Chronic vagus nerve stimulation: a new and promising therapeutic approach for chronic heart failure.
De Ferrari, Gaetano M. 1,*; Crijns, Harry J.G.M. 2; Borggrefe, Martin 3; Milasinovic, Goran 4; Smid, Jan 5; Zabel, Markus 6; Gavazzi, Antonello 7; Sanzo, Antonio 1; Dennert, Robert 3; Kuschyk, Juergen 4; Raspopovic, Srdjan 5; Klein, Helmut 6,8; Swedberg, Karl 9; Schwartz, Peter J. 1,10,11,12,13
[Article]
European Heart Journal.
32(7):847-855, April 2011.
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Aims: In chronic heart failure (CHF), reduced vagal activity correlates with increased mortality and acute decompensation. Experimentally, chronic vagus nerve stimulation (VNS) improved left ventricular (LV) function and survival; clinically, it is used for the treatment of drug-refractory epilepsy. We assessed safety and tolerability of chronic VNS in symptomatic CHF patients, using a novel implantable nerve stimulation system. The secondary goal was to obtain preliminary data on clinical efficacy.
Methods and results: This multi-centre, open-label phase II, two-staged study (8-patient feasibility phase plus 24-patient safety and tolerability phase) enrolled 32 New York Heart Association (NYHA) class II-IV patients [age 56 /- 11 years, LV ejection fraction (LVEF) 23 /- 8%]. Right cervical VNS with CardioFit (BioControl Medical) implantable system started 2-4 weeks after implant, slowly raising intensity; patients were followed 3 and 6 months thereafter with optional 1-year follow-up. Overall, 26 serious adverse events (SAEs) occurred in 13 of 32 patients (40.6%), including three deaths and two clearly device-related AEs (post-operative pulmonary oedema, need of surgical revision). Expected non-serious device-related AEs (cough, dysphonia, and stimulation-related pain) occurred early but were reduced and disappeared after stimulation intensity adjustment. There were significant improvements (P < 0.001) in NYHA class quality of life, 6-minute walk test (from 411 /- 76 to 471 /- 111 m), LVEF (from 22 /- 7 to 29 /- 8%), and LV systolic volumes (P = 0.02). These improvements were maintained at 1 year.
Conclusions: This open-label study shows that chronic VNS in CHF patients with severe systolic dysfunction may be safe and tolerable and may improve quality of life and LV function. A controlled clinical trial appears warranted.
(C) Copyright Oxford University Press 2011.