Diagnostic approach and use of CTPA in patients with suspected pulmonary embolism in an emergency department in Saudi Arabia.

Background: In patients with suspected pulmonary embolism (PE), the literature suggests the overuse of computerized tomography pulmonary angiography (CTPA) and underuse of clinical decision rules before imaging request. This study determined the potential for avoidable CTPA using the modified Wells score (mWS) and D-dimer assay in patients with suspected PE. Methods: This hospital-based retrospective study analyzed the clinical data of 661 consecutive patients with suspected PE who underwent CTPA in the emergency department of a tertiary hospital for the use of a clinical prediction rule (mWS) and D-dimer assay. The score was calculated retrospectively from the available data in the files of patients who did not have a documented clinical prediction rule. Overuse (avoidable) CTPA was defined as D-dimer negativity and PE unlikely for this study. Results: Of 661 patients' data examined, clinical prediction rules were documented in 15 (2.3%). In total, 422 patients (63.8%) had required information on modified Wells criteria and D-dimer assays and were included for further analysis. PE on CTPA was present in 22 (5.21%) of PE unlikely (mWS ≤4) and 1 (0.24%) of D-dimer negative patients. Thirty patients (7.11%) met the avoidable CTPA (DD negative+PE unlikely) criteria, and it was significantly associated with dyspnea. The value of sensitivity of avoidable CTPA was 100%, whereas the positive predictive value was 90.3%. Conclusion: Underutilization of clinical prediction rules before prescribing CTPA is common in emergency departments. Therefore, a mandatory policy should be implemented regarding the evaluation of avoidable CTPA imaging to reduce CTPA overuse.

Safety and Efficacy of the COVID-19 Vaccine in Kidney Transplant Recipients.

BACKGROUND: Kidney transplant recipients appear to be at high risk for critical coronavirus disease 2019 (COVID-19) illness. They are considered a priority for COVID-19 vaccination. Only a few studies report on the safety and efficacy of the COVID-19 vaccine in these patients. METHODS: In this prospective observational study, we measured anti-severe acute respiratory syndrome coronavirus 2 (anti-SARS-CoV-2) spike-specific IgG post first and second COVID-19 mRNA vaccines in 113 kidney transplant recipients and compared them to 62 healthy volunteers. RESULT: After the first COVID-19 vaccine, SARS-CoV-2-specific antibodies were undetectable in 38.9% of kidney transplant recipients, and after the second, it remained undetectable in 12.4%. SARS-CoV-2-specific antibodies were significantly lower in kidney transplant recipients. The average antibody titer after the first vaccine was 1243.6±4137.5 in kidney transplant recipients compared to 20012.2±44436.4 in the controls after the first dose (P=0.002), and 7965.5±12431.3 versus 82891.3±67418.7, respectively, after the second dose (P <0.001). The immune response to the COVID-19 vaccine seemed to be influenced by mycophenolate dose in kidney transplant recipients and pre-vaccination infection. CONCLUSION: Kidney transplant recipients are prone to have attenuated antibody responses (anti-spike IgGs) to mRNA COVID-19 vaccines. Patients on mycophenolate mofetil (2 gm daily) had significantly lower SARS-CoV-2 spike-specific IgG levels as compared to patients on no or reduced dose of mycophenolate. Hence, kidney transplant recipients need to continue all infection control precautionary measures against COVID-19 infection and should be considered a priority for a third COVID-19 vaccine.