By Dr. Daniel E. Forman
A recent news article on blood pressure medications and the elderly is stirring up controversy among cardiologists and physicians who treat older patients.
The article, published in The New York Times earlier this month, analyzes a medical study in which researchers looked at the utility of a walking test to identify patients who may not benefit from anti-hypertensive therapy. But the Times piece misrepresents the study, in my opinion, and will likely exacerbate non-compliance for an already notorious problem: the undertreatment of high blood pressure.
Here's the back story:
The medical study led by Michelle Odden and published online in the journal Archives of Internal Medicine on July 16, was primarily an epidemiologic assessment of a database — not a controlled clinical trial. The study falls far short of an evidence-based randomized trial about hypertension and doesn’t have the rigor of anything that justifies a major therapeutic impact. But The New York Times account on August 8 by Paula Span, described the study as a potential indictment against routine treatment of blood pressure in older adults. Furthermore, the premise of the study, as reported in the NYT, is distorted and the reporter's characterization of the data exaggerated. (For instance, the study doesn’t clearly refute value of anti-hypertensive medications — it is primarily a trial about treatment stratification.) It does not match other blood pressure trials in rigor and substantive clinical method and it simplifies very complex issues regarding frailty/risk stratification/and even old age. On the basis of the NYT article many patients are likely to become more skeptical about the use of their blood pressure meds.
Odden focused on novel steps to stratify care for older adults with hypertension, i.e., assessing the utility of walking speed to identify subgroups of adults aged 65 years and older who are less likely to benefit from standard therapeutic strategies. The concern is that so-called “evidence-based standards” were derived using data from younger adults and/or particularly healthy trial-eligible older adults and that these treatment parameters may not benefit real-world frail older adults.
It's a positive development that the NYT and other news agencies share research studies with the lay public. However, in this case the Times report may have oversimplified the findings of Odden’s complex analysis to the extent that lay readers may conclude that blood pressure control may be safely omitted in older adults.
The basic concept of frailty remains ambiguous and controversial. Walking may be a useful gauge of predominant slowing and weakening that seems to be medically relevant, but walking fails to assess cognition and/or other biological and physiological relationships that might also be pertinent for a reliable, unambiguous health category. Odden’s study advances the application of a walking test as a convenient and useful means to earmark frailty, but the concepts of frailty itself as well as its delineation are still being tested.
Furthermore, Odden’s study utilizes the concept of hypertension therapy as an example wherein stratification of the elderly based on walking speed can be tested as a strategy to tailor care, but it falls short of being a definitive trial of anti-hypertensive therapy. Odden refers to HYVET (Hypertension in the Very Elderly), a large trial in which adults over 80 years of age with systolic BP were randomized to blood pressure treatment vs. placebo. HYVET showed benefit of treatment of very high blood pressure (systolic BP >160 mmHg) to achieve BP goals of 150/80. Similarly, there is a robust literature of many similar randomized controlled trials showing benefits of anti-hypertensive therapy to very high and even mild hypertension in adults aged between 65 and 80 years.
In contrast, Odden analyzed previously collected data that included older adults without hypertension (and the prevalence of hypertension was not clearly reported) and calculated correlations between data pertaining to walking speeds, blood pressures and outcomes in adults aged 65 and older. The conclusions regarding the blood pressures and outcomes are inferred; the cutpoints for blood pressure are 140/80, i.e., much lower than HYVET. Therefore, while Odden’s analysis raises interesting perspectives regarding stratification techniques, it is not clear why patients had lower blood pressures (maybe they were particularly sick and/or dehydrated), nor were specific medications, doses, or therapeutic standards clarified. All of these are crucial details that need further exploration.
[module align="right" width="half" type="pull-quote"]One should not withhold vital medications to someone just because they walk slowly.[/module]
Overall, Odden et al’s study is a valuable addition to the medical literature. Walking speed may serve as an important index of frailty relative to which medical care can be tailored. However further studies can/will help determine the etiology and reversibility of gait limitations, the fundamental nature of frailty, as well as the interrelated goals to preserve/improve vascular health (e.g., blood pressure, compliance, plaque, inflammation, platelets and other relevant parameters) that determine cardiovascular, cognitive, renal and other vital physiology throughout a lifetime.
Odden’s study, and even the Times report also benefit the medical community by provoking more questions regarding utility of blood pressure medications. But while it is reasonable to ask which medications yield benefit amidst complex medical, psychosocial, and economic crosscurrents, overreliance or misinterpretation of data such the Archives paper disregard a preponderance of data that shows significant benefits of treatment of very high blood pressure, even in the oldest old and may potentially lead to underutilization of these evidence-based interventions. A multitude of data shows substantial and significant benefits of anti-hypertensive therapy to moderate risks of death and morbidity (e.g., heart attacks, heart failure, strokes, kidney disease, cognitive decline).
Most diseases increase in prevalence over a lifetime, and as longevity increases, we are living in a time when more people are surviving into their senior years and become burdened with multiple morbidities. If every such senior then receives every “evidence-based” medication for every illness they develop, most will be on a precarious and expensive medication regime prescribed by providers who are intending to administer excellent care. Therefore, it is incumbent on the research community to determine which diseases need to be prioritized with what therapies. Ultimately, gait speed and other markers of frailty may identify subsets of older adults who are less likely to benefit from certain evidence-based therapy, thus achieving tailored, patient-specific medication regimens. However, for now, concepts of frailty, blood pressure, and risk stratification remain complex challenges that are still ambiguous. One should not withhold vital medications to someone just because they walk slowly.
Daniel E. Forman, MD, is an Associate Professor of Medicine, Harvard Medical School; Director, Exercise Testing Laboratory and Cardiac Rehabilitation, Brigham and Women's Hospital; and Physician Scientist, New England Geriatric Research, Education, and Clinical Center. He is also Chair, Council on Cardiovascular Care for Older Adults, American College of Cardiology, Washington, D.C. Finally, he is a very distant cousin of mine.
This program aired on August 21, 2012. The audio for this program is not available.