Clinical Application of Contemporary Definitions of Periprocedural Myocardial Infarction in the BREISGAU PCI Registry

D. Faqe Abdalla (Freiburg)¹, D. Westermann (Freiburg im Breisgau)², D. Hazard (Freiburg)³, K. Kaier (Freiburg)³, T. Keller (Bad Krozingen)⁴, C. M. Valina (Bad Krozingen)⁵, P. Breitbart (Bad Krozingen)⁴, J. Jautz (Bad Krozingen)⁴, P. M. Dinse (Bad Krozingen)⁵, L. Bosch (Bad Krozingen)⁴, J. Rilinger (Freiburg im Breisgau)⁶, A. Asmussen (Freiburg im Breisgau)⁷, M. Welzel (Freiburg im Breisgau)⁷, L. Heger (Freiburg im Breisgau)⁷, A. Maier (Freiburg im Breisgau)⁷, I. Bojti (Freiburg im Breisgau)⁷, J. Kiefer (Bad Krozingen)⁴, P. M. Siegel (Freiburg im Breisgau)⁷, T. Hartikainen (Bad Krozingen)^4
1Universitäts-Herzzentrum Freiburg - Bad Krozingen Klinik für Kardiologie und Angiologie Freiburg, Deutschland; ²Universitäts-Herzzentrum Freiburg - Bad Krozingen Innere Medizin III, Kardiologie und Angiologie Freiburg im Breisgau, Deutschland; ³Universitätsklinikum Freiburg Institut für Medizinische Biometrie und Statistik (IMBI) Freiburg, Deutschland; ⁴Universitäts-Herzzentrum Freiburg - Bad Krozingen Klinik für Kardiologie und Angiologie Bad Krozingen, Deutschland; ⁵Universitäts-Herzzentrum Freiburg / Bad Krozingen Klinik für Kardiologie und Angiologie II Bad Krozingen, Deutschland; ⁶Praxis für Herzgesundheit Freiburg Freiburg im Breisgau, Deutschland; ⁷Universitäts-Herzzentrum Freiburg - Bad Krozingen Klinik für Kardiologie und Angiologie Freiburg im Breisgau, Deutschland

Background
Periprocedural myocardial infarction (PMI) after percutaneous coronary intervention (PCI) is clinically relevant, but its reported incidence and prognostic significance depend on the diagnostic framework applied. Contemporary criteria proposed by the Fourth Universal Definition of Myocardial Infarction (4th UDMI), the Society for Cardiovascular Angiography and Interventions (SCAI), and the Academic Research Consortium-2 (ARC-2) differ in biomarker thresholds and requirements for ancillary ischaemic evidence.

Objective
To compare the incidence and prognostic value of PMI according to 4th UDMI, SCAI and ARC-2 definitions in a large real-world PCI cohort using high-sensitivity cardiac troponin T (hs-cTnT).

Methods
Patients enrolled in the BREISGAU PCI registry between 2010 and 2022 were used for this retrospective analysis. Patients were eligible if baseline hs-cTnT was normal (<99th percentile upper reference limit (URL)) or elevated (≥99th percentile URL) but stable (≤20% delta between two measurements) and when serial post-PCI hs-cTnT sampling was available. Patients with falling and rising pre-PCI hs-cTnT (>20% delta) were excluded. Post-procedural ischaemic evidence was adjudicated using symptoms, ECG, imaging and angiographic findings. PMI was classified according to 4th UDMI Type 4a MI, SCAI and ARC-2 criteria and patients without a significant post-PCI troponin rise (≤2x 99th percentile URL) were used as controls. The primary endpoint was a composite of all-cause mortality or myocardial infarction at 1 year. Outcomes were estimated with Cox models with adjustment for age, sex, eGFR and diabetes. 

Preliminary Results
Among 38’708 PCI procedures between 2010 and 2022, 17’205 met eligibility criteria for PMI classification. The median age of included patients was 67 years (interquartile range (IQR) 59-75) and 75.6% were male.  Application of the different troponin thresholds from each PMI definition resulted in 4762 (27.7%), 823 (4.8%) and 340 (2%) of patients having significant troponin rises according to UDMI, ARC-2 and SCAI, respectively. The adjusted hazard ratios regarding the primary endpoint were 2.53 (95% confidence interval (CI) 2.05-3.13), 2.97 (95% CI 2.37-3.73) and 4.63 (95% CI 3.55-6.03), respectively. Lower troponin thresholds without signs of ischaemia were not significantly associated with an impaired outcome in adjusted analyses. Patients with diagnosis of a PMI had a more complex PCI profile including more frequent three-vessel disease and longer total stent length. 

Conclusion
In this large PCI registry, all contemporary PMI definitions identified clinically relevant phenotypes for 1-year adverse outcomes with progressively smaller but higher-risk groups for UDMI, ARC-2 and SCAI definitions, respectively.