Left Ventricular Longitudinal Function and Myocardial Work in Young Adults with Ambulatory Hypertension Compared with Normotensive Non-Dippers: A Cross-Sectional Speckle-Tracking Study

Background/Objectives: It remains uncertain whether young adults with ambulatory hypertension exhibit subclinical left ventricular (LV) dysfunction relative to normotensive individuals with a blunted nocturnal blood pressure (BP) fall. We compared LV global longitudinal strain (GLS), myocardial work, and conventional echocardiographic indices between these groups. Methods: In this prospective, single-centre, cross-sectional study, adults aged 18–50 years without previously diagnosed or treated hypertension underwent 24-h ambulatory BP monitoring and echocardiography. Participants with ambulatory hypertension (2023 ESH criteria) were matched 1:1 to normotensive non-dippers for age and sex, without replacement. The primary analysis estimated the age- and sex-adjusted between-group difference in GLS. Results: The matched cohort comprised 78 unique individuals (39 per group); 14 hypertensive participants had isolated nocturnal hypertension. Speckle-tracking data were available in 60 participants. Ambulatory hypertension was not significantly associated with GLS (adjusted difference +0.55 percentage points; 95% CI −0.83 to +1.94; p = 0.43), and the results were consistent across five sensitivity analyses, including multiple imputation. No statistically significant between-group differences were detected in myocardial work indices, LV ejection fraction, LV mass index, LV hypertrophy prevalence, or left atrial volumes and function, although the confidence intervals for myocardial work were wide. Conclusions: In young adults with untreated ambulatory hypertension, mostly with modest BP elevation or confined to the night-time period, GLS and myocardial work did not differ significantly from those of normotensive non-dippers. The primary analysis indicates that GLS differences larger than approximately 2 percentage points are unlikely, although smaller differences cannot be excluded.