The Cardiac Effects of Prolonged Hypothermia After Cardiac Arrest
Condition: Cardiac Arrest; Hypothermia
MeSH terms: Heart Arrest; Hypothermia
Study type: Interventional

Summary: 
      This PhD study is a sub study in a randomized clinical controlled multicenter trial named
      "TTH48" (ClinicalTrials.gov Identifier: NCT01689077).

      The TTH48 trial examines prolonged mild therapeutic hypothermia ("MTH") at 32-34°C in 24
      versus 48 hours with the primary outcome Cerebral Performance Category after 6 month in
      comatose out-of-hospital cardiac arrest patients.

      THE OVERALL AIM OF THIS PhD STUDY IS TO INVESTIGATE THE CARDIAC FUNCTION AND THE HEMODYNAMICS
      BY BIOCHEMICAL CARDIAC MARKERS, ECHOCARDIOGRAPHY, BY ANALYZING THE USAGE OF
      INOTROPES/VASOPRESSORS AND BY ANALYZING ECG DATA FOR ARRHYTHMIAS IN THE 24 VERSUS 48 HOURS
      MTH GROUPS.
    

Detailed description: 
      The PhD-study contains 3 sub studies:

        -  Study 1 estimates the extend of myocardial damage resulting from the primary arrest and
           from the reperfusion injuries: Area under the curve of cTnT and CK-MB as 12 repeated
           measurements and NT-proBNP as 4 measurements post arrest

           -Hypothesis: There is a statistically significantly greater release of the cardiac
           biomarkers cTnT and NT-proBNP quantified by the area under the curve in the 24 versus
           the 48 hours group in the intervention period from 24 to 72 hours.

        -  Study 2 investigates MTH´s influence on systolic and diastolic function by standard and
           Tissue Doppler (TDI) echocardiography after 24, 48 and 72 hours. The primary endpoint is
           mitral annular systolic velocity ("S´ max")

           -Primary hypothesis: There is statistically significant improvement in S' max from the
           time T24 to T72 in the 48 versus the 24 hours group.

           -Secondary hypothesis: There is statistically significantly better systolic function at
           T48 measured in terms of individual S' max-change in the 48 hours group (still
           hypothermic) versus the 24 hours group (reached normothermia).

        -  Study 3 investigates MTH´s influence on the need for vasopressor or inotrope and the
           duration of arrhythmias during the first 72 hours post arrest.

             -  Primary hypothesis: There is a statistically significantly increased tendency of
                arrhythmias in the 48 versus the 24 hours group measured in the period from T0 to
                T72.

             -  Secondary hypothesis: There is a statistically significantly reduced need for
                inotropes in the 48 versus the 24 hours group measured by cumulative vasopressor
                index in the period from T0 to T72.
    

Intervention name(s): Mild therapeutic hypothermia
Intervention type(s): Procedure
Intervention description(s): Mild therapeutic hypothermia with a target temperature between 32-34°C.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary purpose: Treatment
Keywords: Cardiac arrest; Therapeutic Hypothermia; Cardioprotectiveness; Hemodynamics