Recurrent Unilateral Transudative Pleural Effusion Due to Low Flow, Low Gradient Severe Aortic Stenosis

BACKGROUND In symptomatic severe aortic stenosis (AS), the majority of patients have high gradient AS. However, some patients have an AS gradient less than 40 with a valve area under 1.0 cm². For patients with a low gradient, severe AS is difficult to detect and requires a high index of suspicion. Transcatheter aortic valve replacement (TAVR) is currently recommended for patients with moderate to high risk AS according to the Society of Thoracic Surgery (STS) risk score. CASE REPORT Here we present the case of an 86-year-old female with recurrent pleural effusion over the course of 2-year; she had multiple thoracentesis procedures and was being considered for a pleurodesis. Later the patient was found to have severe AS; an echocardiogram showed an aortic valve (AV) area of 0.67 cm², AV mean gradient of 34 mmHg, and ejection fraction of 75%. The patient underwent a diagnostic cardiac catheterization and was treated with TAVR. CONCLUSIONS The diagnosis was made after exclusion of all other causes of unilateral pleural effusion and was confirmed by improvement of effusion following the TAVR procedure.