Wendy T Chen

Predictors of warfarin use in atrial fibrillation in the United States: a systematic review and meta-analysis

BackgroundDespite warfarins marked efficacy, not all eligible patients receive it for stroke prevention in AF. The aim of this meta-analysis was to evaluate the association between prescriber and/or patient characteristics and subsequent prescription of warfarin for stroke prevention in patients with atrial fibrillation (AF).MethodsObservational studies conducted in the US using multivariate analysis to determine the relationship between characteristics and the odds of receiving warfarin for stroke prevention were identified in MEDLINE, EMBASE and a manual review of references. Effect estimates of prescriber and/or patient characteristics from individual studies were pooled to calculate odds ratios (ORs) with 95% confidence intervals.ResultsTwenty-eight studies reporting results of 33 unique multivariate analyses were identified. Warfarin use across studies ranged from 9.1%-79.8% (median = 49.1%). There was a moderately-strong correlation between warfarin use and year of study (r = 0.60, p = 0.002). Upon meta-analysis, characteristics associated with a statistically significant increase in the odds of warfarin use included history of cerebrovascular accident (OR = 1.59), heart failure (OR = 1.36), and male gender (OR = 1.12). Those associated with a significant reduction in the odds of warfarin use included alcohol/drug abuse (OR = 0.62), perceived barriers to compliance (OR = 0.87), contraindication(s) to warfarin (OR = 0.81), dementia (OR = 0.32), falls (OR = 0.60), gastrointestinal hemorrhage (OR = 0.47), intracranial hemorrhage (OR = 0.39), hepatic (OR = 0.59), and renal impairment (OR = 0.69). While age per 10-year increase (OR = 0.78) and advancing age as a dichotomized variable (cut-off varied by study) (OR = 0.57) were associated with significant reductions in warfarin use; qualitative review of results of studies evaluating age as a categorical variable did not confirm this relationship.ConclusionsWarfarin use has increased somewhat over time. The decision to prescribe warfarin for stroke prevention in atrial fibrillation is based upon multiple prescriber and patient characteristics. These findings can be used by family practice prescribers and other healthcare decision-makers to target interventions or methods to improve utilization of warfarin when it is indicated for stroke prevention.

Effect of Biologic Agents on Non-PASI Outcomes in Moderate-to-Severe Plaque Psoriasis: Systematic Review and Meta-Analyses

IntroductionThe objective of this review was to conduct a systematic review with meta-analysis and Bayesian mixed treatment comparisons (MTC) evaluating the impact of biologics on non-Psoriasis Area and Severity Index (PASI) health outcomes in patients with moderate-to-severe plaque psoriasis.MethodsMEDLINE and Cochrane Central Register of Controlled Trials were searched from 1966 to May 2009. Citations were screened for randomized, controlled trials of biologics versus either placebo or each other in adults with moderate-to-severe plaque psoriasis and reported any of several outcomes. Traditional and Bayesian MTC meta-analyses were conducted for each endpoint using either a random- or fixed-effect model where appropriate.ResultsThirty-eight studies met eligibility criteria. All biologics showed significant improvement in achieving a good response on the static physician’s global assessment (PGA) versus placebo while, in the MTC, differences were noted between individual drugs. In achieving a good response on the dynamic PGA, all biologics showed significant improvements over placebo, while the MTC showed significant improvements with the anti-interleukins versus anti-T cells. Relative to placebo, antitumor necrosis factor (TNF) agents and anti-interleukins showed significant improvements in the Dermatology Life Quality Index (DLQI). Compared with placebo, the anti-TNF agents showed significant improvements in both 36-item Medical Outcomes Study Short-Form General Health Survey (SF-36) mental and physical component scores, while anti-T cell agents showed no improvements. The MTC showed no differences between any biologics for either the DLQI or SF-36.ConclusionIndividual biologics and classes showed consistent benefits across non-PASI health outcomes in patients with moderate-to-severe plaque psoriasis while MTC meta-analyses suggested that some differences exist.

Recombinant Human Growth Hormone in the Treatment of Patients With Cystic Fibrosis

CONTEXT: Recombinant human growth hormone (rhGH) improves growth in patients with growth hormone deficiency or idiopathic short stature. Its role in patients with cystic fibrosis (CF) is unclear. OBJECTIVE: To review the effectiveness of rhGH in the treatment of patients with CF. METHODS: Medline and the Cochrane Central Register of Controlled Trials were searched from the earliest date through April 2010. Randomized controlled trials, observational studies, systematic reviews/meta-analyses, or case reports were included if rhGH therapy was administered to patients with CF and data on prespecified harms, intermediate outcomes, or final health outcomes were reported. When applicable, end points were pooled by using a random-effects model. The overall body of evidence was graded for each outcome as insufficient, low, moderate, or high. RESULTS: Ten unique controlled trials (n = 312) and 8 observational studies (n = 58) were included. On quantitative synthesis of controlled trials, several markers of pulmonary function, anthropometrics, and bone mineralization were significantly improved versus control. Results of single-arm observational studies for the aforementioned outcomes were generally supportive of findings in clinical trials. There is insufficient evidence to determine the effect of rhGH on intravenous antibiotic use during therapy, pulmonary exacerbations, health-related quality-of-life, bone consequences, or total mortality, but moderate evidence suggests that rhGH therapy reduces the rate of hospitalization versus control. CONCLUSIONS: rhGH improved almost all intermediate measures of pulmonary function, height, and weight in patients with CF. Improvements in bone mineral content are also promising. However, with the exception of hospitalizations, the benefits on final health outcomes cannot be directly determined at this time.

Comparative Effectiveness of Low-Molecular-Weight Heparins versus Other Anticoagulants in Major Orthopedic Surgery: A Systematic Review and Meta-analysis

To evaluate the comparative efficacy and safety of low‐molecular‐weight heparins (LMWHs) versus other anticoagulants as venous thromboembolism prophylaxis in major orthopedic surgery.

Prolonged Versus Standard-Duration Venous Thromboprophylaxis in Major Orthopedic Surgery: A Systematic Review

BACKGROUND The optimal duration of thromboprophylaxis after major orthopedic surgery is unclear. PURPOSE To compare the benefits and harms of prolonged versus standard-duration thromboprophylaxis after major orthopedic surgery in adults. DATA SOURCES Cochrane Central Register of Controlled Trials and Scopus from 1980 to July 2011 and MEDLINE from 1980 through November 2011, without language restrictions. STUDY SELECTION Randomized trials reporting thromboembolic or bleeding outcomes that compared prolonged (≥21 days) with standard-duration (7 to 10 days) thromboprophylaxis. DATA ABSTRACTION Two independent reviewers abstracted data and rated study quality and strength of evidence. DATA SYNTHESIS Eight randomized, controlled trials (3 good-quality and 5 fair-quality) met the inclusion criteria. High-strength evidence showed that compared with standard-duration therapy, prolonged prophylaxis resulted in fewer cases of pulmonary embolism (PE) (5 trials; odds ratio [OR], 0.14 [95% CI, 0.04 to 0.47]; absolute risk reduction [ARR], 0.8%), asymptomatic deep venous thrombosis (DVT) (4 trials; relative risk [RR], 0.48 [CI, 0.31 to 0.75]; ARR, 5.8%), symptomatic DVT (4 trials; OR, 0.36 [CI, 0.16 to 0.81]; ARR, 1.5%), and proximal DVT (6 trials; RR, 0.29 [CI, 0.16 to 0.52]; ARR, 7.1%). Moderate-strength evidence showed fewer symptomatic objectively confirmed episodes of venous thromboembolism (4 trials; RR, 0.38 [CI, 0.19 to 0.77]; ARR, 5.7%), nonfatal PE (4 trials; OR, 0.13 [CI, 0.03 to 0.54]; ARR, 0.7%), and DVT (7 trials; RR, 0.37 [CI, 0.21 to 0.64]; ARR, 12.1%) with prolonged prophylaxis. High-strength evidence showed more minor bleeding events with prolonged prophylaxis (OR, 2.44 [CI, 1.41 to 4.20]; absolute risk increase, 6.3%), and insufficient evidence from 1 trial on hip fracture surgery suggested more surgical-site bleeding events (OR, 7.55 [CI, 1.51 to 37.64]) with prolonged prophylaxis. LIMITATIONS Data relevant to knee replacement or hip fracture surgery were scant and insufficient. Most trials had few events; the strength of evidence ratings that were used may not adequately capture uncertainty in such situations. CONCLUSION Prolonged prophylaxis decreases the risk for venous thromboembolism, PE, and DVT while increasing the risk for minor bleeding in patients undergoing total hip replacement.

Effect of ascorbic acid on inflammatory markers after cardiothoracic surgery.

PURPOSE The effect of ascorbic acid on inflammatory markers after cardiothoracic surgery (CTS) was studied. METHODS In this randomized, double-blind, placebo-controlled trial, patients undergoing cardiopulmonary bypass graft surgery or valve replacement surgery from April 2009 through March 2010 at Hartford Hospital were randomized to receive ascorbic acid (2-g loading dose followed by 500 mg every 12 hours) or matching placebo the evening before surgery and for four days postoperatively. Inflammatory mediators were measured preoperatively and on postoperative days 1-4. Intergroup comparisons were performed using two-tailed t tests and Fishers exact test. Multiple comparisons were conducted using repeated analyses of variance with Bonferroni tests. RESULTS Of the 62 patients screened, 24 met the study inclusion criteria. Of these, 13 were assigned to receive ascorbic acid and 11 received placebo. Ascorbic acid did not affect the natural course of inflammatory marker rise for C-reactive protein (CRP) concentration, white blood cell (WBC) count, or fibrinogen concentration versus placebo at any evaluated time point (p > 0.05 for all intergroup comparisons). Intragroup analyses demonstrated significant differences among baseline and postoperative measures of all inflammatory mediators (p < 0.05). No significant differences were noted in inflammatory markers between patients undergoing cardiothoracic surgery with or without cardiopulmonary bypass, regardless of treatment group. CONCLUSION Ascorbic acid did not attenuate the rise in inflammatory markers after CTS when compared with placebo. The use of off-pump surgery did not significantly change the levels of CRP and fibrinogen or the WBC count postoperatively when compared with on-pump surgery with a biocompatible polymer coating.

Comparative effectiveness of combined pharmacologic and mechanical thromboprophylaxis versus either method alone in major orthopedic surgery: a systematic review and meta-analysis.

To evaluate the comparative efficacy and safety of combination pharmacologic and mechanical venous thromboembolism (VTE) prophylaxis versus either method alone in major orthopedic surgery.

Are the risk factors listed in warfarin prescribing information associated with anticoagulation-related bleeding? A systematic literature review

Warfarin significantly reduces thromboembolic risk, but perceptions of associated bleeding risk limit its use. The evidence supporting the association between bleeding and individual patient risks factors is unclear. This systematic review aims to determine the strength of evidence supporting an accentuated bleeding risk when patients with risk factors listed in the warfarin prescribing information are prescribed the drug. A systematic literature search of MEDLINE and Cochrane CENTRAL was conducted to identify studies reporting multivariate relationships between prespecified covariates and the risk of bleeding in patients receiving warfarin. The prespecified covariates were identified based on patient characteristics for bleeding listed in the warfarin package insert. Each covariate was evaluated for its association with specific types of bleeding. The quality of individual evaluations was rated as ‘good’, ‘fair’ or ‘poor’ using methods consistent with those recommended by the Agency for Healthcare Research and Quality (AHRQ). Overall strength of evidence was determined using the Grading of Recommendations Assessment, Development (GRADE) criteria and categorised as ‘insufficient’, ‘very low’, ‘low’, ‘moderate’ or ‘high’. Thirty‐four studies, reporting 134 multivariate evaluations of the association between a covariate and bleeding risk were identified. The majority of evaluations had a low strength of evidence for the association between covariates and bleeding and none had a high strength of evidence. Malignancy and renal insufficiency were the only two covariates that had a moderate strength of evidence for their association with major and minor bleeding respectively. The associations between covariates listed in the warfarin prescribing information and increased bleeding risk are not well supported by the medical literature.

Systematic review: comparative effectiveness of adjunctive devices in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention of native vessels

BackgroundDuring percutaneous coronary intervention (PCI), dislodgement of atherothrombotic material from coronary lesions can result in distal embolization, and may lead to increased major adverse cardiovascular events (MACE) and mortality. We sought to systematically review the comparative effectiveness of adjunctive devices to remove thrombi or protect against distal embolization in patients with ST-segment elevation myocardial infarction (STEMI) undergoing PCI of native vessels.MethodsWe conducted a systematic literature search of Medline, the Cochrane Database, and Web of Science (January 1996-March 2011), http://www.clinicaltrials.gov, abstracts from major cardiology meetings, TCTMD, and CardioSource Plus. Two investigators independently screened citations and extracted data from randomized controlled trials (RCTs) that compared the use of adjunctive devices plus PCI to PCI alone, evaluated patients with STEMI, enrolled a population with 95% of target lesion(s) in native vessels, and reported data on at least one pre-specified outcome. Quality was graded as good, fair or poor and the strength of evidence was rated as high, moderate, low or insufficient. Disagreement was resolved through consensus.Results37 trials met inclusion criteria. At the maximal duration of follow-up, catheter aspiration devices plus PCI significantly decreased the risk of MACE by 27% compared to PCI alone. Catheter aspiration devices also significantly increased the achievement of ST-segment resolution by 49%, myocardial blush grade of 3 (MBG-3) by 39%, and thrombolysis in myocardial infarction (TIMI) 3 flow by 8%, while reducing the risk of distal embolization by 44%, no reflow by 48% and coronary dissection by 70% versus standard PCI alone. In a majority of trials, the use of catheter aspiration devices increased procedural time upon qualitative assessment.Distal filter embolic protection devices significantly increased the risk of target revascularization by 39% although the use of mechanical thrombectomy or embolic protection devices did not significantly impact other final health outcomes. Distal balloon or any embolic protection device increased the achievement of MBG-3 by 61% and 20% and TIMI3 flow by 11% and 6% but did not significantly impact other intermediate outcomes versus control. Upon qualitative analysis, all device categories, with exception of catheter aspiration devices, appear to significantly prolong procedure time compared to PCI alone while none appear to significantly impact ejection fraction. Many of the final health outcome and adverse event evaluations were underpowered and the safety of devices overall is unclear due to insufficient amounts of data.ConclusionsIn patients with STEMI, for most devices, few RCTs evaluated final health outcomes over a long period of follow-up. Due to insufficient data, the safety of these devices is unclear.