Phenotypic Clustering of Systolic Blood Pressure-Heart Rate Synchronization Using Ambulatory Monitoring

BackgroundInterindividual variation in systolic blood pressure (SBP)-heart rate (HR) coupling reflects differences in autonomic and vascular regulation. The primary objective of this study was to determine whether SBP-HR synchronization identifies distinct hemodynamic phenotypes associated with demographic characteristics and blood pressure (BP) profiles in hypertensive and normotensive individuals. MethodsWe conducted a cross-sectional cohort analysis of 1,122 adults who underwent continuous 24-hour ambulatory monitoring of SBP, diastolic blood pressure (DBP), and HR in an outpatient clinical setting. Participants were classified as hypertensive or normotensive using guideline-based criteria. The primary exposure variable was SBP-HR synchronization, quantified using zero-lag cross-correlation coefficients. The primary outcomes were demographic characteristics (age, sex, stature) and BP phenotypes, including isolated systolic hypertension (ISH). Unsupervised partitioning around medoids clustering was used to identify synchronization-based phenotypes. Group comparisons were performed using Welchs ANOVA and {chi}{superscript 2} testing, with multivariable adjustment for age and sex where applicable. ResultsAll 1,122 participants were included in the final analysis (mean age 60.7 years; 52% female). Three synchronization phenotypes were identified: low, moderate, and high. Compared with the low-synchronization phenotype, the high-synchronization phenotype was younger (55.2 {+/-} 15.0 vs. 66.6 {+/-} 13.9 years), taller (170.4 {+/-} 9.4 vs. 167.4 {+/-} 10.5 cm), more frequently male (56% vs. 38%), and had lower baseline SBP (131.8 {+/-} 17.5 vs. 136.7 {+/-} 24.2 mmHg). Overall hypertension prevalence did not differ across phenotypes; however, ISH was less frequent in the high-synchronization phenotype (15.7% vs. 23.4%). Cluster assignments were robust across sensitivity analyses. ConclusionsSBP-HR synchronization identifies distinct hemodynamic phenotypes associated with age, sex, stature, and BP characteristics. Stronger synchronization reflects a physiological profile consistent with preserved autonomic-vascular integration and lower prevalence of isolated systolic hypertension, supporting its potential role in refined cardiovascular phenotyping.