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.