Central hemodynamic characteristics of young adults with isolated systolic hypertension: an ambulatory blood pressure monitoring-based study of real-world clinical patients

The central hemodynamic characteristics of young adults with isolated systolic hypertension (ISH) remain controversial, particularly regarding the extent of pulse pressure amplification (PPamp) compared with that of normotensives (NTs). Given the lack of ambulatory blood pressure monitoring (ABPM)-based data, this study evaluated 509 untreated young adults (18-35 years) who had undergone ABPM during the last decade, 109 who had undergone both ABPM and SphygmoCor analysis, and 26 newly recruited NTs. The agreement rate between office BP- and ABPM-based subtype classification was alarmingly low (50.7%). ISH was distinguishable from systolic-diastolic hypertension, the predominant subtype characterized by increased central BPs and stiffened arteries. The central hemodynamic parameters were all similar between patients with ISH and white-coat hypertension (WC). ISH patients had central BPs that were, albeit higher than those of NTs, at an upper-normal level that was comparable to those of WC patients. ISH patients had similar cfPWV but significantly higher PPamp than NTs (p = 0.032). The central hemodynamic parameters of the participants were further analyzed according to central pressure waveform types (A vs. B vs. C). Type C waves were associated with the highest PPamp and lowest cfPWV, whereas type A waves were associated with the lowest PPamp and highest cfPWV. Subjects with type B waves, an intermediate form, also had considerably high PPamps. Waveform composition differed significantly across hypertension subtypes (p < 0.001). ISH patients mostly had type B or C waves (96.7%), with only 3.3% having type A waves. This study based on a refined diagnosis showed that the ambulatory ISH of young adults arises from highly elastic arteries and related robustness of PPamp and shares similar central hemodynamic characteristics with WC patients.