Comparison of Diuretic-based With Non-diuretic Based Hypertension Therapy Using Echocardiographic Measures
Condition: Hypertension
MeSH terms: Hypertension
Study type: Interventional

Summary: 
      MAIN: The benefits of treating high blood pressure successfully to normal levels on heart
      function are the same regardless of which particular combination of drugs are used.
      SECONDARY: Measurement of heart function using a comprehensive ultrasound imaging method
      (Echocardiography) and an objective test of functional ability are better predictors of
      changes in heart function with successful hypertension treatment, than subjective signs of
      heart failure.
    

Detailed description: 
      Successful treatment of hypertension with single medications is very rare. On average
      successful treatment requires more than 2 medications. These medications work by different
      methods. One of the ideas behind the use of combinations of medication for hypertension is
      that benefits are additive. There are unresolved questions about whether the observed
      benefits are simply related to effective treatment of hypertension, or whether some of the
      medications have special benefits independent of blood pressure lowering. Each of these
      contentions has been justified by clinical trials. However these trials have in common the
      flaw that hypertension is either not effectively controlled in all the treated subjects, or
      the magnitude of blood pressure change after treatment is different in the groups compared.
      The result of one of the largest blood pressure clinical trials called ALLHAT trial has
      recently fuelled this debate. The ALLHAT trial which utilized only subjective symptoms and
      signs of heart failure, called the FRAMINGHAM score, to determine who has abnormal heart
      function, implied that diuretics (water pills) were superior to the newer drugs in reducing
      the frequency of abnormal heart function. This study shared the flaw of previous trials in
      not having equal blood pressure lowering in the groups. Nevertheless it provided some
      evidence that argued against the notion that newer drugs were better than older drugs like
      diuretics. Shortly after the publication of ALLHAT, another trial called ANBP was published
      showing that the group of drugs that was least effective in ALLHAT was superior to diuretics
      in preventing important cardiovascular outcomes. Hence, it is not currently clear that there
      are differences between various drug combinations, if effective and equal blood pressure
      lowering is achieved. Another finding that may have confounded clinical trials that rely on
      subjective scores of heart dysfunction such as the ALLHAT, is that a significant proportion
      of subjects with advanced heart disease are unaware of their heart problem and hence will
      probably not seek attention. This raises the concern that the true frequency of abnormal
      heart function might not have been reported in those studies. Using more modern tools such as
      Echocardiography, a more complete assessment of heart dysfunction can be obtained. In
      addition objective tests of heart function such as the 6-minute walk distance could yield a
      more reliable assessment of any worsening or improvement in heart function if performed
      serially in treated subjects. In view of the above discussion, only a study in which
      hypertension is effectively and similarly controlled could be used to answer the questions
      regarding different effects of various drug combinations. Such is this study proposed.
    

Intervention name(s): Diuretic-Based or Non-Diuretic Based Hypertension Therapy
Intervention type(s): Drug
Intervention MeSH terms: Diuretics
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Ambulatory blood pressure monitoring; Echocardiography; Diastolic function; Left ventricular mass regression