Changes in ophthalmic artery Doppler during acute blood pressure control in hypertensive women.

OBJECTIVE To examine the changes in ophthalmic artery Doppler indices and their association with changes in mean arterial blood pressure (MAP) and systolic and diastolic blood pressure in women with hypertensive disorders of pregnancy, presenting with high blood pressure and receiving antihypertensive medication. METHODS Prospective cohort study of 31 pregnant women with hypertensive disorders of pregnancy receiving antihypertensive medication at 30+0 to 39+6 weeks' gestation. Paired maternal blood pressure and ophthalmic artery Doppler measurements were performed prior to and at 30 and 60 minutes after starting antihypertensive medication. In some patients who did not achieve blood pressure control at 60 minutes, paired readings were continued up to the point of blood pressure control. Patients who failed to do so within 2 hours from commencement of antihypertensives were admitted to hospital. Univariate linear regression was performed to determine the association between the ophthalmic artery peak systolic velocity (PSV) ratio and systolic blood pressure (SBP), diastolic blood pressure (DBP), and MAP before treatment and at blood pressure control (<140/90 mmHg). The longitudinal changes of MAP and PSV ratio over the three time points were examined by a repeated measure, multilevel linear mixed-effects analysis. RESULTS Treatment was associated with a decrease in SBP, DBP, MAP and PSV ratio. At the time of blood pressure control, the decrease in SBP, DBP, MAP and PSV ratio was 12.1 mmHg (95% CI 9.0 - 15.1, p<0.0001), 9.0 mmHg (95% CI 6.5 - 11.5, p<0.0001), 10.0 mmHg (95% CI 7.6 - 12.4, p<0.0001) and 0.07 (95% CI 0.03 to 0.11, <0.001), respectively. From the total cohort, 20 women (65%) had achieved blood pressure control at 60 minutes and another 7 (22%) by 120 minutes from commencement of antihypertensive treatment. Four women (13%) did not achieve blood pressure control during this period and were admitted to hospital. The relationship between PSV ratio and SBP, DBP and MAP was assessed before treatment (n=31) and at the point of blood pressure control for the women who had achieved blood pressure control (n=27). Prior to treatment there was a significant association between PSV ratio and MAP (p<0.0001, R2 = 0.39). This was primarily due to an association between PSV ratio and DBP (p<0.0001, R2 = 0.39) and less so due to the association between PSV ratio and SBP (p=0.02, R2 = 0.16). At the point of achieving blood pressure control there was no significant association between PSV ratio and MAP (p=0.7), DBP (p=0.5) or SBP (p=0.7). CONCLUSIONS Acute blood pressure control in pregnancy is associated with a concomitant reduction in blood pressure and PSV ratio. There is a significant association between PSV ratio and MAP, SBP and DBP which disappears after reducing blood pressure to levels <140/90 mmHg. This article is protected by copyright. All rights reserved.