the segmental nerves supplying them. Techniques included light and electron microscopy and histological observations following section of intercostal nerves. The touch domes were nearly always supplied from a single stem axon; as expected, their terminals increased in number in association with the differentiation of target Merkel cells from the epidermis. In general, they were supplied from the nearest segmental nerves. The tylotrich follicles were each supplied by several stem fibres. The number of palisade terminals applied to the epithelial root sheaths reached a maximum during the 2nd and 3rd postnatal weeks and declined during the following 2 wk. This overshoot can be regarded as another example of hyperinnervation found in the juvenile peripheral nervous system. During the period of decline, the stem fibres extended their territory, resulting in considerable overlap of the territories of the segmental nerves. By the beginning of the 8th week, overlap was relatively scanty, with an irregular distribution.