Time in Target Range for Blood Pressure and Adverse Health Outcomes: A Systematic Review

Abstract

Background: Blood pressure (BP) time in target range (TTR) reflects the proportion of time that BP measurement is within a specified target range. We aim to summarize the evidence for relationships between TTR and adverse health outcomes.

Methods: Seven databases were searched. After quality assessment and data extraction, meta-analyses were performed to generate pooled estimates of the association (hazard ratios) between TTR and health outcomes. Primary outcomes were all-cause mortality and cardiovascular death. Secondary outcomes included major adverse cardiovascular events, myocardial infarction, stroke, heart failure, atrial fibrillation, and adverse kidney events.

Results: In all, 21 studies were included, mostly rated at low risk of bias. TTR was defined by systolic BP (SBP) in 15 studies and by both SBP and diastolic BP in 6 studies. Per SD increase of TTR was associated with significantly decreased risks of all-cause mortality (110-130 mm Hg SBP TTR: hazard ratios, 0.85 [95% CI, 0.82-0.89]; 120-140 mm Hg SBP TTR: 0.81 [95% CI, 0.70-0.94]; and 70-80 mm Hg diastolic BP TTR: 0.88 [95% CI, 0.83-0.93]), cardiovascular death (110-130 mm Hg SBP TTR: 0.83 [95% CI, 0.78-0.87]; 120-140 mm Hg SBP TTR: 0.76 [95% CI, 0.65-0.89]; and 70-80 mm Hg diastolic BP TTR: 0.85 [95% CI, 0.80-0.90]), major adverse cardiovascular events (120-140 mm Hg SBP TTR: 0.76 [95% CI, 0.70-0.83]), and heart failure (110-130 mm Hg SBP TTR: 0.84 [95% CI, 0.76-0.93] and 120-140 mm Hg SBP TTR: 0.78 [95% CI, 0.68-0.89]). However, there was not sufficient support for the association of TTR with myocardial infarction, stroke, atrial fibrillation, or adverse kidney events.

Conclusions: Higher TTR was associated with reduced risks of all-cause mortality, cardiovascular death, major adverse cardiovascular events, and heart failure, highlighting the importance of sustained BP control in clinical practice.

Registration: URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42023486437.

Keywords: blood pressure; cardiovascular diseases; death; hypertension; secondary prevention.