The Frequency of Type 2 Myocardial Infarction in the Structure of Hospital Mortality According to 7-Years Data of a State University Clinic
Authors: Oblavatckii D. V. , Boldueva S. A. , Soloveva M. V. , Vinnichuk S. A. , Mikhailov R. R. 
Published: July 2020

Aim      To evaluate the proportion of type 2 myocardial infarction (MI) in the structure of mortality at a multidisciplinary hospital; to describe major causes for MI development, and characteristics of patients with a verified diagnosis of type 2 MI by data of postmortem examination.

Material and methods  1574 protocols of the autopsies performed at the Central Pathology Department of the I.I. Mechnikov North-West State Medical University from 01.01.10 through 31.12.16 were studied retrospectively by the continuous sampling method. A group with verified diagnosis of type 2 MI was isolated from the total sample of autopsies. Major causes for and the proportion of type 2 MI among the causes of death were studied. Also, major demographic parameters, hospitalization profile, and condition of coronary arteries (CA) were compared in patients with fatal type 2 MI and those who died from atherothrombotic type 1 MI.

Results Analysis of 1574 fatal cases among patients of the multidisciplinary hospital showed that in 360 cases (22.87 %), the cause of death was MI, including 137 cases of fatal type 2 MI. Proportions of men and women among the patients with postmortem verification of type 2 MI were comparable. Analysis of the age structure showed the highest incidence of type 2 MI in elderly (48.2 %) and senile (34.3 %) age. Mean age of patients with type 2 MI was 71.7 years (68.2 years for men and 75.3 years for women), which was comparable with the age range of patients with fatal type 1 MI. In both groups, men with fatal MI were significantly younger than women. Analysis of causes for type 2 MI demonstrated that the most frequent ones were tachysystolic arrhythmias (59.12 %) and severe hypoxia of different origin (35.04 %). Analysis of the type of CA lesions showed that significant lesions were significantly more frequently absent in type 2 MI (32.85 %) while in type 1 MI, the proportion of patients with unchanged CA was 1.84 %. In the group of patients with fatal type 1 MI, 67.29 % had multivascular lesions, and one in two patients had an occlusive lesion. In the group with type 2 MI, multivascular lesions were half as frequent (31.38 %), and only 4.38 % of patients had a complete occlusion of a coronary vessel. Comparison of death rate in different departments of the multidisciplinary hospital showed that only 29.2 % of patients with type 2 MI originally were managed at a specialized cardiological department; 45.3 % of patients were admitted to an internal medicine department for different conditions often not related with ischemic heart disease. Furthermore, 25.5 % of patients with subsequently developed type 2 MI originally even received scheduled or emergency medical care for a leading surgical condition.

Conclusion      Cardiovascular diseases predominate among causes of mortality in a multidisciplinary hospital. This study showed that almost one in four patients dies from MI, and type 2 MI accounts for more than one third of fatal MIs. Among major causes for type 2 MI, tachysystolic arrhythmias (59.12 %) and pronounced hypoxia associated with anemia and severe respiratory failure (35.04 %) should be noted. Gender and age characteristics of patients with type 2 MI were comparable with those of patients with fatal type 1 MI. Furthermore, surgical patients accounted for 25.5 % of fatal cases of type 2 MI.