We argue that heterogeneity in a meta-analysis of baseline variables should not exist, and therefore removing trials which contribute to heterogeneity from a meta-analysis will produce a more valid result. In our example none of the overall outcomes changed when studies contributing to heterogeneity were removed. We recommend routine use of this technique, using age and a second baseline variable predictive of outcome for the particular study chosen, to help eliminate potential bias in meta-analyses.
Background: His bundle pacing (HBP) remains technically challenging and is currently guided by electrograms and 2-dimensional fluoroscopy. Our objective was to describe a new technique for HBP directly guided by electroanatomic mapping (EAM). Methods: Twenty-eight patients were included. The atrioventricular septum was mapped via EAM, and His bundle (HB) electrograms, selective, and nonselective HB capture sites were tagged. Pacing leads were connected to EAM, navigated to tagged HB target sites and deployed. Intracardiac electrograms and pacing parameters were recorded. Lead location was tagged on the cloud of HB sites, which was divided into 3 arbitrary segments. In 5 patients, atrioventricular nodal ablation was performed with direct visualization of the HBP lead by EAM. Results: Reproducible navigation of the pacing lead to predetermined HBP locations guided by EAM was achieved in all patients. The lead was successfully deployed in 25 patients. HB cloud area was 360 (212) mm 2 . There was no correlation between HBP threshold and lead location on the His cloud. The intracardiac electrograms atrial/ventricular ratio at the lead deployment site correlated with its EAM position on the His cloud ( P =0.045). Procedure, fluoroscopy, and mapping times were 116.0 (38.8), 8.6 (6.3), and 9.0 (11.4) minutes, respectively. HBP threshold at implant was 1.5 (2.3) V at 1.5 (1.0) ms. Distance between HB lead and ablation sites was 10.0 (1.3) mm in patients undergoing atrioventricular nodal ablation. Conclusions: Direct guidance of HBP by EAM allows for direct visualization of the pacing lead on the HB cloud and reproducible navigation to predetermined HB capture sites. Intracardiac electrograms atrial/ventricular ratio at the lead deployment site correlates with His cloud location. EAM can be applied during standard HBP procedures or combined with atrioventricular nodal ablation.
BACKGROUND The use of coronary sinus (CS) sheaths to deliver stylet-driven leads (SDLs) for His-bundle pacing (HBP) has not been described. Conventionally, HBP is achieved using a styletless lead delivered through a customized catheter. OBJECTIVE The purpose of this study was to characterize the acute and early-term HBP experience with stylet-driven, active-fixation leads delivered through CS sheaths compared to the conventional approach. METHODS Delivery of Medtronic 4471 and 7742 SDLs was attempted in 27 patients. Delivery was facilitated using CS guide catheters and custom-shaped stylets. Procedural characteristics and lead performance were compared to those of a group of 17 patients in whom delivery of 3830 lumen-less leads (LLLs) was attempted. Patients had heterogeneous pacing indications. RESULTS HBP with SDL was successful in 24 of 27 patients(89%) compared to 15 of 17 patients (88%) in the LLL group. Mean procedural and fluoroscopy times in the SDL and LLL groups were 129 6 43 minutes vs 104 6 43 minutes and 9.6 6 5.2 minutes vs 8.3 6 5.0 minutes, respectively (both P 5 NS). There was a significant difference in procedure and fluoroscopy times within the SDL group between the first and second halves of the series, probably secondary to a learning curve. Acute HBP thresholds were higher with SDL than with LLL (2.6 6 1.5 V vs 1.5 6 1.2 V; P 5 .02) and remained stable at 8.4 6 5.3 months. Both SDLs exhibited similar pacing thresholds. Two crossovers between groups occurred (1 in each group). Four patients with SDL and 1 patient with LLL exhibited high thresholds during follow-up. CONCLUSION Permanent HBP using stylet-driven, active-fixation leads delivered through conventional CS sheaths is feasible. Procedural characteristics and lead performance were clinically acceptable.
Background & Aims: Liver fibrosis is the critical determinant of liver-related outcomes in persons with nonalcoholic fatty liver disease. The rate that fibrosis develops determines the time taken to reach cirrhosis and consequent clinical outcomes.Estimates of the fibrosis progression rate (FPR) are uncertain having been defined in small observational series that rely largely on nonstandardised repeat biopsy in selected patients. The aim of this study was to evaluate the FPR in placebo-treated participants with nonalcoholic steatohepatitis (NASH) in randomised controlled trials (RCTs).Methods: Systematic review and meta-analysis of RCTs in NASH with data on fibrosis change extracted. Calculated fibrosis progression rates were pooled in meta-analysis.The pooled estimate was then used to model the proportion of hypothetical cohorts starting with no fibrosis at the age of 30 who develop cirrhosis.Results: A total of 35 trials including 1419 placebo-treated participants who underwent repeat liver biopsy were evaluated. Considering all trials, the overall FPR was 0.00 stages per year, increasing to 0.03 stages per year in both trials at low risk of bias and trials including >50 placebo-treated participants. This estimate was markedly lower than the value derived from previously pooled analyses of observational data.Using a FPR of 0.03 resulted in a substantial reduction in the proportion of patients developing cirrhosis compared with the FPR derived from observational studies (13% vs 28%). Conclusions:The FPR in placebo-treated participants in RCTs is lower than that described from observational data. Slower fibrosis progression predicts fewer persons with NASH will progress to cirrhosis than previously estimated.
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