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HFrEF with severe secondary mitral regurgitation and left bundle branch block — ABIM Board MCQ

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HardGuideline-Directed Medical TherapyHFrEF with severe secondary mitral regurgitation and left bundle branch blockABIM Board

A 58-year-old woman with nonischemic dilated cardiomyopathy is evaluated after a second hospitalization for heart failure. Cardiomyopathy was diagnosed 5 months ago. She has subsequently taken maximally tolerated sacubitril-valsartan, carvedilol, spironolactone, and dapagliflozin; furosemide maintains euvolemia. She remains adherent but has dyspnea with ordinary activity and no symptoms at rest. Blood pressure is 108/68 mm Hg, and pulse is regular at 64/min. Examination shows a laterally displaced apical impulse and a holosystolic apical murmur without jugular venous distention or edema. ECG shows sinus rhythm and left bundle branch block with a QRS duration of 168 milliseconds. Echocardiography shows a left ventricular ejection fraction of 28%, left ventricular end-systolic diameter of 61 mm, severe secondary mitral regurgitation, and pulmonary artery systolic pressure of 48 mm Hg. Transesophageal echocardiography shows anatomy suitable for transcatheter edge-to-edge repair. Coronary angiography shows no obstructive coronary artery disease. She is otherwise healthy and has an anticipated survival exceeding 1 year. Which of the following is the most appropriate management strategy?

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Correct answer: E — Implant a cardiac resynchronization therapy defibrillator, continue medical therapy, and reassess for transcatheter repair if severe symptomatic regurgitation persists

This patient has persistent NYHA class III HFrEF despite more than 3 months of comprehensive, maximally tolerated guideline-directed medical therapy. Her LVEF is 28%, she is in sinus rhythm, and she has LBBB with a QRS duration of 168 milliseconds; these are class I features for cardiac resynchronization therapy. Because she also has a primary-prevention defibrillator indication and meaningful anticipated survival, CRT-D is appropriate. Her mitral regurgitation is secondary to left ventricular dysfunction rather than primary leaflet disease. Resynchronization can promote reverse remodeling and improve secondary regurgitation; therefore, indicated device therapy should precede mitral intervention. If severe symptomatic regurgitation persists after CRT and continued medical therapy, her LVEF, LV dimension, pulmonary pressure, and valve anatomy make transcatheter edge-to-edge repair reasonable. A is inadequate because she remains highly symptomatic with a class I CRT indication. B bypasses device optimization, and isolated mitral surgery has a limited role in secondary regurgitation without another indication for cardiac surgery. C proceeds to transcatheter repair before completing indicated CRT and delays defibrillator protection. E provides defibrillation but not biventricular resynchronization, thereby failing to address the marked LBBB-associated dyssynchrony that may improve both ventricular function and regurgitation.

Reference: 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure (April 2022) — https://www.heart.org/-/media/832EA0F4E73948848612F228F7FA2D35.pdf 2020 ACC/AHA Heart Valve Disease Guideline: Key Perspectives, Part 2 (December 2020) — https://www.acc.org/latest-in-cardiology/ten-points-to-remember/2020/12/16/22/00/2020-acc-aha-vhd-gl-pt-2-gl-vhd Secondary MR and Percutaneous Interventions: Key Points (November 2024) — https://www.acc.org/Latest-in-Cardiology/ten-points-to-remember/2024/11/06/15/06/secondary-mitral-regurgitation-updated