Isolated diastolic hypertension in the IDACO study.

Abstract

Background: The prognostic implications of isolated diastolic hypertension (IDH), as defined by 2017 American College of Cardiology (ACC)/ American Heart Association (AHA) guidelines, have not been tested using 24-h ambulatory BP monitor (ABPM) thresholds. Methods: We analyzed data from 11,135 participants in the International Database on Ambulatory Blood Pressure in Relation to Cardiovascular Outcomes (IDACO). Using either 24-h mean ABPM values or mean nighttime ABPM values, we performed Cox regression to test the independent associations of IDH with death or cardiovascular events. Analyses were conducted in the cohort overall, as well as after stratification by age (<50 years vs ≥50 years). Results: The median age at baseline was 54.7 years and 49% were female. Over a median follow-up of 13.8 years, 2,836 participants died and 2,049 experienced a cardiovascular event. Overall, irrespective of age, IDH on 24-h ABPM defined by 2017 ACC/AHA criteria was not significantly associated with death (Hazard Ratio [HR] 0.95 [95% CI 0.79-1.13]) or cardiovascular events (HR 1.14 [95% CI 0.94-1.40]), compared with normotension. However, among the subgroup <50 years old, IDH was associated with excess risk for cardiovascular events (2.87 [95% CI 1.72-4.80]), with evidence for effect modification on the basis of age (P-interaction <0.001). Conclusions: Using ABPM data, this study suggests that IDH defined by 2017 ACC/AHA criteria is not a risk factor for cardiovascular disease in adults aged 50 years or older but is a risk factor among younger adults. Thus, age is an important consideration in the clinical management of adults with IDH.