Chronic Vagus Nerve Stimulation: A New Treatment Modality for Congestive Heart Failure Gaetano M. De Ferrari, MD Dept. of Cardiology, Fondazione IRCCS Policlinico S. Matteo, Pavia, Italy for the CardioFit Vagal Stimulation Multicenter Trial Investigators
Presenter Disclosure Information Gaetano M. De Ferrari The following relationships exist : Research/Research Grants BioControl Ltd Significant level Consultant/Consulting Fees BioControl Ltd Consultant/Consulting Fees Guidant Boston Scientific Modest level Modest level 2
Background Increased sympathetic activity and reduced vagal activity are associated with increased mortality both after myocardial infarction and in heart failure; further vagal withdrawal has been documented to precede acute decompensation. Experimental studies indicate that increased parasympathetic activity by means of vagal stimulation may reduce mortality in animal models of post infarction sudden cardiac death and of chronic heart failure. 3
Goals of the Study To assess feasibility and safety of chronic vagal stimulation in patients with advanced congestive heart failure. To provide preliminary efficacy data on this new therapeutic approach.
Steering Committee: Peter J. Schwartz (Chairman), Gaetano M. De Ferrari, Helmut Klein, Karl Swedberg, Rami Biran. Investigators Italy: Peter J. Schwartz, Gaetano M. De Ferrari, Antonio Sanzo; Pavia. Antonello Gavazzi, Attilio Jacovoni; Bergamo. Germany: Martin Borggrefe, Juergen Kuschyk, Antonina Schoene; Mannheim. Markus Zabel, Dieter Zenker; Goettingen. Helmut Klein, Jan Smid, Ruediger C. Braun-Dullaeus; Magdeburg. Serbia: Goran Milasinovic, Srdjan Raspopovic; Belgrade. The Netherlands: Harry J.G.M. Crijns, Robert Dennert; Maastricht.
Inclusion Criteria Chronic heart failure, NYHA II-III; Age 18-75 years; Sinus rhythm; Average 24-hour heart rate 60-110 b/min; Optimal medical treatment with no change in the previous 3 months with the exception of diuretic dose; Left ventricular ejection fraction 35%.
Main Exclusion Criteria Acute coronary syndrome or revascularization <3 months; Previous stroke; Severe renal or hepatic failure; Diabetes Mellitus treated with insulin for more than two years or diabetic neuropathy; Active peptic disease or history of upper GI bleeding; Asthma, severe COPD or severe restrictive lung disease; PR interval >240msec, 2nd or 3rd degree AV block; Atrial fibrillation or flutter in the previous 3 months; Patient is candidate for CRT.
Population of the Study (n=32) Male/Female Age (years) Duration of HF (years) Ischemic/Non ischemic ICD Diabetes Mellitus Beta-blockers ACE-I/ARB Loop diuretics Anti-aldosterone Nitrates 30/2 56±11 4.1±2.8 20/12 19 (59%) 5 (16%) 31 (97%) 32 (100%) 29 (91%) 19 (59%) 14 (44%)
Study Flow-Chart Recruitment (Baseline) Implantation Activation Parameter Setting Follow-up period End of study weeks < -4 0 3 3-6 6 10 18 30 Baseline 3 months 6 months
Implanted Device
Cuff Electrode Cuff Electrode CardioFit Stimulator Intracardiac Electrode
Adverse Events Unrelated 27 34 related 10 (6 pts) Pain at stimulation site 6 Cough 5 Dysphonia 3 Jaw pain 3 Pocket/temporal/abdominal pain 2 (1 pt) Nausea 1 ECG stimulus artifact 1 Delayed healing 1 Skin abrasion 1 Sweating 1 Headache
Serious Adverse Events Unrelated unexpected 3 Death (<3 months) 8 (5pts) Cardiac decompensation 10 14 Unrelated expected 1 ICD shock and hospitalization 1 Pleural effusion 2 1 New onset of AF leading to CV Related 1 pt Surgical Revision of Device 1 pt Post Operative Pulmonary Oedema
Stimulation Parameters Amplitude 4.1±1.2 mamp Duty cycle (% on) 21±5 %
Effect of Vagal Stimulation in one Patient
Heart Rate 100 80 p=0.014 p=0.038 p=0.007 b/min 60 40 81.9 75.1 76.0 20 0 Baseline 3 Months 6 Months
NYHA Class IV n=2 Died III n=15 Died Died n=4 n=5 II n=15 n=19 n=13 I n=6 n=11 Baseline 3 Months 6 Months
Quality of Life (MLwHF ) 60 p=0.00005 p=0.00002 50 40 p<0.00001 30 20 10 0 47.6 32.6 32.0 Baseline 3 Months 6 Months
Six-Minute Walk Test 500 p=0.00006 p=0.00004 p<0.00001 400 meters 300 200 410 470 471 100 0 Baseline 3 Months 6 Months
Left Ventricular Volumes Indexes ml/m 2 160 140 120 100 80 60 40 20 0 131.0 122.9 129.4 LVEDVI, p=0.32 LVESVI, p=0.12 101.5 91.2 96.1 Baseline 3 Months 6 Months
Left Ventricular Ejection Fraction % 35 30 25 20 15 10 5 0 p=0.04 p=0.007 p=0.004 22.5 27.7 26.6 Baseline 3 Months 6 Months
Conclusions Chronic vagal stimulation in patients with advanced CHF is feasible and appears to be well tolerated and safe. Initial data suggest subjective and objective improvement. A larger controlled study is warranted.