A recent study conducted by researchers at Yonsei University College of Medicine (YUCM) found that forcibly lowering blood pressure below 140mmHg in patients with acute ischemic stroke treated for endovascular thrombectomy (EVT) worsened prognosis by 1.84 times. 

High blood pressure, diabetes, and heart arrhythmias cause blood clots to form in the blood vessels. A blood clot can block a blood vessel in the brain, reducing blood and oxygen flow and causing brain damage. Intravenous thrombolysis, in which drugs are injected into the blood vessels of the brain to dissolve the clot, is often used for treatment, but if the clot is too large, an EVT procedure where a tube is inserted into the artery to remove the clot, is more effective.

After EVT procedures, it is important to control blood pressure to prevent complications such as cerebral hemorrhaging. However, optimal blood pressure control after successful reperfusion with endovascular thrombectomy (EVT) for patients with acute ischemic stroke is unclear.

In the U.S. and Europe, guidelines suggest keeping systolic blood pressure just below 180 mmHg. However, recent retrospective studies have contested this guideline, with many reporting a favorable prognosis when patients' blood pressure is forcibly lowered reduced below this 180 mmHg guideline.

Accordingly, the study led by Professor Nam Hyo-suk of Neurology at YUCM followed 302 patients who underwent EVT for acute ischemic stroke at 19 hospitals nationwide for two and a half years starting in 2020, dividing them into two groups. One group consisted of 155 patients who lowered their blood pressure below guideline standards with a target systolic blood pressure of <140 mmHg, and another 147 patients who followed the guidelines with a target systolic blood pressure of 140 to 180 mmHg.

The results showed that 54.4 percent of those who controlled their systolic blood pressure to less than 180 mmHg had a good outcome, compared to 39.4 percent of those who controlled their systolic blood pressure to less than 140 mmHg. Additionally, this group was also 1.84 times more likely to have a poor outcome.

"In patients with acute cerebral infarction who have undergone EVT, blood pressure is often lowered forcibly to prevent cerebral hemorrhage, but this study confirms that such aggressive treatment negatively impacts patient prognosis," said Professor Nam. "After EVT, blood pressure should be kept below 180 mmHg as recommended by guidelines and the body should be allowed to adapt after the procedure."

The results of the study were published in the latest issue of the world's leading medical journal, the Journal of the American Medical Association (JAMA) on Sept. 5.