Hold the Presses: Landmark Blood Pressure Study Fails to Prove Anything.
September 12, 2015
In a front page article, multiple major newspapers (including the Washington Post and New York Times) cite the results of an NIH study declaring that people over the age of 50 will benefit dramatically from lowering their blood pressure below 120 using aggressive drug treatment. The article has yet to be published, but, according to those the press interviewed, the results are both definitive and life saving. But do we know that? So many prior studies of the elderly have shown just the opposite result: aggressive blood pressure control leads to more disease and disability. As it has done often, the press leaps quickly to draw conclusions from “landmark” studies, and only years later are those conclusions (after scrutiny) modified or debunked. In the process, many people are harmed by overtreatment.
Even before looking at the data of this study (which is not yet available), many potential problems exist with it. The subjects of the study were heavily screened; many were likely excluded from the study, and all subjects had high risk of heart and kidney disease. Perhaps the addition of certain blood pressure drugs to the more intensely treated group helped these people in ways that had nothing to do with their blood pressure lowering effects. For instance, giving people with heart disease beta blockers and ace inhibitors will reduce the risk of death, heart attack, and congestive heart failure independent of how much the blood pressure is lowered. Also, although 28% of the study subjects were over 75, we do not know how they fared, nor do we know how many elderly people were excluded from the study for other health reasons. The study states a 25% reduction in death, and a 30% reduction in cardiac complications and stroke, among those who aggressively reduced their blood pressure compared to those who did not. But what is the absolute reduction in risk? Out of 1000 people who aggressively lowered their blood pressure compared to 1000 people who did not, how many fewer died or had serious cardiac and cerebral complications? The articles do not seem to consider this omission, and yet many prior studies with impressive relative risk reductions turn out to have very negligible absolute risk reductions. With only 2800 people over 75 in the study, a 25% reduction in death may mean that one or two people out of 1000 actually benefited; that would mean that 98% of people who received aggressive treatment did not. Finally we do not know what the side effects and long term health implications are for those who were treated aggressively. The study included approximately 10,000 heavily screened subjects (2800 of them over 75) divided into two groups studied over a relatively short period of time; that is hardly enough data and time to make any definitive conclusions.
What is most concerning about how this study was portrayed in the press is that no health reporter cared to mention that its results stand in contrast with a very robust body of research that reaches just the opposite conclusions. A recent large VA study of elderly men with kidney disease showed that lowering blood pressure below 130 led to increased death rates. Other studies (all of which I cite in my book) have shown that older people with past stroke or heart attack history are more prone to strokes or heart attacks and a higher death rate if their pressure is lowered below 120. All of this data stands in contradiction to the newer study; does not mean everything prior to this new unpublished study should all be discarded? Even the famous SHEP study proving high systolic blood pressure is harmful to the elderly found little evidence that lowering pressures below 160 caused any improvement in outcome. Why did not these newspapers ask why the new study diverges so sharply from everything we already know? Can one study with highly screened subjects, whose data has yet to be published, with only 2800 people over the age of 75, and adding drugs that may be helping the subjects in ways independent of blood pressure lowering, be used to disprove everything else we know about the dangers of lowering blood pressure in the elderly? Apparently so; the articles I read, and the academic super specialists the authors cite, are very clear that these new findings will save lives, change the clinical guidelines, and alter all future medical practice. I suppose it is easy to throw science, past research, journalistic scrutiny, and common sense out the window if you are going to generate an exciting headline!
Aggressive reduction of blood pressure in the elderly is not only potentially dangerous; it has been shown to diminish the quality of people’s lives. It leads to more fatigue, more falls, more dizziness, worse memory, and more stress. I cite articles in my book that demonstrate this, and more are coming out on a regular basis. Those of us who practice geriatrics know this as gospel; our patients with very low blood pressures who are on many medicines do not do as well as those who allow their pressures to drift higher. As with those doctors who believe the much disputed idea that pushing cholesterol as low as possible with medicines leads to better outcomes, giddy blood pressure pundits who want my patients’ pressures to be as low as possible, many of whom were interviewed in these articles and help script the clincial guidelines upon which the "quality" of my medical care will be judged, may be thrilled by the study findings, but that does not prove that what they are proposing is right. In fact, the new article proves nothing, and it is both irresponsible and dangerous for the press, medical societies, and doctors to advocate changing treatment for the elderly based on this tiny slice of unpublished research. Perhaps the NIH study will reveal some important new information. But until it is subjected to more scrutiny, until is it reconciled with prior studies that dispute its outcomes, and until it passes the test of time, we should be cognizant of its findings, but should not yet be swayed. Aggressive care in the elderly is rarely the correct answer. I would be shocked if this article proved that dogma to be wrong.