Cardiovascular magnetic resonance characteristics and clinical outcomes of patients with ST-elevation myocardial infarction and no standard modifiable risk factors-A DANAMI-3 substudy

Abstract

Introduction: A higher 30-day mortality has been observed in patients with first-presentation ST elevation myocardial infarction (STEMI) who have no standard modifiable cardiovascular risk factors (SMuRFs), i. e., diabetes, hypertension, hyperlipidemia, and current smoker. In this study, we evaluate the clinical outcomes and CMR imaging characteristics of patients with and without SMuRFs who presented with first-presentation STEMI.

Methods: Patients from the Third DANish Study of Acute Treatment of Patients With ST-Segment Elevation Myocardial Infarction (DANAMI-3) with first-presentation STEMI were classified into those with no SMuRFs vs. those with at least one SMuRF.

Results: We identified 2,046 patients; 283 (14%) SMuRFless and 1,763 (86%) had >0 SMuRF. SMuRFless patients were older (66 vs. 61 years, p < 0.001) with more males (84 vs. 74%, p < 0.001), more likely to have left anterior descending artery (LAD) as the culprit artery (50 vs. 42%, p = 0.009), and poor pre-PCI (percutaneous coronary intervention) TIMI (thrombolysis in myocardial infarction) flow ≤1 (78 vs. 64%; p < 0.001). There was no difference in all-cause mortality, non-fatal reinfarction, or hospitalization for heart failure at 30 days or at long-term follow-up. CMR imaging was performed on 726 patients. SMuRFless patients had larger acute infarct size (17 vs. 13%, p = 0.04) and a smaller myocardial salvage index (42 vs. 50%, p = 0.02). These differences were attenuated when the higher LAD predominance and/or TIMI 0-1 flow were included in the model.

Conclusion: Despite no difference in 30-day mortality, SMuRFless patients had a larger infarct size and a smaller myocardial salvage index following first-presentation STEMI. This association was mediated by a larger proportion of LAD culprits and poor TIMI flow pre-PCI.

Clinical trial registration: clinicaltrials.gov, unique identifier: NCT01435408 (DANAMI 3-iPOST and DANAMI 3-DEFER) and NCT01960933 (DANAMI 3-PRIMULTI).

Keywords: ST elevation myocardial infarction; atherosclerosis; cardiovascular magnetic resonance; cardiovascular risk factors; coronary artery disease.

Conflict of interest statement

Author LK reports Speakers honorarium from Novo, Novartis, AstraZeneca and Bohringer, unrelated to this manuscript. TE reports personal fees from Abbott, Bayer, and AstraZeneca outside the submitted work. GF reports personal consulting fees from CSL and grants from Abbott Diagnostic outside the submitted work. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Copyright © 2022 Mazhar, Ekström, Kozor, Grieve, Nepper-Christensen, Ahtarovski, Kelbæk, Høfsten, Køber, Vejlstrup, Vernon, Engstrøm, Lønborg and Figtree.

Figures

Figure 1

Flowchart.

Figure 2

Relationship between infarct size and area at risk between SMuRFless and SMuRF >0 individuals. Representative CMR images of mid-ventricular LGE and T2-weighed STIR slices at baseline. SMuRFless patient: (A) LGE contrast enhanced slice showing area with hyperintense signal in the inferior-septal region indicating infarction. (B) T2-weighed STIR slice showing hyperintense signal in the same region indicating the AAR (oedema) and thus acute infarction. Same images are shown for a patient with SMuRF >0: (C) LGE image of the infarction with corresponding (D) T2-weighed STIR image of the AAR. Scatterplot (right panel) of the acute infarct size and AAR in SMuRFless vs. SMuRF patients showing a larger infarct size in SMuRFless patients after adjustment for AAR.

Figure 3

Kaplan-Meier curves. (A) Shows the Kaplan–Meier curve for the long-term composite endpoint of all-cause mortality and hospitalization for heart failure. (B) Shows the Kaplan–Meier curve for the composite endpoint of all-cause mortality and hospitalization for heart failure at 30 days.