Moderate-low blood pressure reduces risks in patients with stroke

This study aimed to investigate the association between blood pressure levels during the initial phase of a stroke and clinical outcome. The main finding of the study was that patients with moderate-low systolic (the amount of pressure when the heart contracts) blood pressure during the acute phase of a stroke had a lower risk of poor outcomes.

An ischemic stroke is caused by a blockage in a blood vessel going to the brain. In the acute phase, the blockage in blood flow causes damage to the brain tissue. High blood pressure (BP) is common during the acute phase of a stroke. However, several trials have shown that lowering the blood pressure immediately during the acute phase does not reduce the risk of death or major disability.

There are two components of BP: systolic and diastolic. The first, larger number, is systolic BP and the smaller number is the diastolic BP. It is unknown whether different trends of BP changed during the acute phase of a stroke are associated with different clinical outcomes.

This study included 4,036 patients with acute ischemic stroke and high blood pressure. BPs were measured regularly until patients were either discharged from the hospital or died. Clinical outcomes such as death or disability were assessed at 3, 12 and 24 months.

5 different trends of BP were identified in the acute phase. Trend 1 was high systolic BP that remained high. Trend 2 was high systolic BP that went to moderate-low. Trend 3 was moderate-high that remained at this level. Trend 4 was moderate-low systolic BP and trend 5 was low systolic BP.

Compared to those with high systolic BP (trend 1), patients with trend 2, trend 3, trend 4 and trend 5 were 66%, 42%, 71%, and 44% less likely to die at 3 months after stroke. Likewise, at 24 months, trends 2, 3, 4 and 5 were 34%, 26%, 55% and 39% less likely to die compared to those with trend 1.

The authors concluded that patients with moderate-low systolic BP during an acute ischemic attack had a lower risk of poor outcomes.

This study did not account for medications used to lower BP or treat stroke symptoms. This may have affected the results.