Case Report:
A 72-year-old male presented to the emergency room with one-week history of progressive exertional dyspnea and lower extremity edema. His past medical history included mitral valve replacement (MVR) eight years ago [27mm Carpentier-Edward (CE) Magna] for severe mitral regurgitation (MR) due to myxomatous mitral valve disease, paroxysmal atrial fibrillation (pAF), and non-ischemic cardiomyopathy with LVEF 30-35% s/p dual chamber implantable cardioverter-defibrillator (ICD). Two years prior to the current admission, he presented with multiple ICD shocks secondary to atrial tachycardia. Work up revealed multiple echodensities on the mitral bioprosthetic valve with BPV stenosis and a transmitral mean gradient of 7mm Hg at heart rate 61 beats per min (bpm). After a detailed workup he was diagnosed with non-bacterial thrombotic endocarditis [Figure 1, Video 1-2]. He was treated with unfractionated heparin (UFH) for two weeks. However, due to lack of improvement, he underwent re-do MVR with a similar valve (27mm CE Magna) and was discharged on warfarin with international normalized ratio (INR) goal 2-3. One month prior to the current presentation, warfarin was interrupted perioperatively for total right hip replacement surgery.
At the time of his current admission, physical examination revealed a chronically ill appearing man with blood pressure 121/94 mmHg, irregularly irregular rhythm with heart rate of 84 bpm, normal S1 and S2 without murmurs, jugular venous pressure 12 cm of water, bibasilar crackles, and bilateral 4+ pitting pedal edema. He was started on intravenous (IV) diuretics and admitted to the cardiology inpatient service. Laboratory evaluation included normal blood counts and metabolic panel, elevated B-type natriuretic peptide (2,751 pg/ml) and INR (2.3). Transthoracic echocardiogram (TTE) showed LVEF 30-35%, mitral BPV leaflet thickening with mean gradient of 10 mmHg at heart rate of 65bpm, and multiple echo densities suspicious for vegetation or thrombus [Figure 2A & 2B, Video 3]. Transesophageal echocardiogram (TEE) revealed severe BPV leaflet thickening with restricted motion, a large echo density encompassing both leaflets with a mobile component measuring 1.4 x 0.4 cm and a mean gradient of 9.2 mmHg at heart rate of 67 bpm [Figure 2C, 2D, 3A, 3B, Video 4-6)]. A detailed laboratory work-up including infectious, rheumatologic, immunologic, and allergic (for bovine pericardial valve) tests was unremarkable. Given echocardiographic findings of BPV stenosis and echodensities and an extensive negative work up for other etiologies, he was treated empirically for BPVT with UFH and eventually transitioned to warfarin with an increased INR goal of 2.5-3.5. After three months of uninterrupted anticoagulation, a repeat TEE showed complete resolution of BPV thickening and echo density with significant reduction in the mean transvalvular gradient to 4 mmHg at heart rate of 65 bpm [Figure 4, and Video 7-8] , indicating that the cause of the patient’s initial presentation was likely BPVT. The patient is currently asymptomatic and is followed clinically and with regular surveillance TTE.