Less Intensive Monitoring After Thrombolysis Is Safe

HELSINKI, Finland — Less intensive monitoring of patients with acute ischemic stroke who have undergone thrombolysis appeared to be safe in new findings that challenge current guidelines.

The large international OPTIMISTmain trial showed that less frequent monitoring of vital signs and neurologic function during the first 24 hours did not compromise recovery or increase the risk for serious adverse events compared with standard protocols.

“The key message from our study is that it is safe to relax the monitoring of these patients, and this will allow nurses to be freed up from taking constant measurements so they can spend more time on delivering direct interventions and generally providing better care of the patients,” study investigator Craig Anderson, MD, George Institute for Global Health, Sydney, Australia, told Medscape Medical News.

“Another benefit will be less disruption to patients, which is especially important if they are trying to sleep.”

The trial also showed that less intensive monitoring was feasible outside of an intensive care unit (ICU), which the researchers said would have benefits such as flexibility in nursing workflow and the release of intensive care resources.

“This trial result has wide applicability and is relevant all around the world, and we believe that hospitals could consider incorporating this approach to improve systems of care for acute stroke,” Anderson said.

Anderson presented the results of the OPTIMISTmain trial on May 21 at the European Stroke Organization Conference (ESOC) 2025. The trial was also simultaneously published online in The Lancet.

Nurse-Driven Research

Anderson noted that this was a nurse-driven study and was the idea of co-lead author Debbie Summers, MSN, a senior nurse practitioner at Saint Luke’s Hospital of Kansas City, Missouri, who questioned whether the high-intensity monitoring of patients with stroke after thrombolysis administration was necessary, given its high burden on nurses and level of disruption to patients.

Current guidelines recommended 37 assessments within the first 24 hours after thrombolysis, including vital signs — such as heart rate and blood pressure — and neurologic checks using the Glasgow Coma Scale or the National Institutes of Health Stroke Scale (NIHSS). These are conducted every 15 minutes for 2 hours, every 30 minutes for the next 6 hours, and then hourly.

The low-intensity monitoring protocol tested in the study involved 17 assessments over the same 24-hour period, with vital signs and neurologic checks conducted every 15 minutes for 2 hours, every 2 hours for the next 8 hours, and then every 4 hours. Investigators were also encouraged to implement the protocol in a stroke unit rather than an ICU, where hospital infrastructure allowed.

Anderson explained that high-intensity monitoring was put in place when thrombolysis was first used in routine clinical practice, as this was the protocol used in the initial randomized clinical trial of alteplase for acute ischemic stroke in the mid-1990s.

“There was concern that use of thrombolysis in this setting could cause intracerebral hemorrhage (ICH), and the trial, therefore, included a careful monitoring strategy to detect any deterioration in the patient as quickly as possible.

“In addition, thorough monitoring and reporting was necessary in the evaluation of a new drug. Then, because this high-intensity monitoring program had been used in the trial, it was adopted after alteplase was approved for use in acute ischemic stroke and rolled out into clinical practice,” Anderson said.

However, this high-intensity monitoring protocol has never been tested in a major study to determine if this intensive monitoring is actually necessary, he added.

Lower Rates of ICU Admission

Guidelines often recommend ICU monitoring for these patients due to the high level of nursing care required. While some countries have relaxed this requirement, others — such as the United States, where medicolegal concerns are more prominent — continue to manage these patients in the ICU.

OPTIMISTmain was an international, cluster-randomized trial conducted at 114 hospitals across eight countries: Australia, Chile, the United Kingdom, the United States, China, Malaysia, Mexico, and Vietnam.

It was designed to test the noninferiority of a new low-intensity monitoring protocol to the standard high-intensity monitoring protocol in patients with acute ischemic stroke who were clinically stable with mild to moderate neurologic impairment (NIHSS score < 10) within 2 hours of initiation of thrombolysis.

The trial enrolled 4922 patients, with 2789 participants assigned to the low-intensity monitoring group and 2133 to the standard monitoring group.

The primary outcome was the proportion of participants with an unfavorable functional outcome defined by a Modified Rankin Scale score from 2 (indicating some disability) to 6 (death) at 90 days.

This occurred in 31.7% of patients in the low-intensity monitoring group and 30.9% of those in the standard monitoring group, giving a relative risk of 1.03 (95% CI, 0.92-1.15), satisfying the noninferiority criteria (P noninferiority = .057).

Symptomatic intracerebral hemorrhage occurred in five (0.2%) patients in the low-intensity group and eight (0.4%) patients in the standard monitoring group, a nonsignificant difference.

The number of participants with a serious adverse event was similar between the low-intensity monitoring group (11.1%) and the standard monitoring group (11.3%).

The low-intensity monitoring protocol was associated with lower rates of ICU admission, with 12.8% in the low-intensity group admitted directly to an ICU compared with 16.8% of patients in the standard monitoring group.

Universally Applicable Results

These figures and the differences between the protocols were much greater in the United States, where immediate ICU admission occurred in 47.1% of patients in the low-intensity monitoring group vs 77.1% of those in the standard monitoring group.

“This was a large trial with hard, accepted, patient-centered outcomes, and the results should be applicable across the world,” Anderson said.

He pointed out that the trial also included process evaluations from the nurses and physicians involved, which he said were “pretty much uniformly comfortable with the less intensive monitoring protocol.”

“It is not for us to recommend what guidelines do,” he added. “But we have suggested that hospitals should consider implementing this intervention according to local circumstances to improve the efficiency of their care.”

While a cost analysis has not yet been published, Anderson said the less intensive monitoring protocol is expected to save costs.

“Just the observation that there was a significant reduction in the use of ICU beds, especially in the United States, will result in significant cost savings,” he noted.

“This trial shows that we can use our nurses in a more efficient manner, and we don’t need to send all our patients to the ICU; we can use our regular beds or stroke unit beds better and be a bit smarter,” he added.

Anderson added that over the many years of using thrombolysis for acute ischemic stroke in clinical practice, it has become apparent that the incidence of ICH is low and that such strict monitoring might not be required. “We have become more confident about how to use thrombolysis and which patients are at higher risk.”

However, he cautioned that the low-intensity protocol would not be appropriate for all patients.

“This study only included patients who had a moderate level of disability when they presented. Patients also had to be alert, with good blood pressure control, heart rate, and respiration, and without other complicating health problems. We estimate that this would account for at least a third, maybe half, of all the stroke patients that come through hospitals around the world,” said Anderson.

‘Less Is More’

Commenting on the OPTIMISTmain trial, Valeria Caso, MD, PhD, professor of neurology and consultant neurologist at Santa Maria della Misericordia Hospital, University of Perugia, Perugia, Italy, and a past president of the European Stroke Organisation, said she was “very impressed” with the study.

She pointed out that nurse-led trials are important as so much of stroke care is carried out by nurses.

“This trial is another example of ‘less is more’ that we are seeing in several aspects of stroke medicine,” said Caso.

“I think we will implement this lower-intensity monitoring protocol for less severe stroke patients in Italy. Nurses are in high demand, and we need to prioritize the resources we have. These results will allow us to prioritize the nursing resources regarding intensive monitoring in the first 24 hours for patients with severe strokes.”

The OPTIMISTmain trial was funded by grants from the National Health and Medical Research Council (NHMRC) of Australia; the New South Wales Health Investigator Development Grant; the University of New South Wales Medicine Non-Communicable Diseases Theme Early and Mid-Career Research Seed Grant Scheme; the Medical Research Future Fund (for conduct in Australia); and Genentech (for conduct in the USA). Professor Anderson had received grants from the NHMRC and Medical Research Futures Fund of Australia, the Medical Research Foundation of the United Kingdom, and AstraZeneca, Australia.