Differences in Coronary Blood Flow in Aortic Regurgitation and Systemic Arterial Hypertension Have Implications for Diastolic Blood Pressure Targets: A Systematic Review and Meta‐Analysis

The objective was to evaluate coronary blood flow ( CBF ) in patients with systemic arterial hypertension ( HTN ) and to compare it with CBF in patients with aortic regurgitation ( AR ). A systematic literature search was conducted using the reference terms “coronary blood flow” and either “aortic regurgitation” or “hypertension.” The selection criteria included CBF measurement in a concomitant control group, except studies evaluating CBF with aortic‐valve replacement surgery. Twenty‐two studies met the inclusion criteria. There were 318 persons with HTN , with 185 controls; and 102 persons with AR , with 144 controls. Despite an overall increase in CBF in HTN , CBF per gram of left ventricular mass was significantly ( P < 0.0001) reduced. In contrast, CBF per gram of left ventricular mass was significantly ( P = 0.004) increased in AR . Aortic regurgitation was associated with a significant ( P < 0.0001) increase in CBF during systole and away from diastole, in contrast to persons with HTN . Aortic‐valve replacement reversed the increase in systolic CBF . These data suggest that patients with HTN are more vulnerable than patients with AR to lower diastolic blood pressure ( DBP ), because resting CBF is compromised in HTN . Furthermore, patients with HTN may not compensate for DBP reductions by shifting CBF to systole, such as can occur with the low DBP in AR . Lower DBP in patients with AR cannot be used to justify treating patients with HTN to similar DBP because of the dramatic differences in CBF between the 2 conditions.