Characteristics and Outcomes of Type 2 Myocardial Infarction

Abstract

IMPORTANCEIn contrast to type 1 myocardial infarction (T1MI) caused by atherothrombosis, characteristics and outcomes of type 2 myocardial infarction (T2MI) caused by supply-demand mismatch are incompletely understood.OBJECTIVE To explore the characteristics and outcomes of patients with T2MI compared with those with T1MI. DESIGN, SETTING, AND PARTICIPANTSIn a prospective, international, multicenter cohort study including 12 emergency departments (EDs) in 5 European countries, unselected patients presenting with acute chest discomfort were enrolled from April 2006 to April 2018. Follow-up was done by telephone or in written form 3, 12, and 24 months after hospital discharge. Data were analyzed from April 2006 to April 2020. INTERVENTIONSThe final diagnoses of T2MI and T1MI were centrally adjudicated according to the Fourth Universal Definition of Myocardial Infarction by 2 independent cardiologists, including the pathophysiological trigger of T2MI.MAIN OUTCOMES AND MEASURES Patient characteristics and outcomes, including 2-year all-cause and cardiovascular mortality and future T2MI and T1MI events. RESULTSOf 6253 included patients, 2078 (33.2%) were women, and the median (IQR) age was 61 (48-74) years. Among 6253 patients with acute chest discomfort, the final adjudicated diagnosis was T2MI in 251 patients (4.0%), with tachyarrhythmia and hypertension responsible for two-thirds of cases, and T1MI in 1027 patients (16.4%). All-cause and cardiovascular mortality were comparable at 2 years (T2MI: adjusted hazard ratio, 1.0; 95% CI, 0.7-1.5; T1MI: adjusted hazard ratio, 0.7; 95% CI, 0.4-1.1). Patients with tachyarrhythmia or hypertension as their underlying trigger of T2MI had a lower mortality compared with patients with hypotension, hypoxemia, or anemia. Future T2MI was more likely among patients with index T2MI compared with patients with index T1MI (hazard ratio, 3.2; 95% CI, 1.4-7.5). Similarly, future T1MI was more likely to occur among patients with index T1MI (hazard ratio, 3.0; 95% CI, 1.2-7.4).CONCLUSIONS AND RELEVANCE Among patients with T2MI, tachyarrhythmia and hypertension were responsible for more than two-thirds of T2MI cases. While T2MI and T1MI had comparable all-cause and cardiovascular mortality at 2 years, patients with tachyarrhythmia or hypertension as their underlying trigger of T2MI had a lower mortality compared with patients with hypotension, hypoxemia, or anemia. Future T2MI occurred 3-fold more frequently among patients with T2MI vs T1MI as the index event. Improved understanding of the specifics of patients with T2MI should help improve management strategies.

Management and outcomes of patients admitted with type 2 myocardial infarction with and without standard modifiable risk factors

“…Several conditions are associated with T2AMI, however there is very little data specifying their prevalence. In our analysis we found SMuRF and SMuRF-less patients had similar secondary diagnoses, with respiratory disorders most prevalent, followed by cardiovascular and renal disorders which was in consistent with other studies [9,22,23]. This is important as the difference in the T2AMI outcomes cannot be associated with the underlying secondary diagnosis, but with the non-accountable characteristics of the population with a common endpoint of myocardial injury.…”

“…The SMuRF-less cohort likely include those with missed standard modifiable risk factors (which may have poor prognostic impact in a causal manner). They may include patients with atypical risk factors such as liver disease or cancer associated with worse prognosis, as shown in the present study and several others [3,9,[21][22][23], but observed not to be an explanation in the SWEDEHEART STEMI cohort. The third category of SMuRF-less AMI individuals particularly relevant to those with demonstrated atherosclerosis and vascular dysfunction, are those with true heightened susceptibility to these processes in the absence of risk factors.…”

Association of Rural Hospital Admissions with Access, Treatment, and Mortality for Patients with Acute Myocardial Infarction in Shanxi, China

“…Future studies should observe the differences in mortality between patients admitted to rural and urban hospitals after discharge, as the urban-rural disparity in quality of care could lead to worse medium- and long-term survival outcomes among patients. Third, we did not have sufficient information identifying the clinical type of AMI [ 19 ]. As patients admitted to rural hospitals were older, more likely to be female, we speculate that a higher percentage of patients were Type 2 AMI in rural hospitals [ 19 , 20 ].…”

“…Third, we did not have sufficient information identifying the clinical type of AMI [ 19 ]. As patients admitted to rural hospitals were older, more likely to be female, we speculate that a higher percentage of patients were Type 2 AMI in rural hospitals [ 19 , 20 ]. Since indications to PCI and fibrinolysis were different according to type of MI, percentage of type 2 patients could potentially influence our results.…”

Clinical Characteristics, Outcomes, and Epidemiological Trends of Patients Admitted With Type 2 Myocardial Infarction

“…Most studies describing the characteristics of patients with T2MI agree that they tend to be older, female, and have more chronic comorbidities. [2][3][4][5][6][7] However, there tends to be a significant discrepancy in reported hospitalization and mortality trends, associated comorbidities, and outcomes. [2][3][4][5][6][7][8] In the present study, we used the most recent data available from the NIS database (January 2018 to December 2019) to compare patients admitted to the hospital with a diagnosis of T2MI with patients admitted with a diagnosis of type 1 MI (T1MI).…”