The authors concluded that in prognostic terms, total and bicaval orthotopic heart transplantations were better than biatrial transplantation. Aspects of this review were well-conducted, but the reliability of the findings is questionable given the poor quality of the included studies and given that pooling included trials with different study designs.

To determine whether the total and bicaval heart transplantation techniques are better than the biatrial technique.

PubMed, LILACS, Web of Science, SCOPUS, SCIRUS and SCIELO databases and Google Scholar were searched up to January 2008 for publications in any language. Search terms were provided. Reference lists of relevant publications were searched.

Randomised controlled trials (RCTs), non-randomised prospective controlled trials and retrospective controlled studies that compared biatrial orthotopic heart transplantation with bicaval or total transplantation were eligible for inclusion. There were no restrictions on patients for gender, age, ethnicity, baseline heart disease and use of medication. Outcomes of interest included intraoperative parameters (extracorporeal circulation time, aortic cross-clamp time, ischaemia time and operative time) and postoperative parameters (mean pulmonary artery pressure, pulmonary capillary pressure, right atrial pressure and cardiac index). Other outcomes included: presence of atrial arrhythmias, mitral and tricuspid valve regurgitation, mortality, number of graft rejections, bleeding volume, embolic events, temporary and permanent pacemaker requirement, mechanical ventilation time, length of hospital stay and length of stay in an intensive care unit. The included studies had to report mean and standard deviation for continuous numerical variables and proportions of events for nominal categorical variables.

Mean age of the participants in the included trials ranged from 14 to 58 years. Where reported, most participants were male.

Two reviewers independently selected the trials. Any discrepancies were resolved by consensus.

The quality of the studies was assessed using two methods. One method involved classifying the method of randomisation into four categories and the other method was the Jadad scale of randomisation, blinding and withdrawals.

Two reviewers were involved in the quality assessment.

Data were extracted into a standardised form.

Two reviewers were involved in data extraction.

A random-effects model was used to pooled relative risks (RR) or odds ratios (ORs) for dichotomous data and weighted mean difference (WMD) for continuous data; 95% confidence intervals (CIs) were also calculated. Statistical heterogeneity was assessed with I² and X².

Thirty-six trials (n=2,857 participants) were included in the review (nine RCTs, 12 non-randomised trials and 15 restrospective trials). Jadad scores ranged from zero to 3.

Bicaval versus biatrial transplantation intraoperative parameters: Outcomes significantly reduced in favour of biatrial transplantation were extracorporeal circulation time (WMD 14.55, 95% CI 7.79 to 21.31; nine trials), aortic cross-clamp time (WMD 10.34, 95% CI 2.0 to 18.67; three trials) and operative time (WMD 17.37, 95% CI 2.04 to 32.09; three trials). Ischaemia time was not significantly different.

Bicaval versus biatrial transplantation postoperative parameters: Outcomes significantly reduced in favour of bicaval transplantation were pulmonary capillary artery pressure (WMD -1.06, 95% CI -1.96 to -0.16; five trials), mean pulmonary artery pressure (WMD -3.07, 95% CI -4.95 to -1.19; five trials) and right atrial pressure (WMD -3.16, 95% CI -4.96 to -1.36; seven trials). Cardiac index was not significantly different. Heterogeneity was not reported. Other significant outcomes that were better with bicaval transplantation were postoperative arrhythmia (RR 0.29, 95% CI 0.13 to 0.65, I²=53.1%; seven trials), tricuspid regurgitation (OR 0.43, 95% CI 0.25 to 0.72, I²=70.0%; 17 trials), mortality (RR 0.62, 95% CI 0.46 to 0.82, I²=0%; 12 trials), temporary pacemaker (RR 0.56, 95% CI 0.44 to 0.17; nine trials), permanent pacemaker (RR 0.25, 95% CI 0.09 to 0.69; six trials), bleeding volume (WMD -141.1, 95% CI -245.1 to -37.1; three trials) and length of stay in intensive care unit (WMD -0.49, 95% CI -0.20 to -1.18; four trials). Heterogeneity was not reported.

Total versus biatrial transplantation intraoperative parameters: Outcomes significantly reduced in favour of biatrial transplantation were ischaemia time (WMD 18.91, 95% CI 10.70 to 27.12; eight trials). Extracorporeal circulation time and aortic cross-clam time were not significant. The outcome right atrial pressure was significant in favour of total transplantation (WMD -1.67, 95% CI -2.64 to -0.69; four trials). Cardiac index, pulmonary capillary pressure and mean pulmonary artery pressure were not significant. Heterogeneity was not reported.

Total versus biatrial transplantation postoperative parameters: The outcome right atrial pressure was significantly reduced in favour of total transplantation (WMD -1.67, 95% CI -2.64 to -0.69; four trials). Cardiac index, pulmonary capillary pressure and mean pulmonary artery pressure were not significant. Heterogeneity was not reported. Other significant outcomes that were better with total transplantation were embolism events (RR 0.13, 95% CI 0.02 to 0.96, I²=0%; two trials), tricuspid regurgitation (RR 0.32, 95% CI 0.19 to 0.53, I²=36.7%; eight trials) and permanent pacemaker (RR 0.08, 95% CI 0.02 to 0.34; five trials, heterogeneity not reported).

In prognostic terms, total and bicaval orthotopic heart transplantations were better than biatrial transplantation.

The review addressed a clear question and was supported by appropriate inclusion criteria. Attempts were made to identify all relevant studies by searching several databases. Trials published in any language were included, which reduced potential for language bias. The authors did not state whether they searched for unpublished trials, so publication bias could not be ruled out. Two reviewers were involved in the review process, which limited potential for reviewer bias. Validity was assessed for the randomised controlled trials and the results suggested that the included trials were of low quality. Validity assessment methods were not reported for non-randomised trials. The appropriateness of pooling RCT and non-RCT data was debatable. It would have been useful to see a sensitivity analysis of the RCT data. There was evidence of statistical heterogeneity for some outcomes and heterogeneity was not reported for other outcomes, so the appropriateness of pooling data was unknown.

Aspects of this review were well-conducted, but the reliability of the findings is questionable given the poor quality of the included studies and given that pooling included trials with different study designs.

Practice: The authors stated that the biatrial technique should no longer be considered the gold standard for transplantation and should be used only in selected cases and special situations.

Research: The authors did not state any implications for research.

No external funding.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.