Effect of Intensive Blood Pressure Lowering on Cardiovascular Outcomes: A Systematic Review Prepared for the 2020 U.S. Department of Veterans Affairs/U.S. Department of Defense Guidelines.

BACKGROUND: Recent clinical trials suggest that treating patients with hypertension to lower blood pressure (BP) targets improves cardiovascular outcomes.

PURPOSE: To summarize the effects of intensive (or targeted) systolic BP (SBP) and diastolic BP (DBP) lowering with pharmacologic treatment on cardiovascular outcomes and harms in adults with hypertension.

DATA SOURCES: Multiple databases, including MEDLINE and EMBASE, were searched for relevant systematic reviews (SRs) published in English from 15 December 2013 through 25 March 2019, with updated targeted searches through 8 January 2020.

STUDY SELECTION: 8 SRs of randomized controlled trials examining either a standardized SBP target of -10 mm Hg (1 SR) or BP lowering below a target threshold (7 SRs).

DATA EXTRACTION: One investigator abstracted data, assessed study quality, and performed GRADE assessments; a second investigator checked abstractions and assessments.

DATA SYNTHESIS: The main outcome of interest was reduction in composite cardiovascular outcomes. High-strength evidence showed benefit of a 10-mm Hg reduction in SBP for cardiovascular outcomes among patients with hypertension in the general population, patients with chronic kidney disease, and patients with heart failure. Evidence on reducing SBP for cardiovascular outcomes in patients with a history of cardiovascular disease (moderate strength) or diabetes mellitus (high strength) to a lower SBP target was mixed. Low-strength evidence supported intensive lowering to a 10-mm Hg reduction in SBP for cardiovascular outcomes in patients with a history of stroke. All reported harms were considered, including general adverse events, serious adverse events, cognitive impairment, fractures, falls, syncope, hypotension, withdrawals due to adverse events, and acute kidney injury. Safety results were mixed or inconclusive.

LIMITATIONS: This was a qualitative synthesis of new evidence with existing meta-analyses. Data were sparse for outcomes related to treating DBP to a lower target or for patients older than 60 years.

CONCLUSION: Overall, current clinical literature supports intensive BP lowering in patients with hypertension for improving cardiovascular outcomes. In most subpopulations, intensive lowering was favored over less-intensive lowering, but the data were less clear for patients with diabetes mellitus or cardiovascular disease.

PRIMARY FUNDING SOURCE: U.S. Department of Veterans Affairs, Veterans Health Administration.