Arterial hypertension. Does the J curve exist? And then?

Area of Science:

• Cardiovascular Medicine
• Geriatrics
• Epidemiology

Background:

• The 'lower the better' concept for blood pressure (BP) management is challenged by the J-shaped curve hypothesis, suggesting risks with very low BP.
• Previous studies indicated a continuous relationship between rising BP and adverse outcomes, even at lower levels.

Purpose of the Study:

• To investigate the existence and specific patient populations associated with the J-shaped relationship between blood pressure and adverse outcomes.
• To clarify the BP-outcome relationship across different age groups and in the presence of comorbidities.

Main Methods:

• Analysis of large cohort data (61 cohorts, 1 million individuals) and contemporary studies (CALIBER, ELSA).
• Review of randomized controlled trials (SPRINT, HYVET, INVEST) focusing on specific patient subgroups.
• Examination of physiological mechanisms like impaired coronary blood flow autoregulation and diastolic dysfunction.

Main Results:

• Contemporary data show a continuous rise in outcomes with increasing BP, without a J-shaped association in the general population, even in octogenarians.
• The J-shaped curve was primarily observed in randomized trials involving patients with significant atherosclerotic burden or multiple comorbidities.
• Physiological factors such as impaired coronary blood flow autoregulation and diastolic dysfunction contribute to adverse outcomes in specific elderly populations.

Conclusions:

• The J-shaped relationship between blood pressure and adverse outcomes is not a universal phenomenon but is confined to specific patient groups.
• Elderly individuals with extensive atherosclerosis, comorbidities, and conditions like heart failure with preserved ejection fraction are at risk for J-curve effects.
• Understanding these specific risk factors is crucial for safe and effective blood pressure management in vulnerable populations.