Background: Cancer patients are at risk of higher readmission rates after hospitalization, which has been associated with increased comorbidity and mortality. Development of acute kidney injury (AKI) is associated with worse clinical outcomes. In the setting of the COVID-19 pandemic, we aim to look at the 30-day readmission rate in our institution’s cancer patients with estimated GFR (eGFR) > 60 and acquired COVID-19 infection who developed AKI within 30 days.
Methods: Under an IRB-approved retrospective observational study, patients demographics, labs and outcomes were aggregated and analyzed in the Syntropy platform, Palantir Foundry, as part of the Data-Driven Determinants of COVID-19 Oncology Discovery Effort (D3CODE) protocol at our tertiary major cancer center. The cohort was defined by the following: (1) Baseline eGFR > 60 ml/min/1.73 m2 on lab results within 30 days prior to the patient’s COVID-19 infection, (2) positive COVID-19 PCR nasal test. AKI was defined by an absolute increase in serum creatinine > 0.3 mg/dl within 30 days after the positive COVID-19 test. Multivariate Cox Proportional cause-specific hazard model regression was used to determine hazard ratios with 95 % confidence intervals.
Results: 635 patients met the inclusion criteria. Within 30 days after COVID-19 diagnosis 124 (19.5%) patients developed AKI. These patients were older with a mean age of 61 ± 13.2 vs 56.9 ± 14.3 years (P=0.002) and had more Hypertension (69.4% vs 56.4%, p=0.011) when compared with the patients who didn’t developed AKI. These patients presented more with cardiac arrhythmias (39.5% vs 20.7%, p=< 0.001), pneumonia (63.7% vs 37%, p=< 0.001) and myocardial infarction (15.3% vs 8.8%, p=0.046). Patients with hematologic malignancies were more likely to develop AKI when compared with solid tumors (35.1% vs 19%, p=0.005). We found no other significant difference in other comorbidities like smoking, diabetes, liver disease and hypothyroidism.Cancer patients with acquired COVID-19 infection and AKI, required more dialysis at 30 days (2.4% vs 0.2%, p=0.025), they also had higher need for intensive care management (43.5% vs 11.5%, p=< 0.001) and associated with more mechanical ventilation (16.1% vs 1.8%, p=< 0.001). The mortality rate at 90 days in the patients that developed AKI vs no AKI was higher as well (20.2% vs 3.7%, p=< 001).The 30-day readmission rate for the cancer patients who acquired AKI after COVID-19 infection was 71% vs 47.4%, p=0.001. Multivariate Cox Proportional hazard model regression analysis identified Diabetes Mellitus (HR 10.8, CI 2.42-48.4, P=0.001) as an independent risk factor for worse clinical outcomes.
Conclusions: In adult cancer patients hospitalized with covid-19 infection, development of AKI poses a major risk factor for hospital readmission within 30 days, and this has been associated with higher mortality. This highlights the importance of medical optimization and close monitoring of hospitalized cancer patients to prevent AKI during hospitalization.