Choosing the optimal blood pressure target to shoot for in managing hypertension requires that we apply the art of medicine, rather than just a cookbook approach. Over recent years, we have gotten dizzy keeping up with various recommendations which have swung back and forth between lower versus higher blood pressure goals. Last year a Joint National Committee on Hypertension recommended higher blood pressure targets: <140/90, but <150/90 in adults over 60 years old. Now we have a new large study published in November (the SPRINT study) which has caused the pendulum to swing back toward a goal of lower blood pressures, specifically in individuals at least 50 years old who already have cardiovascular disease, or who have at least one risk factor for developing it. The SPRINT study found that treating these patients aggressively, with a goal of achieving a systolic (top number) blood pressure <120, rather than to a more conservative target of <140, resulted in a significant decrease in the risk of cardiovascular events such as stroke or heart attack, and of death in general.
As usual, nothing is ever black or white. Getting to the lower target required more blood pressure medications (an average of 3, vs. 2 for the higher target), which increases the chance of side effects. The target of <120 also caused more incidence of blood pressure going too low, as one might expect. This increases the possibility of dizziness and falls which can be devastating, especially in our older patients.
So we must once again apply the art of medicine, treating each patient as an individual, and keeping new information in mind as we attempt to balance the risk of medication side effects against the risk of future adverse events.
Below is a summary published in Journal Watch of the findings of the SPRINT study, followed by some published comments:
SPRINT: A Trial of Intensive Blood Pressure Lowering Allan S. Brett, MD reviewing The SPRINT Research Group. N Engl J Med 2015 Nov 9. Chobanian AV. N Engl J Med 2015 Nov 9.Allan S. Brett, MD
Allan S. Brett, MDTreating to a systolic target of 120 mm Hg lowered the incidence of adverse cardiovascular events in a high-risk population. Allan S. Brett, MD
Treating to a systolic target of 120 mm Hg lowered the incidence of adverse cardiovascular events in a high-risk population. Allan S. Brett, MDFor years, clinicians have debated how far to lower blood pressure (BP) in hypertensive patients. The multicenter Systolic Blood Pressure Intervention Trial (SPRINT) now provides some guidance. SPRINT researchers enrolled 9361 patients (age, ≥50) with systolic BP of 130 to 180 mm Hg and high cardiovascular (CV) risk (defined as one or more of these: known symptomatic or asymptomatic CV disease, chronic kidney disease [CKD] with glomerular filtration rate ( a measure of kidney function) [GFR] 20–59 mL/minute/1.73 m2, 10-year Framingham CV risk ≥15%, or age ≥75). Patients with diabetes and stroke were excluded. Patients were randomized to either intensive or standard treatment (systolic BP targets, 120 or 140 mm Hg, respectively). The protocol included general guidelines for choice of antihypertensive agents, but researchers were permitted discretion in choosing drug regimens. Diuretics, angiotensin-converting–enzyme inhibitors or angiotensin-receptor blockers, calcium-channel blockers, and β-blockers were used extensively. During the trial, intensive- and
For years, clinicians have debated how far to lower blood pressure (BP) in hypertensive patients. The multicenter Systolic Blood Pressure Intervention Trial (SPRINT) now provides some guidance. SPRINT researchers enrolled 9361 patients (age, ≥50) with systolic BP of 130 to 180 mm Hg and high cardiovascular (CV) risk (defined as one or more of these: known symptomatic or asymptomatic CV disease, chronic kidney disease [CKD] with glomerular filtration rate ( a measure of kidney function) [GFR] 20–59 mL/minute/1.73 m2, 10-year Framingham CV risk ≥15%, or age ≥75). Patients with diabetes and stroke were excluded. Patients were randomized to either intensive or standard treatment (systolic BP targets, 120 or 140 mm Hg, respectively). The protocol included general guidelines for choice of antihypertensive agents, but researchers were permitted discretion in choosing drug regimens. Diuretics, angiotensin-converting–enzyme inhibitors or angiotensin-receptor blockers, calcium-channel blockers, and β-blockers were used extensively. During the trial, intensive- and standard-treatment patients required averages of three and two drugs, respectively. The trial was terminated early after median follow-up of 3.3 years, during which participants’ average systolic BPs were 121.5 mm Hg and 134.6 mm Hg in the intensive- and standard-treatment groups, respectively. The primary composite outcome (myocardial infarction [MI], non-MI acute coronary syndrome, stroke, heart failure, or CV-related death) occurred in 5.2% of intensive-treatment patients and 6.8% of standard-treatment patients (P<0.001). Relative reductions in this outcome were similar in subgroups of patients with CKD and of patients older than 75. Two individual components of the composite outcome were significantly lower with intensive treatment — heart failure (1.3% vs. 2.1%) and CV-related death (0.8% vs. 1.4%). All-cause mortality also was significantly lower with intensive treatment (3.3% vs. 4.5%).Several serious adverse events were significantly more common with intensive than with standard treatment: Incidences of hypotension (low blood pressure), syncope (passing out), and electrolyte abnormalities were each about 1 percentage point higher, and incidence of acute kidney injury was about 2 percentage points higher. Among patients without CKD at baseline, the incidence of a >30% decline in GFR was significantly greater with intensive treatment (3.8% vs. 1.1%).Comment — General Medicine Allan S. Brett, MD
Comment — General Medicine Allan S. Brett, MDSPRINT has demonstrated that aiming for a systolic BP of 120 mm Hg can lower the rate of adverse cardiovascular events; to prevent 1 event, 61 patients had to be treated for 3.3 years. Keep in mind that SPRINT was limited to middle-aged and older patients at above-average CV risk and that diabetic patients were excluded because the ACCORD BP researchers had examined this question (and showed no significant lowering of adverse CV events with intensive treatment; NEJM JW Cardiol Apr 2010 and N Engl J Med 2010; 362:1575). Whether the decline in GFR (kidney function) associated with intensive treatment represents a harmless hemodynamic effect or
SPRINT has demonstrated that aiming for a systolic BP of 120 mm Hg can lower the rate of adverse cardiovascular events; to prevent 1 event, 61 patients had to be treated for 3.3 years. Keep in mind that SPRINT was limited to middle-aged and older patients at above-average CV risk and that diabetic patients were excluded because the ACCORD BP researchers had examined this question (and showed no significant lowering of adverse CV events with intensive treatment; NEJM JW Cardiol Apr 2010 and N Engl J Med 2010; 362:1575). Whether the decline in GFR (kidney function) associated with intensive treatment represents a harmless hemodynamic effect or more-serious renal injury is unclear. Because this trial will change practice, clinicians must understand how BP was measured in the study. At each visit, patients were seated in a quiet area for 5 minutes. Then, BP was recorded by a commercially available automated unit that recorded three readings, separated by several minutes, with no clinician in the room. Decisions were based on the average of the three readings. Other studies have shown that this method of BP measurement yields substantially lower readings than does the single rushed measurement typical in many practices. If SPRINT is applied without attention to proper BP measurement, substantial overtreatment — with a higher rate of adverse events — likely will occur .Finally, note that the average achieved systolic BP in the intensive-treatment group (121.5 mm Hg) remained higher than the 120 mm target. This likely represents judicious balancing by treating clinicians who tried to approximate the 120 mm goal while avoiding side effects and excessive polypharmacy. Thus, an editorialist concludes reasonably that “the results from SPRINT warrant reducing the treatment goal for systolic blood pressure to less than 130 mm Hg” in patients who meet SPRINT’s enrollment criteria. – See more at: http://www.jwatch.org/na39551/2015/11/09/sprint-trial-intensive-blood-pressure-lowering#sthash.lYs1viqL.dpuf
Generalizability of the SPRINT Results
Harlan M. Krumholz, MD,
SM reviewing Bress AP et al. J Am Coll Cardiol 2015 Nov 9.
An analysis of NHANES data shows how many U.S. adults with hypertension meet SPRINT eligibility criteria. Harlan M. Krumholz, MD, SMThe SPRINT trial (N Engl J Med 2015 Nov 9; [e-pub]), which tested a blood pressure goal of <120 mm Hg against the standard goal of <140 mm Hg, was released amid much fanfare, but a relevant question is its generalizability. Non-SPRINT investigators used data from the National Health and Nutrition Examination Survey to estimate the prevalence, number, and characteristics of U.S. adults who would meet SPRINT inclusion criteria.They found that in the years 2007–2012, an estimated 7.6% of U.S. adults (17 million people) — including 16.7% of those with treated hypertension (8 million) and 5.0% of those not being treated (8.5 million) — met SPRINT eligibility criteria. Among all U.S. adults with hypertension, an estimated 20% met eligibility criteria.
Comment : Many Americans meet SPRINT eligibility criteria and might benefit from the blood pressure goal of <120 mm Hg. However, importantly, 5 of 6 people with treated hypertension do not meet the eligibility criteria. Decisions about treatment goals for these patients will be based on greater uncertainty than for the patients who meet the eligibility criteria. – See more at: http://www.jwatch.org/na39586/2015/11/09/generalizability-sprint-results#sthash.V6eg6DGx.dpuf
