ACC recommends timely assessment, treatment for mitral regurgitation
Successful care of patients with mitral regurgitation requires proper assessment and treatment by an experienced team, according to an expert consensus decision pathway published in the Journal of the American College of Cardiology.
“This expert consensus decision pathway attempts to integrate the guidelines around a pathway by which patients with mitral regurgitation are identified, they are evaluated, they are assessed for referral for intervention and they are managed long term,” writing committee chair Patrick T. O’Gara, MD, director of strategic planning for the cardiovascular division at Brigham and Women’s Hospital, the Watkins Family distinguished chair in cardiology and professor of medicine at Harvard Medical School, told Cardiology Today.
The expert consensus decision pathway was based on the 2014 American Heart Association/ACC Guideline for the Management of Patients with Valvular Heart Disease and a 2017 focused update.
“This document actually grows out of an ACC survey that suggested that the practicing cardiovascular community had recognition gaps, knowledge gaps and performance gaps around the management of patients with mitral regurgitation,” O’Gara, past president of the ACC, said in an interview.
Directed history and physical examination should be the first steps for assessing a patient with chronic mitral regurgitation, according to the document. Absent or subtle symptoms may lead to patients limiting their physical activity. Exercise testing may help provoke symptoms and validate reduced exercise captivity in patients who are asymptomatic. Echocardiology can also be integrated to reveal worsening mitral regurgitation, elevated pulmonary artery systolic pressures or failure of left ventricular or right ventricular systolic function.
Transthoracic echocardiography can identify the etiology and mechanism of mitral regurgitation, but if the image quality is poor, transesophageal echocardiography can also be used. LV and left atrial volumes and LV dimension measurements should be taken for chamber quantification.
Identifying mitral regurgitation and its etiology is key to managing patients. Primary mitral regurgitation involves principal involvement of the leaflets and/or chordae tendineae in the pathological process such as endocarditis and myxomatous disease. Secondary, or functional, mitral regurgitation is defined as incompetence caused by unfavorable changes in LV shape, size or function with or without annual dilation such as ischemic cardiomyopathy. This can also be caused by pure annular dilation in patients with severe left atrial dilation, which has been termed “atrial functional mitral regurgitation.”
The Carpentier’s classification system should be used to describe leaflet motion once its morphology has been characterized: type I (normal leaflet motion), type II (excessive leaflet motion), type III (restricted leaflet motion), type IIIA (restricted during systole and diastole) and type IIIB (restricted during systole only).
Color-flow Doppler assessment is used to determine the severity of mitral regurgitation during transthoracic or transesophageal echocardiography. Other quantitative parameters to consider include regurgitant volume, effective regurgitant orifice area and regurgitant fraction. Forming a final determination for mitral regurgitation severity should involve a comprehensive approach, according to the document. Cardiac MRI and transesophageal echocardiography should be used to assess mitral regurgitation when transthoracic echocardiography is not definitive.
Chronic mitral regurgitation treatment should be decided upon based on severity and type, disease stage, hemodynamic consequences, patient comorbidities and the team’s experience.
Mitral regurgitation treatment
Primary mitral regurgitation is predominantly treated by surgery. Only one transcatheter mitral valve repair system (MitraClip, Abbott Vascular) is currently approved by the FDA, and it is indicated only for management of symptomatic patients with severe primary mitral regurgitation, reasonable life expectancy and comorbidities that make them poor candidates for surgery. Mitral valve repair is ideal compared with valve replacement in patients with primary mitral regurgitation depending on the surgeon’s skill and the patient’s anatomy, according to the document.
Patients with secondary mitral regurgitation should undergo surgery only after device and medical therapies have been initiated, according to the document.
Surgical techniques for the treatment of primary mitral regurgitation include nonresection techniques with either artificial chord reconstruction or ipsilateral chordal transfer, focal triangular resection with annuloplasty ring, or sliding leaflet valvuoplasty with annuloplasty ring. Second mitral regurgitation can be treated through chord-sparing mitral valve replacement or restrictive remodeling rigid annuloplasty ring.
Successful repair is mainly determined by surgeon experience. Referring patients to a comprehensive valve center with an experienced mitral surgeon is recommended for patients who are asymptomatic with stage C1 mitral regurgitation, those who want a robotic approach or a minimally invasive procedure or patients with complex mitral pathoanatomy.
Assessing functional outcomes, durability and survival requires long-term follow-up of patients after transcatheter or surgical intervention.
“Multidisciplinary heart teams composed of experienced surgeons, interventionalists, expert imagers and others are vital to the provision of advanced care to challenging patients at comprehensive valve centers,” O’Gara and colleagues wrote. “Closing the existing knowledge and treatment gaps in the management of these patients requires ongoing collaboration across primary care, cardiology and cardiac surgical specialties, as emerging technologies for the treatment of [mitral regurgitation] are evaluated with a dedicated focus on high-quality outcomes.” – by Darlene Dobkowski
For more information:
Patrick T. O’Gara, MD, can be reached at Brigham and Women’s Hospital, Cardiovascular Medicine, 75 Francis St., Boston, MA 02115; email: firstname.lastname@example.org.
Disclosure s : O’Gara reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.