Drug Eluting Balloon Versus Drug Eluting Stent in PCI
Condition: Coronary Artery Disease
MeSH terms: Coronary Artery Disease; Myocardial Ischemia; Coronary Disease
Study type: Observational

Summary: 
      Drug eluting balloons (DEB) have been developed to overcome the limitations of drug eluting
      stent (DES), but clinical results of different studies about DEB are not consistent.

      Thus, we planned a meta-analysis to compare outcomes of DEB and DES in coronary artery
      disease (CAD).
    

Detailed description: 
      Drug eluting balloons (DEB) have been developed to overcome the limitations of drug eluting
      stent (DES), but clinical results of different studies about DEB are not consistent. Thus, we
      performed a meta-analysis to compare outcomes of DEB and DES in coronary artery disease
      (CAD).

      The meta-analysis was performed according to the recommended methods [14-15]. A systematic
      search for eligible studies involved MEDLINE, CENTRAL, Embase, Highwire Press, Scopus and
      Google Scholar databases and was conducted without language restriction by two independent
      investigators (A.L. and A.R.), using the following keywords: "drug", "eluting" "balloon(s)",
      "DEB", "coronary", "angioplasty". Divergences were resolved by consensus. Endnote software v.
      10 was used to build up libraries of results that were combined after erasing duplicates. The
      references of retrieved studies were searched manually for additional trials, and efforts to
      contact authors were performed to obtain further study details or additional references. The
      search is updated to December 2012.

      Selection criteria: citations were screened at title and abstract level and retrieved as full
      reports.

        -  Inclusion criteria were: 1) randomized studies or cohort studies reporting a comparison
           between a DEB treated group and a DES treated group; 2) availability of reports of late
           lumen loss (LLL) and/or overall death and/or myocardial infarction (MI) and/or stent
           thrombosis (ST) and/or target lesion revascularization (TLR).

        -  Exclusion criteria were: 1) duplicate reporting (in which case the manuscript reporting
           the largest sample or the longest follow-up was selected), 2) follow up of at least 6
           months; 3) studies presenting composite major adverse cardiac events (MACE) without
           mentioning individual end points. Data were abstracted on pre-specified forms by 2
           unblinded reviewers; divergences were resolved by consensus.

      Internal validity : the present meta-analysis was performed according to the Guidelines for
      randomized controlled trials of the Cochrane Collaboration and for non randomized studies in
      compliance with the Guidelines of the MOOSE group. Quality of included studies was appraised
      by 2 unblinded investigators. The risk of selection, performance, detection, and attrition
      bias (expressed as low risk of bias [A], moderate risk of bias [B], high risk of bias [C], or
      incomplete reporting leading to inability to ensure the underlying risk of bias [D]) were
      evaluated separately, as recommended. Non-randomized studies were evaluated using the
      Newcastle-Ottawa Scale a validated technique in assessing the quality of non-randomized
      studies.

      Data analysis and synthesis: Odds ratios (ORs) were computed from individual studies and
      pooled according to a fixed effect (e.g. inverse variance weighting) or random effect model
      in case of statistical heterogeneity. Two separate subgroup analysis were pre-specified: 1)
      exclusion of studies with small vessel and bifurcation PCI; 2) exclusion of non-randomized
      studies 3) exclusion of studies in which DEBs were not used together with BMS deployment.

      Results will be presented as overall meta-analysis and subgroups meta-analyses for DEB vs DES
      comparisons. Outcomes appraised were in-stent LLL, overall death, MI, ST and TLR. We used the
      Mantel-Haenszel method for combining ORs, a validated method to pool the data in a
      meta-analysis of binary outcomes. For the in-stent LLL outcome, the mean difference of
      6-month LLL compared with baseline was used and the overall weighted mean difference (WMD)
      was built with the inverse variance method. Heterogeneity was assessed by Cochran's Q test,
      with 2-tailed p=0.1. Statistical inconsistency test (I2) was also employed to overcome the
      low statistical power of Cochran's Q test. The potential publication bias was examined by
      constructing a "funnel plot", in which sample size was plotted against odds ratios. In
      addition, a mathematical estimate of the asymmetry of this plot was provided by a linear
      regression approach. Asymmetry was considered to be present if the intercept of the
      regression line did deviate significantly from zero. To explore and mitigate heterogeneity,
      pre-specified covariates (prevalence of diabetes in the study population and reference
      coronary vessel diameter) as potential confounders were considered in the meta-regression
      analysis.

      Pooling of data, subgroup analyses and publication bias tests were performed with Review
      Manager 5.1 (The Nordic Cochrane Center, Købehvn, Denmark) and StatsDirect v 2.7.8
      (StatsDirect Ltd, Cheshire WA, UK). Meta-regression analyses were builded with Comprehensive
      Meta-analysis Version 2 (Biostat, Englewood, New Jersey, United States).
    

Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Patient with CAD treated by coronary angiogrphy
      
Keywords: Coronary angioplasty; Coronary stent; paclitaxel drug-eluting stent; drug eluting balloon