Rescue transventricular off-pump mitral valve repair with artificial neochords for acute mitral regurgitation due to postinfarction papillary muscle rupture

Abstract

Background: We report 3 cases of rescue transventricular off-pump mitral valve (MV) repair in high-risk patients with acute mitral regurgitation (MR) due to post-myocardial infarction (MI) papillary muscle rupture (PMR).

Methods: The 3 patients presented with acute inferior ST elevation myocardial infarction, cardiogenic shock, and pulmonary edema. Their preoperative peak troponin I levels were 1909 ng/L, 16,963 ng/L, and 8299 ng/L. All 3 patients underwent successful percutaneous intervention to the culprit coronary artery, and antiplatelet therapy was initiated. All patients required inotropic support and had an intra-aortic balloon pump inserted preoperatively. Transesophageal echocardiography (TEE) demonstrated severe eccentric MR due to the leaflet prolapse secondary to PMR. The patients' estimated EuroSCORE II scores were 16.03%, 16.68%, and 7.81%, and their Society of Thoracic Surgeons scores were 14.77%, 18.24%, and 9.8%, respectively. All 3 patients underwent urgent transventricular off-pump MV repair using artificial chords, with 2 or 3 three neochords implanted. The duration of operation was <2 hours, and intraoperative and postoperative drainage was minimal in all cases. MV function was assessed by qualitative and semiquantitative TEE.

Results: Intraoperative MR reduction to a mild level was achieved in all 3 patients. All patients had moderate MR at discharge, likely due to left ventricular remodeling. Severe MR recurred in all patients, at 5, 4, and 2 months of follow-up, respectively. All 3 patients underwent an elective MV reoperation via conventional approach.

Conclusions: Off-pump transventricular MV repair may offer a safe and feasible alternative to stabilize high-risk patients with acute MR due to post-MI PMR. Although early MR recurrence is concerning, urgent transventricular MV repair may serve as a bridge to conventional surgery in such unstable patients.

Keywords: AF, atrial fibrillation; ECG, electrocardiography; IABP, intra-aortic balloon pump; LAD, left anterior descending artery; LV, left ventricular; LVEF, left ventricular ejection fraction; MI, myocardial infarction; MR, mitral regurgitation; MV, mitral valve; PCI, percutaneous coronary intervention; PMR, papillary muscle rupture; RCA, right coronary artery; STEMI, ST elevation myocardial infarction; STS, Society of Thoracic Surgeons; TEE, transesophageal echocardiography; TR, tricuspid regurgitation; acute mitral regurgitation; artificial chords; cardiogenic shock; minimally invasive; mitral valve; off-pump; papillary muscle rupture; transventricular mitral repair.

Graphical abstract

Ruptured papillary muscle and native chords are captured using the NeoChord device.

Figure 1

The first-in-human urgent transventricular mitral valve repairs with artificial neochords were successfully performed in 3 high-risk patients with acute severe mitral regurgitation (MR) due to ischemic papillary muscle rupture, cardiogenic shock, and pulmonary edema. The primary intention of hemodynamic stabilization was achieved in all patients, with intraoperative MR reduction to mild (1+). The NeoChord DS1000 device captured the bundle of native chords together with ruptured portion of the papillary muscle during the procedure (schematic view is provided). Predischarge echocardiography demonstrated moderate MR, likely related to LV remodeling. Recurrent severe MR was noted in all patients at 2 to 5 months after the repair. All patients underwent a successful elective reoperation with MV repair or replacement. This is a proof-of-concept that urgent off-pump NeoChord procedure in unstable patients with acute severe MR may serve as a bridge to conventional surgery.

Figure 2

Intraoperative 2- and 3-dimensional transesophageal echocardiograms demonstrating grade 4+ mitral valve (MV) regurgitation and immediate reduction to grade 1+ after the transventricular off-pump MV repair. Preoperatively, the posteromedial papillary muscle (white arrow) was hyperechogenic, elongated, and dysfunctional as a result of inferior ST elevation myocardial infarction. Because of relatively “loose” native chords, the leaflet coaptation was lost (arrowhead), and an eccentric regurgitant jet was noted. A cropped 3-dimensional view of the MV from the left atrial aspect demonstrated a significant prolapse of the A2 segment of the anterior MV leaflet (yellow arrow). Three artificial neochords were implanted to repair the prolapsing leaflet and stabilize the ischemic papillary muscle. An overall mitral regurgitation reduction to grade 1+ was achieved.

Figure 3

Intraoperative transesophageal echocardiography, long-axis views. A, Preoperatively, the ruptured tip (traced by the oval contour) of the papillary muscle is seen flailing into the left atrium together with a large portion of the anterior mitral valve (MV) leaflet, causing severe mitral regurgitation. B, The NeoChord DS1000 device captured the bundle of native chords together with the ruptured portion of the papillary muscle during the procedure; a schematic view of this moment is provided. C, The position of the ruptured papillary muscle after neochord tensioning and fixation at the apex resulted in a good coaptation of the MV leaflets. D, Only a small residual mitral regurgitant jet was noted on color Doppler after the procedure.

Video 1

This video with echocardiographic images provides insight into these case reports of transventricular off-pump mitral valve repair in a setting of acute mitral regurgitation due to ischemic papillary muscle rupture. Video available at: https://www.jtcvs.org/article/S2666-2507(21)00678-7/fulltext.

Figure 4

Cropped views of intraoperative 2- and 3-dimensional transesophageal echocardiograms demonstrating the outcome of transventricular mitral valve (MV) repair. The ruptured posterior head of the posteromedial papillary muscle (A, circled contour) together with the P3 segment (C) protruding into the left atrium at systole caused a very severe anteriorly directed mitral regurgitation (MR). D, The tip of the NeoChord DS 1000 device (yellow arrow) crossing the MV plane, as seen from the left atrial aspect. B and E, Two artificial neochords were implanted and reduced the grade of MR to trivial.