Mechanical Complications of Acute Myocardial Infarction: A Scientific Statement From the American Heart Association

Abstract

Over the past few decades, advances in pharmacological, catheter-based, and surgical reperfusion have improved outcomes for patients with acute myocardial infarctions. However, patients with large infarcts or those who do not receive timely revascularization remain at risk for mechanical complications of acute myocardial infarction. The most commonly encountered mechanical complications are acute mitral regurgitation secondary to papillary muscle rupture, ventricular septal defect, pseudoaneurysm, and free wall rupture; each complication is associated with a significant risk of morbidity, mortality, and hospital resource utilization. The care for patients with mechanical complications is complex and requires a multidisciplinary collaboration for prompt recognition, diagnosis, hemodynamic stabilization, and decision support to assist patients and families in the selection of definitive therapies or palliation. However, because of the relatively small number of high-quality studies that exist to guide clinical practice, there is significant variability in care that mainly depends on local expertise and available resources.

Keywords: AHA Scientific Statements; ST-segment–elevation myocardial infarction; aging; heart rupture; heart septal defects; mitral valve insufficiency; percutaneous coronary intervention; reperfusion; ventricular.

Figure 1.

Timeline of the incidence and mortality rates of mechanical complications of acute myocardial infarction during different reperfusion strategies. STEMI = ST-elevation myocardial infarction.

Figure 2.

Clinical characteristics of mechanical complications of acute myocardial infarction.

Figure 3.

Techniques for surgical repair of post infarct ventricular septal defect. A. Daggett and B. David repair. Note: for the Daggett repair and in the first two images of panel A, stitches are taken from the RV free wall, which is on the other side of the LAD (not as depicted).

Figure 4.

Percutaneous repair of left ventricular pseudoaneurysm. A. Transesophageal echocardiogram with color Doppler flow showing a thinned inferior wall infarction with a jet of flow into the large pseudoaneurysm; B. Transesophageal echocardiography showed the two discs of the occluder device seated across the defect. Spontaneous echo contrast (“smoke”) indicated stasis in the pseudoaneurysm; C. Cardiac MRI showing akinetic inferior wall segment with a jet of flow into the pseudoaneurysm. The bioprosthetic mitral valve is seen. (Bold white arrow = Left atrium; Narrow white arrow = pseudoaneurysm; dotted white arrow = mitral valve.); D. Cardiac MRI seven days after implantation of the occluder device showed no flow into the pseudoaneurysm.

Figure 5.

Multidisciplinary team-based approach to mechanical complications of acute myocardial infarction.

Figure 6.

A treatment pathway for management of stable and unstable mechanical complications of acute myocardial infarction (AMI). For unstable patients, consultation with the Shock Team can be considered prior to inter-hospital transfer to determine immediate medical management and possible candidacy for surgical and/or interventional treatment. In unstable patients where the risk of inter-hospital transfer may be prohibitive, alternative on-site therapies and/or inter-hospital transfer strategies can be considered in patients who are not surgical candidates only after discussion with the multidisciplinary Shock Team based on local on-site expertise and characteristics of the regional systems-of-care.