Prosthetic Valve Thrombosis in the ER

Prosthetic valve thrombosis (PVT) is a rare but serious complication of valve replacement, most often encountered with mechanical prostheses. The significant morbidity and mortality associated with this condition warrant rapid diagnostic evaluation. However, diagnosis can be challenging, mainly because of variable clinical presentations and the degree of valvular obstruction. Risk factors for PVT include mechanical and bioprosthetic heart valves or patient-related risk factors. Mechanisms related to acute valve thrombosis include surface, hemostatic, and hemodynamic factors. High-clinical suspicion for PVT must be considered in all patients with a history of mitral or aortic valve replacement plus dyspnea, acute cardiogenic pulmonary edema, loss of functional class, or acute thromboembolism. The clinical presentation and physical findings of PVT are highly variable, often depending on the presence of partial or severe PVT, previous left ventricular ejection fraction, or thromboembolism location. Severe obstruction is typically associated with clinical instability, whereas partial obstruction is often an incidental finding or presents itself as minor thromboembolism. Thrombosis of a bioprosthetic valve has a similar clinical presentation to that of mechanical valve thrombosis. A multimodal approach including transthoracic and transesophageal echocardiography and four-dimensional cardiac computed tomographic imaging is mandatory to diagnose and identify thrombus or pannus. Although surgical treatment is usually preferred in cases of severe obstructive PVT, optimal treatment remains controversial. The different therapeutic modalities available for PVT, heparin, thrombolysis, and surgery will be largely influenced by the severity of valvular obstruction, clinical status, surgery risk, and availability. Right-sided prosthetic valve thrombosis is out of the scope of this chapter.