Use of Renin-Angiotensin System Blockers During the COVID-19 Pandemic: Early Guidance and Evolving Evidence

The Impact of COVID-19 on Patients With ADPKD

PURPOSE OF REVIEW

Patients with autosomal dominant polycystic kidney disease (ADPKD) have kidney cysts and kidney enlargement decades before progressing to advanced chronic kidney disease (CKD), meaning patients live most of their adult life with a chronic medical condition. The coronavirus disease 2019 (COVID-19) pandemic has created common questions among patients with ADPKD. In this review, we discuss COVID-19 concerns centered around a patient with a common clinical vignette.

SOURCES OF INFORMATION

We performed PubMed and Google scholar searches for English, peer-reviewed studies related to "COVID-19," "ADPKD," "CKD," "tolvaptan," "angiotensin-converting enzyme inhibitors" (ACEi), "angiotensin receptor blockers" (ARB), and "vaccination." We also evaluated transplant data provided by the Ontario Trillium Gift of Life Network.

METHODS

Following an assessment of available literature, this narrative review addresses common questions of patients with ADPKD in the context of the COVID-19 pandemic.

KEY FINDINGS

Data regarding the risk of developing COVID-19 and the risk of adverse COVID-19 outcomes in patients with ADPKD remain limited, but patients with ADPKD with impaired estimated glomerular filtration rate (eGFR), kidney transplants, or on dialysis are likely at similar increased risk as those with generally defined CKD. We provide strategies to improve virtual care, which is likely to persist after the pandemic. Current evidence suggests ACEi, ARB, and tolvaptan treatment should be continued unless contraindicated due to severe illness. When available, and in the absence of a severe allergy, vaccination is recommended for all patients with ADPKD.

LIMITATIONS

This narrative review is limited by a paucity of high-quality data on COVID-19 outcomes in patients specifically with ADPKD.

IMPLICATIONS

Patients with ADPKD who have developed advanced CKD, require dialysis, or who have received a kidney transplant are at elevated risk of COVID-19 complications.

Randomized Prospective Open Label Study Shows No Impact on Clinical Outcome of Adding Losartan to Hospitalized COVID-19 Patients with Mild Hypoxemia

INTRODUCTION

Despite considerable scientific debate, there have been no prospective clinical studies on the effects of angiotensin II receptor blockers (ARBs) on the course of COVID-19 infection. Losartan is the ARB that was chosen to be tested in this study.

METHODS

Patients with COVID-19 and mild hypoxia (receipt of ≤ 3 L/min O2 by nasal cannula) admitted to three hospitals were randomized in a 1:1 ratio within 72 h of SARS-CoV-2 nucleic acid testing confirmation to prospectively receive standard of care (SOC) alone or SOC plus losartan 12.5 mg orally every 12 h for 10 days or until hospital discharge, with the option to titrate upward dependent on blood pressure tolerability. Primary composite endpoint was receipt of mechanical ventilation or death before receiving ventilation. Subjects were followed until discharge to home or until an endpoint was met in the hospital.

RESULTS

Sixteen subjects received an ARB plus SOC and 15 subjects received SOC alone. The median age was 53 years for both groups. Median time from hospital admission to study enrollment was 2 days (range 1-6) for the ARB group and 2 days (range 1-4) for the SOC group. Mean Charlson comorbidity index was 2 for both groups. One subject in each group achieved the composite endpoint.

CONCLUSION

This small prospective randomized open-label study showed no clinically significant impacts of ARB therapy in mildly hypoxemic patients hospitalized with COVID-19 early in the pandemic. A larger prospective randomized placebo-controlled trial would be needed to confirm these findings or capture less pronounced effects and probably should focus on outpatients earlier in disease course.

TRIAL REGISTRATION

clinicaltrials.gov; March 27, 2020; NCT04340557.

Regulation of Angiotensin-Converting Enzyme 2: A Potential Target to Prevent COVID-19?

The renin-angiotensin system (RAS) is crucially involved in the physiology and pathology of all organs in mammals. Angiotensin-converting enzyme 2 (ACE2), which is a homolog of ACE, acts as a negative regulator in the homeostasis of RAS. ACE2 has been proven to be the receptor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which caused the coronavirus disease 2019 (COVID-19) pandemic. As SARS-CoV-2 enters the host cells through binding of viral spike protein with ACE2 in humans, the distribution and expression level of ACE2 may be critical for SARS-CoV-2 infection. Growing evidence shows the implication of ACE2 in pathological progression in tissue injury and several chronic conditions such as hypertension, diabetes, and cardiovascular disease; this suggests that ACE2 is essential in the progression and clinical prognosis of COVID-19 as well. Therefore, we summarized the expression and activity of ACE2 under various conditions and regulators. We further discussed its potential implication in susceptibility to COVID-19 and its potential for being a therapeutic target in COVID-19.