In-Hospital STEMI Patients Face Reperfusion Delays and Worse Outcomes

Patients who have a ST-segment-elevation myocardial infarction while hospitalized for other conditions experience delays in reperfusion when compared with those who have a STEMI while outside the hospital, new research shows.

The time from diagnostic ECG to device was 12 minutes longer in patients who had an in-hospital STEMI versus those who had an event prior to admission, report Jennifer Rymer, MD (Duke Clinical Research Institute, Durham, NC), and colleagues report in Circulation: Cardiovascular Interventions.

The results, published on February 3, 2025, suggest there is an opportunity to improve care for in-hospital STEMI patients by developing an algorithm that teams could tap into when the situation arises, said Rymer.

“Unfortunately, what happens a lot is that the patient will get an EKG if they’re having chest pain on the floor, but there’s no formalized [plan] where somebody takes a look at that immediately,” Rymer told TCTMD. “There has to be a protocol in place where if you’re concerned enough about chest pain or new symptoms, you have a consultation service you can call immediately to look at it.”

Clinical outcomes, including death, major bleeding, need for transfusion, recurrent MI, and stroke were also significantly more common in those with STEMI hospitalized for other indications.

“They had worse in-hospital outcomes, but I don’t think that’s just from the delayed time,” said Rymer. “For people who have STEMI in the hospital, they may have undergone some big surgery or had some sort of physiologic stress that may have resulted in plaque rupture and STEMI. Maybe they’re concurrently septic or have gastrointestinal bleeding. All of these things can complicate the picture versus just a patient that’s having one issue where they come in and that’s really what you’re focused on.”

Timothy Henry, MD (The Christ Hospital, Cincinnati, OH), who has investigated treatment delays and clinical outcomes among in-hospital STEMI patients, said that while there are legitimate reasons for slower reperfusion times, particularly because these are complicated, high-risk cases, many of these MIs are overlooked.

“A lot of the problem is that they’re just missed,” he told TCTMD. “People [are] doing EKGs and not even looking at it until the next morning. I would say this is a well-known problem and this study confirms that it is still a problem. The way to solve it is that every hospital should have a standardized protocol for how they deal with STEMI in hospital.”

No Formalized Protocols

In the US and around the world, there are structured protocols in place for when patients present to hospital with STEMI. The Door-to-Balloon (D2B) Alliance was started 20 years ago with the goal of getting most STEMI patients treated within 90 minutes of hospital arrival. As a result, hospitals now have established systems of care to triage and treat out-of-hospital events.

“If a person comes into our ER or they call 911 with chest pain, they’re getting a 12-lead strip or an EKG immediately,” said Rymer. “It’s part of hospital metrics to do that, but that’s not the case on the floor.”

In-hospital STEMI occurs much less frequently, but there are limited structured protocols in place for minimizing delays to reperfusion. Some hospitals have recently instituted quality-improvement efforts to reduce reperfusion delays for STEMIs that occur after hospital admission. For example, centers designated by the American College of Cardiology as a Chest Pain Accredited Hospital are required to have an inpatient chest pain response protocol.

The study population included 112,590 patients from 670 hospitals enrolled in the National Cardiovascular Data Registry (NCDR) Chest Pain-MI Registry between 2019 and 2022. Of these, 3.8% had an in-hospital STEMI (excluding those in the emergency department) and the remainder had an event outside the hospital (including in the ER). Those with in-hospital STEMI were significantly older (median 67 vs 63 years) and were more likely to be women. They were also more likely to have diabetes and a history of heart failure.

The median time from ECG to device activation was 69 minutes for those with STEMI outside the hospital versus 81 minutes for those with an in-hospital STEMI (P < 0.001). The time from arrival at the cath lab to device was also significantly longer with in-hospital cases (median 28 vs 23 minutes; P < 0.001). Other metrics, including time from diagnostic ECG to activating the cath lab and cath lab arrival, were significantly longer with in-hospital STEMI cases.

In-hospital mortality was 25.9% for those with in-hospital STEMI versus 5.6% for those with preadmission events. The rate of major bleeding was more than threefold higher, and the transfusion rate fourfold higher, in those with an in-hospital STEMI. Recurrent MI occurred in 11.8% and 0.9% of those with in-hospital and preadmission STEMIs, respectively.  

In centers designated as a Chest Pain Accredited Hospital, the median time from diagnostic ECG to device was shorter than in hospitals without the accreditation (82 versus 79 minutes; P = 0.01). The risk of in-hospital mortality for those with in-hospital STEMI was similar between accredited and nonaccredited hospitals.   

AI to Reduce Delays

In 2014, Henry, along with lead author Ross Garberich, MS (Minneapolis Heart Institute Foundation, MN), published 2003-2013 data showing significant delays in the ECG-to-balloon times for in-hospital STEMI patients versus those transported via emergency medical services. Like in the NCDR analysis, the in-hospital patients were a high-risk group.

In an editorial accompanying the current paper, Islam Y. Elgendy, MD (University of Kentucky College of Medicine, Lexington), and George Stouffer, MD (University of North Carolina Medical Center, Chapel Hill), point out that while there’s been increased awareness about delays and worse outcomes with in-hospital STEMI, as well as effort to reduce it, little has changed.

Henry emphasized that identifying STEMI quickly and making a critical decision about sending patients to the cath lab are key in reducing the delays. Like Rymer, Henry said introducing artificial intelligence (AI) into the workflow might help identify in-hospital STEMIs faster. They plan to use AI technology (Queen of Hearts; PMcardio) at their center for nighttime ECG requests as this tool will automatically trigger a cardiology consult if STEMI is detected.       

Both Rymer and Henry emphasized that delays can result from uncertainty about whether a patient can undergo PCI. “It can be a lot of things where you have to talk to the primary team [about] the reason they’re in [the hospital] to understand if [PCI] is appropriate,” said Rymer. “I would still say that most patients benefit from going to the cath lab or getting a stent, but it’s clearly different because of complexity of the patients,” added Henry.