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Effects of Atrial Rate-adaptive Pacing on Exercise Capacity in Patients With Chronic Heart Failure Complicated by Chronotropic Incompetence

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified November 2009 by Federico II University.
Recruitment status was:  Recruiting
Information provided by:
Federico II University Identifier:
First received: November 18, 2009
Last updated: June 24, 2011
Last verified: November 2009

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 Intervention Phase
Heart Failure Exercise Tolerance Other: Rate-adaptive pacemaker programming Other: VVI at 40 bpm Phase 4

Study Type: Interventional
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

Resource links provided by NLM:

Further study details as provided by Federico II University:

Primary Outcome Measures:
  • Peak Oxygen consumption on cardiopulmonary exercise testing [ Time Frame: 1 month ]

Secondary Outcome Measures:
  • 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 ]

Estimated Enrollment: 20
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)
Arms Assigned Interventions
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


Ages Eligible for Study:   18 Years to 75 Years   (Adult, Senior)
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
  Contacts and Locations
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Please refer to this study by its identifier: NCT01016431

Contact: Serafino Fazio, MD +390817463737
Contact: Guido Carlomagno, MD

Federico II University - Department of Internal Medicine Recruiting
Naples, Italy, 80100
Sponsors and Collaborators
Federico II University
  More Information

Responsible Party: Prof. Serafino Fazio, Federico II University Identifier: NCT01016431     History of Changes
Other Study ID Numbers: CHRON-INC-09
Study First Received: November 18, 2009
Last Updated: June 24, 2011

Keywords provided by Federico II University:
cardiac pacing
heart failure
oxygen consumption
ventricular dysfunction
left, exercise tolerance
chronotropic incompetence
pacemaker programming

Additional relevant MeSH terms:
Heart Failure
Heart Diseases
Cardiovascular Diseases processed this record on September 21, 2017