Intra-aortic balloon pump in high-risk percutaneous coronary interventions without cardiogenic shock: Trial sequential analysis of outcomes

Abstract

In evaluating the effectiveness of intra-aortic balloon pump in high-risk percutaneous coronary interventions without cardiogenic shock, the best level of evidence in the meta-analysis by Romeo and co-workers [ [1] Romeo F. Acconcia M.C. Sergi D. et al. Lack of intra-aortic balloon pump effectiveness in high-risk percutaneous coronary interventions without cardiogenic shock: a comprehensive meta-analysis of randomised trials and observational studies. Int J Cardiol. 2013; 167: 1783-1793 Abstract Full Text Full Text PDF PubMed Scopus (22) Google Scholar ] was that obtained from randomized controlled studies (RCTs). With regard to the end-point of in-hospital major adverse cardiac events (MACEs), interpreting the results of the RCTs included in this meta-analysis is made difficult by the nonsignificant difference found between patients who were given intra-aortic balloon pump and the controls. Nonsignificant meta-analyses are increasingly being recognized to be a matter of controversy mainly because their results can be classified as either inconclusive (i.e., no proof of difference) or demonstrated futility (i.e., proof of no difference), and these two categories differ much more than is commonly thought [ 2 Wetterslev J. Thorlund K. Brok J. Gluud C. Estimating required information size by quantifying diversity in a random-effects meta-analysis. BMC Med Res Methodol. 2009; 9 Crossref PubMed Scopus (647) Google Scholar , 3 Wetterslev J. Thorlund K. Brok J. Gluud C. Trial sequential analysis may establish when firm evidence is reached in cumulative meta-analysis. J Clin Epidemiol. 2008; 61: 64-75 Abstract Full Text Full Text PDF PubMed Scopus (1182) Google Scholar , 4 Arruda M.A. No evidence of efficacy or evidence of no efficacy. JAMA Pediatr. 2013 Mar 1; 167: 300-302 Crossref PubMed Scopus (18) Google Scholar ].