Rationale: In critically ill patients, a hemoglobin transfusion threshold of <7.0 g/dl compared with <10.0 g/dl improves organ dysfunction. However, it is unclear if transfusion at a hemoglobin of <7.0 g/dl is superior to no transfusion. Objectives: To compare degrees of organ dysfunction between transfusion and no transfusion at a hemoglobin threshold of <7.0 g/dl among critically ill patients using quasiexperimental regression discontinuity methods. Methods: We performed regression discontinuity analysis using hemoglobin measurements from patients admitted to intensive care units in three cohorts (Medical Information Mart for Intensive Care IV, eICU, and Premier Inc.), estimating the change in organ dysfunction (modified sequential organ failure assessment score) in the 24- to 72-hour window following each hemoglobin measurement. We compared hemoglobin concentrations just above and below 7.0 g/dl using a "fuzzy" discontinuity approach, based on the concept that measurement noise pseudorandomizes similar hemoglobin concentrations on either side of the transfusion threshold. Results: A total of 11,181, 13,664, and 167,142 patients were included in the Medical Information Mart for Intensive Care IV (MIMIC-IV), eICU, and Premier Inc. cohorts, respectively. Patient characteristics below the threshold did not differ from those above the threshold, except that crossing below the threshold resulted in a >20% absolute increase in transfusion rates in all three cohorts. Transfusion was associated with increases in hemoglobin concentration in the subsequent 24-72 hours (MIMIC-IV, 2.4 [95% confidence interval (CI), 1.1 to 3.6] g/dl; eICU, 0.7 [95% CI, 0.3 to 1.2] g/dl; Premier Inc., 1.9 [95% CI, 1.5 to 2.2] g/dl) but not with improvement in organ dysfunction (MIMIC-IV, 4.6 [95% CI, -1.2 to 10] points; eICU, 4.4 [95% CI, 0.9 to 7.8] points; Premier Inc., 1.1 [95% CI, -0.2 to 2.3] points) compared with no transfusion. Conclusions: Transfusion was not associated with improved organ dysfunction compared with no transfusion at a hemoglobin threshold of 7.0 g/dl, suggesting that evaluation of transfusion targets other than a hemoglobin threshold of 7.0 g/dl may be warranted.

Objectives

To determine the association of prior use of renin-angiotensin-aldosterone system inhibitors (RAASIs) with mortality and outcomes in hospitalized patients with COVID-19.

Design

Retrospective observational study.

Setting

Multicenter, international COVID-19 registry.

Subjects

Adult hospitalized COVID-19 patients on antihypertensive agents (AHAs) prior to admission, admitted from March 31, 2020, to March 10, 2021.

Interventions

None.

Measurements and main results

Data were compared between three groups: patients on RAASIs only, other AHAs only, and those on both medications. Multivariable logistic and linear regressions were performed after controlling for prehospitalization characteristics to estimate the effect of RAASIs on mortality and other outcomes during hospitalization. Of 26,652 patients, 7,975 patients were on AHAs prior to hospitalization. Of these, 1,542 patients (19.3%) were on RAASIs only, 3,765 patients (47.2%) were on other AHAs only, and 2,668 (33.5%) patients were on both medications. Compared with those taking other AHAs only, patients on RAASIs only were younger (mean age 63.3 vs 66.9 yr; p < 0.0001), more often male (58.2% vs 52.4%; p = 0.0001) and more often White (55.1% vs 47.2%; p < 0.0001). After adjusting for age, gender, race, location, and comorbidities, patients on combination of RAASIs and other AHAs had higher in-hospital mortality than those on RAASIs only (odds ratio [OR] = 1.28; 95% CI [1.19-1.38]; p < 0.0001) and higher mortality than those on other AHAs only (OR = 1.09; 95% CI [1.03-1.15]; p = 0.0017). Patients on RAASIs only had lower mortality than those on other AHAs only (OR = 0.87; 95% CI [0.81-0.94]; p = 0.0003). Patients on ACEIs only had higher mortality compared with those on ARBs only (OR = 1.37; 95% CI [1.20-1.56]; p < 0.0001).

Conclusions

Among patients hospitalized for COVID-19 who were taking AHAs, prior use of a combination of RAASIs and other AHAs was associated with higher in-hospital mortality than the use of RAASIs alone. When compared with ARBs, ACEIs were associated with significantly higher mortality in hospitalized COVID-19 patients.