Pleural Effusions in Patients With Congestive Heart Failure: Frequency, Pathogenesis, Diagnosis, and Implications

Abstract

Patients with cardiac disease frequently develop pleural effusions; the incidence is approximately 500,000 cases per year in the United States. These effusions often represent important clinical events for patients, indicating that either there has been an acute change in the patient's clinical status or the patient's chronic management program needs review. These effusions usually develop in both the right and left hemithorax but can be unilateral. The pathogenesis involves increased fluid transfer from parietal pleural capillaries into the pleural space and possibly decreased pleural fluid uptake into parietal pleural lymphatic structures. The increased fluid transfer develops due to increased capillary pressure secondary to elevated venous outflow pressure and secondary to decreased lymphatic flow into central vessels secondary to heart failure. Most pleural effusions associated with heart failure are transudates, but 20% to 25% have increased protein and lactate dehydrogenase levels suggesting an exudative process. Additional testing can clarify the situation and requires calculation of the serum albumin to pleural fluid albumin gradient or measurement of N-terminal pro-brain natriuretic peptide in the pleural fluid. An albumin gradient of greater than 1.2 g/dL suggests that the fluid is a transudate. The presence of a pleural effusion in a hospitalized patient at discharge is associated with an increased likelihood of rehospitalization and mortality within the next year. Patients with large symptomatic pleural effusions may require therapeutic thoracentesis. Recurrence of symptomatic effusions presents a management dilemma that might require repeated thoracenteses, indwelling intrapleural catheter placement, or other management steps used in advanced chronic heart failure.

Pleural effusion in severe aortic stenosis: marker of an adverse haemodynamic constellation and poor prognosis

“…However, patients with PE also had higher PVR, right ventricular end‐diastolic pressure and mean right atrial pressure, that is, already more advanced AS‐related ‘cardiac damage’ 11,12 with combined pre‐ and post‐capillary pulmonary hypertension in many cases. The fluid balance in the pleural space depends not only on left atrial pressure but also on right atrial pressure because a higher right atrial pressure limits lymphatic drainage 13 . Notably, there was no evidence of a difference in oncotic pressure between patients with and without PE, and therefore central haemodynamics were most likely the key drivers of pleural fluid formation in the present cohort ( Figure ).…”

“…The fluid balance in the pleural space depends not only on left atrial pressure but also on right atrial pressure because a higher right atrial pressure limits lymphatic drainage. 13 Notably, there was no evidence of a difference in oncotic pressure between patients with and without PE, and therefore central haemodynamics were most likely the key drivers of pleural fluid formation in the present cohort (Figure 2). For a long time right ventricular Pleural effusion in severe aortic stenosis: marker of an adverse haemodynamic constellation and poor prognosis dysfunction/failure and high PVR were thought to protect the lung from pulmonary congestion/edema.…”

“…The association between low haemoglobin and PE would be plausible in this context. On the other hand, the association between impaired renal function and mild anaemia may also be explained by advanced heart failure, and unilateral PE is well known to occur in certain heart failure patients 13 . Furthermore, unilateral PE, which is the typical scenario in the context of malignancy, was not significantly associated with all‐cause mortality, which we would expect if cancer would have been the driver of mortality.…”

“…On the other hand, the association between impaired renal function and mild anaemia may also be explained by advanced heart failure, and unilateral PE is well known to occur in certain heart failure patients. 13 Furthermore, unilateral PE, which is the typical scenario in the context of malignancy, was not significantly associated with all‐cause mortality, which we would expect if cancer would have been the driver of mortality. In contrast, bilateral PE, typically associated with heart failure, and associated with a particularly poor haemodynamic status in our patients, was associated with substantially increased mortality.…”

Expert Review on Contemporary Management of Common Benign Pleural Effusions

“…The interstitial fluid, in turn, is transferred to the pleural cavity via the visceral pleura. 15 16 Concurrently, a decrease in fluid removal through the parietal pleural lymphatics occurs because of an elevation in systemic venous pressures. Male gender, an estimated systolic pulmonary artery pressure >55 mm Hg by echocardiography, and serum levels of NT-proBNP >3,500 pg/mL were associated with PE development in a large Spanish registry of patients with acute HF.…”