Clinical Impact of Computational Heart Valve Models

This paper provides a review of engineering applications and computational methods used to analyze the dynamics of heart valve closures in healthy and diseased states. Computational methods are a cost-effective tool that can be used to evaluate the flow parameters of heart valves. Valve repair and replacement have long-term stability and biocompatibility issues, highlighting the need for a more robust method for resolving valvular disease. For example, while fluid–structure interaction analyses are still scarcely utilized to study aortic valves, computational fluid dynamics is used to assess the effect of different aortic valve morphologies on velocity profiles, flow patterns, helicity, wall shear stress, and oscillatory shear index in the thoracic aorta. It has been analyzed that computational flow dynamic analyses can be integrated with other methods to create a superior, more compatible method of understanding risk and compatibility.     

Recombinant activated factor VII decreases bleeding without increasing arterial thrombosis in rabbits

PURPOSE: To compare the effects of recombinant activated factor VII (rFVIIa) and platelet-rich plasma (PRP) in an experimental model of bleeding and arterial thrombosis. METHODS: The Folts model was used in 60 rabbits. After anesthesia, the carotid artery was exposed and a 75% stenosis was induced. A compression injury of the artery triggered a series of cyclic flow reductions (CFRs). After counting baseline CFRs, animals were assigned randomly to one of four groups (n = 15 in each): control, PRP, rFVIIa and placebo. Control animals received 10 mL.kg(-1) of saline while 10 mL.kg(-1) of a hydroxyethyl starch solution (200,000/6%/0.5) were infused in the three other groups. CFRs were measured again, followed by treatment with PRP, rFVIIa or placebo and by a final measurement of CFRs. At the end of each observation period, an ear immersion bleeding time (BT) was measured and a blood sample was drawn for the evaluation of hematological variables. Microvascular bleeding was evaluated at the end of the experiment in grams of blood shed from liver and spleen sections. Results are presented as median (range). RESULTS: rFVIIa shortened the BT and decreased microvascular bleeding as compared with placebo [60 (35-100) sec vs 110 (50-140) sec, P = 0.0019 and 9 (4-24) g vs 17 (5-28) g, P = 0.002, respectively]. rFVIIa did not increase CFRs [3(0-9) vs |(0-5), P = 0.11]. CONCLUSION: rFVIIa led to a decrease in BT and microvascular bleeding but did not significantly affect arterial thrombosis in rabbits.     

Has the time come to leave the watch-and-wait strategy in newly diagnosed asymptomatic follicular lymphoma patients?

ABSTRACT: BACKGROUND: Historically, the median overall survival for follicular lymphoma (FL) has been considered to be 9-10 years, and no treatment had ever prolonged this time period. Studies conducted more than 20 years ago demonstrated that treating patients with asymptomatic FL at the onset of the disease did not increase their survival, and that almost 20% of these patients did not need any treatment in the first 10 years of follow-up. Based on these facts, most clinical practice guidelines recommend active surveillance policies for patients with asymptomatic FL. DISCUSSION: The introduction of antiCD-20 monoclonal antibodies, over the last 15 years, has significantly increased the median survival rate to above 14 years. This improvement was achieved before the combination of rituximab and chemotherapy regimens became extensively used in patients with symptomatic disease. Therefore, this increase in survival may currently be more significant. At present, several clinical trials have evaluated low-toxicity therapies that prolong progression-free periods, among which rituximab monotherapy, radioimmunotherapy or the combination of rituximab with bendamustine are the most relevant. Unfortunately, these clinical trials have included only patients with symptomatic FL. The results of a recently reported clinical trial show that treatment with single-agent rituximab prolongs progression-free survival rates, time to new treatment and the quality of life of asymptomatic patients, as compared with the active surveillance strategy. Longer follow-up of these results and data regarding overall survival are awaited before this treatment can be recommended as the standard initial therapy. SUMMARY: There are different therapeutic possibilities for asymptomatic FL patients, but no data are currently available to indicate which option is the best. Patients need to understand the risks and benefits of observation versus treatment before a final decision can be made. For patients who want active treatment the administration of four weekly rituximab doses should be considered.     

First inappropriate implantable cardioverter defibrillator therapy is often due to inaccurate device programming: analysis of the French OPERA registry

AIMS: Inappropriate therapy delivered by implantable cardioverter defibrillators (ICDs) remains a challenge. The OPERA registry measured the times to, and studied the determinants of, first appropriate (FAT) and inappropriate (FIT) therapies delivered by single-, dual- and triple-chamber [cardiac resynchronization therapy defibrillator (CRT-D)] ICD. METHODS AND RESULTS: We entered 636 patients (mean age = 62.0 ± 13.5 years; 88% men) in the registry, of whom 251 received single-, 238 dual-, and 147 triple-chamber ICD, for primary (30.5%) or secondary (69.5%) indications. We measured times to FAT and FIT as a function of multiple clinical characteristics, examined the effects of various algorithm components on the likelihood of FAT and FIT delivery, and searched for predictors of FAT and FIT. Over 22.8 ± 8.8 months of observation, 184 patients (28.9%) received FAT and 70 (11.0%) received FIT. Ventricular tachycardia (VT) was the trigger of 88% of FAT, and supraventricular tachycardia was the trigger of 91% of FIT. The median times to FIT (90 days; range 49-258) and FAT (171 days; 50-363) were similar. The rate of FAT was higher (P <0.001) in patients treated for secondary than primary indications, while that of FIT were similar in both groups. Out of 57 analysable FIT, 27 (47.4%) could have been prevented by fine tuning the device programming like the sustained rate duration or the VT discrimination algorithm. CONCLUSIONS: First inappropriate therapy occurred in 11% of 636 ICD recipients followed for ～2 years. Nearly 50% of FIT could have been prevented by improving device programming.     

Living on the Edge of Being Overstretched—A Norwegian Qualitative Study of Employed Pregnant Women

In this study, our aim was to explore female employees’ experiences of work during pregnancy and their expectations of becoming a mother for the first time. We conducted 10 interviews and analyzed the data using qualitative content analysis. The main finding, living on the edge of being overstretched, contained two themes: being exhausted by adapting to professional life and being prepared for becoming a mother. In order to increase the well-being of pregnant employees, women should be provided with information from their supervisors and health care services about pregnancy-related life changes.     

Real-world comorbidities and treatment patterns of patients with acromegaly in two large US health plan databases

Acromegaly is a rare, chronic, and debilitating disease that results from excessive growth hormone production. Clinically, this disease is associated with enlargement of soft tissue, excessive skeletal growth, and increased risk of cardiovascular disease. Acromegaly is often diagnosed late, when a wide range of comorbidities may already be present. First-line therapy for acromegaly is typically surgery; but a number of highly-specific pharmacological agents have recently enabled a more aggressive medical management of acromegaly. Since surgical cure of acromegaly is low for macroadenomas, medical control of active acromegaly is an important component of treatment. There are no published US data currently available regarding real-world rates of comorbidities and treatment patterns among patients with acromegaly. This retrospective study examined the comorbidities and treatment patterns of 949 health plan enrollees, who had acromegaly diagnosis and/or procedure codes in an administrative claims database from July 1, 2002 through June 30, 2010. Acromegaly was associated with high rates of hypertension and diabetes along with a number of other comorbidities. The incidence of comorbidities was highest among patients with acromegaly-related treatment, which may have resulted, in part, from inadequate disease management and/or poor disease control. Unexpectedly, 55 % of patients identified with acromegaly received no treatment for acromegaly (i.e., surgery, radiotherapy, and medication) and only 28 % received a medication treatment during the observation period. However, some patients may have received a curative surgery prior to the observation period, which may have reduced the use of other acromegaly-related treatments during the study period. Of those treated with medications, the most common first medications were octreotide, cabergoline, and bromocriptine. Given the high incidence of serious comorbidities associated with active acromegaly, earlier diagnosis and treatment, along with appropriate follow-up care, may potentially avoid the life-long consequences of uncontrolled disease.     

Subject Index to Volume 3

By monodimensional thin-layer electrophoresis on 5 X 10-cm cellulose layers o-aminolevulinic acid (oAL) is rapidly separated from interfering substances. Detection with a cupric nitrate-Ninhydrin sequence adds specificity and permits detection of as little as 10 ng/lLl of urine. Confirmation can be obtained on two-dimensional chromatograms (5 X 5 em) with the use of either Ninhydrin or a modified MauzeraUasGranick reagent for detection. The quantity of (’)Al can be estimated by visual or densitometric comparison with standards. The method is rapid and inexpensive and is suggested for use in conjunction with the more expensive column chromatographic technique.