Incidence, Trends, and Outcomes of Type 2 Myocardial Infarction in a Community Cohort

Abstract

Background: Type 2 myocardial infarction (T2MI) occurs because of an acute imbalance in myocardial oxygen supply and demand in the absence of atherothrombosis. Despite being frequently encountered in clinical practice, the population-based incidence and trends remain unknown, and the long-term outcomes are incompletely characterized. Methods: We prospectively recruited residents of Olmsted County, Minnesota, who experienced an event associated with a cardiac troponin T >99th percentile of a normal reference population (≥0.01 ng/mL) between January 1, 2003, and December 31, 2012. Events were retrospectively classified into type 1 myocardial infarction (T1MI, atherothombotic event), T2MI, or myocardial injury (troponin rise not meeting criteria for myocardial infarction [MI]) using the universal definition. Outcomes were long-term all-cause and cardiovascular mortality and recurrent MI. T2MI was further subclassified by the inciting event for supply/demand mismatch. Results: A total of 5460 patients had at least one cardiac troponin T ≥0.01 ng/mL; 1365 of these patients were classified as index T1MI (age, 68.5±14.8 years; 63% male) and 1054 were classified as T2MI (age, 73.7±15.8 years; 46% male). The annual incidence of T1MI decreased markedly from 202 to 84 per 100 000 persons between 2003 and 2012 ( P <0.001), whereas the incidence of T2MI declined from 130 to 78 per 100 000 persons ( P =0.02). In comparison with patients with T1MI, patients with T2MI had higher long-term all-cause mortality after adjustment for age and sex, driven by early and noncardiovascular death. Rates of cardiovascular death were similar after either type of MI (hazard ratio, 0.8 [95% CI, 0.7–1.0], P =0.11). Subclassification of T2MI by cause demonstrated a more favorable prognosis when the principal provoking mechanism was arrhythmia, in comparison with postoperative status, hypotension, anemia, and hypoxia. After index T2MI, the most common MI during follow-up was a recurrent T2MI, whereas the occurrence of a new T1MI was relatively rare (estimated rates at 5 years, 9.7% and 1.7%). Conclusions: There has been an evolution in the type of MI occurring in the community over a decade, with the incidence of T2MI now being similar to T1MI. Mortality after T2MI is higher and driven by early and noncardiovascular death. The provoking mechanism of supply/demand mismatch affects long-term survival. These findings underscore the healthcare burden of T2MI and provide benchmarks for clinical trial design.

Long-Term Prognosis of Patients with Myocardial Infarction Type 1 and Type 2 with and without Involvement of Coronary Vasospasm

“…Furthermore, because this study focused on coronary artery disease, patients with myocardial injury, such as Takotsubo cardiomyopathy or pulmonary embolism, were intentionally excluded at the time of entry. This may have affected the lower proportion of Type 2 MI compared with previous observational studies [19,20,25].…”

“…A multicenter study from 5 European countries, APACE, showed that the update of UDMI increased the number of newly diagnosed Type 2 MI patients reclassified in UDMI 2012 by 114% (comparison with UDMI 2007) in the same MI patient group [18]. A community-based study in the United States found that a dramatic reduction in Type 1 MI from 2003 to 2012 resulted in similar incidence of Type 1 and Type 2 MI [19]. Even in a recent investigation restricted to adults aged 50 years and younger, the ratio of Type 2 MI was as high as 32% (the actual proportion was 37%, if the patients with myocardial injury were excluded) [20].…”

Sex differences in investigations and outcomes among patients with type 2 myocardial infarction

“…Raphael et al recently showed that underlying mechanism of the supply/demand imbalance affects long-term outcome, and further investigation is needed to clarify whether the distribution of mechanisms differs by sex. 16 Both men and women with type 2 MI have a poor prognosis. Our study showed that during the follow-up period 50% and 45% of men and women, respectively, died following type 2 MI.…”

“…Raphael et al recently showed that underlying mechanism of the supply/demand imbalance affects long-term outcome, and further investigation is needed to clarify whether the distribution of mechanisms differs by sex. 16 …”

Improved Incidence of Cardiovascular Disease in Patients With Incident Rheumatoid Arthritis in the 2000s: A Population-based Cohort Study

“…This study shows a decrease in the incidence of major CVD events in successive population-based incident RA cohorts. This improvement appears to be largely driven by an over 50% decline in the incidence of MI in patients with RA onset in 2000s versus 1980s, concomitant with the declining incidence of MI in the general population (22). Coronary revascularization procedures are increasingly widespread therapeutic interventions for patients with CAD with potential impact on subsequent CVD events (25,26).…”