Functional Mitral Regurgitation in the Transcatheter Era: Diagnostic and Therapeutic Pathways

Abstract

Functional mitral regurgitation (FMR) is a common condition with significant prognostic implications, primarily driven by left atrial or ventricular remodeling secondary to ischemic or non-ischemic cardiomyopathies. While guideline-directed medical therapy (GDMT) remains the cornerstone of management, reducing mitral regurgitation severity in up to 40-45% of cases, additional interventions are often necessary. In patients where atrial fibrillation (AF) or ventricular dyssynchrony due to abnormal electrical conduction contributes to disease progression, guideline-directed AF management or cardiac resynchronization therapy plays a pivotal role. For those with persistent moderate to severe MR and unresolved symptoms despite optimal GDMT, percutaneous intervention may be warranted, provided specific clinical and echocardiographic criteria are met. This review highlights a precision-medicine approach to patient selection for transcatheter treatment of functional mitral regurgitation (FMR), emphasizing the integration of clinical characteristics with advanced multimodal imaging, including echocardiography, cardiac magnetic resonance, and computed tomography. In anatomically or clinically complex cases, complementary use of these imaging modalities is essential to ensure accurate phenotyping and procedural planning. Once a suitable candidate for percutaneous intervention has been identified, we provide a detailed overview of current transcatheter strategies, with a focus on device selection tailored to anatomical and pathophysiological features. Finally, we discuss emerging technologies and evolving therapeutic paradigms that are shaping the future of individualized FMR management.

Keywords: functional mitral regurgitation; multimodal imaging; percutaneous treatment.

Figure 1

Patient selection for transcatheter treatment of functional mitral regurgitation. Abbreviations: FMR = functional mitral regurgitation; GDMT = guideline-directed medical therapy; MR = mitral regurgitation.

Figure 2

Key procedural steps of transcatheter edge-to-edge repair using the PASCAL system (Edwards Lifesciences). (A) Ultrasound-guided femoral venous puncture using a micropuncture set. (B) Tenting of the interatrial septum during transseptal puncture under transesophageal echocardiography (TEE) guidance (bicaval view), performed using a Mullins transseptal sheath and a Brockenbrough needle. (C) Ultrasound-guided advancement of the PASCAL delivery system (Edwards Lifesciences) into the left atrium (D) Fluoroscopic view showing the PASCAL implant positioned in the left atrium after successful transseptal access. (E) Grasping of the mitral valve leaflets using the PASCAL device under TEE guidance (mid-esophageal commissural view, ~60°), with the paddles and clasps visible. (F) Three-dimensional en face view from the left atrium (LA) showing the mitral valve with the PASCAL device implanted, demonstrating effective leaflet approximation and reduction of mitral regurgitation.

Figure 3

Timeline of transcatheter mitral valve replacement devices (2012–2024). Adapted from TCT 2024 presentations by Granada and M. Leon.