There’s something about reducing D2B Times
Hitchhiker: You heard of this thing, the 8-Minute Abs? Ted: Yeah, sure, 8-Minute Abs. Yeah, the exercise video. Hitchhiker: Yeah, this is going to blow that right out of the water. Listen to this: 7… Minute… Abs.
–There’s Something About Mary
Door-to-balloon time is an ever important quality metric among hospital emergency departments. Numerous papers have shown the morbidity and mortality benefit of transferring a patient with an ECG documented STEMI to the cath lab in less than 90 minutes. But many people have questioned whether the emergency room door is the best place to get that initial ECG and whether it might be more advantageous to start the process before the patient even reaches the hospital. Enter the out-of-hospital ECG and the paper by Ong et. al. titled (and this is a long one): Nationwide Improvement of Door-to-Balloon Times in Patients With Acute ST-Segment Elevation Myocardial Infarction Requiring Primary Percutaneous Coronary Intervention With Out-of-Hospital 12-Lead ECG Recording and Transmission.
In their research, Ong and his team try to demonstrate that a out-of-hospital ECG improves the time it takes to transfer a patient to the cath lab where a potentially life saving intervention could be performed. And for the most part, that’s exactly what they showed. Using the out-of-hospital ECG, the median door to balloon time was reduced from 75 to 51 minutes. Certainly not, insignificant. But an unfortunate part of the paper’s work is that it was not powered to assess mortality, so we have no way of knowing if this improved door to balloon time actually improved outcomes. Not only that, but of all the literature looking at D2B times, 90-minutes appears to be where everything stops, so we have no way of inferring, either, if the reduction seen in this paper was significant.
Another interesting statistic noted in the paper, was the relative lack of false activations. Of the 180 ECG transmitted for potential cath lab evaluation, 156 met criteria while 24 did not. Surprisingly, of those 24, none led to the cardiology team being prematurely notified. This is impressive and may not be entirely reproducible depending on your clinical environment. In some instances–especially where final ED sign-off is not required on out-of-hospital ECGs–the cath lab may be activated in cases where it is not truly justified–leading to unnecessary hospital expenditures.
The paper points out that there are other limitations to the conclusions as well. For example, the study did not control for other quality improvement methods, some of the hospitals had already put in place. This may have led to a decrease in D2B times regardless of when the ECG was taken.
Although, the study isn’t perfect (name a study that is), the goal it sets out to achieve is an important one. Certainly, any endeavor that shows to improve a hospital’s ability to meet the magical 90-minute D2B time, is likely worthwhile. However, like any intervention, we need to continue to measure the cost benefit ratio. We would never prescribe a medication above a certain dose if the desired effect would be minimal compared to the possible complication. Similarly, I think we should take the same type of caution with steps to further reduce D2B times below 90 minutes until the data demonstrates improved outcomes.
Ted: That’s right. That’s – that’s good. That’s good. Unless, of course, somebody comes up with 6-Minute Abs. Then you’re in trouble, huh? Hitchhiker: No! No, no, not 6! I said 7. Nobody’s comin’ up with 6. Who works out in 6 minutes? You won’t even get your heart goin, not even a mouse on a wheel. —There’s Something About Mary