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

Abstract

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.

Diagnostic features, management and prognosis of type 2 myocardial infarction compared to type 1 myocardial infarction: a systematic review and meta-analysis

“…An important finding is the much higher all-cause in-hospital and 1-year mortality in patients with T2MI compared with patients with T1MI, similar to the twofold greater mortality rate in T2MI noted in a recent systematic review of nine studies. 8 In our review, this excess mortality was not driven by an excess of cardiovascular deaths, and likely reflects the competing risks of multiple comorbidities, rather than underlying obstructive coronary artery disease which was seen in 30%–50% of patients with T2MI. 26 31 Studies yielded mixed results as to whether coronary artery disease is an independent predictor of T2MI, 20 42 while others question the angiographic distinction between T2MI and T1MI.…”

“…In the absence of randomised controlled trials that have evaluated different investigational and therapeutic interventions in patients with T2MI, uncertainty remains around the appropriate management of such patients, particularly those with known or suspected coronary artery disease. Past reviews have assessed one or more attributes of T2MI in comparison to T1MI [4][5][6][7][8] but, to our knowledge, none have undertaken a comprehensive analysis of symptoms, physical signs, investigation results, management regimens and clinical outcomes, both short and long term, of T2MI versus T1MI.…”

Long-term clinical outcomes of type 1 vs. type 2 myocardial infarction in patients who underwent angiography: data from the Korea acute myocardial infarction-national institute of health registry

“…On the contrary, the usage rate of calcium channel blockers was significantly higher than that of T1MI patients, which may be due to the influence of spasms. Otherwise, T2MI patients often receive specialized treatments for comorbid diseases, such as the use of anticoagulants to manage atrial fibrillation or of diuretics to manage heart failure (21). Therefore, the treatment of T2MI is very important, and treatment of the primary disease is the key point.…”

Outcome of patients admitted with oxygen mismatch and myocardial injury or infarction in emergency departments

“…Thus, we used as criteria a fall of 20 g/l of haemoglobin below the age cut-offs, an oxygen saturation below 90%, a heart rate greater than 110 per minute, and SBP below 90 mmHg or greater than 160 mmHg. Because of the limited number of cohorts that have considered bradyarrhythmias and the low prevalence of this provoking condition, we did not include this criterion in our study 10,12,15,21,22 . The myocardial injury was considered acute if there was a relative change in troponin of at least 50% of the 99th percentile or any change of at least 20%, and chronic otherwise 23,24 .…”