Caution Expressed Over BP Target in SPRINT HTN Trial

Researchers note that based on the results from the Systolic Blood Pressure Intervention Trial (SPRINT) , 22 people out of 1,000 people treated over 3.2 years with SBP goal

HealthDay News – A small reduction as the primary composite outcome may not justify the increased adverse events and costs associated with an intervention targeting systolic blood pressure (SBP) less than 120 mm Hg, according to an Ideas and Opinions piece published online Feb. 23 in the Annals of Internal Medicine.1

Eduardo Ortiz, MD, MPH, from Washington D.C., and Paul A. James, MD, from the University of Iowa in Iowa City, discuss the results of the Systolic Blood Pressure Intervention Trial (SPRINT), which were promoted before publication. The results showed a risk reduction in the primary composite outcome with a lower target systolic BP.

The researchers note that based on the results, for 1,000 persons treated over 3.2 years with a systolic BP target of less than 120 mmHg versus 140 mmHg, 16 persons would benefit, 22 would be seriously harmed, and 962 would experience no benefits or harms. In addition to a small decrease in event rates, the aggressively treated group more frequently had serious adverse drug events, which were possibly or definitely related to the intervention.

“We do not believe that the small absolute benefit seen in SPRINT provides convincing evidence that large segments of the population should be treated with additional drugs to a systolic BP goal less than 120 mmHg, especially when the adverse events, costs, and burden of such treatment are considered,” the authors write.


Summary and Clinical Applicability

An increasing number of trials have provided evidence that antihypertensive therapy to attain blood pressure control provides some degree of cardiovascular protection. However, the optimal level of control may vary across the population.2 

This is of particular relevance to the practice of rheumatology, as patients with inflammatory diseases like rheumatoid arthritis (RA) are at increased risk of cardiovascular disease (CVD).3  Thus, potentially modifiable risk factors for CVD, including hypertension, must be closely monitored and addressed. Additionally, the use of antiinflammatory drugs such as glucocorticoids, nonsteroidal antiinflammatory drugs (NSAIDs), and cyclooxygenase (COX)-2 selective inhibitors may further contribute to increased risk for coronary thrombosis.3 Patients being prescribed glucocorticoids should be monitored for adverse drug effects, including hypertension, and take appropriate preventive measures to decrease further morbidity in patients with RA.

Findings from the Systolic Blood Pressure Intervention Trial (SPRINT) suggest that among older, hypertensive, nondiabetic adults at high risk for CVD, targeting a systolic pressure of <120 mmHg can reduce mortality and prevent cardiovascular events.4

In generalizing the results of the SPRINT trial to other patients, it is important to note that SPRINT excluded patients with diabetes, symptomatic heart failure, any history of stroke, proteinuria (≥1 g/day total protein or ≥600 mg/day albumin), and nursing home residents. Furthermore, the patients enrolled in SPRINT had diastolic blood pressure >70 mmHg at baseline, which was maintained even in the intensive treatment group. Since many older adults with isolated systolic hypertension have low diastolic pressure, these patients may not tolerate aggressive reduction of the systolic pressure; particularly those patients with preexisting coronary artery disease and relatively fixed coronary blood blood with reduced compensatory mechanisms.5,6

Of note, the ausculatory method of BP measurement is a common technique utilized by clinical trials when evaluating antihypertensive therapy. In contrast, automated oscillometric blood pressure (AOBP) measurements were utilized  in SPRINT trial. In prior studies, systolic BP readings are 5 to 10 mmHg lower when measured by AOBP as compared to ausculatory methodt.7 Thus, if clinicians use ausculatory blood pressure measurement as opposed to AOBP measurement, targeting the systolic pressure of <120 mmHg as suggested by the SPRINT trial may increase the risk of serious adverse events.

Summary and Clinical Applicability Statement by Corinna Panlilio Sison, MD

Reference

1. Ortiz E, James PA. Let’s Not SPRINT to Judgment About New Blood Pressure Goals. Ann Intern Med.2016;

2. Bress AP, Tanner RM, Hess R, et al. Generalizability of results from the Systolic Blood Pressure Intervention Trial (SPRINT) to the US adult population. J Am Coll Cardiol. 2015. 

3. Crepaldi G, Scirè CA, Carrara G, et al. Cardiovascular Comorbidities Relate More than Others with Disease Activity in Rheumatoid Arthritis. PLoS ONE. 2016;11(1):e0146991.

4. SPRINT Research Group, Wright JT Jr, Williamson JD, et al. A Randomized Trial of Intensive versus Standard Blood-Pressure Control. N Engl J Med. 2015; 373:2103.

5.Franklin SS, Gokhale SS, Chow VH, et al. Does low diastolic blood pressure contribute to the risk of recurrent hypertensive cardiovascular disease events? The Framingham Heart Study. Hypertension 2015;65:299.

6. Xie X, Atkins E, Lv J, et al. Effects of intensive blood pressure lowering on cardiovascular and renal outcomes: updated systematic review and meta-analysis. Lancet 2015.

7. Cuckson AC, Moran P, Seed P, Reinders A, Shennan AH. Clinical evaluation of an automated oscillometric blood pressure wrist device. Blood Press Monit. 2004;9(1):31-7.