(Vienna, 23-06-2026) – A recent study by MedUni Vienna shows that the diagnosis of a specific form of heart valve disease, known as arterial functional mitral regurgitation, has so far been inconsistent. These differences in assessment have a direct impact on the prognosis and treatment decisions. The research findings, published in the Journal of the American College of Cardiology, provide, for the first time, the scientific basis for a standardised definition of the condition and thus for a more precise diagnosis and individualised treatment approaches.
Although atrial functional mitral regurgitation (AfMR) has been recognised for several years as a form of functional mitral regurgitation, there is as yet no international consensus on how exactly this condition should be defined. This uncertainty has far-reaching consequences: depending on which criteria are used, diagnosis, assessment of severity, morphological classification and prognosis vary considerably. Consequently, prevalence figures also vary: depending on the definition, AfMR occurs in between two and 62 per cent of patients with heart valve disease – an indication of the enormous need for clarification, which cardiologists at the Department of Medicine II at MedUni Vienna have now systematically investigated for the first time.
72 different definitions identified
In their comprehensive literature review, the researchers found that 72 different definitions of atrial functional mitral regurgitation have been used to date. When these definitions were subsequently compared with data from more than 10,500 patients who had undergone an echocardiogram between 2010 and 2020, the far-reaching consequences of inconsistent assessment became clear: "We were able to show that even small differences in diagnostic criteria lead to significant differences in clinical classification," explains Sophia Koschatko, first author of the study. "This affects not only the question of who is actually considered an AfMR patient, but also what morphological changes are present and how high the risk of death is."
Of particular relevance was the finding that structural enlargement of the left atrium is the key feature of the condition, whilst the mere presence of atrial fibrillation alone is insufficient to reliably diagnose AfMR. The definition provided by the "American College of Cardiology", a leading US professional society for cardiology, which also takes into account patients with restricted heart valve mobility, proved to have particularly strong prognostic value.
New evidence for diagnosis, treatment planning and guidelines
"Our results show that a uniform and morphologically sound definition is urgently needed," emphasises Philipp Bartko, last author of the study. "Only when it is clearly defined which patients actually have atrial functional mitral regurgitation can we make more targeted treatment decisions, apply interventional and surgical procedures more precisely, and compare studies more effectively." The study results therefore have immediate implications for modern heart valve medicine, the further development of international guidelines – and the individualised treatment of patients.
Publication: Journal of the American College of Cardiology
Atrial Functional Mitral Regurgitation: Effect of Phenotype Definition on Classification, Valve Features, and Prognosis.
Sophia Koschatko, Gregor Heitzinger, Charlotte Jantsch, Christoph Torrefranca, Laurenz Hauptmann, Maximillian Autherith, Varius Dannenberg, Kseniya Halavina, Katharina Mascherbauer, Martin Hülsmann, Noemi Pavo, Caglayan Demirel, Christian Hengstenberg, Georg Goliasch, Christian Nitsche und Philipp E. Bartko.
DOI: 10.1016/j.jacc.2026.01.057
https://www.jacc.org/doi/10.1016/j.jacc.2026.01.057