Comparison of Diuretic-based With Non-diuretic Based Hypertension Therapy Using Echocardiographic Measures

Overview

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.

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.

Conditions

Interventions

Eligibility

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Outcomes