Cardiac Arrest Survivors Derive Long-term Survival Benefit from Cooling, PCI

 

Download this article's Factoid in PDF (& PPT for Gold Subscribers)

For patients who make it to the hospital alive after cardiac arrest, treatment with percutaneous coronary intervention (PCI) or therapeutic hypothermia—and preferably both—can substantially increase long-term survival, according to research published in the July 3, 2012, issue of the Journal of the American College of Cardiology.

Investigators led by Florence Dumas, MD, MPH, of the Emergency Medical Services (EMS) Division of Public Health for Seattle and King County (Seattle, WA), retrospectively evaluated the outcomes of patients who suffered nontraumatic out-of-hospital cardiac arrest, were resuscitated by EMS personnel, and discharged alive from the hospital between January 2001 and December 2009.

Of 5,958 patients who received EMS-attempted resuscitation during this period, only 16.8% were discharged alive from hospital. Among the 1,001 survivors, 38.4% underwent PCI, while 25.6% of the 941 patients who were comatose at hospital admission received therapeutic hypothermia. In addition, 9.1% of patients received both therapies.

PCI and therapeutic hypothermia each were associated with improved 1- and 5-year survival (tables 1 and 2).

Table 1. Long-term Survival^a

 

^a Log-rank P < 0.001.

Table 2. Long-term Survival^a

 

^a Log-rank P < 0.001.

In addition, patients who received both treatments experienced the highest survival rates (100% at 1 year, 88.6% at 5 years), while those who received neither had the lowest rates (71.8% at 1 year, 49.2% at 5 years).

In multivariate analysis that adjusted for potential confounders, PCI was associated with a 54% reduced risk of death (HR 0.46; 95% CI 0.34-0.61; P < 0.001) and therapeutic hypothermia a 30% reduced risk (HR 0.70; 95% CI 0.50-0.97; P = 0.04). Moreover, benefits of the intervention remained similar irrespective of calendar year and among subsets of patients stratified by the presence of STEMI or initial rhythm.

“We have shown in a large cohort of survivors that the use of PCI and therapeutic cooling could provide extended [survival benefits] over time after hospital discharge,” Dr. Dumas told TCTMD in an e-mail communication. While PCI has previously been shown to benefit STEMI patients, this study demonstrated that this also extends to non-STEMI patients, he said. “Patients who received both interventions had the best outcome, suggesting the potential synergistic effect over time when combining these strategies.”

Growing Practice Patterns Confirmed

The results come as no great surprise and in fact reflect how out-of-hospital cardiac arrest patients are increasingly being treated at least in large metropolitan areas, Dr. Dumas noted. But this paradigm remains a work in progress, gaining momentum as a working definition of post-cardiac arrest syndrome has been developed and evidence for the clinical benefits of added treatment has grown.

“Because of both technical and logistical issues related to managing these particular patients in the field, the performance of hospital interventions is often challenging for the care team,” said Dr. Dumas. “In addition, although international guidelines recommend PCI for STEMI patients and therapeutic hypothermia for ventricular fibrillation patients, they remain narrow for other settings. Our results suggest that these hospital procedures could benefit a larger population.”

In a telephone interview with TCTMD, Jeffrey W. Moses, MD, of Columbia University Medical Center/Cornell Weill Medical Center (New York, NY), said the results are “encouraging in that they indicate that the interventions we’re prescribing—cooling and PCI—are working.” The study is particularly valuable because of its large cohort and long-term outcomes, he added.

Systems, Training Needed

Even though cooling of cardiac arrest patients who experience a spontaneous return of circulation should be “de rigueur,” Dr. Moses said, lack of expertise and technology in certain centers are barriers to more widespread adoption, which would require the development of systems and training to make the treatment more available to the right patients. He reported that the technology for cooling used at the Columbia cath lab can be administered by a nurse and is very compatible with catheterization.

“It would be prudent to link STEMI centers with cooling centers,” Dr. Moses observed, noting that the New York City Fire Department brings arrest survivors who achieve spontaneous return of circulation to centers that have cooling. “That’s the kind of organization you need to have.”

William O’Neill, MD, of the University of Miami Miller School of Medicine (Miami, FL), agreed. He told TCTMD in a telephone interview that “in many communities in the [United States] where there are organized ambulance programs, we are routinely cooling out-of-hospital cardiac arrest survivors. So the field is going in that direction. I think [this research] will spur things to move along because the combination of angioplasty and cooling really seems to result in a very high rate of survival.

Dr. O’Neill added that it is nearly impossible to do a randomized trial in this population, so the results are “as close as we’re going to get to anything definitive in the area.”

Identifying the Best Candidates

Which patients benefit most from this approach remains to be determined, Dr. Dumas said.

To that end, Dr. Moses suggested analyzing all patients—not just survivors—over 30 days to better understand the clinical factors associated with mortality. “The cooling is pretty clear,” he said. “According to the guidelines, anyone who has arrest and spontaneous return of circulation can benefit from cooling. Who you take to the cath lab is still pretty up in the air, though. If you don’t have an active STEMI, should you go anyway? We need to get a better understanding of what to do with non-STEMI patients.”

 

 

---

 

Source:Dumas F, White L, Stubbs BA, et al. Long-term prognosis following resuscitation from out of hospital cardiac arrest: Role of percutaneous coronary intervention and therapeutic hypothermia. J Am Coll Cardiol. 2012;60:21-27.

 

 

 

 

Related Stories:

• Cooling Out-of-Hospital Cardiac Arrest Patients Improves Outcomes
• Therapeutic Cooling Improves Prognosis for STEMI Patients After Cardiac Arrest

Click here for a listing of companies that provide support to the Cardiovascular Research Foundation, owner and operator of TCTMD.