Assessment of AAIR Pacing Treatment for Heart Failure Patients With Chronotropic Incompetence
Condition: Heart Failure
MeSH terms: Heart Failure
Study type: Observational

Summary: 
      The primary objective of this study is to assess the clinical efficacy of AAIR (Atrial-paced
      Atrial-sensed Inhibitory Rate-Modulated) pacing treatment for heart failure (HF) patients
      with chronotropic incompetence (CI) in terms of exercise tolerance and quality of life.
      Specifically, the study will assess the changes in cardiac function associated with changes
      of physical exercise intensity and heart rate in AAIR pacing mode compared with AAI pacing
      mode.
    

Detailed description: 
      CI is the inability of the heart to increase its rate in response to increased physical
      activity or metabolic demand, leading to exercise intolerance and poor quality of life.
      Studies have demonstrated that patients with CI have a high risk of cardiac morbidity and
      mortality. Recent studies further demonstrate a high incidence of CI in patients with heart
      failure, which is also confirmed by CI in Heart Failure Study Phase I. However, clinical
      attention is often paid to heart failure symptoms instead CI-related symptom. Thus, patients
      with heart failure are often not tested for CI, even though the CI incidence is high in these
      patients. Moreover, such patients could gain significant improvements in exercise tolerance
      and quality of life once they get diagnosed followed by effective therapy for CI and
      long-term management.

      This study is designed to establish clinical evidence that AAIR pacing is beneficial to treat
      CI-caused symptoms in heart failure patients, which will improve the life quality of such
      patients and further support the expansion of Brady therapy indications to the population of
      HF with CI in existing markets and also potential markets.

      CI is rarely seen and has different definition among various animal species. It is impossible
      to use animals to get wanted data for AAIR pacing treatment to CI. Thus, a human clinical
      study is necessary. Furthermore, exercise testings, such as 6 minutes hall walk (6MHW) and
      treadmill, allow objective evaluation of exercise capacity and exertional symptoms, which
      have been suggested as other investigations for HF in "ESC Guidelines for the diagnosis and
      treatment of acute and chronic heart failure 2012". Therefore, exercise testings will be
      applied upon physicians' need or judgment.

      Firstly, this study is to assess the effect of AAIR pacing treatment for HF patients with CI
      in terms of exercise tolerance and quality of life. Specifically, the study will assess the
      changes in cardiac function associated with changes of physical exercise intensity and heart
      rate in AAIR pacing mode compared with AAI pacing mode. Secondly, the study will look at
      clinical outcomes in terms of NYHA class, 6MHW, blood BNP, Echo measurements following
      pacemaker therapy for 1 year. 6MHW and treadmill tests have been suggested as other
      investigations for HF in "ESC Guidelines for the diagnosis and treatment of acute and chronic
      heart failure 2012" and will be performed upon physicians' need or judgment.

      The study will enroll up to 30 subjects that meet the indication for pacing therapy.
      Consented subjects will receive pacing therapy and two follow-ups in the following one year.
    

Observational model: Case-Crossover
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        In the study, total 30 heart failure patients with chronotropic incompetence who meet the
        inclusion and exclusion criteria would be enrolled from the ourtpatients in Fuwai Hospital.
      
Keywords: Heart Failure; Chronotropic Incompetence; Rate Response; Exercise Test