Between Scylla and Charybdis in atrial functional mitral regurgitation

The prevalence of mitral regurgitation (MR) tends to rise with age, and its impact on the elderly population is a subject of clinical significance. Appropriate management is crucial to improve outcomes and the quality of life for these individuals. For operable patients, the gold standard remains surgery, but in high-risk/inoperable patients, transcatheter edge-to-edge repair (TEER) has been shown to be a safe and feasible option, especially if anatomical criteria are favourable (Class IIa indication1). Of note, in the setting of secondary mitral regurgitation, the COAPT study, a randomised control trial comparing TEER with medical therapy, revealed the prognostic benefit of TEER in secondary MR patients2. In recent years, atrial functional mitral regurgitation (AFMR) has been identified as a distinct phenotype in the field of secondary MR with specific echocardiographic criteria (normal left ventricular [LV] systolic function, no or mild LV enlargement without wall abnormality, and moderate or severe left atrial [LA] enlargement3). Until now, neither COAPT nor any other study has described the specific results of TEER in AFMR patients.

In this issue of EuroIntervention, Tanaka and colleagues