Gaetano M De Ferrari1, Craig Stolen2, Anton E Tuinenburg3, D Jay Wright4, Josep Brugada5, Christian Butter6, Helmut Klein7, Petr Neuzil8, Cornelis Botman9, Maria Angeles Castel5, Antonio D'Onofrio10, Gert J de Borst3, Scott Solomon11, Kenneth M Stein2, Bernd Schubert12, Kevin Stalsberg2, Nicholas Wold2, Stephen Ruble2, Faiez Zannad13. 1. Coronary Care Unit - Laboratory of Clinical and Experimental Cardiology - and Cardiovascular Clinical Research Center, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; Department of Molecular Medicine, University of Pavia, Pavia, Italy. Electronic address: g.deferrari@smatteo.pv.it. 2. Boston Scientific Corporation, St. Paul, MN, United States. 3. Department of Cardiology, University Medical Center, Utrecht, The Netherlands. 4. Department of Cardiology, Liverpool Heart and Chest, Liverpool, UK. 5. Thorax Institute, Hospital Clinic, Barcelona, Spain. 6. Heart Centre Brandenburg Hospital, Bernau, Germany. 7. Division of Cardiology, Otto-von-Guericke Universität Magdeburg, Germany. 8. Department of Cardiology, Homolka Hospital, Prague, Czech Republic. 9. Department of Cardiology, Catharina Hospital, Eindhoven, The Netherlands. 10. Azienda Ospedaliera dei Colli - Monaldi, Napoli, Italy. 11. Cardiovascular Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, United States. 12. Guidant Europe, Diegem, Belgium. 13. Inserm, CIC 1433, Centre Hospitalier Universitaire, Department of Cardiology, Nancy University, Université de Lorraine, Nancy, France.
Abstract
BACKGROUND: The NECTAR-HF study evaluated safety and feasibility of vagal nerve stimulation (VNS) for the treatment of heart failure patients. The first six-month randomized phase of the study did not show improvement in left ventricular remodelling in response to VNS. This study reports the 18-month results and provides novel findings aiming to understand the lack of efficacy of VNS, including a new technique assessing the effects of VNS. METHODS:Ninety-six patients were randomized 2:1 to active or inactive VNS for 6months, thereafter VNS was activated for all patients. The primary safety endpoint was 18-month all-cause mortality. RESULTS: Ninety-one patients continued in the long-term evaluation with active VNS. The on-therapy survival estimate at 18months was 95% with a 95% one-sided lower confidence limit of 91%, (better than the predefined criterion). Left ventricular systolic volume decreased in the crossover group (VNS OFF→ON; 144±37 to 139±40, p<0.05) after VNS activation; LVESD (5.02±0.77 to 4.96±0.82, p>0.05) and LVEF (33.2±4.9 to 33.3±6.5, p>0.05) did not change. A new technique to detect subtle heart rate changes during Holter recordings, i.e. "heat maps", revealed that VNS evoked heart rate response in only 13/106 studies (12%) at 6 and 12months with active VNS. CONCLUSIONS: Although a favourable long-term safety profile was found, improvements in the efficacy endpoints were not seen with VNS. A new technique for detecting acute heart rate responses to VNS suggests that the recruitment of nerve fibres responsible for heart rate changes were substantially lower in NECTAR-HF than in pre-clinical models.
RCT Entities:
BACKGROUND: The NECTAR-HF study evaluated safety and feasibility of vagal nerve stimulation (VNS) for the treatment of heart failurepatients. The first six-month randomized phase of the study did not show improvement in left ventricular remodelling in response to VNS. This study reports the 18-month results and provides novel findings aiming to understand the lack of efficacy of VNS, including a new technique assessing the effects of VNS. METHODS: Ninety-six patients were randomized 2:1 to active or inactive VNS for 6months, thereafter VNS was activated for all patients. The primary safety endpoint was 18-month all-cause mortality. RESULTS: Ninety-one patients continued in the long-term evaluation with active VNS. The on-therapy survival estimate at 18months was 95% with a 95% one-sided lower confidence limit of 91%, (better than the predefined criterion). Left ventricular systolic volume decreased in the crossover group (VNS OFF→ON; 144±37 to 139±40, p<0.05) after VNS activation; LVESD (5.02±0.77 to 4.96±0.82, p>0.05) and LVEF (33.2±4.9 to 33.3±6.5, p>0.05) did not change. A new technique to detect subtle heart rate changes during Holter recordings, i.e. "heat maps", revealed that VNS evoked heart rate response in only 13/106 studies (12%) at 6 and 12months with active VNS. CONCLUSIONS: Although a favourable long-term safety profile was found, improvements in the efficacy endpoints were not seen with VNS. A new technique for detecting acute heart rate responses to VNS suggests that the recruitment of nerve fibres responsible for heart rate changes were substantially lower in NECTAR-HF than in pre-clinical models.