Anti-Angiotensin-Receptor 1 (ATR1)-, Anti-Endothelin-Receptor A (ETRA)-Antibodies and T Cells in Cardiomyopathy
Condition: Cardiac Failure
MeSH terms: Cardiomyopathies; Heart Failure
Study type: Observational

Summary: 
      The study aims 1) to determine autoantibody titers against the AGTR1 receptor and against the
      ETA receptor, 2) to characterize cytokine expression profiles of heart-specific activated T
      cells in patients with systolic heart failure. Auto-antibody titers and specific cytokine
      expression profiles in heart-specific activated T cells will then be correlated with heart
      failure progression and outcome.
    

Detailed description: 
      1. AIM OF THE STUDY 1.1. Background Progressive interstitial fibrosis parallels
           pathological remodeling in the failing heart. This is particularly the case in patients
           with post-inflammatory dilated cardiomyopathy, but is also observed in ischemic and
           hypertensive heart disease. Both, Angiotensin II (AngII) and Endothelin-1 (ET1) induce
           the formation of the profibrotic cytokine TGFβ and promote fibrosis. From this point of
           view, it is not surprising that blocking the Renin-Angiotensin-Aldosterone-System (RAAS)
           evolved as key strategy to slow heart failure progression. Furthermore, recent data also
           points to an important role of Angiotensin II signaling in heart failure with preserved
           ejection fraction. In animal models, blocking the effect of AngII or ET1 reduces
           fibrotic remodeling following myocardial ischemia or in pulmonal hypertension. In line
           with these findings, we found no evidence of fibrotic remodeling in AGTR1-/- mice who
           recovered from acute myocarditis. Nevertheless, RAAS blockade is not efficient enough to
           completely prevent heart failure progression or even rapid deterioration in subgroups of
           the affected patients. Only recently, Riemekasten et al demonstrated that
           auto-antibodies against AGTR1 and ETAR are increased in systemic sclerosis and
           associated with increased pulmonary hypertension and lung fibrosis (2). Moreover, these
           auto-antibodies were shown to be functional active and to induce downstream expression
           of TGFβ -mRNA.

           Anti-AGTR1-Ab and Anti-ETAR-Ab might therefore directly promote fibrosis through
           activation of AGTR1 and ETAR. Furthermore, auto-reactive T-cells to the myosin heavy
           chain (MyHC) of the heart muscle were demonstrated to play an important role in both the
           initial inflammation during myocarditis as well as the progression of inflammation.

           1.2. Rationale for the current study Cardiac autoantibody titers are generally elevated
           in patients after myocardial infarction or suffering from systolic heart failure. In
           addition, we found experimental evidence for a critical role of AngII signaling in the
           development of cardiac fibrosis. We hypothesize that auto-immunological effects in
           general, and Anti-AGTR1-Ab, Anti- ETAR-Ab and auto-reactive T-cells in particular, are
           important and so far widely underestimated in the pathogenesis of cardiomyopathies and
           that they interfere with evidence based treatment approaches.

           1.3 Aims The objectives of this study are to

             -  determine the concentration of Anti-AGTR1- and Anti-ETRA-AB in the patients blood.

             -  determine the auto-reactive heart specific T-cells and their cytokine expression
                profile in patients blood.

             -  to correlate these findings to outcome (hospitalizations due to heart failure,
                stroke, myocardial infarction, and death) and to cardiac function of the patient
                (VO2, Ejection fraction, NYHA class).

        2. STUDY DESIGN Prospective pilot study.

        3. PARTICITPANT ENTRY 3.1. Pre---registration evaluation Patients with cardiomyopathy and
           heart failure for 6 months or more will be recruited at the GZO Spital Wetzikon during
           ambulatory visits.

        4. EFFICACY AND SAFETY VARIABLES 4.1. Efficacy variables and examinations 4.1.1 non---study
           specific variables and examinations Medical history

             -  general information: age, gender, weight, height

             -  actual medications

             -  staging of heart failure according to the severty of symptoms and physical activity
                (New York Heart Association-classification) Electrocardiogram (ECG) For all
                electrocardiographic recordings a commercially available 12-lead ECG will be used
                and set at 25mm/s paper speed and 10mm/mV amplitude.

           Transthoracal echocardiography (TTE) TTE will be performed by a cardiologist. The
           following parameters will be recorded:

             -  Left ventricular ejection fraction using Simpson Biplan method

             -  Left ventricular end diastolic and end systolic diameter

             -  Left atrial diameter

             -  Peak velocity E, A; E/A quotient; TDI

             -  Flow in pulmonary veines

           4.1.2 Study specific variables and examinations Determinations of Anti-AGTR1-AB and
           Anti-ETRA-AB Concentrations of Anti-AGTR1-AB and Anti-ETRA-AB will be measured using
           commercially available ELISA-Kits according to manufactures protocol (Celltrend,
           Luckenwalde, Germany).

           Evaluation of auto-reactive T-Cells Auto-reactive T-cells will be isolated from patient
           blood and analysed as described for organ-specificity (cMET+), for their reactivity
           against cardiac self-antigens and for their cytokine expression profile.

        5. ASSESSMENT AND FOLLOW---UP The investigations during the visit are described in
           paragraph 4. The assessment are performed during the initial visit, at 4 months, and at
           12 months.

        6. STATISTICS AND DATA ANALYSIS As this is a pilot study and no published data on the
           observed parameters in cardiomyopathies are available, no power analysis was performed.
           Groups will be compared using ANOVA. Statistical significance will be assumed at a
           probability of p < 0.05.

        7. REGULATORY ISSUES 7.1 Ethic approval The study will be conducted according to the
           current declaration of Helsinki, the Good Clinical Practice-guidelines and Swiss
           regulatory authority´s requirements. The study has been approved by the KEK (local
           ethics committee).

           7.2 Consent Written consent will be sought from participants only after full explanation
           of the study and time allowed for consideration. The right of the participant to refuse
           to participate without giving reasons will be respected. If the participant withdrawls
           his/her consent, data collected to the date of the withdrawal will be used.

           7.3 Confidentiality All study personnel will preserve the confidentiality of
           participants taking part in the study.

           7.4 Insurance Insurance is covered by "Zurich Versicherungsgesellschaft AG" for GZO
           Spital Wetzikon.

        8. QUALITY CONTROL 8.1 Audits The investigators welcome audits by regulatory bodies to
           ensure adherence to GCP and regulatory requirements.

      8.2 Data management A designated research nurse and/or research fellow will be responsible
      for data collection and data management.

      8.3 Data privacy Access to personal data of participants is strictly limited to the
      investigators aforementioned. Raw data will be archieved for at least 10 years. Blood samples
      willbe analysed at the Center for Molecular Cardiology of the University of Zurich in the
      group for cardioimmunology and destroyed after definitive analysis. Blood sample collection
      will be done at GZO Spital Wetzikon. The blood samples will be anonymised directly after
      collection. All data sheets, blood samples and data fromanalysis will be anonymised to a
      two-digit code. The key to match the two-digit-code to the personal data of the patient will
      be stored in a separate, password-protected data base. Only the principal investigator and
      investigator Dr. med. Nazmi Krasniqi will have access to this data base.
    

Observational model: Cohort
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Heart failure patients, EF < 35%, either CAD (re-vascularized) or other type of heart
        failure
      
Biospecimen description: 
      T cells