Cardiac related pleural effusions: a narrative review.

Background and Objective: Pleural effusions (PEs) are commonly seen in various pathologies and have a significant impact on patient health and quality of life. Unlike for malignant PEs, non-malignant PEs (NMPEs) do not have well-established guidelines. Much of the evidence base in this field is from a handful of randomised controlled trials (RCTs) and the majority are from retrospective cohort analyses and cases series. Cardiac related PEs fall within the entity of NMPEs and the aim of this narrative review is to gather the existing evidence in the field of congestive heart failure (CHF), pericarditis and post-cardiac injury syndrome (PCIS). This narrative review investigates the pathophysiology, diagnostic criteria and treatment options for the various cause of cardiac related PEs. Methods: This narrative review is based on a comprehensive literature search analysing RCTs, prospective and retrospective cohort analyses and published case series. Key Content and Findings: CHF related PEs have a substantial mortality rate and carry a worse prognosis if the PEs are bilateral and transudative in nature. Light's criteria have often shown to misclassify transudative effusions in CHF (pseudo-exudates) and hence measuring serum-pleural albumin gradient is an invaluable tool to accurately identify transudates. Elevated serum and pleural N-terminal pro-B type natriuretic peptide (NT-proBNP) has shown increasing evidence of correctly identifying PEs secondary to CHF. However, they should be considered with the pre-test probability of CHF. Therapeutic thoracentesis and indwelling pleural catheter (IPC) placement may be necessary if medical management has failed. PEs can also occur secondary to pericarditis and are often small, bilateral and exudative. PCIS also results in PEs and are commonly seen in post-coronary artery bypass graft (CABG) surgery. Both entities need management of the underlying cause first, but in cases where PEs are refractory, individualised pleural interventions may be necessary. Conclusions: This comprehensive narrative review provides valuable insights into the aetiology, diagnosis and management of PEs secondary to CHF, pericarditis and PCIS. The aim is to enhance the clinicians' knowledge of this complex and controversial topic to improve patient care of cardiac-related PEs. Ongoing trials in this field will be able to provide valuable insights.