TY - JOUR
T1 - Subgroup analysis of a randomized controlled trial evaluating the safety and efficacy of cardiac contractility modulation in advanced heart failure
AU - Abraham, William T.
AU - Nademanee, Koonlawee
AU - Volosin, Kent
AU - Krueger, Steven
AU - Neelagaru, Suresh
AU - Raval, Nirav
AU - Obel, Owen
AU - Weiner, Stanislav
AU - Wish, Marc
AU - Carson, Peter
AU - Ellenbogen, Kenneth
AU - Bourge, Robert
AU - Parides, Michael
AU - Chiacchierini, Richard P.
AU - Goldsmith, Rochelle
AU - Goldstein, Sidney
AU - Mika, Yuval
AU - Burkhoff, Daniel
AU - Kadish, Alan
PY - 2011/9
Y1 - 2011/9
N2 - Background: Cardiac contractility modulation (CCM) signals are nonexcitatory electrical signals delivered during the absolute refractory period intended to improve contraction. We previously tested the safety and efficacy of CCM in 428 NYHA functional class III/IV heart failure patients with EF ≤35% and narrow QRS randomized to optimal medical treatment (OMT) plus CCM (n = 215) versus OMT alone (n = 213) and found no significant effect on ventilatory anaerobic threshold (VAT), the study's primary end point. In the present analysis, we sought to identify if there was a subgroup of patients who showed a response to CCM. Methods and Results: The protocol specified that multiregression analysis would be used to determine if baseline EF, NYHA functional class, pVO 2, or etiology of heart failure influenced the impact of CCM on AT. Etiology and baseline pVO 2 did not affect efficacy. However, baseline NYHA functional class III and EF ≥25% were significant predictors of increased efficacy. In this subgroup (comprising 97 OMT and 109 CCM patients, ∼48% of the entire population) VAT increased by 0.10 ± 2.36 in CCM versus -0.54 ± 1.83 mL kg -1 min -1 in OMT (P =.03) and pVO 2 increased by 0.34 ± 3.11 in CCM versus -0.97 ± 2.31 (P =.001) at 24 weeks compared with baseline; 44% of CCM versus 23% of OMT subjects showed improvement of ≥1 class in NYHA functional class (P =.002), and 59% of CCM versus 42% of OMT subjects showed a ≥10-point reduction in Minnesota Living with Heart Failure Questionnaire (P =.01). All of these findings were similar to those seen at 50 weeks. Conclusions: The results of this retrospective hypothesis-generating analysis indicate that CCM significantly improves objective parameters of exercise tolerance in a subgroup of patients characterized by normal QRS duration, NYHA functional class III symptoms, and EF >25%.
AB - Background: Cardiac contractility modulation (CCM) signals are nonexcitatory electrical signals delivered during the absolute refractory period intended to improve contraction. We previously tested the safety and efficacy of CCM in 428 NYHA functional class III/IV heart failure patients with EF ≤35% and narrow QRS randomized to optimal medical treatment (OMT) plus CCM (n = 215) versus OMT alone (n = 213) and found no significant effect on ventilatory anaerobic threshold (VAT), the study's primary end point. In the present analysis, we sought to identify if there was a subgroup of patients who showed a response to CCM. Methods and Results: The protocol specified that multiregression analysis would be used to determine if baseline EF, NYHA functional class, pVO 2, or etiology of heart failure influenced the impact of CCM on AT. Etiology and baseline pVO 2 did not affect efficacy. However, baseline NYHA functional class III and EF ≥25% were significant predictors of increased efficacy. In this subgroup (comprising 97 OMT and 109 CCM patients, ∼48% of the entire population) VAT increased by 0.10 ± 2.36 in CCM versus -0.54 ± 1.83 mL kg -1 min -1 in OMT (P =.03) and pVO 2 increased by 0.34 ± 3.11 in CCM versus -0.97 ± 2.31 (P =.001) at 24 weeks compared with baseline; 44% of CCM versus 23% of OMT subjects showed improvement of ≥1 class in NYHA functional class (P =.002), and 59% of CCM versus 42% of OMT subjects showed a ≥10-point reduction in Minnesota Living with Heart Failure Questionnaire (P =.01). All of these findings were similar to those seen at 50 weeks. Conclusions: The results of this retrospective hypothesis-generating analysis indicate that CCM significantly improves objective parameters of exercise tolerance in a subgroup of patients characterized by normal QRS duration, NYHA functional class III symptoms, and EF >25%.
KW - Cardiac contractility modulation
KW - Minnesota Living With Heart Failure Questionnaire
KW - New York Heart Failure Classification six minute hall walk test
KW - cardiopulmonary stress testing
KW - peak VO
KW - ventilatory anaerobic threshold
UR - http://www.scopus.com/inward/record.url?scp=80052269340&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80052269340&partnerID=8YFLogxK
U2 - 10.1016/j.cardfail.2011.05.006
DO - 10.1016/j.cardfail.2011.05.006
M3 - Article
C2 - 21872139
AN - SCOPUS:80052269340
SN - 1071-9164
VL - 17
SP - 710
EP - 717
JO - Journal of Cardiac Failure
JF - Journal of Cardiac Failure
IS - 9
ER -