Author + information
- Caroline M. Van De Heyning, MD, PhD∗ (, )
- Philippe B. Bertrand, MD, MSc,
- Philippe Debonnaire, MD,
- Catherine De Maeyer, MD,
- Pieter M. Vandervoort, MD,
- Patrick Coussement, MD,
- Bernard P. Paelinck, MD, PhD,
- Dina De Bock, MD,
- Christiaan J. Vrints, MD, PhD and
- Marc J. Claeys, MD, PhD
- ↵∗Department of Cardiology, University Hospital of Antwerp, Wilrijkstraat 10, 2650 Edegem, Belgium
Percutaneous mitral valve repair using the MitraClip (Abbott Vascular, Santa Clara, California) is a promising technique to treat symptomatic severe mitral regurgitation (MR) in patients at high or prohibitive surgical risk. Large observational registries of patients treated with this device for predominantly secondary MR show symptomatic relief and improvement of hemodynamics at rest (1,2). Comparative data on exercise hemodynamics before versus after percutaneous mitral valve repair therapy are currently lacking, although such data are most relevant in secondary MR. First, secondary MR is characteristically dynamic and sensitive to changes in ventricular geometry and loading conditions (3). It remains unclear whether, besides a reduction in resting MR, percutaneous mitral valve repair therapy is effective in reducing secondary MR during exercise. Second, mitral valve area is typically reduced following the procedure (4). It remains to be determined whether such mild iatrogenic stenosis might have an adverse effect on exercise hemodynamics.
We have therefore performed a prospective exercise echocardiographic study at 3 Belgian centers to assess the effect of percutaneous mitral valve repair therapy on resting and exercise hemodynamics in secondary MR patients (NCT02506387). After written informed consent, 31 patients (age 72 ± 10 years, 61% male, left ventricular ejection fraction 37 ± 8%, history of coronary artery disease 87%, and EuroSCORE II 8.3 ± 5.7%) with optimally treated, symptomatic moderate-to-severe or severe secondary MR were evaluated by Doppler echocardiography at rest and during a symptom-limited exercise test on a semisupine bicycle, before and 6 months after the procedure. MR severity, cardiac output (CO), mean transmitral gradient, systolic pulmonary artery pressure (SPAP), and a flow-corrected SPAP/CO ratio were assessed at rest and during peak exercise. MR severity was graded qualitatively using a multi-integrative approach and quantitatively as percentage MR jet area over left atrial area in the absence of other validated techniques. New York Heart Association functional class was obtained before and 6 months after percutaneous therapy.
At rest, 6 months after the procedure, MR severity was reduced (MR grade 3+/4+: 75% vs. 26%; p < 0.001; MR jet area/left atrial area 34 ± 12% vs. 18 ± 13%; p < 0.001), CO increased (3.4 ± 1.0 l/min vs. 3.9 ± 1.3 l/min; p = 0.033), and SPAP diminished (42 ± 11 mm Hg vs. 38 ± 10 mm Hg; p = 0.041), despite a significant increase in mean transmitral gradient (2.7 ± 1.5 mm Hg vs. 4.3 ± 2.2 mm Hg; p < 0.001). During exercise, MR severity was equally reduced post-procedure (peak MR jet area/left atrial area 32 ± 12% vs. 21 ± 14%; p < 0.001), as is depicted in Figure 1A. Furthermore, peak CO was increased post-procedure (5.5 ± 2.0 l/min vs. 6.5 ± 2.6 l/min; p = 0.039), whereas a similar exercise SPAP (63 ± 13 mm Hg vs. 59 ± 16 mm Hg; p = 0.170) was obtained at these higher flow rates (Figure 1B). Therefore, the flow-corrected SPAP/CO ratio was significantly better post-procedure compared with baseline, both at rest (13.8 ± 5.4 mm Hg/l·min−1 vs. 11.2 ± 4.7 mm Hg/l·min−1; p = 0.030) and during peak exercise (13.1 ± 5.6 mm Hg/l·min−1 vs. 10.6 ± 4.8 mm Hg/l·min−1; p = 0.036), implying that a higher CO can be achieved at lower SPAP after percutaneous mitral valve repair therapy. These beneficial hemodynamic alterations coincided with significant functional improvement (New York Heart Association functional class III to IV: 61% vs. 13%; p < 0.001; achieved peak workload 58 ± 23 W vs. 68 ± 25 W; p = 0.021) 6 months post-procedure.
These data provide the first clinical evidence of hemodynamic improvement during exercise following procedure in a secondary MR population. Our findings lend further support to promote percutaneous therapy to alleviate symptoms in patients with secondary MR and are at least partly explained by improved resting and exercise hemodynamics coinciding with dynamic MR reduction and despite transmitral gradient increase. Therefore, maximization of MR reduction seems to be key to performing successful percutaneous mitral valve repair, a contention sustained by recent reports indicating that the extent of secondary MR reduction strongly relates to outcome after device therapy (5). Furthermore, the current data are especially relevant in the anticipation of large prospective trials that investigate the clinical potential of percutaneous mitral valve repair therapy for secondary MR patients.
Please note: Dr. Debonnaire has received speaker fees from Abbott Vascular; and is a faculty member of Crossroads (MitraClip, Abbott Vascular). Prof. Claeys has received speaker fees from Abbott Vascular. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose. Drs. Van De Heyning and Bertrand have contributed equally to this paper.
- American College of Cardiology Foundation
- Maisano F.,
- Franzen O.,
- Baldus S.,
- et al.
- Puls M.,
- Lubos E.,
- Boekstegers P.,
- et al.