WhatsApp Enables Swift Diagnosis of STEMI and Cath Lab Activation

In an effort to improve STEMI outcomes in their region, Argentine researchers have determined that using an instant messaging app to diagnose STEMI in the ambulance, and therefore have the patient bypass the emergency department, results in faster treatment and lower in-hospital mortality.

Huge strides in improvements in door-to-balloon time for STEMI—and hence outcomes—have been made in various parts of the world through STEMI care networks, which often involve coordinated emergency medical services (EMS) cath lab activation and emergency room bypass. But in places like Argentina, where more than 42,000 MIs occur every year, mortality rates have fallen over time yet they still hover around 8-12%, noticeably higher than what has been achieved in the United States and in Europe of late, study co-author Gerardo Nau, MD (Cardiovascular Institute of Buenos Aires, Sanatorio Anchorena, Argentina), told TCTMD.

Co-author Nicolás Lalor, MD (Cardiovascular Institute of Buenos Aires), presented results from Nau et al’s study at the Argentine Congress of Cardiology on October 19, 2017.

Investigators looked prospectively at almost 900 STEMI patients who were treated at two institutions between 2012 and 2016. Patients either arranged their own transport to the hospital (n = 211), were delivered via ambulance to the emergency department (n = 325), or were delivered directly to the cath lab via ambulance (n = 360). Those in the last group were confirmed to have STEMI while still in the ambulance after EMS sent their electrocardiogram to the attending cardiologist at the hospital via the free messaging service WhatsApp.

Symptom-onset-to-treatment time was significantly lower for those in the WhatsApp group compared with the other patients 150 vs 200 minutes (P < 0.001). The overall STEMI mortality rate for the study was 2.23%, and patients who bypassed the emergency department had lower mortality rates than all others (0.83% vs 3.17%; P < 0.001). These patients also had shorter hospital stays (mean 4.88 vs 5.58 days; P < 0.001) and better LVEF at discharge (51% vs 48%; P < 0.03).

“We found that notifying the cath lab in advance using WhatsApp and transferring patients directly from the ambulance, bypassing the emergency department, led to quicker treatment and better outcomes for patients with STEMI. Advanced notification enables hospital staff to prepare the cath lab, and the doctor is ready to start primary angioplasty when the patient arrives,” Lalor said in a press release. “Using WhatsApp on a smartphone is a cheap and easy way for [the] ambulance and hospital doctors to communicate, and we will be rolling this procedure out to other hospitals in Argentina.”

The main challenge facing institutions in Buenos Aires in particular, Nau said, is that there are several ambulance companies, meaning more moving parts in setting up a single protocol for STEMI cath lab activation.

Preactivation Is Key

Commenting on the study, Christopher Granger, MD (Duke University, Durham, NC), told TCTMD that while his perception of WhatsApp is that it’s more widely used outside of the United States, similar smartphone apps and even simple texting is used to send electrocardiograms between ambulances and cardiologists in the United States. “I think using cell phones makes a lot of sense, especially in regions where there may be constrained resources,” he said, adding that WhatsApp is a “very efficient” means of communicating since all one needs is internet access.

Granger said he has no qualms about the privacy aspect of sending this information via WhatsApp, which is not HIPAA-compliant. Americans “of course have to be more concerned about privacy, but frankly I’m less concerned about privacy [in this case]. If it will make the difference between somebody surviving or dying, then I think privacy becomes a little bit less of a super-sensitive issue,” he observed.

Of note, though, Nau confirmed that no identifying information is sent via WhatsApp, only the ECG images.

“The key is to have some mechanism whereby ambulances can diagnose STEMI at the first medical contact, and then that information can be used to both activate the cath lab and get the patient to the most suitable hospital and then shorten the reperfusion time,” Granger said. “That’s essentially what was done here.”

There are limitations with this type of analysis, however, he commented. Importantly, the patients not taken directly to the cath lab in this study were “not a perfect control group,” Granger said. “If a patient is really sick or has had a cardiac arrest, then we tend to stop in the emergency department. So that's a confounding factor. It’s hard for me to tell how well they tried to control for those things.”

Still, this does not “decrease my enthusiasm for this type of work,” he observed. “What they have shown is that in a large number of patients, . . . they were able to do this [and] it seemed to work.”

Granger’s advice for these researchers and others conducting similar projects would be to “keep doing what they’re doing, that is to collect data and implement tools and systems to provide more integrated and rapid care for STEMI.” The app is not the crucial component, but rather the early diagnosis and preactivation, he added.