Sprint study

Introduction

Study characteristics:

• 9400 patients age >=50 years
• systolic BP of 130-180 mm Hg
• high cardiovascular risk
• no history of diabetes mellitus or stroke
• trial terminated early after a median follow-up of 3.3 years due to questions about trial design & how the results should be applied

• subgroup 2: 2600 adults >= 75 years with increased CV risk

Treatment:

• target systolic blood pressure 120 mm Hg vs 140 mm Hg
• antihypertensive(s) chosen at discretion of provider

Results:

• average systolic BPs were 121.5 mm Hg for target of 120 mm Hg vs 134.6 mm Hg for target of 140 mm Hg
• primary outcome (MI, acute coronary syndrome, stroke, heart failure, or CV-related death) occurred in 5.2% of 120 mm Hg target group vs 6.8% of 140 mm Hg target group
• number needed to treat: 62 for 3.2 years to prevent 1 event
• number needed to harm: 45 for 3.2 years to cause 1 adverse event
• target of 120 mm Hg vs 140 mm Hg lowered risk of
  • heart failure (1.3% vs 2.1%)
  • CV-related death (0.8% vs. 1.4%)*
  • all-cause mortality (3.3% vs. 4.5%)*
• serious adverse events were significantly more common with target of 120 mm Hg vs 140 mm Hg
  • incidences of hypotension, syncope, & electrolyte imbalances ~ 1% higher
• greater time in the target systolic range predicted a lower risk of major cardiovascular events
• incidence of acute kidney injury ~2% higher
  • SPRINT investigators claim that a hemodynamic effect, rather than a true kidney damage effect accounts for the decline in GFR
• subgroup of patients >= 75 years
  • absolute risk reduction for cardiovascular events & mortality = 3.5% (NNT = 28)
• mobility unaffected by lower target blood pressure in subgroup > 75 years of age
• in subgroup >= 60 years intensive BP control reduced risk of heart failure & cardiovascular death, but increased risk of hypotension, syncope, & acute renal failure
• adding an antihypertensive from a new class resulted in reduction in mean systolic BP (- 14 mm Hg) & major cardiovascular events (- 6.6 per 1000 patient years)
  • similar reductions in systolic BP regardless of whether patients were taking 1,2,3 or 4 classes of antihypertensives
  • adding a new class of hypertensive not associated with increase in adverse effects
• SPRINT BP targets increase cardiovascular risk in smokers
• patients at high cardiovascular risk may gain 6 months to 3 years in life expectancy from intensive blood pressure treatment
• low diastolic BP is associated with adverse cardiovascular events
  • increased mortality from intensive BP therapy vs standard therapy when diastolic BP is low: RR=1.8 for 50 mm Hg vs RR=0.77 for 80 mm Hg
• compared with a standard blood pressure target (SBP < 140 mm Hg), an intensive blood pressure target (SBP < 120 mm Hg) is associated with increased, rather than decreased, cerebral perfusion

* no explanation is provided; what did they die of?

Notes

• 8% of adults eligible for tighter blood pressure control by SPRINT criteria
• at baseline, mean BP was 138/77 mm Hg
• mean systolic BP 6 mm Hg lower at SPRINT visits than in routine practice
• Korean study finds RR=1.17 for utilization of JNC8 goals vs SPRINT goals
• two trials (ONTARGET & TRANSCEND trials) report that lowering systolic BP <120 mm Hg is associated with greater CV-related & all-cause mortality
• SPRINT group reports reduction in mild cognitive impairment, but not dementia using SPRINT goals (14.6 vs 18.3 per 1000 person-years)
• small but statistically significantly lower amount of white matter lesions & a slightly greater decrease in brain volume
  • 4.57-5.49 vs 5.85 uL over 4 years, mean age 67, median Montreal Cognitive Assessment score was 24.
  • no significant change in total brain volume
  • pattern hypertension at midlife with low blood pressure in late-life confounds findings
  • obvious issue of adequate perfusion pressure sensed by carotid sinus
• mean standardized memory domain scores & mean standardized processing speed declined more with SPRINT group than with targeting systolic BP to 140 mm Hg but difference not clinically significant
• intensive blood pressure control (target systolic BP < 120 mm Hg vs < 140 mm Hg) did not reduce brain MRI markers of Alzheimer's disease
• racial disparities in hypertension control & associated cardiovascular risk may not be predominantly associated with genetic factors, but more likely driven by extrinsic, societal factors
• intensive systolic BP control reduces combined risk of mild cognitive impairment or dementia to a greater degree in persons at higher risk

More general terms

• hypertension clinical trials

Additional terms

• Strategy of Blood Pressure Intervention in the Elderly Hypertensive Patients (STEP) trial