Few Clinical Studies Address Optimal Ways to Treat Cardiac Arrest
November 16th, 2016
ANN ARBOR, MI – A new study points out that cardiac arrest kills 10 times more victims than breast cancer, but relatively few studies address how to improve survival related to the heart condition.
In fact, according to the report published online by Circulation: Cardiovascular Quality and Outcomes, only one in 10 patients survive it, adding that rates are even low when cardiac arrest occurs in the hospital.
Yet, looking at published trials over two decades ending in 2014, the University of Michigan-led team found that only 92 gold-standard clinical trials have been done on the immediate treatment of non-traumatic cardiac arrest. Just 64,000 patients were included in those randomized, controlled trials (RCTs), and fewer than five studies a year published their results on cardiac arrest, according to the review.
Furthermore, many of those studies were focused on ways to improve the system of caring for cardiac arrest, not direct treatment, the authors added.
"What we found in a nutshell was a striking paucity of randomized clinical trials relative to the burden of cardiac arrest in this country," explained Shashank S. Sinha, MD, MSc, a cardiovascular medicine fellow at the U-M Medical School. "We estimate that only 2.5 such trials have been done for every 10,000 out-of-hospital cardiac arrests, and the number is even lower for in-hospital cardiac arrests."
He emphasized that 25 to 86 times more clinical trials are published for heart failure, heart attack, and stroke than for cardiac arrest.
Overall, the researchers found that 92 RCTs were published during the study period — 88.0% involving out-of-hospital cardiac arrest, and just 4.3% involving in-hospital cardiac arrest, while 7.6% involved both.
Relatively few, 19.6%, were performed in the United States, with another 6.5% involving international data that included the United States.
In terms of what issues were examined overall:
- 41.3% evaluated drug therapy;
- 42.4% evaluated device therapy; and
- 16.3% evaluated protocol improvements.
While most, 80.4%, looked at interventions during the cardiac arrest, just 16.3% looked at post-cardiac arrest treatment, and 3.3% studied both.
“Important gaps in RCTs of cardiac arrest treatments exist, especially those examining in-hospital cardiac arrest, protocol improvement, post-cardiac arrest care, and long-term or quality-of-life outcomes,” researchers conclude.
"Cardiac arrests remain a significant public health need worldwide, and the limited progress in improving poor survival in the U.S. and globally may be due to inadequate research," Sinha added. "We need to move the needle."