Comparison of a point-of-care and a standard RT-PCR assay for COVID-19 detection in the emergency department

Introduction: With the rapid spreading of the coronavirus (COVID-19) pandemic and the limited capacities of realtime reverse transcriptase-PCR (RT-PCR) at the laboratory level, there is an emerging need for rapid, point-of-care (POC), molecular testing in the Emergency Department (ED). Aims and objectives: To compare the diagnostic performance of ID NOW COVID-19 assay (Abbott, Chicago, Il, USA) performed by ED doctors with a gold standard reference RT-PCR test (GeneXpert assay developed by Cepheid). Method(s): Paired nasopharyngeal swabs were collected from consecutive adult patients suspected of having COVID-19 in the ED of a tertiary hospital in Athens (Greece);the first swab was directly used for the ID NOW COVID-19 assay in POC by an emergency physician and the second was analyzed with reference RT-PCR by a central laboratory technician. Cohen's kappa was run to determine if there was sufficient agreement between the two diagnostic methods. Result(s): Seventy one consecutive patients (36 female, mean age 64.6) were enrolled in the present study from 15th January to 21th February, 2022. The two tests agreed on 20 positive and 50 negative results. On the contrary, ID NOW COVID-19 assay was found positive in one patient with a negative reference RT-PCR test. There was very good agreement between the two diagnostic methods [kappa = 0.966 (95% CI, 0.900 to 1.032), p < 0.0001]. Conclusion(s): Comparison of a POC and a standard laboratory RT-PCR test in an ED patient population yielded high positive (95%) and negative percent agreement (100%). ID NOW COVID-19 assay seems to be a highly reliable POC test for early screening and triage of suspected COVID-19 patients.

Deformation analysis in post-hospitalised patients with moderate SARS-CoV-2 infection

Background: SARS-CoV-2 infection is associated with multiple cardiac manifestations (1,2). Global longitudinal strain (GLS) by speckle tracking echocardiography (STE) is a novel transthoracic echocardiography (TTE) measure of myocardial deformation, which could early recognize subclinical cardiac injury in COVID-19 patients (3,4). Purpose: We aimed to explore GLS profiles in post-hospitalized COVID-19 patients to identify features of eventual subclinical cardiac injury and to investigate the possible correlation with the severity of infection. Methods: We enrolled 33 patients (mean age 59.2 ± 13, 64% men) with positive SARS-CoV-2 RT-PCR, hospitalized for moderate COVID-19 disease, with no admission to intensive care unit. Patients were submitted to TTE 1-2 months after discharge. Images were anonymised and analysed offline by two accredited cardiologists. Clinical parameters and laboratory findings from hospitalization were also collected. Acute myocardial infarction and pulmonary embolism were exclusion criteria. Results: Mean duration of hospitalization was 12.9 ± 8.0 days. Study population had normal systolic function with a mean LV ejection fraction 58.6% (±3.6) while the majority of patients had relative low values of LV global longitudinal strain, mean 15.2% (±2.3). Arterial hypertension was present in 51.5% of patients and a history of previous myocardial infarction was referred in 6.1% of the population. Only 24.2% of patients had elevated troponin levels during the previous in-hospital period (mean maximal value of hs-troponin was 18.1 ±16.6 pg/mL) whereas 81.8% had abnormal D-Dimers values (mean 2424 μg /L, range ±2825) and 93.1% had high hs-CRP values (138.2 ±92.0 mg/L) . Duration of hospitalization had strong significant correlation with D-Dimers (rho: 0.708, p: <0.001) and hs CRP (rho:0383, p:0.028) and marginal association with troponin ( rho: 0.335, p:0.056). Moreover, global longitudinal strain showed significant association with duration of hospitalization (rho:-0.545, p: 0.007). Traditional systolic indices as LVEF and the various diastolic parameters showed no significant association with severity of disease reflected by the duration of hospitalization and the other clinical and laboratory biomarkers. Conclusion: Cardiac manifestations of SARS-CoV-2 infections could be present in mild to moderate disease and seems to associate with the severity of infection. The novel echocardiographic parameters such as GLS could add valuable information and identify possible subclinical cardiac injury often unrecognized by traditional TTE examination.

Dobutamine stress echocardiography during covid-19 pandemic: impact on volume and positivity rates in a tertiary hospital

Introduction: The emergence of coronavirus 2019 infection (covid-19) was accompanied by severe social and economic restrictions and applied significant pressure to the healthcare systems. The first pandemic wave started in March to May 2020 and was characterized by the peak of confinement measures and lockdown application. The second wave started in September and peaked in November to December 2020 and was characterized by improved healthcare organization but significant burden for the hospitals and intensive care units. Dobutamine stress echocardiography (DSE) is used for evaluation of ischemia in patients with known or suspected coronary artery disease. Purpose: To compare DSE volume and positivity rates between 2019 and 2020 time periods in a department of a public tertiary hospital. Methods: We retrospectively analysed DSE studies performed in our department in 2020 including the peak of covid-19 restrictions and compared the data to the 2019. Results: Volume of DSE studies decreased from 1516 in 2019 to 996 in 2020 (-34.3%). The study volume reduction was greater in April (-93.7%) and May (-54.5%) when the covid-19 restrictions were at the peak. Great decreases were also recorded in November (-46.8%) and December (-53.5%) when the second wave of covid-19 disease emerged. Conversely, small increases were recorded in September (7.1%) and October (10.6%) (figure 1). Regarding positivity rates, a statistically non-significant increase was recorded (33.6% vs 34.2% in 2019 and 2020 respectively, p = 0.73). Interestingly a statistically significant increase in positivity levels was recorded during the period March to May 2020 compared to the same period of 2019 (44.7% vs 36.9%, p = 0.029). On the contrary, positivity rates were decreased at the period September to December (27.1% vs 34.2%, p = 0.019) (figure 2). Conclusions: Volume of DSE studies was significantly reduced in 2020 when compared to 2019 during respective peaks of the pandemic and the accompanying restriction measures. Positivity rates were higher during the first pandemic wave, possibly due to decreased hospital attendance of mildly symptomatic patients in combination with stricter admission criteria at the emergency department. Lower positivity rates during the second pandemic wave possibly reflect an adjustment of both healthcare systems and patients to the new conditions imposed by the covid-19 pandemic.