In 2019, the international study titled CAUTION Study - 1 (MeChanical complicAtions of acUte myocardial infarcTion: an InternatiOnal multiceNter cohort study), a retrospective multicenter study, was launched and registered on ClinicalTrials.gov (Identifier: NCT03848429). This study highlighted the outcomes of surgical treatment of post-infarction mechanical complications in patients operated between 2000 and 2019. Several scientific publications have resulted from this registry, which involved 27 international centers and recruited about 800 patients. However, retrospective studies are inherently limited by factors such as selection bias and a high number of missing data, affecting data interpretation and consistency of results. Moreover, most registries report only data about surgical patients or, in rare situations, about patients treated percutaneously. To overcome these limitations, a prospective study has been designed to collect more precise and focused data and achieve results that better reflect the current clinical practice, including all the patients diagnosed with post-infarction mechanical complications, independently from the treatment assigned. CAUTION Study - 2 is, therefore, a prospective, multicenter cohort study with the primary aim of analyzing the outcomes of surgical, percutaneous and conservative treatment of post-infarction mechanical complications in the contemporary era.