Chest. 2023 Sep 23:S0012-3692(23)05542-3. doi: 10.1016/j.chest.2023.09.020. Online ahead of print.
BACKGROUND: Trajectories of bedside vital signs have been used to identify sepsis subphenotypes with distinct outcomes and treatment responses. The objective of this study is to validate the vitals trajectory model in a multicenter cohort of hospitalized COVID-19 patients and to evaluate the clinical characteristics and outcomes of the resulting subphenotypes.
RESEARCH QUESTION: Can the trajectory of routine bedside vital signs identify COVID-19 subphenotypes with distinct clinical characteristics and outcomes?
STUDY DESIGN AND METHODS: The study included adult patients admitted with COVID-19 to four academic hospitals in the Emory Healthcare system between March 1st, 2020 and May 31st, 2022. Using a validated group-based trajectory model, we classified patients into previously defined vital sign trajectories using oral temperature, heart rate, respiratory rate, systolic and diastolic blood pressure measured in the first 8 hours of hospitalization. Clinical characteristics, biomarkers, and outcomes were compared between subphenotypes. Heterogeneity of treatment effect (HTE) to tocilizumab was evaluated.
RESULTS: The 7,065 hospitalized COVID-19 patients were classified into four subphenotypes: Group A (n=1429, 20%) - high temperature, heart rate, respiratory rate, and hypotensive; Group B (1454, 21%) - high temperature, heart rate, respiratory rate, and hypertensive; Group C (2996, 42%) - low temperature, heart rate, respiratory rate, and normotensive; Group D (1186, 17%) - low temperature, heart rate, respiratory rate, and hypotensive. Group A and D had higher odds ratio of mechanical ventilation, vasopressors, and 30-day inpatient mortality (p<0.001). Comparing patients receiving tocilizumab (n=55) to those who met criteria for tocilizumab but were admitted before its use (n=461), there was significant HTE across subphenotypes in the association of tocilizumab with 30-day mortality (p=0.001).
INTERPRETATION: By using bedside vital signs available in even low-resource settings, we found novel subphenotypes associated with distinct manifestations of COVID-19, which could lead to preemptive and targeted treatments.