The SPRINT Alzheimer's, Seniors and Kidney Study (SPRINT ASK)
SPRINT ASK Project Summary Results from the Systolic Blood Pressure Intervention Trial (SPRINT) are likely to change clinical practice. For many people with hypertension, including those over age 75, the benefit on cardiovascular (CV) outcomes and total mortality supports treatment to more intensive BP goals. Because hypertension and CV disease burden is associated with increased Alzheimer's disease, the more important long term public health benefit of SBP lowering may be to reduce the incidence of Alzheimer's disease and other dementias. Yet clinicians have reason to be cautious about lower SBP goals for older patients due to the possibility of adverse effects on brain structure and function. Early stopping of the main trial reduced the planned follow-up for incidence of all- cause dementia and renal outcomes, but a separation in SBP persisted between randomized arms at the final main study visits, and over 90% of the cohort agreed to additional follow-up. The main study will not collect any data on these outcomes after June 30 2016. The proposed study, however, would complete the intended protocol, achieving several critical research objectives: testing whether, after 5 years of follow-up, (1) the incidence of adjudicated all-cause dementia (which will be predominantly Alzheimer's Dementia) and (2) adjudicated mild cognitive impairment (MCI) will be lower in participants randomized to intensive SBP treatment. It will also assess long term effects on kidney outcomes. All participants will undergo one clinic visit approximately 12 months after their final main study visit to assess blood pressure, cognitive and renal function. SPRINT operations were highly effective and contributed to the success of the trial, and there will be some continuity of staff and operating infrastructure to support these visits early in 2017. The transition will be largely seamless, following closely the main study's protocol for leadership, organization, operations and data collection. It is doubtful that another large scale trial in the US will ascertain incident Alzheimer's and other dementia or examine the renal effects of treating SBP to <120 mm Hg versus <140 mm Hg. If new guidelines encourage an SBP treatment target of <120 mm Hg, patients will be exposed to many years of intensive anti- hypertensive therapy. The SPRINT cohort is uniquely place for a low cost opportunity to determine whether longer term effects of exposure to a lower SBP target is beneficial, harmful, or has no clinically important effect for brain and kidney.