Posted on March 19, 2001 at 12:51 p.m.
BIRMINGHAM, AL — We've all heard the joke about the man who wouldn't stop to ask for directions, but have you heard the one about the man having a heart attack who wouldn't stop to call an ambulance? Well, UAB cardiologist John Canto, M.D., says it's no joke, but a serious issue that could affect lives.
Canto, director of UAB's Chest Pain Center, will present findings at next week's American College of Cardiology meeting in Orlando, Florida, that only half of more than 700,000 patients suffering from a heart attack between 1994 and 1998 were transported to the hospital by an ambulance. Not surprisingly, those who did not use the emergency management system were frequently younger, male and were at lower risk of death on initial presentation. Canto and colleagues also found that the ability to pay did not appear to influence the decision to call 911.
Canto said it is also no surprise that the half who did use the 911 system received significantly faster life-saving therapies. Previous studies have shown significant reductions in mortality with the early use of these life-saving therapies, such as cardiac defibrillation, thrombolytic therapy and primary percutaneous transluminal coronary angioplasty (PTCA).
"When you're dealing with heart attacks, the timing of therapy is vitally important," Canto said. "It's a well-known fact that time is muscle. By using the EMS system, you're more likely to get these therapies faster and more likely to bypass the triage system and go directly to a treatment area. So our key objective in this study was to examine the contemporary usage of the EMS in the United States and determine the factors which may influence its use."
Canto and colleagues examined 772,586 hospital records from the National Registry of Myocardial Infarction 2 database between April 1994 and March 1998. The NRMI 2 is an observational database that includes hospital data on patients admitted with confirmed myocardial infarction, or heart attack, at more than 1,600 hospitals in the United States. Patients who arrived at the hospital in cardiogenic shock, whose symptoms had occurred for more than six hours or who were transferred in to a hospital were excluded from the study.
Comparison results were as follows:
| Transported by ambulance | Self-transport | |
| Number of Patients | 175,517 | 153,365 |
| Percent of Patients | 53.4% | 46.6% |
| Mean age of patients | 68.1 | 63.7 |
| Percent of men | 60.0% | 69.0% |
| Percent using an HMO | 11.2% | 11.8% |
| Percent who suffered from prior heart attack | 27.8% | 24.2% |
| Percent with prior heart failure | 15.1% | 8.2% |
| Time between onset of symptoms and hospital arrival | 90.0 minutes | 102.0 minutes |
| Mean time to first electrocardiogram | 13.7 minutes | 15.0 minutes |
| Mean time between hospital arrival and receipt of thrombolytic therapy | 54.7 minutes | 66.9 minutes |
| Mean Time Between Hospital arrival and receipt of balloon therapy | 141.7 minutes | 173.0 minutes |
"Obviously we're advocating wider use of the EMS here," Canto said. "We suspect that wider use among patients with suspected heart attacks may offer considerable opportunity for improvement in public health." He added that national practice guidelines strongly recommend that patients with symptoms consistent with an acute myocardial infarction call 911.
Canto's study will be presented at the 50th annual Scientific Sessions of the American College of Cardiology in Orlando at 10 a.m. EST March 19.