Exploring the Role of Atrial Functional MR in Mitral Regurgitation Pathology

It’s another session of CardioNerds Rounds! In these rounds, Dr. Natalie Stokes (Formerly FIT at University of Pittsburgh and now General Cardiology Faculty at University of Pittsburgh) and Dr. Karan Desai (formerly FIT at University of Maryland and now General Cardiology faculty at Johns Hopkins) join Dr. Rick Nishimura (Professor of Medicine at Mayo Clinic) to discuss the nuances of managing mitral regurgitation through real cases. Dr. Nishimura has been an author or Chair of the ACC/AHA valve guidelines going back 20 years and has been recognized internationally as one of the world’s best educators, so you don’t want to miss the #NishFactor on these #CardsRounds! Audio editing by CardioNerds academy intern, Pace Wetstein. This episode is supported with unrestricted funding from Zoll LifeVest. A special thank you to Mitzy Applegate and Ivan Chevere for their production skills that help make CardioNerds Rounds such an amazing success. All CardioNerds content is planned, produced, and reviewed solely by CardioNerds. Case details are altered to protect patient health information. CardioNerds Rounds is co-chaired by Dr. Karan Desai and Dr. Natalie Stokes.  Speaker disclosures: None Challenging Cases - Atrial Fibrillation with Dr. Hugh Calkins CardioNerds Rounds PageCardioNerds Episode PageCardioNerds AcademyCardionerds Healy Honor Roll CardioNerds Journal ClubSubscribe to The Heartbeat Newsletter!Check out CardioNerds SWAG!Become a CardioNerds Patron! Show notes - Mitral Regurgitation with Dr. Rick Nishimura Case #1 Synopsis: A man in his 70s with a history of non-ischemic cardiomyopathy (last known LVEF 15-20%) and atrial fibrillation, presented with decompensated heart failure in the setting of moderate to severe mitral regurgitation. He was diuresed, transitioned to GDMT, and referred to cardiac rehabilitation. Over the next 6 months, he continued to have debilitating dyspnea (NHYA Class IIIa) and his outpatient physicians were limited on titrating GDMT further due to hypotension. A TEE was done which demonstrated EF 15%, severe MR by color and quantitation (EROA of 0.5 cm2; Regurgitant Volume of 65 mL), systolic flow reversal in the pulmonary vein and severe tricuspid regurgitation. We were asked how we would approach this case Case #1Takeaways In attempting to keep the evaluation of chronic mitral regurgitation relatively simple, we should ask ourselves three primary questions: (1) What is causing the MR; (2) How much MR is there; and (3) What is the hemodynamic consequence of the MR.To the first question of what is the etiology of the MR – a simple framework is to think of the etiology as an issue of the valve (primary) or an issue of the ventricle/atria (secondary). There is further classification that can be made based on the Carpentier Classification which speaks to the valve leaflet movement and position (normal leaflet motion, excessive leaflet motion [e.g., prolapse], or restricted in systole and/or diastole [e.g., rheumatic heart disease]).During rounds, Dr. Nishimura provided some historical context in that the original valve guidelines had recommendations for intervention on primary mitral regurgitation and not secondary – given that it is considered a disease of the ventricle. Trials like the COAPT trial have greatly shifted our practice in treating secondary mitral regurgitation. Though, we have to be familiar with which patients with secondary MR would truly derive benefit from mitral valve interventionIn regards to the COAPT trial, patients with moderate to severe (3+) or severe (4+) mitral regurgitation who remained symptomatic despite maximally tolerated guideline-directed medical therapy (GDMT) were included. Dr. Nishimura makes the point that about one-third of patients intended to be enrolled in the trial were not included because they improved so much on GDMT. And thus, when evaluating patients for consideration of mitral valve intervention in secondary MR – a...