Abstract P199: Low Diastolic Blood Pressure and Risk of Stroke in the Setting of Intensive Systolic Blood Pressure Control: The SPS3 study
There are conflicting results on the effect of lowering diastolic blood pressure (DBP) in the setting of treatment for high systolic blood pressure (SBP). We examined the impact of DBP on outcomes in the Secondary Prevention of Small Subcortical Strokes (SPS3) study. SPS3 is an international randomized clinical trial of antiplatelet therapy and optimal level of SBP control for secondary prevention of lacunar stroke (NCT00059306). Participants were randomized to two groups targeting “higher” (130-149 mmHg), and “lower” (<130 mmHg) SBP. The primary outcome was all stroke. The present study includes 2,748 participants followed for a mean of 3.7 (SD 2.0) years. Multivariable models were adjusted for demographic and health variables, baseline SBP and DBP, randomization group, and medication use. Over the follow-up period, the mean achieved DBP was 75 mmHg (5% decrease from baseline) in the higher group and 69 mmHg (12% decrease) in the lower group. There was a J-shaped association between DPB and stroke (Figure); the lowest risk of stroke was at 67 mmHg. Above this level, higher DBP was associated with an increased risk of stroke (adjusted hazard ratio per SD DBP (8.2 mmHg): 1.7, 95% confidence interval: 1.2, 2.3), major vascular events (1.9, 95% CI: 1.4, 2.5), and death (1.6, 95% CI: 1.1, 2.3). Below this level, higher DBP was associated with a lower risk of stroke (0.45, 95% CI: 0.23, 0.87) and major vascular events (0.49, 95% CI: 0.26, 0.90), but not death (1.3, 95% CI: 0.66, 2.7). In conclusion, among patients with recent lacunar stroke, both high and very low DBP levels are associated with an increased risk of stroke. Further study of the potential harms of very low DBP in the setting of treatment for SBP is warranted.
Author Disclosures: M.C. Odden: None. C. Peralta: None. L. McClure: None. C. White: None. P. Pergola: None. O. Benevente: None. B.P. Sawaya: None.
- © 2015 by American Heart Association, Inc.