COVID‐19, Contrast, and CREST‐2: A Survey of Investigators

Abstract

Shocks to supply chains triggered by the COVID‐19 pandemic and a COVID‐19–driven shutdown of a manufacturing facility in Shanghai, China, have resulted in a severe and unanticipated shortage in iodinated contrast media (ICM). To address this challenge, radiology and other specialties using contrast agents have been called on to prioritize indications for and conserve use of ICM. ¹ Steps to prioritize indications and conserve contrast have the potential to restrict access to stenting for patients with asymptomatic atherosclerotic carotid stenosis. In addition to adversely affecting clinical practice, an ICM shortage has the potential to compromise enrollment into clinical trials of revascularization.

CREST‐2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial) includes randomization to stenting versus intensive medical management. ² CREST‐2 leadership was particularly concerned about the effects of ICM shortage because in recent years, enrollment has been slower in the stenting trial than in the endarterectomy trial. As of June 6, 2022, a total of 973 patients have been enrolled in the stenting trial and 1101 in the endarterectomy trial. The purpose of this study was to gain insights into how the ICM shortage was affecting CREST‐2 investigators.

Data are available upon request to the corresponding author. The reporting guideline used was the Standards for Reporting Qualitative Research. ³ CREST‐2 has 143 clinical performance sites across the United States, Canada, and Spain. On May 12, 2022, the CREST‐2 Clinical Coordinating Center electronically mailed a 2‐question pulse survey to CREST‐2 physician investigators. The survey was closed to responses on May 19, 2022. The survey was intentionally very brief to encourage responses. The survey was also strictly anonymous. A second survey was not sent because it would have had to be sent to all investigators and coordinators regardless of whether they had previously responded and because a second survey might generate different results reflecting a rapidly changing supply chain situation.

To the question “Is your health care center experiencing a shortage of intravenous contrast agent?,” 60% (41/68) responded “Yes” and 40% (27/68) responded “No.” Survey participants were then asked, “If yes, is this shortage affecting elective carotid stenting at your site?” To this question, 29% (11/38) responded “Yes” and 71% (27/38) responded “No.”

We found that nearly two‐thirds of investigators said that the ICM shortage had affected their site and that one‐third of those who reported having been affected by the ICM shortage reported that the shortage had affected elective carotid stenting. The limitations of our survey include less than optimum response rates, lack of independent validation of responses, and the possibility that findings among CREST‐2 investigators may not generalize to the larger community of interventionists.

The CREST‐2 investigators have had to respond to many unexpected headwinds in the COVID‐19 pandemic. ⁴ Adaptation to the pandemic has included development and formal testing of at‐home monitoring of blood pressure and low‐density lipoprotein cholesterol management. ⁵ CREST‐2 investigators have been resourceful, but there can be no stenting without contrast. We are hopeful that this latest challenge of ICM shortage will soon pass and that the gap in enrollment in the stenting trial versus the endarterectomy trial will narrow. A worsening or protracted ICM shortage might lead to compromises in care beyond elective procedures and have potentially disastrous consequences for patients with symptomatic large‐vessel occlusive strokes who depend on catheter‐based therapies. To avoid these challenges in the future, more attention should be given to supply chain diversity. ⁶ Conservation of contrast is also a useful approach to the ICM shortage. Physicians can institute conservation immediately, whereas increasing supply may take time and is not under direct physician control. Conservation strategies relevant to neurovascular practice include taking patients with stroke directly to angiography when they present with high stroke scales, triaging patients with low stroke scales to magnetic resonance imaging and angiography, avoiding CT altogether, using emergent magnetic resonance imaging and angiography where available, and eschewing injection of the external carotid and vertebral arteries unless indicated. ⁷

Sources of Funding

Drs JF Meschia, B Lal, and TG Brott receive funds from the National Institute of Neurological Disorders and Stroke to support the CREST‐2 trial activities.

Disclosures

None.