Effects of Atrial Rate-adaptive Pacing on Exercise Capacity in Patients With Chronic Heart Failure Complicated by Chronotropic Incompetence
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ClinicalTrials.gov Identifier: NCT01016431 |
Recruitment Status : Unknown
Verified November 2009 by Federico II University.
Recruitment status was: Recruiting
First Posted : November 19, 2009
Last Update Posted : June 27, 2011
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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.
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Heart Failure Exercise Tolerance | Other: Rate-adaptive pacemaker programming Other: VVI at 40 bpm | Phase 4 |
Study Type : | Interventional (Clinical Trial) |
Estimated Enrollment : | 20 participants |
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 |
Study Start Date : | November 2009 |
Estimated Primary Completion Date : | July 2012 |
Estimated Study Completion Date : | August 2012 |

Arm | Intervention/treatment |
---|---|
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
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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
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Other: VVI at 40 bpm
ICDs will be programmed in VVI mode at 40 bpm |
- 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 ]

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Ages Eligible for Study: | 18 Years to 75 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Inclusion Criteria:
- NYHA II/III chronic heart failure on optimal medical therapy
- Sinus Rhythm
- Left ventricular ejection fraction less than 40 %
- Chronotropic incompetence on maximal exercise testing (maximum heart rate < 80% of predicted value)
- Age 18-75
- carrier of dual chamber ICD device
- Informed Consent
Exclusion criteria:
- Unable to perform cardiopulmonary exercise testing (for any reason)
- Absolute contraindication to maximal exercise testing
- Moderate to severe anemia (Hb<10 g/dL)
- Diagnosis of Sick Sinus Syndrome or high-degree atrioventricular block
- recent hospitalization for acute decompensated heart failure (<1 month)
- recent acute coronary syndrome (<3 months)
- Active neoplastic disease
- Active myocarditis / endocarditis
- Acute decompensated heart failure during study

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01016431
Contact: Serafino Fazio, MD | +390817463737 | fazio@unina.it | |
Contact: Guido Carlomagno, MD | guido.carlomagno@yahoo.it |
Italy | |
Federico II University - Department of Internal Medicine | Recruiting |
Naples, Italy, 80100 |
Responsible Party: | Prof. Serafino Fazio, Federico II University |
ClinicalTrials.gov Identifier: | NCT01016431 |
Other Study ID Numbers: |
CHRON-INC-09 |
First Posted: | November 19, 2009 Key Record Dates |
Last Update Posted: | June 27, 2011 |
Last Verified: | November 2009 |
cardiac pacing heart failure oxygen consumption ventricular dysfunction |
left, exercise tolerance chronotropic incompetence pacemaker programming |
Heart Failure Heart Diseases Cardiovascular Diseases |