Relationship between dynamic changes in subpopulations of blood monocytes and the development of complications in patients with acute myocardial infarction

Abstract

The aim – to determine the extent of different subpopulations of blood monocytes in acute myocardial infarction (AMI) with ST-segment elevation patients on day 1 and 7 and to evaluate the relationship between their content and the dynamics of changes and the risk of complications after AMI.Materials and methods. The composition of individual subpopulations of monocytes in the peripheral venous blood (and general clinical and biochemical blood tests) was evaluated in 50 pts with STEMI (who were admitted within 6 hours after the onset of the disease) at admission (before primary PCI) and on day 7. All patients received standard recommended therapy. Dynamic heart echocardiography was also performed on the 1st and 7th day. All patients were divided into 2 groups depending on the dynamical increase (1 group – 21 pts) or decrease (2 group – 29 pts) of classical monocytes (CD14hiCD16–) subpopulation during 7 days of follow-up. The control group included 15 healthy subjects with no signs of coronary heart disease and 23 pts with chronic coronary heart disease without AMI.Results and discussion. In subgroup 1, the percentage of the «classical» fraction of monocytes during the observation increased to 89.0±1.2 %, which was 4.2 % more than on the 1st day and 12.5 % more than in the control group (р<0.05), while the absolute amount of classic monocytes on day 7 increased by 48 % compared to initial value (р<0.01). The percentage of «intermediate» (CD14hiCD16+) blood monocytes in patients of this subgroup on the 1st day of hospitalization was 70 % higher than in the control group, and 42 % higher than in the 2nd subgroup of patients (р<0,001), however, on the 7th day it decreased by 30 % compared to baseline, although it remained by 8 % more than in the control group (the absolute number of «intermediate» monocytes did not change). The activation index (IA) of the «intermediate» monocytes on the first day did not differ between subgroups and was 40 % higher than in the control group (р<0.001). However, in the dynamics of observation, in patients of subgroup 1, this figure did not change, while in subgroup 2 IA decreased by 60 % (р<0.001). Despite the fact that the absolute number of anti-inflammatory («patrolling») (CD14+lowCD16++) monocytes did not change until the 7th day of observation (and their percentage decreased slightly), their IA was significantly lower than in the control group (95 %) and in patients of subgroup 2 (92 %, р<0,001). In patients of subgroup 2, the decrease of the percentage of «classic» monocytes was –7.7 % (from 90.4±0.8 to 83.4±1.2 %). Despite the fact that the number and percentage of intermediate monocytes increased in dynamics, their IA decreased almost 2 times, which may indicate a decrease in the pro-inflammatory ability these monocytes. The percentage and number of «patrolling» monocytes increased in dynamics by 37.4 % (р<0.0001) and by 268.3 % (р<0.01), respectively. IA of patrolling monocytes was almost 12 and 7 times higher than in patients of subgroup 1 on the 1st and 7th day of observation, respectively, which may indicate a significant activation of anti-inflammatory activity of patrolling monocytes. Intracardiac thrombosis was 3.3 times more common in patients of subgroup 1, in this subgroup was also more often noted (compared to the subgroup 2): dilatation of the left ventricle (almost 8 times), reduction of left ventricular ejection fraction (4 times), and pathological post-infarction remodeling of the left ventricle (almost 7 times).Conclusions. The results of the study indicate the important role of different subpopulations of blood monocytes in the processes of myocardial damage and recovery (in particular, the pro-inflammatory role of increasing the number of classical monocytes and increasing the activity of intermediate monocytes, as well as the anti-inflammatory role of increasing the number, percentage and activity of patrolling monocytes) in patients with AMI and can be the basis for developing new approaches to the diagnosis and prevention of complications of this disease.