Abstract
MitraClip therapy has been proposed as therapeutic option in selected patients with degenerative or functional mitral regurgitation (FMR), leading to clinical and prognostic benefits. Previous studies demonstrated the safety and the efficacy of MitraClip therapy on symptoms and left ventricular remodeling in cardiac resynchronization therapy (CRT) non-responder patients. We report a case of a CRT non-responder patient treated with MitraClip implantation followed by a new upgrading of the CRT for persistent FMR at the follow-up. The optimization of the interventricular delay, guided by echocardiographic parameters, resulted in a significant clinical and functional benefit. Echo-guided CRT upgrading can provide additive efficacy for patients in whom MitraClip implantation does not significantly improve FMR and symptoms.
Highlights
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MitraClip therapy has been proposed as therapeutic option in selected patients with degenerative or functional mitral regurgitation (FMR), leading to clinical and prognostic benefits.
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Previous studies demonstrated the safety and the efficacy of MitraClip therapy on symptoms and left ventricular remodeling in cardiac resynchronization therapy (CRT) non-responder patients.
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The optimization of the interventricular delay, guided by echocardiographic parameters, results in a significant clinical and functional benefit.
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We highlight the importance of an echo-guided CRT upgrading to provide additive efficacy for patients in whom MitraClip implantation does not significantly improve FMR and symptoms.
1
Introduction
Treatment with MitraClip percutaneous mitral valve repair system has been proposed as therapeutic option in selected patients with degenerative or functional mitral regurgitation (FMR), leading to clinical and prognostic benefits . In particular, previous studies demonstrated the safety and the efficacy of MitraClip therapy on symptoms and left ventricular (LV) remodeling in cardiac resynchronization therapy (CRT) non-responders patients .
We report a case of a CRT non-responder patient treated with the MitraClip implantation, followed by a new optimization of the CRT device for persistent FMR at the follow-up. The optimization of the device interventricular (VV) delay , guided by echocardiographic parameters, resulted in a significant and persistent clinical and functional benefit.
2
Case report
We report the case of a 76-year-old man who had been admitted for recurrent, refractory congestive heart failure (HF). When he was 62, he suffered an acute coronary syndrome with left bundle branch block (QRS duration >120 msec) and preserved LV function (ejection fraction 67%); later he underwent coronary artery bypass graft intervention. Twelve years later he was admitted for acute pulmonary edema and atrial fibrillation and echocardiography showed a LV dilation with posterior–inferior akinesia and hypokinesis of the other walls, with an ejection fraction (EF) of 30% and a severe FMR, documented by standard echocardiographic measurements. Cardiac catheterization demonstrated patency of coronary artery bypass grafts. On the basis of the clinical and echocardiographic characteristics, the patient was treated with CRT and implantable cardioverter-defibrillator (ICD). Leads were placed in right atrial appendage, right ventricle apex and left lateral branch of coronary sinus venous system, using standard technique with bipolar leads; atrioventricular (AV) delay was programmed in order to achieve the maximum transmitral VTI (velocity time integral), assessed in four chamber view with pulsed-wave Doppler, and the VV delay was set at a nominal value of 0 msec. Despite optimal pharmacological and device therapy, with subsequent CRT optimization based on the common electrocardiographic criteria (QRS duration), during the consecutive year he remained highly symptomatic (NYHA class IV) with several episodes of acute HF. Echocardiography showed a progressive remodeling (LV end-diastolic volume: 200 ml, LV end-systolic volume: 140 ml) and a worsening of FMR which had become severe ( Fig. 1 ). In order to prevent further volume overload, a direct correction of mitral regurgitation (MR) was indicated . Since Euroscore II resulted 20%, it was decided to proceed with transcatheter implantation of the MitraClip system (Abbott Vascular Structural Heart, Menlo Park, California). Two clips were implanted, getting a significant functional improvement up to NYHA class II and a reduction of the FMR from severe to mild ( Figs. 2 and 3 ); due to immediate clinical benefit, no CRT modification was performed at this point. At 6 months follow-up, transthoracic echocardiography showed an improvement in volumes and EF (LV end-diastolic volume: 150 ml, LV end-systolic volume: 90 ml, EF 40%) but a worsening of both FMR (from mild to moderate) and symptoms (NYHA 3 class), requiring the increase of diuretic dosage. Then, an optimization of CRT was made during echocardiographic monitoring: in particular, echocardiographic measurements were performed during both simultaneous biventricular (BiV) pacing and progressive sequential delay between left and right ventricle activation, until a significant reduction of the MR jet area was achieved.
During simultaneous BiV pacing, the VV delay was set to a nominal value of 0 msec, whereas during sequential BiV pacing, progressive VV delays of +10, −10, −20, −30, −40 and −50 msec were programmed in a sequential order. Pacing with each programmed setting was maintained for 1 min at least before performing echo measurement and changing the VV delay, in order to compare all the different VV intervals. A single sonographer did echo measurements and was blinded to the device programming. FMR severity was determined through integrative assessment based on recommendations of the American Society of Echocardiography (ASE). A progressive reduction of the regurgitation jet was observed increasing the delay from 0 msec, to −10 msec, −20 msec, −30 msec, −40 msec and finally to −50 msec ( Fig. 4 ), so the VV delay was set on this value. At 2 years follow-up, a mild FMR was detected and the patient was asymptomatic (NYHA class I).
2
Case report
We report the case of a 76-year-old man who had been admitted for recurrent, refractory congestive heart failure (HF). When he was 62, he suffered an acute coronary syndrome with left bundle branch block (QRS duration >120 msec) and preserved LV function (ejection fraction 67%); later he underwent coronary artery bypass graft intervention. Twelve years later he was admitted for acute pulmonary edema and atrial fibrillation and echocardiography showed a LV dilation with posterior–inferior akinesia and hypokinesis of the other walls, with an ejection fraction (EF) of 30% and a severe FMR, documented by standard echocardiographic measurements. Cardiac catheterization demonstrated patency of coronary artery bypass grafts. On the basis of the clinical and echocardiographic characteristics, the patient was treated with CRT and implantable cardioverter-defibrillator (ICD). Leads were placed in right atrial appendage, right ventricle apex and left lateral branch of coronary sinus venous system, using standard technique with bipolar leads; atrioventricular (AV) delay was programmed in order to achieve the maximum transmitral VTI (velocity time integral), assessed in four chamber view with pulsed-wave Doppler, and the VV delay was set at a nominal value of 0 msec. Despite optimal pharmacological and device therapy, with subsequent CRT optimization based on the common electrocardiographic criteria (QRS duration), during the consecutive year he remained highly symptomatic (NYHA class IV) with several episodes of acute HF. Echocardiography showed a progressive remodeling (LV end-diastolic volume: 200 ml, LV end-systolic volume: 140 ml) and a worsening of FMR which had become severe ( Fig. 1 ). In order to prevent further volume overload, a direct correction of mitral regurgitation (MR) was indicated . Since Euroscore II resulted 20%, it was decided to proceed with transcatheter implantation of the MitraClip system (Abbott Vascular Structural Heart, Menlo Park, California). Two clips were implanted, getting a significant functional improvement up to NYHA class II and a reduction of the FMR from severe to mild ( Figs. 2 and 3 ); due to immediate clinical benefit, no CRT modification was performed at this point. At 6 months follow-up, transthoracic echocardiography showed an improvement in volumes and EF (LV end-diastolic volume: 150 ml, LV end-systolic volume: 90 ml, EF 40%) but a worsening of both FMR (from mild to moderate) and symptoms (NYHA 3 class), requiring the increase of diuretic dosage. Then, an optimization of CRT was made during echocardiographic monitoring: in particular, echocardiographic measurements were performed during both simultaneous biventricular (BiV) pacing and progressive sequential delay between left and right ventricle activation, until a significant reduction of the MR jet area was achieved.
