Long-term follow-up of patients recovering from moderate-to-severe COVID-19

Abstract

Rationale: The long-term imaging findings of COVID-19, its underlying causes, and their relation to persistent clinical symptoms have not yet been sufficiently clarified. Methods: Our study included 94 patients admitted to Istanbul Medical Faculty Hospital diagnosed with moderate-to-severe COVID-19 pneumonia, with PCR test, thoracic CT findings, and clinical evaluation, and who had follow-up CT scans over ten months. Two radiologists calculated semi-quantitative volumetric scores on the initial thoracic CT scans. Two radiologists and one pulmonologist retrospectively examined the persistence of follow-up imaging findings and interpreted them using the relevant clinical and laboratory findings. Results: Of the 94 patients with long-term follow-up imaging, non-fibrotic changes persisted in 34 (36.6%) scans, while fibrotic-like changes persisted in 70 (75.3%) scans. The most common non-fibrotic changes were focal air trapping 25.8% (n=24) and ground glass opacities 17.2% (n=16), and fibrotic-like changes were parenchymal bands/micro atelectasis 57.4% (n=54), reticulation 52.1% (n=49) and subpleural linear/curvilinear bands 34.4% (n=32). Non-fibrotic and fibrotic-like persistent changes were statistically significant with the initial CT score(p=<0.001), LDH(p=<0.001), and ferritin levels (p=0,008, p=0,003, respectively). Fatigue(p=0.025) and chest tightness(p=<0.001) were reported more in the patients with persistent non-fibrotic changes, while chest tightness(p=0.033) was reported more in those with persistent fibrotic-like changes. Conclusion: Some initial imaging and laboratory findings may indicate the onset of long-COVID disease. There is a strong correlation between persistent radiological and clinical findings, which need further investigation.