28th Annual Scientific Meeting of the American Society of Hypertension
San Francisco, CA
The 28th Annual Scientific Meeting of the American Society of Hypertension (ASH) brought together the top scientists in clinical hypertension to present state-of-the-art lectures on a wide variety of topics in hypertension and related clinical concerns. While the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure Guidelines was not officially released, attendees at the ASH meeting did hear an unofficial review of the guidelines, which will be summarized, along with 3 studies presented at the meeting: BARBER-1, SYMPLICITY HTN-2, and a study on aerobic fitness in the elderly.
JNC 2013: Speculation Continues About HTN Treatment Targets, Report Release
It remains unclear when the National Heart, Lung, and Blood Institute will release the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure Guidelines (formerly known as JNC 8, and now renamed JNC 2013), but the expected JNC 2013 update is likely to settle on a hypertension treatment target of 140/90 mm Hg for all patients except older adults. The JNC 7 recommended a target of less than 140/90 mm Hg overall and 130/80 mm Hg for patients with diabetes, heart failure, or chronic kidney disease.
Raymond Townsend, MD, of the University of Pennsylvania, said that a “one-size-fits-all” goal appears to work well. The treatment target was the major question facing the committee in this update, according to ASH president-elect Domenic Sica, MD, of Virginia Commonwealth University, Richmond, Virginia.
Dr. Townsend said there might be a single target in the JNC 2013 because it “turns out the wisdom we’ve used in the past, which we’ve been arguing about for the past decade, turns out to have been fairly wise.”
Suzanne Oparil, MD, of the University of Alabama at Birmingham, and a board member of both the American Heart Association (AHA) and the American College of Cardiology (ACC), said that the evidence for an aggressive approach [lowered target] wasn’t there, and careful analyses from large trials in high-risk people showed that you can do harm by lowering blood pressure too much. “JNC is strictly evidence based, with some necessity for expert opinion where there is no evidence. We don’t feel obliged to reconcile our recommendations with anybody else’s,” Dr. Oparil noted, when asked about the stricter AHA and ACC guidelines targeting 130 mm Hg/80 mm Hg for blood pressure control.
The guidelines will not go in depth into pharmacology such as beta-alpha blockers versus beta-blockers alone because there is not enough data to allow that, Dr. Townsend explained.
Physician Undertreatment Blamed for Small BP Changes in BARBER-1 Study
A new analysis of the Barber-Assisted Reduction in Blood Pressure in Ethnic Residents (BARBER-1) study suggests that physician inertia might be the reason men in the study did not reduce systolic blood pressure more than the 2.5 mm Hg via the intervention of using local barbers as gatekeepers for encouraging African American hypertensive men to visit their health care providers to get blood pressure under control.
This interesting approach to dealing with a known cardiovascular risk factor in the African American community produced disappointing results. A new post hoc analysis by Dr. Florian Rader of Cedar-Sinai Medical Center in Los Angeles found that it was likely that the undertreatment of hypertension in primary care limited the ability of the barber-based intervention to lower blood pressure. “Hypertension specialists should be made accessible to all hypertensive black patrons to realize the full promise of the barber-based intervention,” said Dr. Rader. BARBER-1 included 17 black-owned barbershops with clients made up almost entirely of African American men. Study participants were randomized to the intervention barbershops (n = 9; mean, 75 hypertensive patrons per shop) or the comparator shops (n = 8; mean, 77 hypertensive patients per shop). Analysis was carried out on the follow-up patients in the intervention arm, who were seen by hypertension specialists, and those treated by primary care physicians (PCPs), as well as on follow up data of patients in the comparator arm.
The blood pressure reduction among men treated by PCPs was similar to the change in blood pressure among those randomized to the comparator group. In BARBER-1, the comparator arm, men received standard educational information about hypertension in African Americans but were not given any other encouragement to get blood pressure checked. Men who were treated by hypertension specialists had a significant 16.6 mm Hg reduction in systolic blood pressure versus the comparator arm, suggesting that the reason for the small blood pressure reductions in BARBER-1 among PCPs might be physician inertia.
After adjustment for baseline blood pressure and other confounding variables, a large intervention effect remained in those treated by hypertension specialists. Dr. Rader also said that the patients treated by hypertension specialists were more likely to be treated with ACE inhibitors and calcium-channel blockers and on 3 or more medications.
Reduction of Blood Pressure With Renal Denervation Lasts 30 Months
The long-term efficacy of renal denervation in patients with resistant hypertension was confirmed by new data from the ongoing SYMPLICITY HTN-2 study. Researchers reported 30-month data showing that the catheter- based approach produces sustained blood pressure reductions in this group of patients.
The 30-month follow-up included data on 37 patients randomized to renal denervation. From baseline, systolic and diastolic blood pressure were reduced by 35 mm Hg and 13 mm Hg, respectively. Over the 30 months, 84% of patients achieved a >10 mm Hg reduction in systolic blood pressure and over 70% of patients achieved a >20 mm Hg reduction in systolic blood pressure. Additionally, there was a reduction in heart rate, from 74 bpm at baseline to 69 bpm at 30 months. Lead investigator Dr. Murray Esler of Baker IDI Heart and Diabetes Institute, Melbourne, Australia, said that although the results were positive, they leave some questions unanswered. “There are many unknowns,” said Dr. Esler, some of which will soon be answered with the SYMPLICITY-3 study.
The original SYMPLICITY-2 was a 6-month study. The ongoing SYMPLICITY HTN-3 is a multicenter, 500-patient-plus, randomized, controlled trial testing the safety and effectiveness of the treatment in patients with uncontrolled hypertension, receiving at least 3 antihypertensive medications, one of which must be a diuretic. The trial will use ambulatory blood-pressure monitoring, in contrast to previous trials, which used office blood-pressure measurements.
ASH President-elect Domenic Sica, MD, of Virginia Commonwealth University, Richmond, Virginia, said the renal denervation field is changing rapidly enough that the long-term data from SYMPLICITY HTN-2 will soon be dated. He advised caution and prudent understanding to determine how the procedure is used in the best patients. Dr. Sica noted that although it may not be possible to determine the patient best suited for this procedure based on demographics, it might be possible to identify a group of patients more receptive to renal denervation. Hypertensive patients who are medication intolerant, or taking multiple medications but are having adverse reactions, might be examples.
Investigators cautioned that the study was small, and that renal denervation is not a cure for resistant hypertension, but a complement to drug treatment.
The Symplicity renal denervation system is a product of Medtronic.
High Aerobic Fitness Lowers Risk of Death in Elderly
Elderly patients who maintained a high level of aerobic fitness had a reduction in mortality, a benefit seen in individuals as old as 93 years. Senior Investigator Peter Kokkinos, MD, of the VA Medical Center in Washington, DC, said the results of his large study showed that no matter what age the patient, a certain amount of fitness must be maintained because “The body goes into hibernation if it thinks it isn’t needed anymore.”
Although age is associated with declines in muscle mass, strength, endurance, and aerobic fitness, older people responded well to exercise, and exercise can play a role in preventing these age-related declines.
Michael Doumas, also from the VA Medical Center, examined the benefits of exercise in 2077 hypertensive men 70 years of age and older. All patients underwent routine exercisetolerance testing. Their peak workload was estimated in metabolic equivalents (METs).
Among the participating men, a total of 685 were classified as having low levels of aerobic fitness (METs ≤4.5), 786 had moderate levels of aerobic fitness (METs 4.6-6.5), and 606 had high levels of aerobic fitness (METs 1100>6.5). For every 1-MET increase in exercise capacity, the risk of all-cause mortality was reduced by 8%; overall mortality was 15% lower among those with moderate levels of aerobic fitness, and 37% lower among those with high-levels of aerobic fitness compared with the low-fitness group.
Average follow-up was 9 years.
Dr. Kokkinos said that the main message is that we need to be active. “We don’t have to do a lot to stay healthy, but we have to do something. You don’t have to run a marathon; a brisk walk is all you need.”