Intensive BP Management in Older Patients Significantly Lowers Heart Disease Rates and Mortality

By George Thomas, MD, MPH, FACP

Intensively managing high blood pressure in older adults to achieve systolic levels below commonly recommended hypertension targets significantly reduces cardiovascular disease rates and mortality risk, according to the results of a landmark federally sponsored study.

Hypertension is highly prevalent in the adult population in the United States and is an established risk factor for heart disease, stroke, heart failure and kidney disease. Observational studies show a progressive increase in cardiovascular risk associated with blood pressure (BP) levels above 115/75 mm Hg.

While it is well-established that reducing elevated BP lowers cardiovascular risk, the optimal BP goal for patients with a diagnosis of hypertension and who are being treated has been a matter of some debate. Should clinicians try to lower BP to “optimal levels,” i.e., less than 120/80 mm Hg? Would such an approach be beneficial or harmful? Would it be costly or burdensome to patients?

Current clinical practice, endorsed by hypertension guidelines, is to lower systolic blood pressure (SBP) to less than 140 mm Hg in most patients. The 2014 report from the Joint National Committee (JNC 8) recommends relaxing BP goals in elderly patients to SBP of less than 150 mm Hg, citing lack of evidence for more aggressive control.

Cleveland Clinic’s Department of Nephrology and Hypertension was involved in the Systolic Blood Pressure Intervention Trial (SPRINT), a multi-center, randomized controlled trial sponsored by the National Institutes of Health (NIH). SPRINT was designed to answer the following question: “Will more aggressive BP control to SBP < 120 mm Hg (intensive group) reduce the risk of cardiovascular, kidney and cognitive outcomes, compared with the current standard practice of BP control to SBP < 140 mm Hg (standard group)?”

A Sizeable Study Cohort

The study enrolled 9,361 volunteers age 50 and above with established cardiovascular disease or cardiovascular risk factors. It placed particular emphasis on patients with chronic kidney disease (CKD) who had estimated glomerular filtration rates (eGFR) of 20-50 mL/min/1.73 m2 and patients age 75 years and older. Patients with diabetes, stroke or polycystic kidney disease were not included in the study (as other studies aimed to answer the BP control question in these patients).

The primary outcome was the first occurrence of a myocardial infarction, acute coronary syndrome, stroke, heart failure or cardiovascular disease death. Secondary outcomes included all-cause mortality, decline in kidney function or development of end stage renal disease, decline in cognitive function and small vessel cerebral ischemic disease.

The study’s median follow-up period was 3.2 years. Average age of participants was 68 years; 28 percent were older than 75. Thirty-six percent were female and 30 percent were black. Twenty-eight percent had baseline CKD (9.5 percent of participants had an eGFR > 45 mL/min/1.73 m2).

Significant Risk Reductions

The results indicate there was a significant 30 percent lower incidence for primary outcome and a 25 percent lower risk of death among participants in the intensive group compared with the standard group.

The lower incidence for primary outcome was primarily driven by a reduction in heart failure. The benefits extended to the elderly older than the age of 75 and to those with CKD.

Adverse events, including hypotension, hyponatremia, and a decline in renal function in those without a history of CKD, were more common in the intensive group. Based on National Health and Nutrition Examination Survey data from 2007-2012, it is estimated that 7.6 percent or 16.8 million U.S. adults would meet eligibility criteria for SPRINT. Other study results are pending, including cognitive outcomes and additional details on long-term renal function.

An Impact on Future Guidelines

In summary, results from this well-designed trial provide scientific evidence favoring aggressive blood pressure control in patients older than 50 with established cardiovascular disease or cardiovascular risks (without a history of diabetes or stroke).

These results will obviously influence future hypertension guidelines and clinical practice. The benefits and risks of intensive blood pressure control have to be weighed carefully, rather than using a blanket approach to intensify treatment in all older adults.

At this time, from available evidence, it is unclear whether intensive blood pressure control would show a similar benefit in diabetics, younger patients and low-risk individuals.

Dr. Thomas is Director of the Center for Blood Pressure Disorders in the Glickman Urological & Kidney Institute’s Department of Nephrology and Hypertension, and an Assistant Professor of Medicine at Cleveland Clinic Lerner College of Medicine. He is Cleveland Clinic’s principal investigator for the SPRINT trial.