The angiotensin sensitivity test and low-dose aspirin are ineffective methods to predict and prevent hypertensive disorders in nulliparous pregnancy

OBJECTIVE: Our purpose was to assess the efficiency of the angiotensin sensitivity test as a predictive test for preeclampsia and the effectiveness of low-dose aspirin to prevent preeclampsia when commenced at 28 weeks' gestation in angiotensin II-sensitive women.

STUDY DESIGN: A total of 495 healthy nulliparous women underwent the angiotensin sensitivity test at 28 weeks' gestation. The angiotensin II-sensitive women were randomized to 60 mg of aspirin or placebo as a subset of a large multicenter, randomized, controlled trial of low-dose aspirin therapy in pregnancy. Assessment of the efficiency of the angiotensin sensitivity test and low-dose aspirin in pregnancy was performed after detailed review of case notes after delivery. The Oxford definition of preeclampsia was used. This includes women without proteinuria but requires blood pressure increments that have been validated to bias the selection to primigravid women.

RESULTS: Five women had proteinuric preeclampsia in the angiotensin II-sensitive group randomized to aspirin compared with none in the group randomized to placebo. Overall, 11 (25%) of the women randomized to aspirin had preeclampsia compared with four (11%) randomized to placebo (p < 0.05, not significant). The positive and negative predictive values for the angiotensin sensitivity test were 19% and 87%, respectively.

CONCLUSION: The angiotensin sensitivity test is not an effective screening test for preeclampsia, and low-dose aspirin does not prevent preeclampsia when commenced at 28 weeks' gestation in angiotensin II-sensitive women.