Circulatory phenotypes in hypertension identified by 24-h ambulatory blood pressure monitoring.

Background: Although 24-h ambulatory blood-pressure monitoring (ABPM) is widely available, its diagnostic potential beyond confirming different types of hypertension remains under-utilized.

Objective: To derive and externally validate against echocardiographic hemodynamic indices a purely ABPM-based classification of circulatory phenotypes that extends conventional blood-pressure staging.

Methods: We retrospectively analyzed 29 743 consecutive adults who underwent 24-h ABPM. After excluding anyone previously treated for hypertension, 12 876 de-novo participants (50.2 ± 13.6 years; 51.4% men; 24.7% obese) were included, 9195 of whom were hypertensive. Pearson correlation matrices identified diastolic blood pressure (DBP), pulse pressure (PP) and heart rate (HR) as the least-collinear variables. These were z-standardized and submitted to K-means clustering.

Results: Four reproducible phenotypes were yielded: cardiogenic - elevated HR and cardiac output (CO) without arterial dysfunction (ΔHR = +10.5 bpm vs. normotensives, 95% CI 10.0-10.9); vaso-resistive - raised DBP with reduced HR, resulting in a higher DBP/HR index (ΔDBP/HR = +0.23 mmHg bpm-1, 95% CI 0.22-0.24); mixed - simultaneously increased HR and DBP, giving the highest DBP/HR index (P < 0.001 vs. normotensives); arterial-stiffness - widened PP with lower DBP, reflected in an elevated PP/DBP index (ΔPP/DBP = +0.16, 95% CI 0.15-0.17). Cluster-derived proxies of CO, systemic vascular resistance, and arterial stiffness showed good agreement with echocardiographic measurements, confirming their physiological validity.

Conclusions: A simple, unsupervised cluster analysis of routine ABPM data uncovers four reproducible circulatory phenotypes that enrich traditional blood pressure staging. Incorporating these phenotypes into clinical practice could refine risk stratification and enable mechanism-targeted antihypertensive therapy.