In-hospital prognosis in patients with myocardial infarction and atrial fibrillation
Authors: Leonova I , Solovyeva M , Boldueva S , Bykova E 
Published: April 2021

Abstract

Funding Acknowledgements
Type of funding sources: None.

Introduction
The number of patients with myocardial infarction (MI) and atrial fibrillation (AF) is increasing every year.

Purpose
to assess the incidence of AF among the patients with MI, the features of the in-hospital prognosis among the patients with MI and AF compared with MI without AF.

Methods
The patients with type 1 MI and preexisting AF have been selected from all MI patients MI admitted in 2013-18. They have formed the main group (100 patients). The control group (200 patients with type 1 MI without AF), has been created by "pair selection" method. Patients in the groups did not differ in gender, age, MI date and had not severe comorbidities.

Results
1660 patients with MI were analyzed. AF occurred in 309 patients (18.6% of patients with MI). Preexisting AF was in 59.2%. Patients with MI and AF were older than MI without AF (mean age 75.2 ± 10.1 versus 64.6 ± 12.8, p &lt;0.0001) with women’s prevalence (52.4% versus 35.5%, p &lt;0.0001). Type 1 MI predominates among all patients. Type 2 MI occurred 5 times more often among main group (p &lt;0.0001). 2 groups were adjusted for sex (58% of women in both groups), age (mean age 75.5 ± 8, 7 in the main versus 75.2 ± 8.5 in the control group, p = 0.775). Diabetes (45% versus 31.5%, p = 0.030), previous MI (40% versus 25.5%, p = 0.012) and stroke (21% versus 11.5%, p = 0.037) were more common in the main than in the control. Patients with MI and AF had lower GFR (56.8 ± 19.4 versus 61.7 ± 17.9 ml/min/1.73 m2, p = 0.031), LDL (2.8 ± 0.9 versus 3.3 ± 1.0 mmol/L, p = 0.0002). Patients with AF had a lower left ventricular ejection fraction (55.2 ± 10.5 versus 59.8 ± 10.0 %, p = 0.0005). Significant mitral regurgitation was more common in the main group (53.9% versus 30.3% in the control group, p = 0.0002). There were no differences in the incidence of acute heart failure (HF) Killip’s 3-4 (20% versus 13%, p = 0.127). Patients did not differ in the number of affected coronary artery (p = 0.7327), the level of stenosis (p = 0.1956), in the frequency of revascularization (p = 0.0686). Patients with MI and AF had worse in-hospital prognosis. Pulmonary embolism (PE) (9% in main versus 1% in control group, p = 0.0011), minor bleeding (21% versus 9.5%, p = 0.0057), combined endpoint (stroke + PE + mortality) (19% versus 10.5%, p = 0.0415) were more common in the main group. At discharge, patients with AF had HF III NYHA in 21.8% cases versus 5.5% in patients without AF, p = 0.0001. There were no significant differences in other in-hospital endpoints (recurrent myocardial infarction, stroke, major bleeding, and mortality) between the groups. In-hospital mortality was 13% in the main versus 9.5% in the control group (p = 0.4276).

Conclusion
AF occurs in 18.6% of patients with MI. Patients with AF and MI are older with female prevalence. Type 1 MI predominates. Patients with type 1 MI and pre-existing AF is a group of high risk because of more severe HF, PE, minor bleeding and combined endpoint (stroke + PE + mortality)