Although neurologist Amie Hsia was hundreds of miles away from the emergency room team caring for her ailing aunt last February, she knew her symptoms and imaging pointed to a severe stroke. Hsia’s aunt needed treatment fast with a clot-busting medicine and a procedure known as an endovascular thrombectomy, which removes the clot and restores blood flow to oxygen-starved patches of the brain.

The hospital caring for her wasn’t equipped to perform the surgery, however, so Hsia insisted she be transferred to a nearby hospital, where the clot was removed from her brain. Hsia’s aunt survived and is able to live independently, despite some remaining symptoms from the stroke. Still, the travel to another hospital cost her valuable time—and could have hurt her in the long run.

That’s the implication of a study published Monday in the Journal of the American Medical Association that found that the sooner patients with severe strokes receive a thrombectomy, the less disabled they tend to be three months later. The research indicates that the brain-saving benefits of thrombectomy are most pronounced within the first few hours after signs of a stroke begin, and that these effects decline with each passing hour.

To some experts, the study is a call to rejigger the current method of determining where ambulances ought to take stroke patients, which is based solely on proximity. Instead, they say, patients with apparent severe strokes should be rushed to hospitals that perform thrombectomies.

“This study emphasizes that speed is essential,” said Dr. Mitchell Elkind, a neurologist at Columbia University Medical Center in New York City and a spokesman for the American Stroke Association. “We have to be as efficient and quick as possible.”

The need to get the right patients to the right hospital, Elkind said, transforms this medical issue into an organizational one.

The benefits of treating serious strokes with clot removal were shown in 2015, when five separate studies analyzing a total of 1,287 patients showed that severe stroke patients—usually with clots involving the largest blood vessels in the brain—who received both the clot-snatching procedure and the medicine did significantly better than those who got medicine alone.

This new analysis uses the same data to show that the longer patients with major strokes wait for a thrombectomy, the worse their outcomes. Among patients whose brain’s bloodflow was restored three hours after symptoms started, nearly two-thirds were fully independent three months later, as compared to only 46 percent of patients who waited eight hours. Thrombectomy combined with the clot-busting medicine was no better than medicine alone if the procedure was performed more than about seven hours after stroke symptoms began.

All hospitals can give the medicine that dissolves blood clots, called tPA, so emergency medical responders typically take all stroke patients to the nearest hospital. If patients turn out to be candidates for a thrombectomy—and only about 5 percent of stroke patients are—they’re transferred to another medical center.

That’s surprising to stroke experts because patients facing similarly life-threatening issues—such as a major injury or a heart attack—are shuttled directly to the facility best equipped to treat them.

“Even if the team at the initial hospital works quickly, it’s often a two-hour wait to get to the one that does the procedure,” said Dr. Michael Hill, an author of the new study and a neurologist at the University of Calgary. “Two hours is too long.”

Dr. Steven Warach, a neurologist in Austin, Texas, and lead author of an editorial in JAMA accompanying the new study, said in an interview with STAT, “We want to help the most patients, and to do that we need to cut down the time it takes to get them to the procedure.”

Some states have already gotten to work changing the system that dictates where patients go first.

“The closest center is not necessarily the best for every patient,” said Dr. Mahesh Jayaraman, a Rhode Island interventional neuroradiologist who helped develop a new statewide system to get patients with severe strokes to full-service hospitals.

Identifying patients with the worst strokes in this new system requires training first responders to grade a patient’s symptoms on a five-point scale and allowing them to divert the patient directly to a stroke center, even if it’s not the closest facility.

Mobile stroke units—ambulances equipped with a CT scanner, blood lab, and medications—are another option for identifying patients early who might benefit from the procedure. These units, such as one used by the Cleveland Clinic, rely on telemedicine to enable neurologists, radiologists, and other medical personnel to remotely evaluate the patient.

The JAMA study underscores the responsibility of lawmakers and doctors to ensure that critically ill patients reach the necessary destination as quickly as possible—without requiring medically inclined family members to get involved, Hsia wrote in a commentary published Monday in JAMA Neurology.

“How can we make sure that every patient can receive the same opportunity for care as someone whose family member is a stroke specialist?” Hsia said in an interview.

Like any issue involving hospital revenue, these changes could instigate political battles between institutions. But experts such as Hsia hope that hospitals will put patients first—and they emphasize that it’s a moral imperative to do so.

Allison Bond, MD, is a resident in internal medicine at Massachusetts General Hospital.

Editor's Note (9/27/16): This story by our partner was taken down on September 26 after it was inadvertently posted before the embargo lifted. While the situation was corrected, Scientific American also pulled the story originally posted here at 12:45 P.M. on September 26.

Republished with permission from STAT. This article originally appeared on September 26, 2016