Restrictive mitral annuloplasty in refractory cardiogenic shock with acute postinfarction mitral insufficiency and intact papillary muscle

Abstract

Acute severe mitral insufficiency after myocardial infarction usually results from rupture of a papillary muscle, which should be treated on an emergency basis with mitral valve repair or replacement. In the case of acute postinfarction mitral regurgitation with intact papillary muscle, no consensus exists, even with regard to the indication for surgery. Restrictive mitral annuloplasty (RMA) has been applied in chronic ischemic mitral insufficiency, with encouraging midterm results. 1,2 In this report, we describe 2 patients in whom RMA was applied as a lifesaving procedure in the presence of refractory cardiogenic shock in postinfarction mitral insufficiency with intact papillary muscle. Clinical Summaries PATIENT 1. A 55-year-old woman had an acute inferior wall infarction with cardiogenic shock. She received an intra-aortic balloon pump (IABP) and inotropes and was intubated. Coronary angiography revealed occlusion of the right coronary and circumflex arteries. Transesophageal echocardiography (TEE) showed grade 4 mitral insufficiency resulting from systolic restrictive motion of both leaflets (Carpentier type IIIb; Figures 1 and 2). The regurgitation jet was slightly eccentric because of the more restrictive posterior leaflet. Because of further hemodynamic deterioration, we decided to attempt correction of the mitral regurgitation as a lifesaving procedure. During the operation, a fresh infarction of the posterolateral wall involving the posterior papillary muscle was observed. The subvalvular apparatus was intact, and there was no structural anomaly of the mitral valve leaflets. RMA was performed with a size 28 Carpentier-Edwards Physioring (Baxter Healthcare Corporation CardioVascular Group, Irvine, Calif), thereby downsizing the prosthetic ring by two sizes. Tentative revascularization of the circumflex and right coronary artery territory was performed with a sequential saphenous vein graft. The patient was weaned from extracorporeal circulation with inotropic support (epinephrine at 0.22 g/kg/min, dobutamine at 15 g/kg/min, dopamine at 8 g/kg/min, and enoximon at 4 g/kg/min). Intraoperative TEE showed trivial mitral regurgitation with a mean transvalvular mitral gradient of 3 mm Hg (mitral valve surface area 2c m 2 ) and