Monday, July 04, 2005

American Society Hypertension proposes new definition of hypertension

The American Society of Hypertension (ASH-actually the other ASH, as the American Society of Hematology is also ASH) announced at its recent meeting a new definition of hypertension, criticized ALLHAT and emphasized global risk rather than rigid BP categories. A more precise definition and explanation of ASH's position awaits publication. However, the president of ASH Dr. Thomas Giles of LSU Medical School in New Orleans, said that the new definition incorporates the presence or absence of risk factors and target organ damage markers . The current BP classification uses cut points to define the various stage of hypertension without assessing the patient's actual risk based on other factors. Giles characterizes JNC 7's "prehypertension"as a transitional category and says that if a person with a low BP - in the prehypertension range- has no signs of vascular disease, they should be considered normal.
The ALLHAT trial received criticism as well by Dr. Richard Devereau of Cornell who pointed out some of the methodologic problems with the study. He is certainly not the first to do this:see here and here. The importance of determing global risk of patients and placing BP within that context was a topic discussed at the 2003 ASH meeting and JNC7 was faulted for moving to BP numbers to guide therapy rather than the overall risk assessment approach.
The ASCOT trial ,which showed that the combination of a CCB and an ACEi was superior to the beta blocker-diuretic combination, should prompt a redoing of the JNC recommendation regarding mediation choices. These views of the ASH leader stand in contrast to a recent JAMA editorial. published April 6, 2005.The editorialists say " It is now time to move beyond comparison of diuretics with other classes of BP lowering drugs -that issue has been settled." The issue of the best combination of BP pills is not settled.The ASCOT trial may well bring about a shift in thinking.
Rethinking concepts of disease and treatment is much of what the science part of the art and science of medicine is about.Settled issues have a way of becoming unsettled as we learn more.Stone is a poorly suited medium to record recommendations for treatment.

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