SBP Time in Target Range Associated with Decrease in CV Risk, Study Finds

April 12, 2021
Grace Halsey

Post-hoc analysis of the SPRINT trial found greater time spent with systolic blood pressure in target range was significantly associated with decreased risk of MACE.

Time spent in systolic blood pressure (SBP) target range among adults with hypertension is an independent predictor of major adverse cardiovascular events (MACE), according to a new post-hoc analysis of the SPRINT trial published recently in the Journal of the American College of Cardiology.

The analysis revealed that in a cohort with hypertension and at increased cardiovascular (CV) risk, greater time in systolic target range (TTR) was associated with decreased MACE; the association was independent of traditional CV risk factors and persisted after adjustment for mean SBP and SBP variability.

The analysis was led by Nayyra Fatani. PharmD, of the College of Pharmacy at King Abdulaziz University, Jeddah, Saudi Arabia, with coauthors from the Massachusetts College of Pharmacy and Health Sciences, Brigham and Women’s Hospital, and the Department of Pharmacotherapy and Outcomes Science, Virginia Commonwealth University.

The landmark SPRINT trial, published in 2015, compared intensive (target <120 mm Hg) and standard (target <140 mm Hg) systolic BP treatment interventions in 6 162 adults with hypertension and high CV risk (mean age, 68 years; 38% women; 17% with history of clinical CVD).

Fatani et al established the systolic target range in the current study at 110-130 mm Hg for the intensive control group and 120-140 mm Hg for the standard control group.CV outcomes included individual MACE components, and treatment-related serious adverse events.

In the original SPRINT trial, BP was measured at monthly intervals for the first 3 months, then every 3 months unless target BP had not yet been achieved, or medication intensification occurred. TTR in the current study was estimated over the first 3 months of follow-up by linear interpolation. Investigators used adjusted Cox proportional hazards regression models to examine the association between TTR and major CV events and compared them to mean SBP and SBP variability.

The analysis found overall median TTR for SBP was 47% (interquartile range [IQR], 18%-72%) for the intensive group and 51% (IQR, 25%-75%) for the standard group.

Participants with greater time in target range were younger, had lower 10-year cardiovascular risk and lower baseline systolic blood pressure, and were more likely women and statin users.

Participants with >75% TTR were younger, had lower 10-year CV risk, and lower baseline SBP vs participants with <25% TTR (p <.001 for all). First MACE was observed in 356 patients over a median follow-up of 3.3 years. Each 1-SD increase in TTR was significantly associated with a decreased risk of first MACE (hazard ratio [HR], 0.78; 95% confidence interval [CI], 0.7-0.87; p <.001).

The authors found the association persisted after adjustment for age, sex, race (HR, 0.78; 95% CI, 0.7-0.87; p <.001) and for demographics, medical history, baseline SBP (HR, 0.78; 95% CI, 0.73-0.91; p <.001).

TTR remained significantly associated with MACE even after adjustment for mean SBP or SBP variability (HR, 0.85; 95% CI, 0.74-0.96; p=0.011).

The association between TTR and MACE also persisted among study participants with mean SBP at or below target.

With the caveat that TTR will need to be validated in prospective studies using larger, more general populations not participating in BP management trials, the authors concluded that: “These results suggest that time in target range provides incremental value beyond mean systolic blood pressure to population-based hypertension quality monitoring and clinical trial-based blood pressure interventions.”