Baroreflex activation therapy (BAT) has recently been shown to reduce muscle sympathetic nerve activity and hospitalization rate while improving clinical variables through 6 months of therapy in patients with heart failure and reduced ejection fraction (HFrEF). The objective of the present study is to extend the information on this patient cohort over a long-term follow-up.
Eleven patients were enrolled in the study and presented with optimized, stable medical therapy, New York Heart Association Class III HFrEF with left ventricular ejection fraction 40% or less, impaired functional capacity and no active cardiac resynchronization therapy. For the present report, muscle sympathetic nerve activity, baroreflex sensitivity data and hospitalization rate together with standard clinical data were collected at 12 and 21.5 ± 4.2 months following BAT activation. Two patients died during long-term follow-up. The remaining nine patients maintained the improvements observed at 6 months, including reduced sympathetic activity and rates of hospitalization.
BAT provides long-term chronic reductions in sympathetic activity and utilization of hospital resources in patients with HFrEF. General clinical presentation, quality of life and functional capacity are likewise improved and maintained. The temporal association of BAT with sympathetic drive diminution and improvement in objective clinical measures suggests a cause-and-effect relationship that will be verified in future randomized controlled trials of outcome.
aCardiovascular Department, IRCCS MultiMedica, Sesto San Giovanni
bIstituto Scientifico IRCCS Auxologico
cClinica Medica, Dipartimento di Scienze della Salute, Università Milano-Bicocca, Milan, Italy
dCVRx, Inc., Minneapolis, Minnesota, USA
eUniversità Milano-Bicocca, Milan
fDepartment of Molecular Medicine, University of Pavia, Pavia, Italy
Correspondence to Edoardo Gronda, MD, IRCCS MultiMedica, Sesto San Giovanni, Via Milanese 300, Milano 20141, Italy. Tel: +39 0224209460; fax: +39 0224209051; e-mail: firstname.lastname@example.org
Abbreviations: BAT, baroreflex activation therapy; BNP, B-type natriuretic peptide; BP, blood pressure; BRS, baroreflex sensitivity; eGFR, estimated glomerular filtration rate; HFrEF, heart failure with reduced ejection fraction; LVEF, left ventricular ejection fraction; MSNA, muscle sympathetic nerve activity; NYHA, New York Heart Association
Received 20 October, 2014
Revised 18 March, 2015
Accepted 18 March, 2015