Statistical analysis

Standard descriptive statistical analyses were used. Continuous data are presented as a mean ± standard deviation and categorical data are presented as proportions. Comparisons between patients who underwent subxiphoid and thoracotomy incisions were performed between the groups using unpaired two-sided Student’s t tests, Chi-squared tests or Fisher’s exact tests. Specifically, the two groups were compared in terms of the amount of fluid drained in the operating room, the time to extubation, the amount of intravenous morphine equivalents required within 48 h, hospital length of stay and perioperative mortality. Moreover, the development of a recurrent moderate or large pericardial effusion and the need for a repeat pericardial window procedure were compared between the two groups. All reported P values are two-sided and considered significant if <0.05. All analyses were performed using Stata/MP version 11.2 (StataCorp, College Station, TX).