By Michael Crawford, MD, Editor
SOURCE: Press release from the National Institutes of Health (NIH). Landmark NIH study shows intensive blood pressure management may save lives. Available at http://www.nih.gov/news/health/sep2015/nhlbi-11.htm. Accessed on Sept. 11, 2015.
The Systolic Blood Pressure Intervention Trial (SPRINT) study compared pharmacologic systolic blood pressure lowering to < 120 vs 120-140 mmHg in more than 9300 subjects > 50 years of age with hypertension and at least one additional risk factor for heart disease or who have kidney disease.
The study population was diverse and included women, racial/ethnic minorities, and the elderly. The study excluded patients with diabetes, prior stroke, or polycystic kidney disease. The trial, which began in 2009, ended early due to the significant results that showed achieving a systolic blood pressure < 120 mmHg was associated with reduced rates of cardiovascular events, such as myocardial infarction, heart failure, and stroke, by almost one-third and the risk of death by almost one-quarter, as compared to the target systolic pressure of 120-140 mmHg.
The 120-140 group needed an average of two drugs to achieve this goal and the < 120 group required an average of three drugs. Lawrence Fine, MD, chief, Clinical Applications and Prevention Branch at the National Heart, Lung, and Blood Institute concluded on behalf of the investigators that, “Our results provide important evidence that treating blood pressure to a lower goal in older or high-risk patients can be beneficial and yield better health results overall.”
At the time the trial began, the systolic blood pressure targets were < 140 mmHg for otherwise healthy adults and < 130 mmHg for those with diabetes or kidney disease. Also, when this study began, the results of the Hypertension in the Very Elderly (HYVET) trial had been released. This trial of patients > 80 years of age also ended early because of the significant 21% reduction in all-cause mortality, 30% reduction in stroke, 64% reduction in heart failure, and 34% reduction in all cardiovascular events, when systolic blood pressure was treated to a goal of < 150/80 mmHg using a thiazide diuretic with the addition of an ACE inhibitor when necessary.1 A meta-analysis of all the trials by Bangalore et al showed that reducing systolic blood pressure below 130 may be beneficial in stroke and kidney disease prevention, but not other cardiovascular endpoints.2 Hence, the various guidelines published subsequently have not recommended aggressive systolic blood pressure lowering (< 120). Thus, this trial could be a game changer if the results are robust.
Unfortunately, at this time we only have the press release, as the trial has not been published in a peer-reviewed journal yet. Also, researchers provided no upper age cut off, so we don’t know how many were > 80 years of age and what their results were. Additionally, we don’t know what the complications of lowering systolic blood pressure to < 120 were in these high-risk patients. It is well known that excessively low blood pressure can precipitate strokes or myocardial infarctions in some patients with extensive atherosclerosis. Perhaps that is why Dr. Fine provided this caveat: “But patients should talk to their doctor to determine whether this lower goal is best for their individual care.” Indeed.
- Beckett NS, et al. Treatment of hypertension in patients 80 years of age or older. N Engl J Med 2008 May 1;358:1887-98. doi:10.1056/NEJMoa0801369. Epub 2008 Mar 31.
- Bangalore S, et al. Blood pressure targets in subjects with type 2 diabetes mellitus/impaired fasting glucose: Observations from traditional and bayesian random-effects meta-analyses of randomized trials. Circulation 2011;123:2799-2810.