Acute severe mitral regurgitation following balloon mitral valvotomy: echocardiographic features, operative findings, and outcome in 50 surgical cases.

OBJECTIVE: To analyze the echocardiographic and operative findings with respect to mitral valve anatomy in individuals undergoing emergency surgery for acute severe mitral regurgitation (MR) following balloon mitral valvotomy (BMV). In addition, the clinical profile and outcomes are highlighted.

BACKGROUND: Acute severe MR is a major complication of BMV. There are only a few reports which have studied the echocardiographic and operative findings in this setting. In addition, optimal timing of surgery is uncertain.

METHODS: Prospective study of 50 consecutive patients undergoing emergency mitral valve replacement (MVR) for acute severe MR following BMV.

RESULTS: In 3855 patients who underwent BMV, acute severe MR developed in 50 cases (1.3%) and was referred for emergency MVR. Hypotension (72%), hypoxia (64%), orthopnea (14%), and pulmonary edema (12%) were the clinical manifestations. Severe MR was secondary to anterior mitral leaflet tear in 36 cases (72%), paracommisural tear with annular involvement in seven cases (14%), posterior mitral leaflet tear in five cases (10%) and chordal tear in two cases (4%). The correlation between two-dimensional transthoracic echocardiography (2D-TTE) and operative finding for mitral valve calcification was found to be strong (r = 0.862), in contrast to submitral fusion, where it was found to be moderate (r = 0.536). In-hospital mortality was 12%. Mortality was higher in patients whose time to surgery was ≥24 hr when compared to those who underwent MVR within 24 hr (P < 0.001).

CONCLUSIONS: Hypotension and hypoxia are the predominant manifestations of acute severe MR following BMV. Anterior mitral leaflet tear is the most common etiology for severe MR. 2D-TTE underestimated the severity of submitral disease. Early MVR (<24 hr) is recommended for optimal outcome.