Among patients presenting with non-ST-elevation myocardial infarction (NSTEMI), those who received catheter intervention within 48 hours of symptom onset had a lower risk of mortality than patients who had intervention after 48 hours, according to data from the Korea Acute Myocardial Infarction Registry–National Institutes of Health.
SungA Bae, MD, of the Chonnam National University Hospital and Medical School, Gwangju, and Yongin Severance Hospital, Yonsei University College of Medicine, Gyeonggi-do, both in South Korea, Jung-Joon Cha, MD, of Korea University Anam Hospital, Korea University College of Medicine, Seoul, South Korea, and colleagues reported these findings in a manuscript published Monday online and in the Jan. 9 issue of JACC: Cardiovascular Interventions.
The timing of intervention for patients with NSTEMI, per current guidelines, is dictated by presence of high-risk criteria. In the broad NSTEMI population, however, studies have not shown a clear benefit of an early invasive strategy. Prior studies based timing of intervention on time of randomization rather than symptom onset, which would correspond with initial ischemic time. Bae, Cha and colleagues aimed to investigate the effect of an early invasive strategy in NSTEMI patients based on symptom onset rather than time of presentation.
The authors utilized the Korea Acute Myocardial Infarction Registry–National Institutes of Health, including all NSTEMI and excluding patients with very high risk criteria. The cohort was dichotomized into patients who received intervention within 48 hours vs. 48 hours or later. The primary outcome was 3-year all-cause mortality. The registry enrolled patients from November 2011 to December 2015.
A total of 5,856 patients with NSTEMI were evaluated. Of these, 3,919 patients (66.9%) were classified into the symptom-to-catheter (StC)time <48 hours group. Compared to the later-treatment group, patients in the early invasive group were younger (63.1 ± 12.1 vs. 66.4 ± 12.2 years, p < 0.001) and more likely to be male (73.8% vs. 68.4%, p < 0.001) and have typical chest pain on hospital admission (88.1% vs. 78.0%, p < 0.001).
The all-cause mortality rate was lower in the early invasive group (7.3% vs 13.4%; P < 0.001) . This effect was consistent across all subgroups, including age, gender, chest pain type, ST changes, diabetes, chronic kidney disease, left ventricular dysfunction , Global Registry of Acute Coronary Events (GRACE) score and whether percutaneous coronary intervention was performed). Notably, emergency medical service use (hazard ratio [HR]: 0.31; 95% confidence interval [CI]: 0.19-0.52) showed a lower risk for all-cause mortality than no emergency medical service use (HR: 0.54; 95% CI: 0.46-0.65; P value for interaction = 0.008).
Jean-Philippe Collet, MD, of Groupe Hospitalier Pitié-Salpêtrière (APHP), Paris, and Sripal Bangalore, MD, MHA, of the New York University Grossman School of Medicine, provided the editorial comment.
The editorialists commended Bae, Cha and colleagues for shedding new light on an unresolved issue of timing in NSTEMI. The commenters emphasized that though registry data is subject to confounding, the study’s sensitivity analysis, subgroup analysis and analysis of secondary endpoints were all consistent. Further questions remain as to what leads to delayed intervention – patient factors, systemic factors or both?
The editorialists concluded: “The time delay of 24 hours for an early invasive strategy is confirmed, and considering ischemic time as opposed to admission is a potential game changer.”
Bae S, Cha J-J, Lim S, et al. Early Invasive Strategy Based on the Time of Symptom Onset of Non-ST-Segment Elevation Myocardial Infarction. JACC Cardiovasc Interv 2023;16:64–75.
Collet J-P, Bangalore S. Timing of Invasive Coronary Angiography in NSTEMI. JACC Cardiovasc Interv 2023;16:76–78.
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