Water Conservation Overrides Osmotic Diuresis During SGLT2 Inhibition in Patients With Heart Failure

BACKGROUND

Sodium-glucose cotransporter 2 inhibitors are believed to improve cardiac outcomes due to their osmotic diuretic potential.

OBJECTIVES

The goal of this study was to test the hypothesis that vasopressin-driven urine concentration overrides the osmotic diuretic effect of glucosuria induced by dapagliflozin treatment.

METHODS

DAPA-Shuttle1 (Hepato-renal Regulation of Water Conservation in Heart Failure Patients With SGLT-2 Inhibitor Treatment) was a single-center, double-blind, randomized, placebo-controlled trial, in which patients with chronic heart failure NYHA functional classes I/II and reduced ejection fraction were randomly assigned to receive dapagliflozin 10 mg daily or placebo (1:1) for 4 weeks. The primary endpoint was change from baseline in urine osmolyte concentration. Secondary endpoints included changes in copeptin levels and solute free water clearance.

RESULTS

Thirty-three randomized, sodium-glucose cotransporter 2 inhibitor-naïve participants completed the study, 29 of whom (placebo: n = 14; dapagliflozin: n = 15) provided accurate 24-hour urine collections (mean age 59 ± 14 years; left ventricular ejection fraction 31% ± 9%). Dapagliflozin treatment led to an isolated increase in urine glucose excretion by 3.3 mmol/kg/d (95% CI: 2.51-4.04; P < 0.0001) within 48 hours (early) which persisted after 4 weeks (late; 2.7 mmol/kg/d [95% CI: 1.98-3.51]; P < 0.0001). Dapagliflozin treatment increased serum copeptin early (5.5 pmol/L [95% CI: 0.45-10.5]; P < 0.05) and late (7.8 pmol/L [95% CI: 2.77-12.81]; P < 0.01), leading to proportional reductions in free water clearance (early: -9.1 mL/kg/d [95% CI: -14 to -4.12; P < 0.001]; late: -11.0 mL/kg/d [95% CI: -15.94 to -6.07; P < 0.0001]) and elevated urine concentrations (late: 134 mmol/L [95% CI: 39.28-229.12]; P < 0.01). Therefore, urine volume did not significantly increase with dapagliflozin (mean difference early: 2.8 mL/kg/d [95% CI: -1.97 to 7.48; P = 0.25]; mean difference late: 0.9 mL/kg/d [95% CI: -3.83 to 5.62]; P = 0.70).

CONCLUSIONS

Physiological-adaptive water conservation eliminated the expected osmotic diuretic potential of dapagliflozin and thereby prevented a glucose-driven increase in urine volume of approximately 10 mL/kg/d · 75 kg = 750 mL/kg/d. (Hepato-renal Regulation of Water Conservation in Heart Failure Patients With SGLT-2 Inhibitor Treatment [DAPA-Shuttle1]; NCT04080518).

Comparative Clinical Evaluation of the Roche Elecsys and Abbott Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Serology Assays for Coronavirus Disease 2019 (COVID-19)

CONTEXT.—

The use of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serologic tests detects antibodies in the host, contributing to the identification of individuals who have been exposed to coronavirus disease 2019 (COVID-19).

OBJECTIVE.—

To critically evaluate 2 commercially available SARS-CoV-2 serology tests.

DESIGN.—

A total of 333 unique, nonduplicated serum samples obtained from COVID-19 patients (n = 170) and negative controls (n = 163) obtained before December 2019 were used in the study. Samples were tested on the Roche E411 and Abbott Architect i4000SR platforms, and results were correlated to reverse transcription polymerase chain reaction (PCR) results and clinical symptoms.

RESULTS.—

There was a strong level of agreement in the qualitative results between both assays, with a Cohen κ value of .840, P < .001. The specificity for both Roche and Abbott were excellent at 100%. Roche exhibited marginally better performance in the 21 days or more group with a sensitivity of 90.6% (95% CI, 75.8%-96.8%) versus an Abbott sensitivity of 84.4% (95% CI, 68.3%-93.1%), as well as in the 14- to 20-day group with a sensitivity of 85.7% (95% CI, 65.4%-95.0%) versus an Abbott sensitivity of 81.0% (95% CI, 60.0%-92.3%). Less than 14 days of symptoms groups exhibited poor sensitivity at less than 50% for both assays. The areas under curve (± standard error) for Roche (0.894 ± 0.025, P < .001) and Abbott (0.884 ± 0.026, P < .001) were very similar. Potential confounders for negative serologic results include antiretroviral medication use and pauci-symptomatic patients.

CONCLUSIONS.—

Specificities for high-throughput Roche and Abbott immunoassays are excellent, but users need to be cautious to interpret serologic test results after 14 days of symptoms to avoid false negatives.

Clinical evaluation of serological IgG antibody response on the Abbott Architect for established SARS-CoV-2 infection

OBJECTIVE

This study aimed to evaluate the diagnostic performance of the Abbott Architect SARS-CoV-2 IgG assay in COVID-19 patients.

METHODS

Residual sera from 177 symptomatic SARS-CoV-2-positive patients and 163 non-COVID-19 patients were tested for antibody with the Abbott SARS-CoV-2 IgG assay (Abbott Diagnostics, Chicago, USA). Clinical records for COVID-19 patients were reviewed to determine the time from onset of clinical illness to testing.

RESULTS

Specificity of the assay was 100.0% (95%CI: 97.1-100.0%). The clinical sensitivity of the assay varied depending on time from onset of symptoms, increasing with longer periods from the onset of clinical illness. The clinical sensitivity at ≤6 days was 8.6% (7/81; 95%CI: 3.8-17.5%), at 7-13 days 43.6% (17/39; 95%CI: 28.2-60.2%), at 14-20 days 84.0% (21/25; 95%CI: 63.1-94.7%), and at ≥21 days 84.4% (27/32; 95%CI: 66.5-94.1%). Clinical sensitivity was higher in the ≥14-day group compared to <14 days. There were no differences between the 14-20-day and ≥21-days groups; the combined clinical sensitivity for these groups (≥14 days) was 84.2% (49/57; 71.6-92.1%).

CONCLUSION

The Abbott SARS-CoV-2 IgG test has high specificity. Clinical sensitivity was limited in the early stages of disease but improved from 14 days after the onset of clinical symptoms.