What are the consequences of papillary muscle rupture?

From the Guidelines

Papillary muscle rupture is a medical emergency that requires immediate surgical intervention, with mitral valve replacement being the preferred treatment, as it improves survival and ventricular function compared to medical therapy alone 1. Papillary muscle rupture is a life-threatening complication of myocardial infarction that typically occurs 2-7 days after a heart attack, causing acute mitral valve regurgitation and potentially cardiogenic shock. Patients present with sudden severe shortness of breath, hypotension, and a new heart murmur.

Key Points

• Diagnosis involves echocardiography, which shows severe mitral regurgitation and the ruptured papillary muscle.
• Initial management includes stabilization with vasopressors, inotropes, and mechanical circulatory support such as an intra-aortic balloon pump.
• The posterior papillary muscle ruptures more commonly than the anterior one because it typically has a single blood supply from the right coronary artery, making it more vulnerable to ischemic damage.
• Urgent surgical mitral valve replacement is the treatment of choice, as it improves survival and ventricular function, with five-year survival rates averaging 60% to 70% 1. Some key considerations in the management of papillary muscle rupture include:
• The importance of prompt diagnosis and treatment to prevent further myocardial injury, organ failure, and death.
• The use of intra-aortic balloon pump placement to support the patient during preparation for surgery and coronary angiography.
• The potential for mitral valve repair in selected cases, although valve replacement is generally the preferred treatment. According to the 2013 ACCF/AHA guideline for the management of ST-elevation myocardial infarction, suitable patients with papillary muscle rupture should be considered for urgent surgery, with mitral valve replacement being the preferred treatment 1.

From the Research

Papillary Muscle Rupture Overview

• Papillary muscle rupture (PMR) is a rare and serious mechanical complication of acute myocardial infarction, often requiring immediate surgical intervention 2, 3, 4, 5, 6.
• The condition can lead to severe mitral regurgitation, cardiogenic shock, and high mortality rates if left untreated or not managed properly 2, 3, 5.

Treatment Options

• Surgical repair or replacement of the mitral valve is traditionally considered the first-line therapy for PMR 2, 3, 4, 5, 6.
• Mitral valve repair is a viable alternative to replacement, offering lower operative mortality, shorter hospitalization time, and similar incidence of postoperative complications 5, 6.
• Percutaneous mitral valve repair with devices like MitraClip is also an established therapy for treating degenerative and functional mitral regurgitation, and can be used in patients with PMR who are at high surgical risk 2.

Outcomes and Prognosis

• Operative mortality rates for PMR patients undergoing surgical intervention can be high, ranging from 12.5% to 17.5% 3, 5.
• Long-term outcomes for patients undergoing mitral valve repair for PMR are generally good, with estimated 1-, 5-, 10-, and 15-year survival rates of 100%, 83.3%, 66.7%, and 44.4%, respectively 6.
• The type of PMR and the quality of adjacent tissue can determine the feasibility and durability of repair 6.

Comparison of Mitral Valve Replacement and Repair

• A meta-analysis comparing mitral valve replacement (MVR) and mitral valve repair (MVr) for PMR post-myocardial infarction found that MVr had lower operative mortality, shorter hospitalization time, and similar incidence of postoperative complications compared to MVR 5.
• However, MVR was often performed in more critical patients, and the overall survival and quality of life benefits between the two procedures are still uncertain 5.