Multisite Pacing as a Supplemental Treatment of Congestive Heart Failure: Preliminary Results of the Medtronic Inc. InSync Study

Abstract

This report describes the initial results of the "InSync" study, a European and Canadian multicenter trial that examines the safety and efficacy of a multisite pacemaker (Medtronic InSync) and of left ventricular pacing leads (Medtronic 2187 and 2188) implanted via a cardiac vein as a supplemental treatment of refractory congestive heart failure. Over a 10-month period, the system was implanted successfully in 68 of the 81 (84%) patients who had been enrolled in the study. The 68 patients were, on average, 66 +/- 10 years old, had a mean left ventricular ejection fraction (LVEF) = 21% +/- 9%, and 63% were in NYHA functional Class III and 37% were in Class IV. No system implant related complication occurred. During follow-up, 7 of 10 patients who exited the study had died, 4 suddenly. There was a clinical benefit among surviving patients, which was corroborated by a significant improvement in NYHA functional class and in the Minnesota Living with Heart Failure Quality of Life Questionnaire Score (MLS) and by a longer distance covered during a 6-minute walk test. This clinical improvement was associated with a significant narrowing of the paced QRS complex during biventricular pacing, a significant decrease in the interventricular mechanical delay, and a trend towards an increase in the duration of ventricular filling. These encouraging preliminary results confirm the feasibility and reliability of this new multisite pacing system in the management of dilated cardiomyopathy and support the continuation of further evaluations of this complementary treatment of refractory congestive heart failure.

Predictors of Systolic Augmentation From Left Ventricular Preexcitation in Patients With Dilated Cardiomyopathy and Intraventricular Conduction Delay

“…The extent of QRS narrowing from pacing has been proposed to correlate with optimal responses. 13 However, we found only a weak trend (Pϭ0.16) between %⌬QRS and %⌬dP/dt max ( Figure 1B) and no relation between %⌬QRS and %⌬PP ( Figure 1C, Pϭ0.88).…”

Diretrizes para Avaliação e Tratamento de Pacientes com Arritmias Cardíacas

“…Brecker, entretanto, demonstrou resultados divergentes e efeitos contrários desse procedimento 99 . Vários estudos têm demonstrado as vantagens da estimulação multi-sítio no tratamento de portadores de cardiomiopatia dilatada e BCRE que demonstraram o papel dessa técnica, na ressincronização dos ventrículos através de avaliações clínicas, hemodinâmicas e funcionais [100][101][102][103][104][105] . A expectativa atual se dirige aos resultados do estudo Miracle, em andamento, cujo tamanho amostral relevante e promissora avaliação da longevidade prometem revelar o valor definitivo dessa técnica de estimulação 106 .…”

All Patients With Heart Failure and Intraventricular Conduction Defect or Dyssynchrony Should Not Receive Cardiac Resynchronization Therapy

“…7,16 These short-term hemodynamic investigations of CRT led to long-term observational (uncontrolled) trials of CRT that showed consistent, sustained improvements in exercise tolerance, quality of life, NYHA functional class, and cardiac performance. [17][18][19][20][21][22][23][24][25] Of course, the definitive proof supporting a role for CRT in heart failure management awaited the completion of subsequent largescale, randomized, single-and double-blind, controlled clinical trials.…”