Clinical, instrumental and laboratory data on consequences of COVID-19 in delayed period after admission

Objective. To assess the consequences of COVID-19 in 3—7 months after discharge according to clinical, instrumental and laboratory data. Material and methods. The study included patients who underwent inpatient treatment at the COVID-19 center between April 2020 and June 2020. All ones agreed to participate in outpatient examination program «COVID-19 — follow-up study» in 3—7 months after discharge. All patients (n=213) underwent outpatient laboratory examination (general blood test, biochemical blood test, highly sensitive troponin I, highly sensitive C-reactive protein (HCRP), D-dimer, N-terminal fragment of the brain natriuretic hormone precursor (NT-proBNP)), electrocardiography and echocardiography. A 24-hour ECG monitoring and Doppler ultrasound of the lower extremity veins were performed in patients who underwent these procedures in acute period of disease. Contrast-enhanced MRI of the heart was performed in patients whose troponin I concentration was 10-fold higher than the 99th percentile in acute period of disease. Results. The study included 213 patients (55.4% men, median age 57 [49; 64] years). General blood test was normal in most pa-tients. However, mild anemia, neutropenia and lymphopenia were detected in up to 10% of persons. Biochemical blood test revealed high level of NT-proBNP in 70 (32.9%) people, HCRP in 35 (16.4%), D-dimer in 32 (15.1%) and troponin I in 14 (6.6%) patients. GFR <60 ml/min/1.73 m2 was detected in 16 (7.5%) patients, heart rhythm disturbances — in 25 (11.8%) patients, PQ prolongation — in 11 (5.4%) patients, QT prolongation — in 6 (2.8%) cases, bundle branch block — in 47.6% of patients, ST segment depression/elevation — in 33 (15.6%) patients. According to ECG monitoring data, cardiac arrhythmias (atrial fibrillation, non-sustained supraventricular tachycardia and ventricular tachycardia) in acute period of infection were reported in 14 (61%) patients (n=23), after 3—7 months — in 18 (78%) patients. Non-sustained supraventricular tachycardia was more common in post-COVID period (p=0.01). There were no significant pauses or ST segment changes. According to echocardiography data, local con-tractility disorders were detected in 12 (5.7%) patients. None patient had clinical signs of previous myocarditis. According to con-trast-enhanced MRI (n=5), no data on acute myocarditis and post-inflammatory fibrous myocardial changes in long-term period were confirmed in any patient. Doppler ultrasound of lower extremity veins in acute period of infection (n=24) revealed signs of phlebitis in 3 (12.5%) people, post-thrombophlebitis syndrome — in 1 (4.2%) patient, signs of thrombosis — in 2 (8.3%) pa-tients, signs of thrombosis and PTFS — in 1 (4.2%) patient. No venous lesions were found in 70.8% of patients. In long-term pe-riod, only one patient had signs of lower extremity vein thrombosis de novo. Conclusion. These data indicate certain changes in patients with previous COVID-19 infection. Further study of post-COVID syn-drome, its clinical manifestations and pathophysiological mechanisms is one of the most important objectives. © 2023, Media Sphera Publishing Group. All rights reserved.