Rates of false activation of a cardiac catheterization laboratory for primary PCI increased from 15 percent in 2007 to 40 percent in 2011 at one facility, an analysis published in the August issue of the American Journal of Managed Care found.

In 2006, the American College of Cardiology initiated a drive to reduce door-to-balloon (D2B) times for primary PCI to 90 minutes or less, based on evidence that showed mortality benefits for STEMI patients who received timely reperfusion. Strategies to meet that window included activation of the cardiac cath lab by paramedics or emergency department (ED) physicians prior to consultation with a cardiologist. But while the practice may shorten D2B times, it also may prove premature if the patient is later deemed not in need of primary PCI.

To assess trends in D2B times and false activation rates, Geoffrey D. Barnes, MD, of the University of Michigan Health System in Ann Arbor, and colleagues reviewed data on suspected STEMI cases from their facility’s ED from 2007 to 2011. They defined false activation as a case in which the cardiac cath lab was activated by the emergency medical service or the ED for STEMI or left bundle branch block and was ruled by a cardiologist as not requiring emergent cardiac catheterization.    

They found that the cath lab was activated 717 times over five years. The number of activations increased from 96 in 2007 to 190 in 2011, and the median D2B time for patients who received primary PCI dropped from 67 minutes in 2007 to 55 minutes in 2011.  

The overall rate of false activations was 28 percent. The rate for false activations grew steadily over the five years, from 15 percent in 2007 to 40 percent in 2011.

“While we cannot directly link the increase in false [cardiac cath lab] activations with the initiation of national D2B efforts, their concurrence is notable,” Barnes and colleagues wrote.    

They cited other studies that have shown recent false activation rates and suggested it is likely common in the U.S.

The researchers warned of down sides from false activation, such as strains on staff and resources and lost productivity. In response to the trend, their institution put together a multidisciplinary team to identify and initiate ways to nip at false activations without lowering quality.

“Changes include making urgent cardiology consultation available in the ED for cases without a clear-cut STEMI presentation,” as well as incorporating strategies designed by other programs.