Effects of Atrial Rate-adaptive Pacing on Exercise Capacity in Patients With Chronic Heart Failure Complicated by Chronotropic Incompetence
Recruitment status was: Recruiting
Chronotropic incompetence consists of an insufficient increase in heart rate during effort, and its presence is recognized as a common feature in patients with heart failure due to left ventricular systolic dysfunction, apparently suggesting a worse prognosis. Little is known about the possible benefits of its reversal in such patients.
The investigators working hypothesis is that the modulation of chronotropic response, as obtained by means of atrial rate-adaptive pacing may improve functional capacity in persons with chronic heart failure and chronotropic incompetence.
To explore this hypothesis,the investigators will enroll 20 patients with NYHA II/III heart failure, low left ventricular ejection fraction (<40%) and chronotropic incompetence (Maximal heart rate <80% of predicted value in a symptom-limited incremental test), who already underwent implantation of dual-chamber implantable defibrillator for prevention of sudden cardiac death. The study will have a randomized, double-blind, cross-over design.
The procedures, to be carried out at one month from each reprogramming (VVI backup pacing vs. AAI-R "active" pacing), will comprise: blood sampling for NT-proBNP, incremental symptom-limited cardiopulmonary exercise testing (CPX), constant-workload cardiopulmonary test (50% of max WR), quality-of-life questionnaire, 24-hour ECG monitoring.
The primary end-point will be peak oxygen consumption on CPX. Secondary end-points will include acute response to reprogramming, and data derived from constant-WR tests, Holter monitoring and QoL.
|Heart Failure Exercise Tolerance||Other: Rate-adaptive pacemaker programming Other: VVI at 40 bpm||Phase 4|
|Study Design:||Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
|Official Title:||Effects of Atrial Rate-adaptive Pacing on Exercise Capacity in Patients With Chronic Heart Failure Complicated by Chronotropic Incompetence|
- Peak Oxygen consumption on cardiopulmonary exercise testing [ Time Frame: 1 month ]
- Peak Heart Rate on Cardiopulmonary exercise testing [ Time Frame: 1 month ]
- Quality of life as assessed by Minnesota Living with Heart Failure and SF-36 Questionnaires [ Time Frame: 1 month ]
- Heart Rate Variability on Holter Monitoring [ Time Frame: 1 month ]
- Acute Change in Peak Oxygen Consumption after reprogrammation [ Time Frame: 1 hour ]
- NT-proBNP levels [ Time Frame: 1 Month ]
|Study Start Date:||November 2009|
|Estimated Study Completion Date:||August 2012|
|Estimated Primary Completion Date:||July 2012 (Final data collection date for primary outcome measure)|
Experimental: Rate adaptive
Patients will have their ICD programmed in a AAI-R mode, with peak atrial rate set at 85% of age-adjusted predicted maximal HR
Other: Rate-adaptive pacemaker programming
The ICD will be programmed in a AAI-R mode, with peak atrial stimulation rate set at 85% of maximal predicted heart rate, and ongoing protection VVI backup at 40 bpm
Active Comparator: Control
ICDs will be programmed in the usual VVI backup pacing mode at 40 bpm
Other: VVI at 40 bpm
ICDs will be programmed in VVI mode at 40 bpm
Please refer to this study by its ClinicalTrials.gov identifier: NCT01016431
|Contact: Serafino Fazio, MDfirstname.lastname@example.org|
|Contact: Guido Carlomagno, MDemail@example.com|
|Federico II University - Department of Internal Medicine||Recruiting|
|Naples, Italy, 80100|