Systolic and diastolic blood pressure time in target range and cardiovascular outcomes in patients with hypertension and pre-frailty or frailty status

Abstract

In patients with hypertension and pre-frailty or frailty, the influence of systolic (SBP) and diastolic blood pressure (DBP) time in target range (TTR) on clinical outcomes is unclear. Thus, we conducted a post hoc analysis of the Systolic Blood Pressure Intervention Trial (SPRINT). Classifying 4208 participants into frail and non-frail groups using a frailty index, the study calculated blood pressure time in target range (BP-TTR) for the first three months using the Rosendaal method. The primary endpoint included a composite of nonfatal myocardial infarction (MI), acute coronary syndromes, stroke, acute decompensated heart failure (ADHF), and cardiovascular death. Relationships between BP-TTR and outcomes were analyzed using Kaplan-Meier curves, Cox models, and restricted cubic spline curves, with subgroup analysis for further insights. In a median follow-up of 3.17 years, primary outcomes occurred in 6.7% of participants. Kaplan-Meier analysis showed that a lower systolic blood pressure time in target range (SBP-TTR) (0%-25%) correlated with an increased cumulative incidence of the primary outcome (p < .001), nonfatal MI (P = .021), stroke (P = .004), and cardiovascular death (P = .002). A higher SBP-TTR (75%-<100%) was linked to a reduced risk of these outcomes. The restricted cubic spline (RCS) curve revealed a linear association between SBP-TTR and the primary outcome (non-linear P = .704). Similar patterns were observed for diastolic blood pressure time in target range (DBP-TTR). Subgroup analysis showed that the protective effect of higher SBP-TTR was less pronounced at low DBP-TTR levels (P for interaction = .023). In conclusion, this study highlights the importance of maintaining BP within the target range to mitigate cardiovascular risks in this population.

Keywords: blood pressure; diastolic blood pressure time in target range; frailty; hypertension; systolic blood pressure time in target range.

FIGURE 1

Flowchart of the study. DBP, diastolic blood pressure; SBP, systolic blood pressure; SPRINT, systolic blood pressure intervention trial.

FIGURE 2

Kaplan‐Meier estimation of study outcomes by SBP‐TTR (A: primary outcomes; B: nonfatal MI; C: NONMIACS; D: stroke; E: ADHF; F: cardiovascular death). ADHF, acute decompensated heart failure; MI, myocardial infarction; NONMIACS, acute coronary syndrome not resulting in myocardial infarction; SBP, systolic blood pressure; TTR, time in target range.

FIGURE 3

Kaplan‐Meier estimation of study outcomes by DBP‐TTR (A: primary outcome; B: nonfatal MI; C: NONMIACS; D: stroke; E: ADHF; F: cardiovascular death). ADHF, acute decompensated heart failure; DBP, diastolic blood pressure; MI, myocardial infarction; NONMIACS, acute coronary syndrome not resulting in myocardial infarction; TTR, time in target range.

FIGURE 4

Restricted cubic splines for primary outcome by TTR (A: SBP‐TTR; B: DBP‐TTR). CI, confidence interval; DBP, diastolic blood pressure; HR, hazard ratio; SBP, systolic blood pressure; TTR, time in target range.

FIGURE 5

Subgroup analysis of associations between primary outcome and SBP‐TTR by univariate cox regression analysis. HR per 1‐SD (28.7%) increase in TTR. BMI, body mass index; CI, confidence interval; CVD, cardiovascular diseases; DBP, diastolic blood pressure; HR, hazard ratio; SBP, systolic blood pressure; TTR, time in target range.