Jara, Ramiro J Valdes

Abstract Background Interindividual 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. Methods We 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 Welch’s ANOVA and χ² testing, with multivariable adjustment for age and sex where applicable. Results All 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. Conclusions SBP–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.