[Method of information synthesis--meta analysis of endomyocardial biopsy complications]

The "information explosion" in the last 20 years has created a need for technique that synthesizes information from various sources. One of the methods for synthetasing information from various independent but similar studies is meta analysis. The aim of this study was to estimate complication rate of endomyocardial biopsy and therefore to assess its routine clinical applicability. In order to identify published studies regarding endomyocardial biopsy between 1980-1993, we performed computer and manual literature search. A total of 255 papers were retrieved but only 18 studies fulfilled separately predefined inclusion/exclusion criteria for meta analysis of complications. For each study, numerical weights were calculated according to the sample size and magnitude of effect size (proportion of each of the observed diagnostic categories). Weighted average of proportions was used to obtain a 95 posto study-specific confidence interval (CI) for each category. To compare incidence of complications of endomyocardial biopsy of the right to the endomyocardial biopsy of the left ventricle, modified Mantel-Haenszel test of the effect size for summarizing data from individual studies was used. Complication rate in analyzed studies was compared to the Poisson's rule of rare events and showed no significant difference (Chi2=2.02, p>0.05). Mild complications were present in 1.55 posto pts (95% CI 1.27-1.87%) while severe complications were present in 0.62% (95% CI 0.47-0.88%). Heart perforations, included in severe complications, were present in 0.31% pts (95% CI 0.16-0.46%). Overall complication rate was 1.68% (95% CI 1.41-1.96%). According to the results obtained, the overall complication rate was demonstrated to be significantly higher following the right (prv=6.5%) than following the left (plv=3.7%) ventricular endomyocardial biopsy (Chi2 =8.784, p<0.05). Thus, using meta analysis complication rate was estimated objectively. These pooled data suggest that endomyocardial biopsy is a safe procedure with infrequent complications. They were estimated to occurred more often during endomyocardial biopsy of right ventricle.