Author + information
- Stavros Dimopoulos, MD, PhD∗ (, )
- Stamatis Adamopoulos, MD, PhD,
- Michael Bonios, MD, PhD,
- Christos Charitos, MD, PhD,
- Antigoni Koliopoulou, MD,
- Andreas Karabinis, MD, PhD and
- Serafim Nanas, MD, PhD
- ↵∗Cardiopulmonary Exercise Testing and Rehabilitation Laboratory, National and Kapodistrian University of Athens, 45-47 Ypsilantou Street, 10676, Athens, Greece
We read with great interest the recent published study by Jakovljevic et al. (1). These investigators examined whether patients who underwent a left ventricular assist device (LVAD) bridge-to-recovery protocol could achieve cardiac and physical functional capacities equivalent to those of healthy control subjects. They found that 38% of the LVAD explanted patients achieved peak exercise cardiac power output and 69% achieved peak oxygen consumption within the ranges of healthy control subjects. Despite its limitations, this study provided evidence of the significant beneficial effects of LVAD support in patients who underwent an LVAD bridge-to-recovery protocol.
We have to emphasize that patients with advanced heart failure, apart from their marked exercise intolerance, are also characterized by significant ventilatory and autonomic nervous system abnormalities. Cardiopulmonary exercise testing can detect such abnormalities as expressed by “oscillatory” breathing, increased ventilatory response to exercise (minute ventilation-carbon dioxide output relationship during exercise, VE/VCO2 slope), low chronotropic reserve, and delayed heart rate recovery, which are well-known poor prognostic indicators in heart failure (2,3).
Their prognostic value in LVAD patients has been poorly studied so far, which may have significant clinical and prognostic implications. We showed previously (4,5) that LVAD implantation induced a significant improvement in inspiratory muscle strength with parallel improvement in exercise capacity in the post-LVAD implantation follow-up period, particularly in those patients who underwent an LVAD bridge-to-recovery protocol. However, in that study exercise ventilatory efficiency only slightly improved, whereas chronotropic reserve and heart rate recovery remained significantly impaired. Importantly, oscillatory breathing has not yet been thoroughly assessed in LVAD patients.
We would strongly encourage researchers to further investigate their study data exploring the potential additive beneficial effects of LVAD in heart failure patients. Providing evidence of ventilatory inefficiency and autonomic nervous system abnormalities recovery in LVAD explanted patients would further demonstrate global functional capacity improvement and equivalence to the healthy population.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2017 American College of Cardiology Foundation