Cluster Analysis of Pulse Wave Velocity Longitudinal Trends in Hypertensive Patients

Objective: Arterial stiffness (AS) is an important predictor of cardiovascular disease and mortality. Its trend over time, assessed through multiple measurements, is still largely unexplored. The aim of this study was to assess the determinants of trajectories of carotid-femoral pulse wave velocity (PWV) in a cohort of Italian hypertensive adults. Design and method: From a population of 2581 hypertensive patients referred to Hypertension Unit of Internal Medicine Division at University Hospital Città della Salute e della Scienza of Turin (Italy) from 2005 to 2023, those who had at least 3 PWV recordings over time were included in this study. Those with rare vascular diseases were excluded. Cluster analysis of PWV trajectories was performed using K-means method. Results: A total of 271 patients were included. Median follow-up time was 4.5 [0.6-8.4] years). Three clusters of PWV trends were identified: low-stable (A, n=126), high-increasing (B, n=107), and high-stable (C, n= 38) clusters. Patients in the clusters B and C were progressively older than those in cluster A (60.4±8.9 and 65.8±10.3 vs. 51.9±13.3 years, respectively). Mean BP (MBP) and PWV at baseline were progressively higher in the high-increasing and high-stable clusters compared to the low-stable one (MBP was 103±15 and 111±22 mmHg in clusters B, and C vs. 97±11mmHg in cluster A; PWV was 10.1±0.7 and 13.6±1.4 m/s in clusters B, and C vs. 7.8±0.9 m/s in cluster A; all p<0.001). There were no significant differences in sex distribution or anti-hypertensive treatment among the clusters. On multinomial regression analysis, older age and higher MBP at baseline were independently associated to increased probability of belonging to either B or C clusters when compared to the low-stable one. Conclusions: Through multiple PWV assessment in hypertensive patients during a large time span, this study shows that patients with less favorable arterial stiffness behavior present higher PWV values at baseline. Older age and higher MBP at baseline are associated with worse evolution of PWV over time.