Background
The Systolic Blood Pressure Intervention Trial (SPRINT) demonstrated a 27% reduction in all-cause mortality with a systolic blood-pressure (SBP) goal of <120 mmHg versus <140 mmHg among U.S. adults at high cardiovascular disease (CVD) risk but without diabetes, stroke, or heart failure. To quantify the potential benefits and risks of SPRINT intensive goal implementation, we estimated the deaths prevented and excess serious adverse events (SAEs) incurred if the SPRINT intensive SBP treatment goal was implemented in all eligible U.S. adults.
Methods
SPRINT eligibility criteria were applied to the 1999–2006 National Health and Nutrition Examination Survey and linked with the National Death Index through December 2011. SPRINT eligibility included age ≥ 50 years, SBP of 130–180 mmHg (depending on the number of antihypertensive medications being taken), and high CVD risk. Exclusion criteria were diabetes, history of stroke, >1 gram of proteinuria, heart failure, estimated glomerular filtration rate < 20 ml/min/1.73m2, or dialysis. Annual mortality rates were calculated by dividing the Kaplan-Meier 5-year mortality by 5. Hazard ratios for all-cause mortality and heart failure and absolute risks for SAEs in SPRINT were used to estimate the number of potential deaths and heart failure cases prevented and SAEs incurred with intensive SBP treatment.
Results
The mean age was 68.6 years and 83.2% and 7.4% were non-Hispanic white and non-Hispanic black, respectively. The annual mortality rate was 2.20% (95%CI 1.91%–2.48%) and intensive SBP treatment was projected to prevent about 107,500 deaths per year (95%CI 93,300–121,200) and give rise to 56,100 (95%CI 50,800–61,400) episodes of hypotension, 34,400 (95%CI 31,200–37,600) episodes of syncope, 43,400 (95%CI 39,400–47,500) serious electrolyte disorders, and 88,700 (95%CI 80,400–97,000) cases of acute kidney injury per year. The analysis of extremes approach indicated that the range of estimated lower and upper bound number of deaths prevented per year with intensive SBP control was 34,600 to 179,600. Intensive SBP control was projected to prevent 46,100 (95%CI 41,800–50,400) cases of heart failure annually.
Conclusions
If fully implemented in eligible U.S. adults, intensive SBP treatment could prevent about 107,500 deaths per year. A consequence of this treatment strategy, however, could be an increase in SAEs.