JAMA Feature: Treatment time, more than strategy, important for STEMIs

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When treatment for STEMI patients meets guideline-suggested timeframes, patients fare substantially better, whether that treatment is primary PCI or fibrinolysis, Laura Lambert, PhD, of the Quebec Healthcare Assessment Agency in Montreal, told Cardiovascular Business News.

Lambert and colleagues conducted an evaluation of 80 hospitals throughout the Quebec province in Canada that treated at least 30 patients with a heart attack over a six-month observational period during 2006-2007. The study was published in the June 2 issue of the Journal of the American Medical Association.

Because Lambert said that the Canadian Ministry of Health was concerned about treatment delays and outcomes for STEMI patients, she and her colleagues were mandated by the agency to evaluate STEMI patients who presented at acute care hospitals throughout Quebec.

While Lambert said that a literature review comparing the two treatments—primary PCI and fibrinolysis—was conducted previously, “we wanted to also observe what happened in the real world."

She said what they found was unlike what was found in randomized trials. Previous literature suggests that primary PCI often has better outcomes. “We didn’t find this in the real world,” she said. “We believe this finding is due to the fact that in the real world, primary PCI in the Quebec context, is often done with an in-hospital transfer and is not done within 90 minutes.”

Lambert said that neither primary PCI nor fibinolysis was completed very often within the recommended timeframe.

However, because results showed that outcomes for both treatments were similar, “it is the timeliness of the treatment as opposed to which treatment that was the most important thing in determining patient outcomes.”

During the systemic evaluation, the researchers identified 2,356 patients with STEMI. Of those, 1,440 were treated with primary PCI—34.7 percent arrived directly at a primary PCI center, while 65.3 percent were transferred from a non-PCI center to a PCI center.

Seventeen percent, or 392 STEMI patients, underwent fibrinolysis and 310 were later admitted for cardiac catheterization. They also found that 22 percent of all patients were not treated with either strategy within four hours of arriving at the emergency department.

For each procedure, the mean age of patients was similar—58 years for those receiving fibrinolysis and 60 years for those who underwent primary PCI.

Results showed that 30-day mortality rates were 6.1 percent for the fibrinolysis group and 5.6 percent for the primary PCI group. At one year, these same rates were 7.4 and 8.3 percent, respectively.

The researchers found that the average treatment times for those undergoing primary PCI was 110 minutes—32 percent had a delay within the recommended times of 90 minutes.

More patients who were admitted directly to a PCI center met the 90 minute recommended time; 57 percent with an average treatment time of 83 minutes.

Additionally, for patients who were transferred from a non-PCI center to a PCI center, only 19 percent were treated in less than 90 minutes and median D2B time was 123 minutes.

“We found that for patients who were transferred for primary PCI, the median time of being in that first ER for transfers was around 55 minutes,” she said. “We know to be able to do a primary PCI in 90 minutes that time would have to be reduced.”

For those treated with fibrinolysis, the average delay was 33 minutes and 46 percent reached the international guidelines of receiving treatment within 30 minutes.

"However, it didn’t matter whether you did a fibrinolysis or a primary PCI, if it was done within the recommended guidelines…those patients had better outcomes than those who were not treated within the recommended guidelines,” said Lambert.

“If you had a fibrinolysis done on time, than mortality was lower than if you had a pPCI that was done late and if you had a primary PCI done on time, those patients did better than patients who had a fibrinolysis that was done late,” she said. “It was the timing that was the crucial determinate.”

Lambert said that reducing these treatment times is a “complex process” that calls for an interdisciplinary effort for improvement.

“We found that patients who arrived at the hospital by ambulance tended to be treated more quickly,” said Lambert. If a patient can call an ambulance, treatment times will most likely be faster, she said.

Additionally, Lambert said that new guidelines suggest that an ECG should be performed and interpreted within 10 minutes upon the patient’s arrival into the ER. This could help improve these treatment times, while also helping to identify STEMI patients quicker.

During the study, Lambert et al compared the timeliness of treatment in patients who had an admission ECG performed. The results showed that for primary PCI patient’s delivered directly to PCI centers, the numbers increased from 57 to 70 percent. In comparison, the numbers for transfer patients increased from 19 to 25 percent and for fibrinolysis from 46 to 55 percent.

Lambert said only about half of all patients call an ambulance for transportation to the hospital.

Because many regions are now using pre-hospital ECGs, she said it is important for patients to call an ambulance because pre-hospital ECGs have the ability to identify STEMI patients before they hit the hospital. “The first hospital can be advised that a patient is coming in with a STEMI patient and this we know can help improve treatment times as well,” she explained.

“It’s getting that ECG, getting the ECG interpreted, making the decision about which treatment should be done and having that treatment happen as quickly as possible that’s most important,” Lambert concluded.

The study was funded by the Ministry of Health for the province of Quebec.