Active Clearance of Chest Tubes After Cardiac Surgery: A Prospective Randomized Controlled Study

Overview

The purpose of this study is to assess the effectiveness of the PleuraFlow® Active Tube Clearance (ATC) technology in reducing the rate of postoperative atrial fibrillation (POAF) among post cardiac surgery patients and to evaluate the impact of Active Tube Clearance (ATC) on other complications, such as retained blood syndrome (RBS), a composite endpoint including re-exploration for bleeding or tamponade, and interventions for hemothorax, pericardial or pleural effusion.

Data will be collected and stored at the department of surgery of Montreal Heart Institute. Only the principal investigator and study coordinators will have access to the database. The primary analysis will be an intention-to-treat (ITT) analysis comparing the POAF rate in the PleuraFlow® group to the POAF rate in the control group. Based on findings from our institutional clinical database at the Montreal Heart Institute, the local incidence of POAF after cardiac surgery is approximately 25% (control group). The proportion in ATC group (the treatment group) is assumed to be 0,2500 under the null hypothesis and 0,1500 under the alternative hypothesis. Group sample sizes of 254 in each group achieve 80% power to detect a difference between the group proportions of 0,1000 using a Chi-Square test with a significance level of 0.0476. This significance level is computed using the O'Brien-Fleming method and accounts for the interim analysis that is planned after 300 randomized subjects have completed their 30-day follow-up. POAF and intervention to treat RBS rates and all other categorical event rates will be compared using chi-square tests. Multiple logistic regressions to adjust for potential confounding factors will also be used. Odds ratio and associated 95% confidence intervals will be computed for descriptive purpose. Goodness of fit will be checked using Hosmer-Lemeshow statistics. Quantitative endpoints will be investigated using Student t-tests. Analysis of covariance may also be used to account for potential confounding factors. Nonparametric tests or data transformation may be used if quantitative endpoints are not normally distributed. Correlations and associated 95% confidence intervals will be computed for descriptive purpose. An interim analysis will be conducted on the first 300 randomized subjects completing their 30-day follow-up. The primary endpoint (POAF rate) will be compared between the PleuraFlow® group and the control group using a chi-square test. The significance level for this test will be 0.0076, as computed using the O'Brien-Fleming method. If the p-value of the chi-square test is below this bound at the interim analysis, the study will be stopped for efficacy. Otherwise, the study will continue up to the planned 508 patients. As a result of this interim look, the final analysis of the primary endpoint would require a p \< 0.0476 to be declared statistically significant. Analysis of the secondary endpoints and other outcomes will be conducted at the 0.05 significance level.