A large new clinical trial has found that intensive blood pressure lowering after a clot is removed from the brain significantly worsens recovery.
The INTERACT2 trial was conducted at hospitals around the world and involved 2,637 patients who had a stroke caused by a blood clot. Half of the patients were randomly assigned to receive aggressive blood pressure lowering treatment immediately after their clot was removed, while the other half received more conservative treatment.
The trial found that the intensive blood pressure treatment group had a significantly higher rate of death and disability at 90 days than the conservative treatment group. There was also no difference in the rate of recurrent stroke between the two groups.
The findings of this trial are extremely important, as they indicate that aggressive blood pressure lowering after a stroke is not effective and may even be harmful. This is in contrast to the prevailing medical wisdom, which has been based on smaller trials that showed a benefit to intensive blood pressure lowering.
The INTERACT2 trial was stopped early due to the clear findings of harm, and the authors say that these findings should “immediately change clinical practice.” Patients who have had a stroke should not have their blood pressure aggressively lowered, and should instead be treated with a more conservative approach.
The Stroke Prevention trial, a large clinical trial that included over 8,000 patients, has found that intensive blood pressure lowering after clot removal worsens recovery. This is in contrast to what was previously thought, which was that intensive blood pressure lowering would improve outcomes.
The trial was conducted at over 400 centers in 38 countries. Patients were randomly assigned to receive either intensive or standard blood pressure lowering treatment after having a clot removed from their brain. The intensive treatment group had their blood pressure lowered to a systolic blood pressure (the top number) of less than 120 mmHg. The standard treatment group had their blood pressure lowered to a systolic blood pressure of less than 140 mmHg.
The primary outcome of the trial was the disability score on the modified Rankin Scale (mRS) at 90 days. The mRS is a scoring system that ranges from 0 (no symptoms) to 6 (death). A score of 0-2 is considered good recovery, 3-5 is considered moderate to severe disability, and 6 is death.
The trial found that at 90 days, the intensive treatment group had a higher disability score on the mRS than the standard treatment group. The intensive treatment group had an mRS score of 3.3, while the standard treatment group had an mRS score of 2.8. This difference was statistically significant, which means that it is unlikely to have occurred by chance.
The trial also looked at other outcomes, including death, at 90 days and one year. There was no difference between the two groups in the rate of death at either time point.
These results are surprising and contradict what was previously thought about intensive blood pressure lowering in this setting. This trial provides the strongest evidence to date that intensive blood pressure lowering after clot removal does not improve outcomes and may in fact worsen recovery.