Table 1.
Characteristics of patients undergoing computed tomography pulmonary angiography (CTPA) investigations performed in first wave versus second wave of SARS-CoV-2 infection.
| First wave 20/3/20 to 24/4/20 | Second wave 1/12/20 to 5/01/21 | p-Value | |
|---|---|---|---|
| SARS-CoV-2 PCR positive cases at our institution (n) | 487 | 1073 | |
| CTPA examinations performed with “COVID” on the clinical request form (n) | 99 | 273 | |
| Median age (years) | 58.4 | 61.4 | p=0.11 |
| Male: female ratio | 0.56 | 0.62 | p=0.30 |
| Requesting location (%) | |||
| ED | 29 (29.2) | 73 (26.7) | p=0.70 |
| ICU | 10 (10.1) | 7 (2.6) | p<0.01 |
| Respiratory HDU | 7 (7.0) | 43 (15.8) | p<0.01 |
| Other | 54 (54.5) | 150 (54.9) | p=0.95 |
| SARS-CoV-2 PCR results (%) in individuals with CTPA requests | |||
| Positive | 39 (39.3) | 205 (75.0) | p<0.01 |
| Negative | 58 (58.6) | 22 (8.1) | p<0.01 |
| Not performed | 2 (2.0) | 46 (16.8) | p<0.01 |
| CT features of COVID-19 (%) | |||
| Positive | 61 (61.6) | 239 (87.5) | p<0.01 |
| Negative | 33 (33.0) | 14 (5.1) | p<0.01 |
| Indeterminate | 5 (5.1) | 20 (7.3) | p=0.45 |
| Proportion of CTPA examinations positive for PE excluding non-diagnostic or equivocal studies (%) | 21/96 (21.9) | 31/264 (11.7) | p=0.02 |
| Proportion of CTPA positive for PE in patients with CT features of COVID-19 (%) | 19/59 (32.2) | 29/232 (12.5) | p<0.01 |
| Proportion of CTPA positive for PE incidence in PCR positive cases (%) | 11/35 (31.4) | 24/193(12.4) | p<0.01 |
| CTPA burden | 0.20 | 0.25 | p=0.02 |
Mann-Whitney U-test was used for non-parametric values and the chi-squared test was used for comparison of proportions.
PCR, polymerase chain reaction, SARS-CoV-2, severe acute respiratory syndrome coronavirus 2, ED, emergency department, ICU, intensive care unit, HDU, high dependency unit, PE, pulmonary embolism.