nonvalvular

Nonvalvular is a medical descriptor used to indicate the absence of disease or prosthetic involvement of the heart valves in a given condition. In cardiology, the term is most commonly applied to atrial fibrillation, distinguishing it from atrial fibrillation associated with certain valve problems or prosthetic valves. The distinction is important because it can influence prognosis and treatment, particularly choices around anticoagulation.

In the context of atrial fibrillation, nonvalvular atrial fibrillation (NVAF) typically refers to AF occurring without moderate-to-severe rheumatic mitral valve disease or the presence of a mechanical heart valve. Some guidelines also exclude certain bioprosthetic valves or recent valve replacements, since these scenarios may be considered differently for anticoagulation decisions. The key idea is that the underlying valvular pathology directly affecting clot risk and the need for long-term anticoagulation differs from NVAF.

Outside atrial fibrillation, nonvalvular may be used to describe other heart conditions not primarily caused by valve disease, or to distinguish findings not related to valvular pathology. However, the term’s most common and standardized use is in relation to AF.

Clinical implications include risk assessment for stroke and decisions about anticoagulation. In NVAF, oral anticoagulants, including direct oral anticoagulants (DOACs) or warfarin, are commonly used based on risk scores, while certain valvular conditions may require alternative management. The nonvalvular label is a guideline-driven simplification that helps categorize patients for evidence-based therapy.