First-in-man MitraClip implantation to treat late postoperative systolic anterior motion: rare cause of tardive mitral repair failure.

A 52-year-old man underwent surgical mitral repair for P2 flail. A conventional Carpentier technique was used (quadrangular resection+sliding plasty and annuloplasty with a 35-mm flexible band). Predischarge echocardiography showed no residual MR and no systolic anterior motion (SAM). One year after surgery, the patient came to our attention complaining dyspnoea on effort (New York Heart Association III). Rest echo-cardiography showed absence of recurrent MR, but evidence of SAM with mild left ventricular outflow tract (LVOT) obstruction. Exercise echocardiography revealed a significant SAM with severe LVOT obstruction (Figure 1; Movies I–III in the Data Supplement). An induced pressure gradient of 144 mm Hg and a dynamic flow acceleration with late systolic peak velocity were observed across the LVOT with concomitant moderate MR and mild pulmonary hypertension (systolic pulmonary pressure , 40 mm Hg; Figure 1). A pharmacological approach was attempted first (atenolol, 100 mg QID; diltiazem 180 mg QID) without clinical improvements and changes in SAM and LVOT obstruction. Therefore, an interventional strategy was considered. A MitraClip procedure was planned to correct the SAM. Adrenaline infusion was used to induce SAM. After ineffective attempts to place the clip in the central portion of the valve, a single clip was definitively placed just medial to the suture line of the resected portion of leaflet. Before the final detachment of the clip, mitral valve area and a transvalvular gradient were measured to evaluate the residual stenosis (mean transmitral gradient , 8 mm Hg). After MitraClip implantation, an evident displacement of the leaflets coaptation point toward the LV inflow was observed and LVOT obstruction disappeared (Figure 2; Movies IV–IX in the Data Supplement). No LVOT obstruction and MR were observed under adrenaline infusion. Six months after the MitraClip procedure, the patient is asymptomatic (New York Heart Association I) with active lifestyle. Follow-up rest and exercise echocardiography shows no residual MR, moderate stenosis (rest and exercise mean transmitral gradient 6 and 14 mm Hg, respectively), normal stress pulmonary pressure (systolic pulmonary pressure, 25 mm Hg), and a reduction of dynamic LVOT obstruction (peak gradients, 11 and 22 mm Hg, respectively; Figure 3; Movies VIII–X in the Data Supplement). Discussion SAM after mitral valve repair in the setting of degenerative disease is a well-known postoperative complication occurring in 9% to 11% of patients. 1,2 Usually, postoperative SAM is evident immediately after cardiopulmonary bypass discontinuation, and it can be managed conservatively with medical therapy and volume optimization. …