A systematic review on the triggers and clinical features of type 2 myocardial infarction.

Little is known about the correlation between triggering factors, clinical characteristics, diagnosis, and prognosis of patients with type 2 myocardial infarction (T2MI). The triggers and features of T2MI are linked to its diagnosis and prognosis. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed. A structured search of three databases (PubMed, Embase, and Medline) was undertaken to identify peer-reviewed articles related to the triggers and clinical features of T2MI published between January 2012 and August 2018. Seven retrospective cohort studies and seven prospective cohort studies involving 3867 patients with T2MI were included. All selected studies were rated as being of high or acceptable quality. Nine studies revealed that the leading trigger of T2MI was arrhythmia, especially tachyarrhythmia. Six studies revealed that the proportion of single-trigger T2MIs was higher than that of multiple triggers and two studies showed that two-trigger cases formed the majority of multiple trigger cases. All included studies found that a greater prevalence of T2MI in the older population. Thirteen studies revealed that the patients with T2MI often had a previous relevant medical history. The leading trigger of T2MI is arrhythmia, especially tachyarrhythmia, and the majority of cases arise from a single trigger. Two-trigger is the most common form of multiple-trigger T2MI, which often occurs in older patients with cardiovascular risk factors or comorbidities. Non-cardiovascular causes may be the triggering factors and are strongly associated with the diagnosis, treatment, and prognosis of T2MI.