Coronary Flow Velocity Reserve by Stress Echocardiography: The Prognostic Key of Multiple Heart Diseases

Although evaluating coronary flow velocity reserve (CFVR) via stress echocardiography (SE) has been available for over three decades, its integration into routine clinical practice remains underutilized globally despite substantial technical and conceptual advances. A diminished CFVR serves as a potent predictor of major adverse cardiovascular events (MACE) and all-cause mortality across a broad spectrum of cardiovascular diseases. Its prognostic value is particularly robust in epicardial coronary artery disease, heart failure, coronary microvascular dysfunction, nonischemic cardiomyopathies, metabolic disorders (e.g., diabetes mellitus and obesity), hypertrophic cardiomyopathy, systemic autoimmune diseases, and cardiac allograft vasculopathy. This comprehensive narrative review details the technical methodology for interrogating resting and stress-induced coronary flow velocity (CFV) under physical and pharmacological protocols. Furthermore, it highlights the clinical applicability of CFVR by synthesizing single-center observational insights with evidence from large-scale multicenter registries, advocating for its broader adoption into diagnostic workflows to refine risk stratification and guide therapeutic management.