Sobia Khan

Quality and Strength of Evidence of the Infectious Diseases Society of America Clinical Practice Guidelines

OBJECTIVE To describe the distribution and temporal trends of the quality and strength of evidence supporting recommendations in the Infectious Diseases Society of America (IDSA) clinical practice guidelines. METHODS Guidelines either issued or endorsed by IDSA from March 1994 to July 2009 were evaluated using the IDSA-US Public Health Service Grading System. In this system, the letters A-E signify the strength of the recommendation, and numerals I-III indicate the quality of evidence supporting these recommendations. The distribution of the guideline recommendations among strength of recommendation and quality of evidence classes was quantified. Temporal changes between the first and current guideline version were evaluated. RESULTS Approximately one-half (median, 50.0%; interquartile range [IQR], 38.1%-58.6%) of the recommendations in the current guidelines are supported by level III evidence (derived from expert opinion). Evidence from observational studies (level II) supports 31% of recommendations (median, 30.9%; IQR, 23.3%-43.2%), whereas evidence based on ≥ 1 randomized clinical trial (level I) constitutes 16% of the recommendations (median, 15.8%; IQR, 5.8%-28.3%). The strength of recommendation was mainly distributed among classes A (median, 41.5%; IQR, 28.7%-55.6%) and B (median, 40.3%; IQR, 27.1%-47.9%). Among guidelines with ≥ 1 revised version, the recommendations moved proportionately toward more level I evidence (+12.4%). Consequently, there was a proportional increase in class A recommendations (+11.1%) with a decrease in class C recommendations (-23.5%). CONCLUSIONS The IDSA guideline recommendations are primarily based on low-quality evidence derived from nonrandomized studies or expert opinion. These findings highlight the limitations of current clinical infectious diseases research that can provide high-quality evidence. There is an urgent need to support high-quality research to strengthen the evidence available for the formulation of guidelines.

Cardioprotective role of ischemic postconditioning in acute myocardial infarction: A systematic review and meta-analysis

BACKGROUND Evidence suggests that ischemic postconditioning (IPoC) may reduce the extent of reperfusion injury. We performed a meta-analysis of randomized controlled trials, which compared the role of IPoC during primary percutaneous coronary intervention (PCI) to PCI alone (control group) in ST-segment elevation myocardial infarction. METHODS Several databases were searched, which yielded 19 studies. The outcomes of interest were measures of myocardial damage (serum cardiac enzymes and infarct size by imaging) and left ventricular function (left ventricular ejection fraction and wall motion score index). Mean difference (MD) and standardized mean difference (SMD) were used to assess the treatment effect. An inverse variance method was used to pool data into a random-effects model. RESULTS Ischemic postconditioning demonstrated a decrease in serum cardiac enzymes (SMD -0.48, 95% CI -0.92 to -0.05, I(2) = 92%), reduction in infarct size by imaging (SMD -0.30, 95% CI -0.58 to -0.01, I(2) = 80%), wall motion score index (MD -0.19, 95% CI -0.29 to -0.09, I(2) = 44%), and showed improvement in left ventricular ejection fraction (IPoC 52 ± 0.4, control 49.7 ± 0.4) (MD 2.78, 95% CI 0.66-4.91, I(2) = 69%). All included studies were limited by high risk of performance and publication bias. CONCLUSIONS Ischemic postconditioning during PCI in ST-segment elevation myocardial infarction appears to be superior to PCI alone in reduction of both myocardial injury or damage and improvement in global and regional left ventricular function. The effect seems to be more pronounced when a greater myocardial area is at risk. Given the limitations of the current available evidence, additional data from large randomized controlled trials are warranted.

Catheter Ablation and Antiarrhythmic Drug Therapy as First- or Second-Line Therapy in the Management of Atrial Fibrillation Systematic Review and Meta-Analysis

Background—The optimal management of atrial fibrillation remains unclear. We performed a meta-analysis of randomized controlled trials to examine the safety and the efficacy of catheter ablation (CA) when compared with antiarrhythmic drug therapy both as first- and second-line therapy for the maintenance of sinus rhythm in atrial fibrillation. Methods and Results—Several databases were searched from inception to March 2014, which yielded 11 studies with 1481 patients with atrial fibrillation. The outcomes measured were recurrence of atrial tachyarrhythmia and the incidence of adverse events. A subgroup analysis was done to evaluate the efficacy of CA as first- or second-line therapy. There was recurrence of atrial tachyarrhythmia in 222 of 785 (28%) patients who underwent CA and in 451 of 696 (65%) patients who were on antiarrhythmic drug therapy (relative risk, 0.40; 95% confidence interval, 0.31−0.52; P=0.00001). Subgroup analysis revealed a beneficial effect of CA both as a first-line (relative risk, 0.52; 95% confidence interval, 0.30−0.91; P=0.02) and as a second-line (relative risk, 0.37; 95% confidence interval, 0.29−0.48; P<0.00001) therapeutic modality. There was a significantly higher incidence of major adverse events in the CA group when compared with those in the antiarrhythmic drug therapy group (relative risk, 2.04; 95% confidence interval, 1.10–3.77; P=0.02, I2=0%). Conclusions—CA seems to be superior to antiarrhythmic drug therapy in drug naïve, resistant, and intolerant patients with atrial fibrillation. However, it should be performed in carefully selected patients after weighing the risks and benefits of the procedure.

Systematic review and meta-analysis of the possible association between pharmacological gastric acid suppression and spontaneous bacterial peritonitis.

Background Observational studies have presented conflicting results with regard to an association between gastric acid suppression and spontaneous bacterial peritonitis (SBP). Our aim was to carry out a meta-analysis investigating the possible association between the use of proton pump inhibitors or H2-receptor antagonists and SBP. Methods We searched several databases from inception through 15 December 2014 to identify observational studies that provided data on the association of gastric acid suppression with SBP as their primary outcome, and carried out random effects meta-analyses. Results Fourteen observational studies (six case–control and eight cohort) evaluating the association between proton pump inhibitors and SBP revealed a pooled odds ratio (OR) of 2.32 [95% confidence interval (CI) 1.57–3.42, I2=82%]. The subgroup analysis based on study design revealed a pooled OR of 2.52 (95% CI 1.71–3.71, I2=16%) for case–control studies, and a pooled OR of 2.18 (95% CI 1.24–3.82, I2=89%) for cohort studies. Sensitivity analysis including only the peer-reviewed publications in the cohort subgroup revealed a pooled OR of 1.49 (95% CI 1.15–1.95, I2=27%). The subgroup analysis for high-quality studies revealed a pooled OR of 1.49 (95% CI 1.19–1.88, I2=21%). The pooled OR for H2-receptor antagonists and SBP was 1.93 (95% CI 1.15–3.24, I2=0%). Conclusions There appear to be statistically significant, but quantitatively small, associations between gastric acid suppression and SBP. However, the magnitude of the possible association diminished when analysis focused on higher quality data that were more robust. Furthermore, the quality evidence in support of the association, as per the GRADE framework, was very low.

Efficacy and safety of transcatheter aortic valve replacement in intermediate surgical risk patients: A systematic review and meta-analysis.

The efficacy of transcatheter aortic valve replacement (TAVR) in aortic stenosis patients at high surgical risk has been established. The data on patients with intermediate risk is not conclusive. We performed a meta‐analysis of studies which compared TAVR with surgical aortic valve replacement (SAVR) in patients at intermediate surgical risk.

Left dominant circulation increases mortality in acute coronary syndrome: A systematic review and meta-analysis of observational studies involving 2,55,718 patients

The effect of coronary dominance on mortality in patients with acute coronary syndrome (ACS) remains unclear. We performed a meta‐analysis to evaluate the effect of coronary dominance in patients with ACS.

Catheter Ablation and Antiarrhythmic Drug Therapy as First- or Second-Line Therapy in the Management of Atrial FibrillationCLINICAL PERSPECTIVE: Systematic Review and Meta-Analysis

Background—The optimal management of atrial fibrillation remains unclear. We performed a meta-analysis of randomized controlled trials to examine the safety and the efficacy of catheter ablation (CA) when compared with antiarrhythmic drug therapy both as first- and second-line therapy for the maintenance of sinus rhythm in atrial fibrillation. Methods and Results—Several databases were searched from inception to March 2014, which yielded 11 studies with 1481 patients with atrial fibrillation. The outcomes measured were recurrence of atrial tachyarrhythmia and the incidence of adverse events. A subgroup analysis was done to evaluate the efficacy of CA as first- or second-line therapy. There was recurrence of atrial tachyarrhythmia in 222 of 785 (28%) patients who underwent CA and in 451 of 696 (65%) patients who were on antiarrhythmic drug therapy (relative risk, 0.40; 95% confidence interval, 0.31−0.52; P=0.00001). Subgroup analysis revealed a beneficial effect of CA both as a first-line (relative risk, 0.52; 95% confidence interval, 0.30−0.91; P=0.02) and as a second-line (relative risk, 0.37; 95% confidence interval, 0.29−0.48; P<0.00001) therapeutic modality. There was a significantly higher incidence of major adverse events in the CA group when compared with those in the antiarrhythmic drug therapy group (relative risk, 2.04; 95% confidence interval, 1.10–3.77; P=0.02, I2=0%). Conclusions—CA seems to be superior to antiarrhythmic drug therapy in drug naïve, resistant, and intolerant patients with atrial fibrillation. However, it should be performed in carefully selected patients after weighing the risks and benefits of the procedure.

Catheter Ablation and Antiarrhythmic Drug Therapy as First- or Second-Line Therapy in the Management of Atrial FibrillationCLINICAL PERSPECTIVE

Background—The optimal management of atrial fibrillation remains unclear. We performed a meta-analysis of randomized controlled trials to examine the safety and the efficacy of catheter ablation (CA) when compared with antiarrhythmic drug therapy both as first- and second-line therapy for the maintenance of sinus rhythm in atrial fibrillation. Methods and Results—Several databases were searched from inception to March 2014, which yielded 11 studies with 1481 patients with atrial fibrillation. The outcomes measured were recurrence of atrial tachyarrhythmia and the incidence of adverse events. A subgroup analysis was done to evaluate the efficacy of CA as first- or second-line therapy. There was recurrence of atrial tachyarrhythmia in 222 of 785 (28%) patients who underwent CA and in 451 of 696 (65%) patients who were on antiarrhythmic drug therapy (relative risk, 0.40; 95% confidence interval, 0.31−0.52; P=0.00001). Subgroup analysis revealed a beneficial effect of CA both as a first-line (relative risk, 0.52; 95% confidence interval, 0.30−0.91; P=0.02) and as a second-line (relative risk, 0.37; 95% confidence interval, 0.29−0.48; P<0.00001) therapeutic modality. There was a significantly higher incidence of major adverse events in the CA group when compared with those in the antiarrhythmic drug therapy group (relative risk, 2.04; 95% confidence interval, 1.10–3.77; P=0.02, I2=0%). Conclusions—CA seems to be superior to antiarrhythmic drug therapy in drug naïve, resistant, and intolerant patients with atrial fibrillation. However, it should be performed in carefully selected patients after weighing the risks and benefits of the procedure.