Pixel-wise statistical analysis of myocardial injury in STEMI patients with delayed enhancement MRI

Nicolas Duchateau; Magalie Viallon; Lorena Petrusca; Patrick Clarysse; Nathan Mewton; Loic Belle; Pierre Croisille

doi:10.3389/fcvm.2023.1136760

Pixel-wise statistical analysis of myocardial injury in STEMI patients with delayed enhancement MRI

Front Cardiovasc Med. 2023 Jun 16:10:1136760. doi: 10.3389/fcvm.2023.1136760. eCollection 2023.

Authors

Nicolas Duchateau^{1

2}, Magalie Viallon^{1

3}, Lorena Petrusca¹, Patrick Clarysse¹, Nathan Mewton⁴, Loic Belle⁵, Pierre Croisille^{1

3}

Affiliations

¹ Univ Lyon, CREATIS, INSA, CNRS UMR 5220, INSERM U1294, Université Lyon 1, UJM Saint-Etienne, Lyon, France.
² Institut Universitaire de France (IUF), Paris, France.
³ Department of Radiology, Hôpital Nord, University Hospital of Saint-Étienne, Saint-Étienne, France.
⁴ Department of Cardiology, Clinical Investigation Center, INSERM 1407, Hôpital Cardiovasculaire Louis Pradel, Lyon, France.
⁵ Department of Cardiology, Centre Hospitalier Annecy-Genevois, Annecy, France.

Abstract

Objectives: Myocardial injury assessment from delayed enhancement magnetic resonance images is routinely limited to global descriptors such as size and transmurality. Statistical tools from computational anatomy can drastically improve this characterization, and refine the assessment of therapeutic procedures aiming at infarct size reduction. Based on these techniques, we propose a new characterization of myocardial injury up to the pixel resolution. We demonstrate it on the imaging data from the Minimalist Immediate Mechanical Intervention randomized clinical trial (MIMI: NCT01360242), which aimed at comparing immediate and delayed stenting in acute ST-Elevation Myocardial Infarction (STEMI) patients.

Methods: We analyzed 123 patients from the MIMI trial (62 ± 12 years, 98 male, 65 immediate 58 delayed stenting). Early and late enhancement images were transported onto a common geometry using techniques inspired by statistical atlases, allowing pixel-wise comparisons across population subgroups. A practical visualization of lesion patterns against specific clinical and therapeutic characteristics was also proposed using state-of-the-art dimensionality reduction.

Results: Infarct patterns were roughly comparable between the two treatments across the whole myocardium. Subtle but significant local differences were observed for the LCX and RCA territories with higher transmurality for delayed stenting at lateral and inferior/inferoseptal locations, respectively (15% and 23% of myocardial locations with a p-value <0.05, mainly in these regions). In contrast, global measurements were comparable for all territories (no statistically significant differences for all-except-one measurements before standardization / for all after standardization), although immediate stenting resulted in more subjects without reperfusion injury.

Conclusion: Our approach substantially empowers the analysis of lesion patterns with standardized comparisons up to the pixel resolution, and may reveal subtle differences not accessible with global observations. On the MIMI trial data as illustrative case, it confirmed its general conclusions regarding the lack of benefit of delayed stenting, but revealed subgroups differences thanks to the standardized and finer analysis scale.

Keywords: acute myocadial infarction; delayed enhancement MRI; infarct size; microvascular obstruction; statistical atlas.

Grants and funding

The authors acknowledge the partial support from the LABEX PRIMES of Université de Lyon (ANR−11-LABX−0063), the French ANR (MIC-MAC project, ANR−19-CE45–0005), the Fédération Francaise de Cardiologie (MI-MIX project, Allocation René Foudon), and the Institut Universitaire de France. These funding sources had no involvement in study design; in the collection, analysis and interpretation of data; in the writing of the report; nor in the decision to submit the article for publication.