Managing hypertension: The knowns and unknowns

Hypertension is a major cause of morbidity and mortality, and the lifetime risk of developing hypertension is high. It is also widely known that treating hypertension reduces morbidity and mortality even in very old persons, and that an important aspect of blood pressure management is lifestyle modification.

“We have come a long way in our knowledge of the morbidity and mortality associated with hypertension, the importance of treating hypertension, and the strategies (medications and lifestyle) that work,” said Karol Watson, MD, Professor of Medicine/Cardiology and Co-Director of the UCLA Program in Preventive Cardiology, Geffen School of Medicine at UCLA, Los Angeles, CA, in her presentation entitled “Hypertension Management: What We Know and What We Don’t.”

Along with describing current data on what is known about hypertension and its management, Dr. Watson highlighted a number of areas that remain unknown including the optimal blood pressure goal in the elderly, why chlorthalidone is not used more often, whether there is still a role for beta blockers in treating hypertension, the optimal blood pressure medication addition/titration strategy, and whether there is a real “J” curve.

One area of current debate is hypertension management in the elderly. Dr. Watson cited data from a study published in the New England Journal of Medicine that showed a significant reduction in mortality outcomes in patients 80 years of age or older treated with anti-hypertensive medication.

However, evidence from more recent guidelines in the JNC 8 report for management of high blood pressure in adults recommended easing up on hypertension treatment starting at 60 years of age.   Dr. Watson also noted the ongoing issue of finding the optimal blood pressure goal for the elderly.

Another area of debate is whether there is a “J” curve, the hypothesis that lowering diastolic blood pressure (DBP) too much increases the risk, particularly in patients with coronary artery disease and wide pulse pressures, of coronary events.  Dr. Watson said that in the usual ranges of BP lowering there is no J curve, but that the J curve is most evidence for DBP when it falls below 60 mm Hg. She also said it is most evident in people with arteriosclerotic cardiovascular disease, and that that the J curve causes increased myocardial infarctions but not strokes.

Commentary by William Elliott, MD, Professor of Preventive Medicine, Internal Medicine and Pharmacology, Head, Division of Pharmacology, Chairman, Department of Biomedical Sciences, Pacific Northwest University of Health Sciences, Yakima, Washington:

Much of the current controversy involving hypertension revolves around what kind of evidence is strong enough to adequately support clinical practice guidelines. JNC 8 was driven by the NIH-mandated policy that only primary hypotheses of well-done randomized clinical trials involving patient populations that are generally representative of the US should inform practice guidelines. Other national and international guidelines have gone beyond these limitations, and included information derived from very large cohort studies, epidemiological surveys and vital statistics information, and meta-analyses, so it is not surprising that they come to different conclusions.

Another welcome recent change is the much broader selection of generically-available and better tolerated antihypertensive agents, which has driven down the estimated cost of hypertension treatment in the US by more than 10% in the last decade. A recent Monte Carlo simulation of hypertension treatment concluded that prescribing medications to hypertensive adults in the US is cost-saving, overall, even if the relaxed blood pressure targets of JNC 8 are used. Most worrisome to many is that if the systolic blood pressure of 150 mm Hg recommended by JNC 8 for people over 60 years of age is broadly adopted, the continuous, year-over-year decrease in the proportion of deaths in the US due to stroke (which dropped to fifth place among the leading causes of death, for the first time in 2013) will cease.

There is little doubt that controlling blood pressure has important health benefits, but as Dr. Watson implies, “the devil is in the details.”