Prognostic and diagnostic impact of new pathophysiology-based categorization of type 1 and type 2 myocardial infarction: data from the French RICO survey

Abstract Background A new classification of type 1 and 2 myocardial infarction (MI) derived from the fourth universal definition of MI (UDMI) has been recently proposed, based on pathophysiology of coronary artery disease (CAD),. We assessed the impact of this new MI categorization on epidemiology and outcomes. Methods Retrospective study including all consecutive patients hospitalized for an acute MI in a multicenter database (RICO). MI was defined according to current UDMI. Rates and outcomes of T1MI and T2MI were addressed according to the new classification. Results Among the 4573 patients included on our study, 3710 patients (81.1%) were initially diagnosed with T1M1 and 863 (18.9%) with T2MI. After reclassification, 96 T2MI patients were moved into the T1MI category. Out of the remaining 767 patients with T2MI, 567 underwent coronary angiography, and were adjudicated as type 2A MI (68.6%) with obstructive CAD, and type 2B MI (31.4%) without obstructive CAD. When compared with T1MI and T2BMI, T2AMI patients had worse in-hospital outcomes, including heart failure (p<0.001), recurrent infarction (p<0.048) and mechanical complications such as mitral insufficiency (p=0.001). The 3 groups (T1AMI, T2AMI and T2BMI) had similar all-cause and cardiovascular death rates, with a trend for a higher all-cause mortality in T2AMI patients. Kaplan-Meier one-year survival curves showed higher all-cause and cardiovascular causes mortality in T2AMI patients compared to T1MI and T2BMI (p<0.001). In multivariate Cox regression, type of MI was independent predictor of death. Conclusion Our large observational multicenter study shows major disparities in mortality according to type of MI and support the relevance of the new MI classification to improve risk classification. Our findings may will help identifying specific phenotypes and considering personalized diagnostic and management strategies. Funding Acknowledgement Type of funding sources: Public Institution(s). Main funding source(s): Agence Régionale de Santé (ARS) de Bourgogne Franche-ComtéRegional Council of Bourgogne Franche-Comté.