ED Protocol for Acute Chest Pain Patients Reduces Cardiac Testing, Doubles Early Discharge

A protocol called the HEART Pathway safely and effectively identifies patients presenting to the emergency department (ED) with acute chest pain who can safely be sent home early, according to single-center study published online March 3, 2015, ahead of print in Circulation: Cardiovascular Quality and Outcomes.

The HEART score, a preexisting decision aid, consists of 5 components (history, ECG, age, risk factors, and troponin) that are measured on a scale of 0-2. Patients with overall scores below 4 are considered low-risk, whereas those with scores of 4 and higher are high-risk. The HEART Pathway adds serial troponin measurements, assessing the biomarker not only at 0 hours but also at 3 hours after presentation.

Researchers led by Simon A. Mahler, MD, MS, of Wake Forest School of Medicine (Winston-Salem, NC), randomized 282 patients presenting with ACS symptoms but without ST-segment elevation at their institution to the HEART Pathway (n = 141) or usual care (n = 141), as defined by American College of Cardiology (ACC) guidelines. Average patient age was 53 years, and 57.4% were female; baseline characteristics were similar between the study arms.

Pathway to Efficiency

Of those stratified to the HEART Pathway, 46.8% were identified as low-risk and the remainder classified as high-risk. Patients in the study arm were less likely to receive objective cardiac testing (primary endpoint; any stress testing modality, coronary CTA, or invasive coronary angiography) within 30 days, were more likely to be discharged early, and had shorter hospital stays than those in the usual care group (table 1).

Repeat cardiac-related ED visits were low and similar between the study and control groups (2.8% vs 4.3%; P = .75), as were cardiac-related nonindex hospitalizations (3.6% vs 2.8%; P > .999). At 30 days, MACE (all-cause mortality, MI, or coronary revascularization) were reported in 17 patients overall, and no patients identified for early discharge experienced MACE in either group.

Nonadherence to HEART Pathway suggestions by providers was noted for 29% and 13% of low- and high-risk patients, respectively. Perfect adherence would have increased the early discharge rate to 46.8% in the study arm.

Outreach, Education Could Improve Outcomes Further

“[T]he HEART Pathway substantively reduces healthcare utilization… among patients with symptoms related to ACS,” Dr. Mahler and colleagues write, and does so “without missing adverse cardiac events or increasing cardiac-related ED visits or nonindex hospitalizations.”

Although previous studies have looked at the HEART score and Pathway, the authors say this is the first randomized trial comparing them with usual care in the “real-world.” But, they caution, the tool should be used “as a decision aid rather than a substitute for clinical judgment.”

Pooling the current results with previous studies now lends “strong evidence to support structured implementation of the HEART Pathway,” the authors observe. “The HEART score has been examined in > 6,000 patients and has demonstrated a high [negative predictive value] for MACE at 6 weeks exceeding 98%. The HEART Pathway… has a higher sensitivity and [negative predictive value] for adverse cardiac events than the HEART score alone.”

In the current study, the Pathway had a sensitivity of 100%, specificity of 49.6%, negative predictive value of 100%, and positive predictive value of 10.7%.

While this protocol has not been directly compared with the ADAPT 2-hour accelerated diagnostic protocol, the researchers write, “recent evidence suggests that the HEART Pathway is likely to increase the early discharge rate relative to ADAPT without increasing missed MACE.”

But implementing new processes takes time, Dr. Mahler and colleagues note. “We suspect that the main driver of outpatient objective testing among low-risk patients was a lack of comfort with risk stratification without objective cardiac testing among primary care physicians,” they write, adding that the study did not formally educate primary care providers on the HEART Pathway. “It is possible that outreach and education could have facilitated a greater decrease in outpatient objective testing among low-risk patients.”

Good for Patients, Good for the System

“This study [validates] a tool that emergency providers and cardiologists can use to justify not testing patients that are found to be low-risk by this assessment,” Dr. Mahler told TCTMD in a telephone interview. “This is going to be good for patients because they don't want to be unnecessarily tested, and it’s in the health system’s best interest because it’s going to save resources.”

He reported that his team is in the midst of an implementation study for the HEART Pathway at their institution—building it into their electronic medical records. “We are doing it in a careful way where we are collecting quality assurance data and making sure that this implementation is working in the way we expect,” Dr. Mahler said. “Other multicenter studies should be performed before we can fully advocate widespread implementation.”

If high-sensitivity troponin tests are approved by the FDA, however, the utility of the HEART Pathway and other alternative protocols will shift, he suggested. “The threat is that we'll decrease the specificity by using high-sensitivity troponins, so that we might actually identify more people as needing testing and being higher-risk. There may need to be modifications of the rules to work better with high-sensitivity troponins so that you can still send low-risk patients home.”

In a telephone interview with TCTMD, Samin K. Sharma, MD, of Mount Sinai Medical Center (New York, NY), said he would advocate the use of this protocol, especially because the simple application of any protocol “always results in positive [outcomes].

“The strength of the Pathway is that [practice] becomes more generalized, so that it is consistent and there is very little room for individuality,” he continued. “Of course, you can always change things, but everyone is thinking the same way.”

The value in this specific protocol is for low-risk patients who might be able to go home within 6 to 10 hours of presentation rather than upwards of 12, Dr. Sharma observed.

Is the HEART Pathway Applicable Everywhere?

Ian C. Gilchrist, MD, of Hershey Medical Center (Hershey, PA), told TCTMD in a telephone interview that ED physicians use pathways to avoid the too-many-chefs-in-the-kitchen dilemma. “Whenever you have a protocol like this where you outline what the key issues are to be aware of and help physicians feel confident in their decisions, you can improve your throughput through the emergency room and hopefully provide more efficient, cost-effective care.”

Unfortunately, he added, a protocol is never 100% successful—and “everyone remembers the one exception.”

Dr. Gilchrist said that the biggest issue with the HEART Pathway in particular is that it might not work well across the country. “The patient population [in the study] is unique to that medical center. What would happen if it was more elderly patients? More ethnically diverse patients? Would you get the same results?” he said. “It's not easy to generalize these protocols.”

Mahler SA, Riley RF, Hiestand BC, et al. The HEART Pathway randomized trial: identifying emergency department patients with acute chest pain for early discharge. Circ Cardiovasc Qual Outcomes. 2015;Epub ahead of print.

Disclosures:

The study was funded by the American Heart Association Clinical Research Program.

Drs. Mahler, Gilchrist, and Sharma report no relevant conflicts of interest.

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