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

Abstract

While prognoses in relation to myocardial infarction (MI) type have been elucidated in past reports, the results were not consistent, perhaps due to occurrence of Type 2 MI with CVS and its mortality. The Japanese registry of acute Myocardial Infarction diagnosed by Universal Definition (J-MINUET) is a prospective multicenter registry in Japan. In contrast to thromboembolic event-related Type 1 myocardial infarction (MI), clinical features of Type 2 MI, including coronary vasospasm (CVS), are varied due to the heterogeneous nature of its development. To elucidate the MI type-related all-cause mortality, 2989 consecutive patients with AMI were stratified as Type 1 MI, Type 2 MI with CVS, and Type 2 MI with non-CVS. Most patients (n = 2834; 94.8%) were classified as Type 1 MI and 155 patients (5.2%) were classified as Type 2 MI. Of the Type 2 MI patients, 87 (56% of Type 2 MI) were diagnosed as MI with CVS. Although the 3-year mortality was comparable between Type 1 and Type 2 MI patients, significant differences were observed between Type 2 MI with CVS and with non-CVS (3.4% and 22.1%, p < 0.001). Among Japanese patients with AMI, mortality rates between Type 1 MI and Type 2 MI are comparable, but further stratification of Type 2 MI (with or without CVS) may be useful in predicting the prognosis of patients with Type 2 MI.

Keywords: acute myocardial infarction; clinical outcomes; coronary vasospasm; universal definition of myocardial infarction.

Figure 1

Flowchart of the current study. MI, myocardial infarction; CVS, coronary vasospasm.

Figure 2

Kaplan–Meier estimates of all-cause mortality between Type 1 MI and Type 2 MI (A) and Table 2. MI is stratified into two groups (B) over a 3-year period.

Figure 3

Event rates and Kaplan–Meier estimates of all-cause mortality at 1year period. (Upper) All-cause mortality between Type 1 MI and Type 2 MI (A) and the mortality among the 3 groups, when Type 2 MI is stratified into 2 groups (B) within 1-year period. (Lower) Kaplan–Meier estimates of all-cause mortality between Type 1 MI and Type 2 MI (C) and the mortality among the three groups, when Type 2 MI is stratified into two groups (D) within 1-year period.