Time in target range TTR in the field of hypertension management
Hypertension is one of the most common comorbidities and risk factors for cardiovascular disease including heart failure (HF). However, standard BP control metrics may not reflect the variability in BP over time. Recently, researchers have proposed the concept of "time in target range" (TTR) in the field of hypertension management.
The study was Published in Journal of the American College of Cardiology.
Utilizing this tool, Chen et al in post hoc analysis of TOPCAT and BEST trials have shown that "time in target range" independently predicts major adverse cardiovascular events (MACE) in hypertensive patients with HF with both preserved and reduced ejection fractions.
"time in target range" can incorporate both the average BP value prevailing during long-term follow-up and the degree of BP variability. Also, it can account for variation both within and outside of target range. The present study aimed to assess the value of adopting time in BP target range by exploring its association with clinical outcomes among hypertensive patients with HF.
Seated office BP was measured by trained staff during each visit with the mean number of visits per subject of 11(range, 2 to 16) for the TOPCAT and 13 (range, 2 to 28) for the BEST trial. "time in target range" for each patient was calculated using linear interpolation across the study period with the target range of systolic BP between 120 and 130 mm Hg.
This post hoc analysis has shown that in hypertensive HF patients, higher "time in target range" with a systolic BP target of 120 to 130 mm Hg was associated with lower risk of cardiovascular death or HF hospitalization.
This observation was consistent across all important clinical outcomes considered among HF patients. The results also held for an SBP target of 110 to 130 mm Hg and diastolic BP target of 70 to 80 mm Hg.
Meanwhile, a linear relationship was found between "time in target range" and primary outcome, which suggested that longer "time in target range" is associated with better outcomes. This study explored the value of "time in target range" in HF patients for BP control and found a significant association with cardiovascular death or HF hospitalization even among population with a relatively low "time in target range".
"Our study emphasizes the importance of monitoring BP in everyday clinical practice and maintaining the consistency of BP control over time", noted the authors. Efforts to lower cardiovascular risk among these patients should be taken by attaining a high "time in target range" of multiple measurements of BP in usual care or via self-monitoring.