InSync ICD - InSync ICD


The InSync trial was undertaken to verify the utility of combined resynchronization and ICD function of the newly developed, Model 7272 InSync ICD, which features dual-chamber VT and VF detection, antitachycardia pacing, cardioversion and defibrillation therapies, simultaneous biventricular pacing, and right ventricular sensing only.

Study Design

Study Design:

Patients Enrolled: 636
NYHA Class: NYHA Class II, III, or IV
Mean Follow Up: 6 months
Mean Patient Age: Mean age 68 years

Patient Populations:

Patient criteria for the InSync-ICD trial were: NYHA Class II, III, or IV QRS duration of =130 ms. LVEF =35%. LVEDD =55 millimeters by echo measurement. Stable HF controlled with appropriate drug therapy for at least 1 month. On an ACE inhibitor or substitute, if tolerated. If on beta blocker therapy, a stable regimen maintained for over 3 months prior to enrollment. Indication for an ICD.

Drug/Procedures Used:

Patients with NYHA Class II-IV heart failure, QRS duration of =130 ms, LVEF =35%, LVEDD =55 mm, who were stabilized on appropriate medical therapy, and indicated for an ICD were randomized to either implantation of the device with the cardiac resynchronization mode on, or to a control group, in whom the cardiac resynchronization mode was turned off. The ICD function was active in all patients. In all, there were a total of 636 subjects of NYHA Class II (n=215) or NYHA Class III/IV (n=421). Of the Class II subjects, 192 were randomized to either control or CRT. Of Class III/IV subjects, 362 were randomized to either control or CRT. In all, 371 patients received the implants. Patients in both the treatment and control groups were similar as far as heart rate, 6-minute walk distance, systolic and diastolic blood pressures, and the use of diuretic, ACE-I or ARB, and beta-blocker use. Similar percentages of patients with NYHA Class III were present in both groups (89% of controls and 88% in treatment group), and heart failure of ischemic etiology was present in 74% and 63%, respectively.

Principal Findings:

Insertion of the device was achieved with 88% safety and efficacy, with roughly 90% of the implants implanted successfully. There were a total of 49 events observed in 44 patients, with an observed 6-month rate of 85.1%. Significant changes in NYHA functional class were seen in the treatment group, compared with controls; 63% of the treatment group improved, compared with 47% of the control group; 34% and 48% of the groups, respectively, stayed the same; while 3% of the treatment group worsened, compared with 5% of the control group. Clinical composite response results were improved in 55% of treatment patients, compared with 40% of controls; no change in 19% vs. 26%, respectively; and worsening in 26% vs. 33%, respectively.

Clinical Topics: Arrhythmias and Clinical EP, Heart Failure and Cardiomyopathies, Implantable Devices, EP Basic Science, SCD/Ventricular Arrhythmias, Acute Heart Failure

Keywords: Cardiac Pacing, Artificial, Diuretics, Electric Countershock, Heart Failure, Blood Pressure, Heart Rate, Defibrillators, Implantable, Cardiac Resynchronization Therapy

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