A cohort study and meta-analysis of isolated diastolic hypertension: searching for a threshold to guide treatment

Area of Science:

• Cardiology
• Hypertension Research
• Public Health

Background:

• The 2017 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines redefined hypertension criteria, potentially increasing the prevalence of isolated diastolic hypertension (IDH).
• Previous studies have yielded conflicting results regarding the association between IDH and cardiovascular disease (CVD).
• Understanding the clinical significance of IDH is crucial for guiding patient management and public health recommendations.

Purpose of the Study:

• To investigate the association between isolated diastolic hypertension (IDH), defined by 2017 ACC/AHA criteria, and subclinical CVD (coronary artery calcium).
• To examine the relationship between IDH and the incidence of systolic hypertension and major CVD events.
• To conduct a meta-analysis combining data from the Multi-Ethnic Study of Atherosclerosis (MESA) with other cohorts to assess IDH's link to CVD events.

Main Methods:

• Utilized multivariable-adjusted logistic and Cox regression analyses within the MESA cohort (n=5104) to evaluate IDH (systolic BP <130 mmHg and diastolic BP ≥80 mmHg) against coronary artery calcium (CAC), incident systolic hypertension, and CVD events.
• Performed a random-effects meta-analysis, incorporating MESA findings with seven other published cohort studies (totaling 10,037,843 participants), to determine the association between the 2017 IDH definition and CVD events.
• Stratified meta-analysis was employed to explore potential variations in the association based on different inclusion criteria.

Main Results:

• In the MESA study, 7.5% of participants met the 2017 criteria for IDH. No significant association was found between IDH and the presence of CAC (OR 0.88, 95% CI 0.66-1.17).
• IDH was associated with an increased risk of developing incident systolic hypertension, but not statistically significantly with incident CVD (HR 1.19, 95% CI 0.77-1.84) or mortality (HR 0.94, 95% CI 0.65-1.36) over 13 years.
• The meta-analysis of eight cohort studies indicated that the 2017 IDH definition was not consistently associated with CVD events, with observed associations being numerically small (adjusted HRs ranging from 1.04 to 1.09).

Conclusions:

• The findings suggest that for middle-aged and older adults meeting the 2017 IDH criteria, lifestyle modifications are likely sufficient, and drug therapy may not be necessary, pending follow-up for incident systolic hypertension.
• These results may not be generalizable to individuals under 40 years of age, highlighting the need for further research in this demographic.
• The study underscores the importance of continued monitoring for the development of systolic hypertension in individuals diagnosed with isolated diastolic hypertension.