Reply to ‘Benefits of transvenous mitral annuloplasty in heart failure with lower degrees of functional mitral regurgitation’

European Journal of Heart Failure, vol. 23, pp. 1985–1986

Abstract

We are grateful to Dandel and Hetzer for their insightful comments about our work1 and agree with them that ejection fraction measured in the traditional way in terms of the difference between diastolic and systolic volume has limitations as an outcome measure particularly, but not limited to, studies of treatments for mitral regurgitation (MR). Their proposal is that left ventricular (LV) function (or cardiac output) would be more robust if it were presented in terms of flow through the aortic valve (forward stroke volume, SVf). They further comment that despite benefits on remodelling the neutral effect of the Carillon device on LV ejection fraction in our recently published data1 could be the consequence of increased afterload due to reduced MR following treatment. An approach to LV function in patients with MR that takes into account the changing mitral lesion and the effect of this on loading has previously been discussed with regard to leaflet-based treatments2 but has not yet been applied to data from the studies of the Carillon device for the treatment of MR. We have taken their suggestion of measuring flow through the aortic valve using Doppler-derived velocity-time integral and applied it to those patients in our dataset with heart failure with reduced ejection fraction (≤40%) with sufficient echocardiographic data (n = 22) to calculate SVf at baseline and follow-up. This subgroup was similar to the whole group in terms of mean (standard deviation) age (67 ± 9 years), sex distribution (86% male), regurgitant volume (27.4 ± 10.8 mL), with a baseline Simpson's ejection fraction of 31.4 ± 7.4% and LV end-diastolic volume of 188.5 ± 44 mL. One year after treatment, mean ejection fraction using volumes was unchanged (31.4 ± 7.4% to 32.0 ± 6.6%; P = ns), whilst, due to a significant improvement in SVf, ejection fraction measured using Doppler measurements, increased by almost 6% (27.6 ± 7.4% to 33.2 ± 12.8%; P = 0.02) (Figure 1). Describing clinical and mechanistic outcomes in patients following treatments for secondary MR is fraught with challenges of determining both the degree of MR at baseline and the efficacy of the intervention.1 This is especially difficult in patients with milder MR in whom limiting rises in left atrial pressure during activity might also be critical to symptomatic improvements and slowing disease progression. Using the suggested technique, it seems that even in people with mild secondary MR, the Carillon device can reduce MR and improve effective LV function after 12 months. Whether this leads to improved patient-orientated outcomes, specifically preventing or delaying future clinical deterioration, remains unproven. Given the challenges of demonstrating improvements in baseline variables in patients with mild secondary MR, ideally, future trials should be designed to describe a slowing of clinical disease progression rather than improvements in surrogate mechanistic variables.

Authors 4

1. Klaus Karl Witte corresponding Aachen

   RWTH Aachen University · Universitätsklinikum Aachen

   Affiliation as printed

   University Hospital of Aachen, RWTH Aachen Germany

   University Hospital of Aachen, RWTH, Aachen, Germany

2. Steven L. Goldberg

   Cardiac Dimensions (United States)

   Affiliation as printed

   Cardiac Dimensions Kirkland WA USA

   Tyler Heart Institute at Community Hospital of the Monterey Peninsula Monterey CA USA

   Cardiac Dimensions, Kirkland, WA, USA

   Tyler Heart Institute at Community Hospital of the Monterey Peninsula, Monterey, CA, USA

3. David M. Kaye

   The Alfred Hospital

   Affiliation as printed

   Department of Cardiology Alfred Hospital Melbourne Australia

   Department of Cardiology, Alfred Hospital, Melbourne, Australia

4. Randall C. Starling

   Cleveland Clinic

   Affiliation as printed

   Section of Heart Failure and Cardiac Transplant Medicine, Kaufman Center for Heart Failure Treatment and Recovery, Heart and Vascular Institute, Cleveland Clinic Cleveland OH USA

   Section of Heart Failure and Cardiac Transplant Medicine, Kaufman Center for Heart Failure Treatment and Recovery, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA