9
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Postconditioning in ST-elevation myocardial infarction: a systematic review, critical appraisal, and meta-analysis of randomized clinical trials

      review-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Objective

          We aimed to summarize the evidence from randomized clinical trials studies examining the efficacy of ischemic postconditioning (IPost) in ST-elevation myocardial infarction.

          Design

          The study was a systematic review and critical appraisal, with meta-analysis of randomized clinical trials.

          Materials and methods

          We searched the literature. A total of 21 randomized clinical trials were identified. Both fixed effect and random effects models were used to synthesize the results of individual studies. Heterogeneity between studies was examined by subgroup and random effects meta-regression analyses, considering ptient-related and study-level variables. Publication bias, or “small-study effect”, was evaluated.

          Results

          Substantial heterogeneity was present. The random effects model pooled estimate for the outcome infarct size assessed by cardiac magnetic resonance was estimated by the standardized mean difference (SMD) =−0.06, 95% confidence interval (CI): −0.34 to 0.21, ie, no effect of IPost. For the end point infarct size, estimated by biomarkers of myocardial necrosis, an overall pooled effect was SMD =−0.58, 95% CI: −0.96 to −0.19. This effect disappeared in powered and nonbiased studies (SMD =0.03, 95% CI: −0.48 to 0.55). Finally, for the outcome left ventricular ejection fraction, SMD =0.47 95% CI: 0.20 to 0.74. Unfortunately, selection bias (small-study effect) was present. For this outcome, the meta-regression showed that both presence of hypertension and the inclusion of nonbiased studies explained 28.3% of the heterogeneity among the studies. Simulation by the “trim and fill” method, which controlled for selection bias using random effects model, diluted the effect (SMD =0.17 95% CI: −0.13 to 0.48). No effects by IPost on ST-segment resolution or on the majority of adverse clinical events were observed during follow up, except the incidence of congestive heart failure was found.

          Conclusion

          Evidence from this study suggests no cardioprotection from IPost, on surrogate and the majority of clinical end points. A possible beneficial effect on the incidence of congestive heart failure needs to be replicated by a large clinical trial.

          Related collections

          Most cited references48

          • Record: found
          • Abstract: found
          • Article: not found

          Empirical evidence of bias. Dimensions of methodological quality associated with estimates of treatment effects in controlled trials.

          To determine if inadequate approaches to randomized controlled trial design and execution are associated with evidence of bias in estimating treatment effects. An observational study in which we assessed the methodological quality of 250 controlled trials from 33 meta-analyses and then analyzed, using multiple logistic regression models, the associations between those assessments and estimated treatment effects. Meta-analyses from the Cochrane Pregnancy and Childbirth Database. The associations between estimates of treatment effects and inadequate allocation concealment, exclusions after randomization, and lack of double-blinding. Compared with trials in which authors reported adequately concealed treatment allocation, trials in which concealment was either inadequate or unclear (did not report or incompletely reported a concealment approach) yielded larger estimates of treatment effects (P < .001). Odds ratios were exaggerated by 41% for inadequately concealed trials and by 30% for unclearly concealed trials (adjusted for other aspects of quality). Trials in which participants had been excluded after randomization did not yield larger estimates of effects, but that lack of association may be due to incomplete reporting. Trials that were not double-blind also yielded larger estimates of effects (P = .01), with odds ratios being exaggerated by 17%. This study provides empirical evidence that inadequate methodological approaches in controlled trials, particularly those representing poor allocation concealment, are associated with bias. Readers of trial reports should be wary of these pitfalls, and investigators must improve their design, execution, and reporting of trials.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Improving the quality of reports of meta-analyses of randomised controlled trials: the QUOROM statement. Quality of Reporting of Meta-analyses.

            The Quality of Reporting of Meta-analyses (QUOROM) conference was convened to address standards for improving the quality of reporting of meta-analyses of clinical randomised controlled trials (RCTs). The QUOROM group consisted of 30 clinical epidemiologists, clinicians, statisticians, editors, and researchers. In conference, the group was asked to identify items they thought should be included in a checklist of standards. Whenever possible, checklist items were guided by research evidence suggesting that failure to adhere to the item proposed could lead to biased results. A modified Delphi technique was used in assessing candidate items. The conference resulted in the QUOROM statement, a checklist, and a flow diagram. The checklist describes our preferred way to present the abstract, introduction, methods, results, and discussion sections of a report of a meta-analysis. It is organised into 21 headings and subheadings regarding searches, selection, validity assessment, data abstraction, study characteristics, and quantitative data synthesis, and in the results with "trial flow", study characteristics, and quantitative data synthesis; research documentation was identified for eight of the 18 items. The flow diagram provides information about both the numbers of RCTs identified, included, and excluded and the reasons for exclusion of trials. We hope this report will generate further thought about ways to improve the quality of reports of meta-analyses of RCTs and that interested readers, reviewers, researchers, and editors will use the QUOROM statement and generate ideas for its improvement.
              Bookmark
              • Record: found
              • Abstract: not found
              • Article: not found

              The hazards of scoring the quality of clinical trials for meta-analysis.

              Although it is widely recommended that clinical trials undergo some type of quality review, the number and variety of quality assessment scales that exist make it unclear how to achieve the best assessment. To determine whether the type of quality assessment scale used affects the conclusions of meta-analytic studies. Meta-analysis of 17 trials comparing low-molecular-weight heparin (LMWH) with standard heparin for prevention of postoperative thrombosis using 25 different scales to identify high-quality trials. The association between treatment effect and summary scores and the association with 3 key domains (concealment of treatment allocation, blinding of outcome assessment, and handling of withdrawals) were examined in regression models. Pooled relative risks of deep vein thrombosis with LMWH vs standard heparin in high-quality vs low-quality trials as determined by 25 quality scales. Pooled relative risks from high-quality trials ranged from 0.63 (95% confidence interval [CI], 0.44-0.90) to 0.90 (95% CI, 0.67-1.21) vs 0.52 (95% CI, 0.24-1.09) to 1.13 (95% CI, 0.70-1.82) for low-quality trials. For 6 scales, relative risks of high-quality trials were close to unity, indicating that LMWH was not significantly superior to standard heparin, whereas low-quality trials showed better protection with LMWH (P<.05). Seven scales showed the opposite: high quality trials showed an effect whereas low quality trials did not. For the remaining 12 scales, effect estimates were similar in the 2 quality strata. In regression analysis, summary quality scores were not significantly associated with treatment effects. There was no significant association of treatment effects with allocation concealment and handling of withdrawals. Open outcome assessment, however, influenced effect size with the effect of LMWH, on average, being exaggerated by 35% (95% CI, 1%-57%; P= .046). Our data indicate that the use of summary scores to identify trials of high quality is problematic. Relevant methodological aspects should be assessed individually and their influence on effect sizes explored.
                Bookmark

                Author and article information

                Journal
                Vasc Health Risk Manag
                Vasc Health Risk Manag
                Vascular Health and Risk Management
                Vascular Health and Risk Management
                Dove Medical Press
                1176-6344
                1178-2048
                2014
                08 August 2014
                : 10
                : 477-491
                Affiliations
                [1 ]Centre of Epidemiology and Biostatistics, Oslo University Hospital, Ullevål, Norway
                [2 ]Centre of Clinical Heart Research, Oslo University Hospital, Ullevål, Norway
                [3 ]Department of Cardiology, Oslo University Hospital, Ullevål, Norway
                Author notes
                Correspondence: M Abdelnoor, Centre of Epidemiology and Biostatistics, Centre of Clinical Heart Research, Oslo University Hospital, Ullevaal, 0407 Oslo, Norway, Tel +47 995 40 888, Fax +47 221 18 479, Email michelab@ 123456online.no
                Article
                vhrm-10-477
                10.2147/VHRM.S67154
                4134024
                25143742
                a2b8732a-8c53-431a-8067-a48cd3e069b5
                © 2014 Abdelnoor et al. This work is published by Dove Medical Press Limited, and licensed under Creative Commons Attribution – Non Commercial (unported, v3.0) License

                The full terms of the License are available at http://creativecommons.org/licenses/by-nc/3.0/. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed.

                History
                Categories
                Review

                Cardiovascular Medicine
                ischemic postconditioning,acute myocardial infarction,percutaneous coronary intervention

                Comments

                Comment on this article