A day after I posted about the benefits of reducing door-to-balloon times to improve mortality, Door-to-Balloon Time and Mortality the New England Medical Journal released a major new observational study that showed that despite a significant reduction in door to balloon time in recent years, there has not been a corresponding decline in 30 Ėday in-hospital mortality.
It is a provacative article and I look forward to the medical community discussion about the findings.
Here is my initial reaction:
In-hospital mortality is not the best measure of effectiveness of door-to-balloon time. Very few STEMI patients actually die in the hospital. 4.7% in this study. Most of the ones who die are very sick (patients in cardiogenic shock etc, some post ROSC) when they come in. Most STEMI patients, particularly those who come in shortly after presentation, do quite well and are out of the hospital within 2 or 3 days. Many leave with no loss of heart function at all! Perhaps a better measure of the effectiveness of door-to-balloon time would be heart function and post MI quality of life.
The authors suggest, and I agree, that we need to look less at door-to-balloon time and more at symptom onset-to-balloon time.
Here again is an article I mentioned in my previous post, Association of onset to balloon and door to balloon time with long term clinical outcome in patients with ST elevation acute myocardial infarction having primary percutaneous coronary intervention: observational study, which concluded:
“Short onset to balloon time was associated with better 3 year clinical outcome in patients with STEMI having primary percutaneous coronary intervention, whereas the benefit of short door to balloon time was limited to patients who presented early.”
The NEMJ article suggests that hospitals have gotten their in-house systems down so well that perhaps, they are saving everyone that can be saved and there is no more room for improvement.
An accompanying editorial to yesterday’s New England Medical Journal article, Time to treatment in patients with STEMI suggests that:
“Itís unlikely that reducing in-hospital delays by another few minutes will affect clinical outcomes, given the small portion of total ischemic time those minutes would represent and the success thatís been achieved in the system of in-hospital STEMI care. The primary opportunity for reducing total ischemic time and time to treatment, and for improving outcomes, now lies in the prehospital STEMI system of care.”
The time period for this study was 2005 to 2009, before most EMS systems started transmitting ECGs, using STEMI alerts, and field activations.