Author’s Reply

Dear Editor,

We thank Kow et al. for their observations and comments on our prospective study on the incidence, risk factors, and outcomes of acute kidney injury (AKI) in COVID-19 patients.¹ Microvascular thrombosis and inflammation can contribute to various organ injuries, including AKI in COVID-19 patients. These can be mitigated by anticoagulation treatment. The prespecified secondary analysis of A multicenter, adaptive, randomized controlled platform trial of the safety and efficacy of antithrombotic strategies in hospitalized adults with COVID-19 (ACTIV-4a) and antithrombotic therapy to ameliorate complications of Covid-19 (ATTACC) trial compared therapeutic anticoagulation with prophylactic anticoagulation in noncritical COVID-19 patients and showed a reduced risk of the combined endpoint of severe AKI and death in the therapeutic anticoagulation group (4.4% vs 5.5%).² However, the therapeutic heparin group had a higher risk of bleeding (2.4% vs 0.8%). Therapeutic versus prophylactic anticoagulation for patients admitted to hospital with COVID-19 and elevated D -Dimer concentration (ACTION): An Open label multicentric, randomized controlled trial (RCTs).³ In another multicenter, adaptive, randomized controlled platform trial including the REMAP-CAP, ACTIV-4a, and ATTACC trials involving more than 1000 critically ill COVID-19 patients, therapeutic anticoagulation did not show better survival or other benefits when compared to thromboprophylaxis and was terminated early due to futility.⁴ Since most of the patients who developed AKI were critically ill and 88% required ventilatory support, the evidence does not support the use of therapeutic anticoagulation for our patient population.⁵

We reviewed our data and found that all our patients received prophylactic anticoagulation. Further multicentric RCTs are required to prove whether therapeutic anticoagulation is beneficial in reducing AKI as a primary endpoint in noncritical COVID-19 patients. However, as the pandemic has already passed, there is little possibility of confirming this hypothesis.