The following is a summary of “Longitudinal analysis of chest Q-SPECT/CT in patients with severe COVID-19,” published in the DECEMBER 2023 issue of Pulmonology by Zivkovic, et al.

Patients afflicted with COVID-19 are at an escalated risk of microvascular lung thrombosis. To discern the nature and prevalence of perfusion defects associated with this condition, researchers, for a study, embarked on a longitudinal study utilizing combined perfusion single-photon emission and low-dose computed tomography (Q-SPECT/CT scan) in individuals diagnosed with COVID-19 pneumonia.

The study encompassed patients suffering from severe COVID-19, specifically the B.1.1.7 variant of SARS-CoV-2, and respiratory insufficiency. These patients underwent chest Q-SPECT/CT scans during their hospitalization and three months post-discharge. Upon follow-up (FU), the Q-SPECT/CT scans were juxtaposed with pulmonary function tests (PFT), blood analyses encompassing CRP, D-dimers, and ferritin levels, the modified Medical Research Council (mMRC) dyspnea scale, and high-resolution CT scans (HRCT). Those exhibiting one or more segmental perfusion defects outside the inflammatory zone (PDOI) were subjected to anticoagulation therapy until their FU.

In the initial assessment, 50 out of 105 patients (47.6%) exhibited PDOI. However, by the time of the FU, there was a noteworthy decline in the prevalence, with PDOI evident in only 14 out of 77 patients (18.2%) (P < 0.001). A substantial correlation was identified between the mMRC score and the count of segmental perfusion defects (r = 0.511, P < 0.001). A moderate correlation was observed between these defects and parameters like DLCO (r = −0.333, P = 0.002) and KCO (r = −0.373, P = 0.001) during FU. Intriguingly, neither the administration of corticosteroid therapy nor the results from HRCT appeared to influence the Q-SPECT/CT alterations (P = 0.94, P = 0.74). Furthermore, while there was an improvement in CRP, D-dimers, and ferritin levels, these did not correlate with the Q-SPECT/CT outcomes during FU (P = 0.08).

The findings underscored that segmental mismatched perfusion defects are prevalent among severe COVID-19 patients and are directly proportional to the severity of dyspnea experienced. Engaging in longitudinal analyses of Q-SPECT/CT scans in patients with severe COVID-19 may offer insights into potential mechanisms behind long COVID and persistent dyspnea.

Source: resmedjournal.com/article/S0954-6111(23)00349-9/fulltext