Is it safe to stop anticoagulants after successful surgery for atrial fibrillation?

A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was: is it safe to stop anticoagulants after successful surgery for atrial fibrillation? Altogether, 177 papers were found using the reported search, of which 14 were selected that represented the best evidence to answer the clinical question. Selection criteria included study relevance, primary outcome, size of study population and length of follow-up. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. The weight of evidence, including over 10,000 patient-years of follow-up, supports the discontinuation of warfarin following atrial fibrillation correction procedures as being safe, with an associated annual thromboembolic stroke rate of 0-3.8% off warfarin, in studies where warfarin was stopped at a mean of 3.6 months (range 0-8 months) after the procedure. However, the confidence of this conclusion suffers from a paucity of high-quality randomized controlled trials in the field, with the main body of evidence coming instead from observational non-randomized studies. The stroke rate also varies with the exact procedure performed; pulmonary vein isolation procedures are the most extensively evaluated and carry the lowest stroke rate following warfarin discontinuation (0-0.4% per annum when performed as an isolated procedure). By contrast, left atrial appendage occlusion by insertion of a transcatheter device has an associated annual stroke rate of 0-3.8% off warfarin. Thus, discontinuation of warfarin following such transcatheter procedures cannot be recommended at this time. Concomitant heart surgeries, such as mitral valve repair have been shown to increase the thromboembolic rate both unpredictably and dramatically, and this review thus identifies concomitant mitral valve surgery as a potentially substantial risk factor for late thromboembolic stroke in patients undergoing corrective surgeries for atrial fibrillation. This review finds in favour of warfarin discontinuation in selected patients at three months post-procedure, emphasizing consideration of the patient's individual risk-factor profile as paramount. This recommendation is in line with the 2010 guidelines for the management of atrial fibrillation produced by the European Society of Cardiology.     

In patients with an enlarged left atrium does left atrial size reduction improve maze surgery success?

A best evidence topic in cardiothoracic surgery was written according to a structured protocol. The question addressed was: In [adults undergoing a maze procedure for atrial fibrillation (AF)], [does left atrial size reduction] compared to [maze surgery alone] improve [maze surgery success]? A total of 58 papers were found using the reported search, of which eight represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. Four out of eight papers compared a volume reduction technique as an adjunct to the maze procedure to a maze procedure alone--all four papers reported that atrial volume reduction significantly increased restoration of sinus rhythm: 89.3% vs. 67.2%, P<0.001; 85% vs. 68%, P<0.05; 84% vs. 68%, P<0.05; 90% vs. 69%, P<0.05. Three out of eight papers had no control group but reported good rates of sinus rhythm restoration at last follow-up--90%, 92% and 89%, respectively--despite the study population including atrial enlargement, a risk factor for failure of a maze procedure. One paper reported no benefit of an atrial reduction plasty in patients with a left atrium (LA) >70 mm. An enlarged LA is a risk factor for failure of a maze procedure, and various models of AF suggest that reducing atrial mass and/or diameter may help to abolish the re-entry circuits underlying AF. Furthermore, AF is uncommon when left atrial diameter is <40 mm, so there is at least some physiological basis for atrial reduction surgery in aiding the success of a maze procedure. The evidence suggests that patients with an enlarged (≥ 55 mm) or giant (≥ 75 mm) LA who are at risk of failing to obtain sinus conversion after a standard maze procedure may derive benefit from concomitant atrial reduction surgery using either a tissue excision or a tissue plication technique. However, the evidence is not strong since the papers available are not readily comparable owing to substantial variations in the populations and procedures involved. We therefore, emphasise the need for prospective randomised studies in this area.     

Initial combination therapy with metformin plus colesevelam in drug-naïve Hispanic patients with early type 2 diabetes

Objective: To evaluate initial combination therapy with metformin plus colesevelam in drug-na?ve Hispanic patients with type 2 diabetes mellitus. Research Design and Methods: Patients self-identified as Hispanic from a previous study were included in this exploratory post hoc analysis. Patients were randomized to metformin plus colesevelam or metformin plus placebo. The primary efficacy parameter was the mean change in glycated hemoglobin (HbA1c) levels from baseline. Results: Metformin plus colesevelam had a greater mean HbA1c reduction (-1.2 ± 0.1%) than metformin plus placebo (-0.8 ± 0.1%; P = 0.001) from mean baselines of 7.7% and 7.6%, respectively. Low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol, total cholesterol, and apolipoprotein (apo) B levels were also reduced (P < 0.0001 for all), while triglyceride (P < 0.0001) and apoA-I (P < 0.05) levels were increased with metformin plus colesevelam treatment compared with metformin plus placebo. With metformin plus colesevelam versus metformin plus placebo, more patients achieved an HbA1c of < 7.0% (75% vs 56%) and LDL-C of < 100 mg/dL (49% vs 14%; both P < 0.05). Conclusion: Metformin plus colesevelam may be an effective initial treatment option for Hispanic patients with early type 2 diabetes mellitus.     

Tamoxifen inhibits malignant peripheral nerve sheath tumor growth in an estrogen receptor-independent manner

Few therapeutic options are available for malignant peripheral nerve sheath tumors (MPNSTs), the most common malignancy associated with neurofibromatosis type 1 (NF1). Guided by clinical observations suggesting that some NF1-associated nerve sheath tumors are hormonally responsive, we hypothesized that the selective estrogen receptor (ER) modulator tamoxifen would inhibit MPNST tumorigenesis in vitro and in vivo. To test this hypothesis, we examined tamoxifen effects on MPNST cell proliferation and survival, MPNST xenograft growth, and the mechanism by which tamoxifen impeded these processes. We found that 1-5 μM 4-hydroxy-tamoxifen induced MPNST cell death, whereas 0.01-0.1 μM 4-hydroxy-tamoxifen inhibited mitogenesis. Dermal and plexiform neurofibromas, MPNSTs, and MPNST cell lines expressed ERβ and G-protein-coupled ER-1 (GPER); MPNSTs also expressed estrogen biosynthetic enzymes. However, MPNST cells did not secrete 17β-estradiol, exogenous 17β-estradiol did not stimulate mitogenesis or rescue 4-hydroxy-tamoxifen effects on MPNST cells, and the steroidal antiestrogen ICI-182,780 did not mimic tamoxifen effects on MPNST cells. Further, ablation of ERβ and GPER had no effect on MPNST proliferation, survival, or tamoxifen sensitivity, indicating that tamoxifen acts via an ER-independent mechanism. Consistent with this hypothesis, inhibitors of calmodulin (trifluoperazine, W-7), another known tamoxifen target, recapitulated 4-hydroxy-tamoxifen effects on MPNST cells. Tamoxifen was also effective in vivo, demonstrating potent antitumor activity in mice orthotopically xenografted with human MPNST cells. We conclude that 4-hydroxy-tamoxifen inhibits MPNST cell proliferation and survival via an ER-independent mechanism. The in vivo effectiveness of tamoxifen provides a rationale for clinical trials in cases of MPNSTs.     

Comparison of central corneal thickness measurements with the Galilei dual Scheimpflug analyzer and ultrasound pachymetry

Purpose:

To compare corneal pachymetry assessment by the Galilei dual Scheimpflug analyzer with that done by ultrasound (US) pachymetry.

Materials and Methods:

Forty six patients (92 eyes) were subjected to corneal pachymetry assessment by Galilei dual Scheimpflug analyzer and US. All the readings were taken by a single operator. Intraoperator repeatability for the Galilei was assessed by taking 10 readings in one eye each of 10 patients. To study the interoperator reproducibility for the Galilei, two observers took a single reading in both the eyes of 25 patients.

Results:

The mean central corneal thickness (CCT) measured by US was 541.83 ± 30.56 μm standard deviation (SD) and that measured by Galilei was 541.27 ± 30.07 μm (SD). There was no statistically significant difference between both the methods (P < 0.001). The coefficient of repeatability was 0.43% while the coefficient of reproducibility was 0.377% for the Galilei.

Conclusion:

Objective, noncontact measurement of the CCT with the Galilei dual Scheimpflug analyzer was convenient, had excellent intraoperator repeatability and interoperator reproducibility, and findings were similar to those obtained with standard US pachymetry.     

Massive osteolysis of hemimandible: a case report

Massive osteolysis or Gorham’s stout disease or phantom bone is a rare disorder which normally appears in adulthood with no specific predilection for any sex. Work to find out exact etiology of disorder has been done. But actual cause has not yet been found. Any of the bone could be involved in this disease. A clinical, radiographic and histological evaluation of massive osteolysis of mandible is presented and discussed.