Monday, May 5, 2008

Hypertension in Persons Older Than 80 Years: Time for a Disease Management Program

If you believe Li Ching-Yun really made it to the age of 256 years, you can pretty much assume that he didn’t have high blood pressure. He wouldn’t have lived that long and he sure wouldn’t have been able to father so many children. Compared to the elderly in the U.S., he’s the exception; almost three quarters of persons over the age of 65 has hypertension. Because persons who are among the very old (in their 80’s) are the among the fastest growing group in the United States, more are making it into their 80's with high blood pressure. How should they be treated so that they can also lead the happy boomer life of Mr. Li?

The Disease Management Care Blog knows many physicians are reluctant to treat the ‘very’ elderly (often defined as age > 80 years) for hypertension. While clinical inertia and ‘elder’ bias may be playing roles, the DMCB suspects docs have a healthy respect for medication side effects that could violate the 'first do no harm' adage. What’s more, there has been some science supporting the notion that in the very elderly, treating high blood pressure results in trade-offs. The bible of hypertension treatment guidelines, JNC VII, is also silent on how to treat this group of individuals.

Enter the May 1 New England Journal of Medicine. The lead article was a huge international multi-centre (if it were in the U.S., the ever-urbane DMCB would need to describe it as multi-center) prospective, blinded, placebo control study that randomly allocated very elderly hypertensives with a blood pressure > 160 systolic to treatment versus no treatment. First-line treatment was a less commonly used water pill (diuretic) called indapamide. If that didn’t get the patient to a target blood pressure of less than 150 systolic and 80 diastolic, escalating doses of an ACE inhibitor were added. Two years later, data from over 3800 patients showed treatment beat placebo with a 21% ‘relative’ reduction in the occurrence of any death, 64% relative risk of heart failure and 30% relative reduction in the risk of stroke. Side effects were minimal: ‘Only five… events... were classified by the local investigator as possible having been due to the trial medication.’

The DMCB says it may be time to think about a population-based disease management initiative aimed at the very elderly hypertensives. Using the trusty ‘number needed to treat’ (NNT) calculation, the DMCB notes the treatment group had a death-from-any-cause rate of 47.2 per 1000 patient years, versus 59.6 in the placebo group. That’s 4.7 per 100 patient-years vs. 5.9 or really a difference of 1.2%. To calculate the NNT, take 1 divided by the reduction in absolute risk, which in this case is 83. So, the death rate will decrease by just over 1%. You have to treat 83 persons to save one life. The ‘any cardiovascular event’ rates (stroke, heart attack or heart failure) went from 5.1 to 3.4 per 100 patient-years or 1.7%; the NNT is 58. While the NNT numbers are not nearly as impressive as other widely accepted interventions, they are still respectable, especially when the treatment appeared to be so well tolerated and cardiovascular event rates in the very elderly are otherwise high.

In the opinion of the DMCB, the study protocol lends itself quite nicely to a population-based approach. The exclusion criteria not only included a generic contraindication (relying on physician judgment), there was a list of other diagnoses (for example, dementia) that precluded treatment. Once the patient was in the protocol, the steps that followed were very easily implemented outside of the usual time consuming face-to-face physician visits. Standing orders are well within reach that could be followed by non-physician health care professionals with or without home monitoring. Given the low baseline rate of treatment and low expense of the medications (and assuming ACE inhibitors are interchangeable), an efficient disease management program could, based on these data, readily reduce the admission rate from cardiovascular events and demonstrate a ‘return on investment’ or a beneficial impact on trend. Medicare Advantage programs take note. In fact, so should our colleagues in running the Medicare program.

The growing population of Mr. Li's, his wives and children would also appreciate it also.

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