First case report of the use of two stents following coronary artery obstruction during indirect mitral annuloplasty

Abstract

The case of a 71‐year‐old male with end stage heart failure and severe mitral regurgitation is presented, where percutaneous indirect mitral annuloplasty was performed. During device implantation in the coronary sinus the circumflex artery was compromised at two anatomic locations, while the mitral regurgitation was efficiently reduced. After weighing risks and alternative therapeutic options, stent implantation was chosen as bailout strategy to leave the device in place and retain the efficient MR reduction. The anatomical proximity of Cx and coronary sinus in the mitral valve plane bears the risk of circumflex artery damage during surgical and interventional mitral repair. Usually, a device exchange solves the problem of arterial flow limitation in most cases. While stent implantation remains off label use in this setting and should not be performed without critical evaluation, it has been performed successfully in similar clinical settings as well (e.g. artery stenosis by surgical suture).

Introduction

We report a 71‐year‐old male patient with severe dilated cardiomyopathy (left ventricular ejection fraction 20%) and severe secondary mitral valve (MV) regurgitation due to ring dilatation (Carpentier type I, annular dilatation). The patient was highly symptomatic with exertional dyspnoea (NYHA III) despite guideline‐directed pharmacotherapy and cardiac cachexia. Currently, the transcatheter MV repair options of severe mitral regurgitation (MR) are rapidly evolving (Table  1 ). ¹ At the hospital site, direct MV repair by clipping (MitraClip, Abbott) and indirect annuloplasty (Carillon, Cardiac Dimensions) were performed regularly. After heart team evaluation, the patient was offered an interventional approach to reduce the MR. Based on the clinical patient characteristics with highly reduced cardiac index associated with an increased anaesthesia risk and the echocardiographic features of dominant mitral ring dilatation and leaflet coaptation defect, indirect percutaneous MV annuloplasty was preferred. The aim was to apply circumferential traction around the dilated mitral ring to counteract the annular dilatation and reduce MV regurgitation subsequently.

Table 1.

Transcatheter mitral valve repair techniques (mod. De Backer et al. 2021 ¹ )

Transcatheter mitral annuloplasty	Transcatheter edge‐to‐edge mitral valve repair
Indirect mitral annuloplasty ‐ Carillon Mitral Contour System ‐ ARTO system Direct mitral annuloplasty ‐ Cardioband Mitral System ‐ Millipede Transcatheter Mitral Annuloplasty System	MitraClip G4 system PASCAL Transcatheter Valve Repair System

Case Report

The procedure was performed using local anaesthesia and conscious sedation. After ultrasound‐guided cannulation of the right internal jugular vein and introduction of a 10F‐sheath, the device delivery catheter was placed into the coronary sinus (CS), followed by the placement of the sizing catheter. After sizing and deployment of the device, coronary angiography showed a relevant narrowing of the left circumflex (LCx) coronary artery at two locations (Figure 1 A ) near the proximal and distal device anchor. However, the echocardiographic evaluation revealed a promising decrease of MR due to reduction of the annulus from 42 to 37 mm. After discussion of alternative treatment options, the decision was made to leave the annuloplasty device in place and to perform percutaneous coronary intervention. The device was released, and two primary stent implantations were performed (Promus 3.0 × 16 mm and 2.5 × 20 mm) to protect the LCx, with a subsequent good angiographic (Figure 1 B ) and echocardiographic result (Figure  2 ).

Figure 1.

(A) Coronary angiogram showing the compression of the proximal circumflex artery due to the distal anchor of the annuloplasty device as well as compression due to device pull between the two anchors (yellow arrows). (B) Coronary angiogram after implantation of two coronary artery stents with TIMI‐III flow.

Figure 2.

Echocardiography showing reduction of the mitral regurgitation after mitral annuloplasty. While the colour jets may look quite similar, the EROA had significantly improved.

Discussion

Impingement or obstruction of the LCx due to the indirect CS based MV annuloplasty is a potential periprocedural consideration, which must be managed to avoid a clinical complication. ² The CS crosses the LCx in 80% of patients. ³ The location of the crossing is variable, which allow CS based annuloplasty in most patients, but in a small number of patients, the removability of the device must be used to prevent myocardial ischaemia (Figure  3 ). This can be performed up until the time the device is finally released. In the REDUCE‐FMR trial, eight of 87 patients (9%) did not receive the device due to a transient obstruction of the LCx, which resolves with device recapture. ⁴ The implantation was aborted in 17% of the cases in the earlier TITAN II trial. ⁵ The release of device tension or recapture of the device resolves the impingement and flow limitations. The instructions for use advise against leaving a device in which causes a reduction in coronary artery flow. In addition, it is recommended not to release the device, which will come into ‘direct’ contact with a coronary stent, to minimize any theoretic risk of erosion. Compression of a coronary artery due to mitral annular treatment is not limited to the indirect mitral annuloplasty device. The possibility of the LCx injury may occur with surgical annular rings, or MV replacements, as well as other interventions around the mitral ring. According to the 2010 Society of Surgeons database, the risk of perioperative circumflex artery injury is up to 2.2% for MV repair. ⁶ To our knowledge, this is the first report of occurrence of two functional LCx stenoses during indirect mitral annuloplasty, which were successfully treated by percutaneous coronary intervention, although this group previously mentioned placing stents in two patients undergoing mitral annuloplasty with the same device. ⁷ While the implantation of drug‐eluting stents in device‐associated mechanical coronary flow limitation takes place outside the scope of the approved label, this approach has been used in other situations as well. Stent implantation has been reported as treatment option in right coronary injury after aortic valve surgery. ⁸ Surgical repair for LCx compression after MV surgery has been described, with about 87% success rate. ⁹ The Cardioband® annuloplasty system has been reported to cause LCx flow limitation, which has been successfully treated by coronary stent implantation. ¹⁰ Further, despite the theoretic concerns, direct mechanic compression, deformation, and collapse of the stent by the anchor has never been reported, nor has erosion. At Leipzig University Hospital, we performed 37 implantations with the indirect mitral annuloplasty system from 2014 to 2020 with transient angiographic LCx obstruction in nine patients (24%). While the change of the device to a different location in the CS solved the problem in most cases, three patients had coronary stent implantation, because there were no other options. Placement of coronary stents to allow for implantation of a Carillon device is not currently allowed for in the product instructions for use. However, it is recognized that coronary artery compression may rarely not be fully realized until after the device is deployed and released, when recapture is no longer a possibility, although this hardly ever occurs if careful attention is applied during the implant procedure. Although not recommended by the instructions for use, we propose considering the use of stent implantation in device‐associated LCx obstruction only as a last resort to prevent ischaemia in patients who show limited alternative treatment options (e.g. reposition the device, MV surgery), in the face of significant coronary artery compression by the implanted Carillon device.

Figure 3.

Anatomy of the proximity of the coronary sinus (CS) and the left circumflex artery (Cx) in the dorsolateral aspect of the mitral valve (MV) plane. The proximity of both vessels varies. The tethering area described the anatomical location where the pull force of the annuloplasty device (Carillon) in the CS is transmitted directly on the Cx causing coronary flow obstruction.

Conflict of interest

Michael Metze, Stephan Stöbe, Karsten Lenk and Ulrich Laufs declare that they have no conflict of interest. Dietrich Pfeiffer received proctoring fees by Cardiac Dimension, and Andreas Hagendorff received lecture fees by Cardiac dimensions.

Metze, M. , Stöbe, S. , Pfeiffer, D. , Hagendorff, A. , Laufs, U. , and Lenk, K. (2023) First case report of the use of two stents following coronary artery obstruction during indirect mitral annuloplasty. ESC Heart Failure, 10: 2694–2697. 10.1002/ehf2.14382.