A 72-year-old man with ischaemic cardiomyopathy and secondary mitral regurgitation developed heart failure. Due to the absence of options for revascularisation that would improve left ventricular function, poor functional status and a high Euro-SCORE II, the patient was deemed unfit for surgery. Furthermore, a cleft mitral valve also made him unsuitable for MitraClip [1]. To reduce mitral regurgitation he received treatment with a Carillon device for mitral valve annuloplasty in the coronary sinus (Fig. 1; [2]). Unfortunately, this did not reduce MR. In time he developed a left bundle branch block which made him eligible for placement of a cardiac resynchronisation therapy defibrillator (CRT-D) [3].

Fig. 1
figure 1

a The Carillon device (1) with the right atrial (2) and right ventricular (3) leads; b the Carillon device (1) and the left ventricular epicardial lead (4) in the coronary sinus. This illustrates the possibility of placing a Carillon device and a left ventricular lead in the coronary sinus in the treatment of mitral regurgitation and heart failure

There were no complications and the patient’s functional status improved significantly.