Bioprosthetic Aortic Valve Thrombosis and Literature Review

Abstract

An 83-year-old gentleman with a history of 23-mm Hancock-II-bioprosthetic aortic valve (BAV) replacement ten-years prior presented with symptoms of dyspnea and lower extremity edema. During the preceding seven-years, he had been noted to have asymptomatic increased mean transvalvular gradients (MG; 36–50 mmHg) felt to be due to either early bioprosthetic degeneration, pannus formation, or patient–prosthesis mismatch. An echocardiogram at the time of symptom development demonstrated significant flow acceleration through the aortic valve, mild regurgitation, and severely increased MG (48 mmHg) with prolonged acceleration time (AT, 140 msec). A trial of warfarin anticoagulation resulted in dramatic improvement after only 6 weeks with laminar flow through the AV, near-total resolution of regurgitation, and a decrease in MG to 14 mmHg and AT to 114 msec. These findings strongly suggest that BAV thrombosis was the predominant mechanism responsible for the longstanding high MG. Our case highlights that BAV thrombosis should be considered in the differential of elevated gradients regardless of the age of prosthesis, and that a trial of warfarin anticoagulation may be beneficial even if elevated gradients have been present for a prolonged period. Valvular gradients are often abnormal long before a formal diagnosis; however, these may reverse quickly with anticoagulation therapy.

Hydrogel‐polyurethane fiber composites with enhanced microarchitectural control for heart valve replacement

“…Current bioprosthetic valves do not require patients to be on long‐term anticoagulant therapy and as such, this 38% reduction in platelet attachment compared to the glutaraldehyde‐fixed control is anticipated to confer an even greater degree of thromboresistance. This finding is even more significant in light of investigations into subclinical thrombus in tissue‐based bioprosthetic valves that are suggested to have a role in major failure mechanisms such as structural degeneration 62,63 . Significantly, areas of calcification in not only bioprosthetic valves, but also in attempts in previous polymeric valves have been correlated with subclinical microthrombus that may provide initial nucleation sites 64 .…”

“…This finding is even more significant in light of investigations into subclinical thrombus in tissue-based bioprosthetic valves that are suggested to have a role in major failure mechanisms such as structural degeneration. 62,63 Significantly, areas of calcification in not only bioprosthetic valves, but also in attempts in previous polymeric valves have been correlated with subclinical microthrombus that may provide initial nucleation sites. 64 Thus, the enhanced thromboresistance serves not only to mitigate thrombus based failure, but also aid in mitigating calcification-based failure.…”

Hydrogel-polyurethane fiber composites with enhanced microarchitectural control for heart valve replacement

“…This finding is even more significant in light of investigations into subclinical thrombus in tissue based bioprosthetic valves that are suggested to have a role in major failures mechanisms such as structural degeneration. 62,63 Significantly, areas of calcification in not only bioprosthetic valves, but also in attempts in previous polymeric valves have been correlated with subclinical microthrombus that may provide initial nucleation sites. 64 Thus, the enhanced thromboresistance serves not only to mitigate thrombus based failure, but also aid in mitigating calcification-based failure.…”

Recent Advances in the Modification and Improvement of Bioprosthetic Heart Valves

“…[94][95][96][97] Moreover, clinical thrombosis in BHVs can lead to restricted leaflet motion and valve dysfunction, leading to an increase in the average transvalvular pressure and the heart load, ultimately resulting in heart failure, which can be lifethreatening in severe cases. [98]…”