REsynchronization reVErses Remodeling in Systolic left vEntricular dysfunction (REVERSE) Study Group. Cardiac resynchronization induces major structural and functional reverse remodeling in patients with New York Heart Association class I/II heart failure
St John Sutton M, Ghio S, Plappert T, Tavazzi L, Scelsi L, Daubert C, Abraham WT, Gold MR, Hassager C, Herre JM, Linde C.
Circulation 2009;120(19):1858-65.
Synopsis
The study was performed among 610 patients with chronic heart failure (NYHA class I/II, QRS duration ≥120 ms, LVEDD ≥55 mm, LVEF ≤40%), among them 419 and 191 were randomized to CRT and control, respectively, for 12 months. LV mass, mitral regurgitation, and LV diastolic function did not change in either group by 12 months. During this time, LV end-diastolic and end-systolic volume indexes and LV ejection fraction significantly increased. CRT improved left ventricle performance in both patients with ischaemic and non-ischaemic chronic heart failure, but the magnitude of improvements differed significantly between these two aetiologies, favouring non-ischaemic chronic heart failure.
Commentary
This study demonstrated for the first time that CRT applied in patients with asymptomatic or mild systolic chronic heart failure with a broad QRS width was followed by structural and functional reverse remodeling of left ventricle. CRT resulted in beneficial changes in LV architecture and function that occurred almost exclusively in CRT-ON patients, although both patient groups were given stable optimal medical therapy. It is suggested that CRT might delay or permanently interrupt the natural history of disease progression in patients at early stages of chronic heart failure.
Short-term hemodynamic effects of cardiac resynchronization therapy in patients with heart failure, a narrow QRS duration, and no dyssynchrony.
Williams LK, Ellery S, Patel K, Leyva F, Bleasdale RA, Phan TT, Stegemann B, Paul V, Steendijk P, Frenneaux M.
Circulation 2009;120(17):1687-94.
Synopsis
Short-term haemodynamic effects of cardiac resynchronization therapy (CRT) were studied in patients with systolic chronic heart failure (NYHA class III-IV, LVEF≤35%) in a sinus rhythm with a QRS duration <120 ms and no evidence of dyssynchrony. CRT resulted in an increase in cardiac output, absolute left ventricular stroke work, the slope of the preload recruitable stroke work relation, and dP/dtmax. CRT was also followed by a complete relief in external constraint to left ventricular filling in all patients in whom this pathology had been present before CRT.
Commentary
There is no agreement about the effectiveness of CRT in patients with systolic chronic heart failure with both a narrow QRS duration and a lack of dyssynchrony. The study provides the pathophysiological argument that such an intervention has beneficial effects on haemodynamics together with a reduction of pericardial constraint in an acute model. The precise mechanisms of these beneficial effects and the long-term persistence of these changes remain unclear.
Extended mechanical circulatory support with a continuous-flow rotary left ventricular assist device
Pagani FD, Miller LW, Russell SD, Aaronson KD, John R, Boyle AJ, Conte JV, Bogaev RC, MacGillivray TE, Naka Y, Mancini D, Massey HT, Chen L, Klodell CT, Aranda JM, Moazami N, Ewald GA, Farrar DJ, Frazier OH; HeartMate II Investigators.
J Am Coll Cardiol. 2009 Jul 21;54(4):312-21
Synopsis
This prospective, multicenter study demonstrated the feasibility, safety, and efficacy of extended mechanical circulatory support with a new type of a left ventricular assist device (LVAD), the HeartMate II continuous flow rotary pump among 281 patients with end-stage heart failure who were waiting for heart transplantation. At 18 months after LVAD implantation, the majority of patients (79%) reached the primary end point of receiving a transplant, having the device explanted for cardiac recovery, or ongoing mechanical circulatory support. The median duration of mechanical support for all patients was 155 days. Overall patient survival with LVAD support was 82%, 73% and 72% at 6, 12 and 18 months, respectively. At 6 months, there were significant improvements in functional status, a distance during 6-minute walk test and quality of life. Major complications included bleeding, stroke, right heart failure, percutaneous lead infection. There was no mechanical pump failure, although 11 (4%) patients required a pump exchange due to device thrombosis, infection, percutaneous lead fracture, or complications at the time of implantation.
Commentary
Left ventricular assist device (LVAD) is applied in patients with advanced refractory heart failure, also as a bridge to heart transplantation. The first LVADs were pulsatile flow devices with an internal volume-displacement mechanism for pumping blood, powered by pneumatic or electric sources, and inflow and outflow valves, however with several disadvantages such as: a large pump size, an extensive surgical dissection for implant, a large-diameter percutaneous lead for venting air, an audible pump operation, and the high incidence of reoperation for device exchange due to device infection or malfunction. In the REMATCH (Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure) trial, 1-year survival for patients with pulsatile LVAD implanted was only 52%, and the device failure was quite frequent. Recently developed LVAD are based on continuous-flow technology. These devices offer several potential advantages, including smaller size, less extensive surgical procedures for implantation, and the rotary, continuous flow design that improves durability and reduces the likelihood of device breakdown and malfunction.
The current study demonstrates that the haemodynamic support provided by HeartMte II continuous flow rotary pump LVAD is feasible, related with an improvement in exercise capacity and quality of life, with lower, as compared to pulsatile devices, rates of complications (including infection, post-operative bleeding, right ventricular failure, non-stroke neurological events). The demonstrated advantages of continuous flow devices seem to be particularly encouraging in the context of long-term therapy in patients with advanced heart failure who on the one hand are awaiting heart transplantation, but on the other hand may be applicable also for those who are not candidates for a heart transplant and receive mechanical support as the destination therapy.
Percutaneous Mitral Annuloplasty for Functional Mitral Regurgitation. Results of the CARILLON Mitral Annuloplasty Device European Union Study
Schofer J, Siminiak T, Haude M, Herrman JP, Vainer J, Wu JC, Levy WC, Mauri L, Feldman T, Kwong RY, Kaye DM, Duffy SJ, Tübler T, Degen H, Brandt MC, Van Bibber R, Goldberg S, Reuter DG, Hoppe UC.
Circulation. 2009 Jul 28;120(4):326-33
Synopsis
The CARILLON Mitral Annuloplasty Device European Union Study (AMADEUS) was aiming to evaluate the feasibility, safety and efficacy of a novel percutaneous mitral annuloplasty device (the CARILLON Mitral Contour System) in patients with dilated cardiomyopathy and functional moderate to severe mitral regurgitation (FMR). The procedure appeared to be feasible and was associated with a low rate of major adverse events. Thirty patients implanted with the device experienced significant improvements in NYHA class, 6-minute walk distance, and quality of life which was accompanied by a reduction in mitral regurgitation over a 6-month follow-up period.
Commentary
Functional mitral regurgitation (FMR) is common in patients with chronic heart failure (CHF), compromises forward stroke volume, augments the severity of heart failure, and is associated with the worse outcome. Surgical valve repair aiming at attenuating FMR is not available to a significant group of patients with CHF due to a unbalanced advantage/risk balance. Therefore, percutaneous techniques for mitral annuloplasty (based on an implantation of a mitral annuloplasty device into the coronary veins to modify the shape and reduce the diameter of the annulus allowing the proper coaptation of the mitral leaflets) seem to be more promising. The presented study evaluated one of the most advanced devices for trans-coronary venous mitral annuloplasty, the Carillon Mitral Contour System, and demonstrated its safety and efficacy. The promising results place percutaneous techniques for mitral annuloplasty as an attractive alternative to surgery in patients with CHF, however further randomized studies are needed to establish their long-term efficacy and impact on overall survival.
Long term vagal stimulation in patients with advanced heart failure: first experience in man
Schwartz PJ, FESC, De Ferrari GM, Sanzo A, Landolina M, Rordorf R, Raineri C, Campana C, Revera M, Ajmone-Marsan N, Tavazzi L, FESC, Odero A.
Eur J Heart Fail. 2008 Sep;10(9):884-91.
Synopsis
The paper provides the data on feasibility and safety, and preliminary evidence on efficacy of 6-month vagal stimulation by an implantable neuro-stimulator system in men with systolic chronic heart failure (LVEF ≤30%, NYHA class II/III: 1/7) in a sinus rhythm. There were few non-serious events that finally were resolved: cough, pain at stimulation site, mandibular pain and voice alteration. The intervention resulted in an improvement in NYHA class, quality of life, an increase in a distance during a 6-minute walk test, a reduction in left ventricular end-systolic volume and a trend towards a reduction in left ventricular end-diastolic volume.
Commentary
Counteracting the augmented sympathetic drive by using beta-blockers in chronic heart failure (CHF) has brought several advantages. Depleted vagal drive is also considered as a risk factor of ventricular arrhythmias and increased mortality in these patients. Pharmacological interventions aiming at an augmentation of cholinergic signaling are limited, hence the first human experience of electrical vagal stimulation is very promising. Further studies are needed, as there is evidence from experimental studies and other clinical models that cholinergic signaling reveals several advantageous effects, such as an attenuation of inflammation and an improvement in insulin sensitivity, that also may be involved in the pathophysiology of CHF.
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