A new multidisciplinary approach is needed to identify late presenters of ST-segment elevation myocardial infarction (STEMI) who could benefit from invasive interventional procedures, researchers on a real-world Korean study have urged.
Their call was based on findings in 5,826 patients of an abrupt decrease in use of interventional procedures between early and late presenters, as well as remarkably worse outcomes for late presenters – those presenting between 12 and 24 hours after symptom onset.
Editorialists argued, however, that the Korean registry “can neither support nor refute the current guidelines for late primary PCI,” because it had no adequately powered comparison and insufficient patient stratification.
The evidence was reported online on Monday and in the April 20 issue of the Journal of the American College of Cardiology, with authors led by Kyung Hoon Cho, MD, PHD, of the Chonnam National University Hospital, South Korea.
Around 10% to 12% of patients with STEMI are believed to present later than 12 hours after symptom onset.
American guidelines recommend primary percutaneous coronary intervention (PCI) for STEMI patients presenting at 12 to 24 hours of symptom onset who show evidence of ongoing ischemia, while European guidelines advocate PCI for unstable patients with signs of ongoing ischemia and suggest routine primary PCI for stable late-presenting STEMI patients.
However, researchers in the current study note that the evidence supporting these recommendations remains “insufficient,” adding that the limit of 12 hours was established because STEMI patients presenting at more than 12 hours after symptom onset did not benefit from fibrinolysis. Real-world data have also been limited, they said, adding that data of this kind could address questions that cannot be sufficiently addressed in randomized controlled trials.
The researchers, therefore, set out to investigate real-world evidence on STEMI late-presenters in the Korea Acute Myocardial Infarction Registry-National Institutes of Health database. Of the 13,707 patients in the database, between 2011 and 2015, 5,826 consecutive patients were diagnosed with STEMI within 48 hours of symptom onset, 624 of whom were late presenters (12 to 48 hours) and 5,202 early (<12 hours).
The late presenters were older (65.5 ± 13.1 years vs. 62.2 ± 12.7 years), less likely to be admitted during off hours (45.8 off-hours admission vs. 60.9% for early presenters), less often obese, and more likely to have a high heart rate.
All-cause mortality was measured at 180 days and 3 years as coprimary outcome measures.
Late presenters had worse outcomes at both endpoints, with 10.7% all-cause mortality vs. 6.8% for early presenters at 180 days, and 16.2% vs. 10.6% at 3 years (p < 0.001 for both).
In particular, there was an abrupt increase in mortality rates between the first two 12-hour intervals in terms of symptom-to-door time. For the group under 12 hours, the 180-day mortality rate was 6.8%, whereas for those between 12 to 25 hours, it was 11.2% (p < 0.05). For 3-year mortality, the same groups had 10.6% and 17.3% rates (p < 0.05).
Presentation at 12 hours or more of symptom onset was not, however, independently associated with increased mortality after STEMI.
Use of invasive interventional procedures “abruptly decreased” from the first 12-hour interval (<12 hours) to the second interval (12 to 24 hours) in terms of symptom-to-door time, with “no primary PCI strategy” in just 4.9% of the earliest group compared to 12.4% of the later responders (p < 0.01). PCI was not performed in just 2.3% of those presenting in less than 12 hours compared to 6.6% of those presenting between 12 to 24 hours (p < 0.01).
“These real-world findings suggest that a multidisciplinary approach is required in identifying late presenters of STEMI who can benefit from invasive interventional procedures until further studies become available,” Cho and team said.
Nevertheless, an accompanying editorial, Harold L. Dauerman, MD, of the University of Vermont, and Borja Ibanez, MD, PhD, from the Spanish National Cardiovascular Research Center, Fundación Jiménez Díaz University Hospital and Centro de Investigación Biomédica en Red, Spain, argued that the registry is not enough to alter views on current guidelines.
“Two key elements are missing: 1) an adequately powered comparison (randomized or propensity matched) of late-presenting STEMI patients undergoing medical therapy versus primary PCI; and 2) stratification of patients by symptoms/instability versus no symptoms/no instability on late arrival with persistent ST-segment elevations,” the editorialists argued.
Still, they conceded that the current study does seem to concur with previous randomized clinical trial data and multiple mechanistic studies that there is a “presumed benefit” for prompt restoration of coronary flow.
Cho KH, Han X, Ahn JH, et al. Long-Term Outcomes of Patients With Late Presentation of ST-Segment Elevation Myocardial Infarction. J Am Coll Cardiol 2021;77:1859–70.
Dauerman HL, Ibanez B. The Edge of Time in Acute Myocardial Infarction. J Am Coll Cardiol 2021;77:1871-4.