Abstract 153: The Preserve Trial: Intensive Blood Pressure Lowering and Cerebral Blood Flow in Small Vessel Disease

Abstract

Background and Aims: In patients with severe cerebral small vessel disease (SVD), in whom both cerebral blood flow and cerebral autoregulation are reduced, intensive BP lowering might reduce cerebral blood flow (CBF) and increase the rate of white matter hyperintensity (WMH) progression. In an RCT we determined the effect of intensive BP lowering on CBF in lacunar stroke with confluent WMH. Method: In the PRESERVE trial Perfusion sub-study, patients from 2 sites with MRI confirmed symptomatic lacunar infarct and confluent WMH were randomised to “normal” (systolic=130-140mmHg, N=33) versus “intensive” (systolic=<125mmHg, N=29) BP targets. CBF was determined using arterial spin labelling; the primary end point was change in global CBF between baseline and 3 months. Linear regression was performed comparing change in CBF against change in BP. Analyses controlled for site. Results: Mean(SD) systolic BP reduced by 8(12) and 27(17)mmHg in the standard/intensive groups, respectively (difference between groups p <0.001) with achieved BP of 141(13) and 126(10) mmHg respectively. Baseline global CBF was 32(10) and 31(10)ml/min/100g in the standard/intensive groups. There was no difference in change in global CBF between treatment arms: standard, mean(SD) (ml/min/100g)= -0.46 (9.39); intensive, 0.73 (8.62), p =0.63. No differences were observed when analysis examined grey or white matter only, or was confined to those achieving target BP. Change in CBF did not have a significant association with change in systolic or diastolic BP. Conclusion: Intensive BP lowering did not reduce CBF in severe SVD characterised by lacunar stroke and confluent WMH. This suggests intensive CBF reduction is unlikely to accelerate WMH progression.