Incidence, presentation and risk factors of late postoperative pericardial effusions requiring invasive treatment after cardiac surgery

OBJECTIVES: Occurrence and risk factors of late postoperative pericardial effusions requiring invasive treatment, i.e. pretamponade and tamponade, following cardiac surgery are incompletely described in current literature. The purpose of this study was to define the incidence and presentation of late pretamponade and tamponade as well as to outline significant predisposing factors. METHODS: A cohort of 1356 consecutive cardiac surgery patients treated in a tertiary academic centre between January 2013 and December 2014 was followed up for 6 months after surgery. Pericardial effusion was considered late when presenting after the 7th postoperative day. The incidence, timing and risk factors, as well as symptoms and clinical findings associated with late pretamponade and tamponade in patients surviving at least 7 days was analysed. RESULTS: Of 1308 patients included in the analysis, 81 (6.2%) underwent invasive treatment for late postoperative pericardial effusion, 27 (2.1%) for pretamponade and 54 (4.1%) for tamponade, respectively, with a median delay of 11 (range 8-87) days after the primary operation. Haemodynamic instability was present in 34.6%, signs of cardiac chamber compression in 54.3% and subjective symptoms, mostly dyspnoea, in 56.8% of patients, respectively. Treated patients were younger, had lower EuroSCORE-II rating, less coronary disease, better cardiac function, higher preoperative haemoglobin values and had mostly undergone elective surgery involving cardiac valves. In multivariable analysis, independent risk factors were single valve surgery and high preoperative haemoglobin level, whereas age 60-69 years was associated with lower risk. CONCLUSIONS: Younger, generally healthier patients undergoing valve surgery are at greatest risk for developing late tamponade or pretamponade.