Strategies to Minimize the Use of Iodinated Contrast in the Electrophysiology Lab

Dear Readers,

In May 2022, hospitals were informed by a main supplier of iodinated intravenous (IV) radiographic contrast that their product was suddenly in very short supply. The lack of availability was reportedly due to the COVID-19-related shutdown in Shanghai, China, a major global producer of contrast. The supply problem is expected to last a couple of months, and unfortunately, most hospitals had only about a week’s worth of inventory when the crisis occurred. Initial reactions by hospitals to the shortage of IV contrast were to defer elective procedures that require IV contrast. This is a very disruptive plan and would put some patients at risk. Other strategies being implemented include the adoption of strategies to minimize its use in individual patients. These efforts include alternative medical imaging strategies that use less or no iodinated contrast.

Most contrast is used in the radiology department. Efforts there will likely have the biggest impact on overall hospital usage. However, the cardiac department is also a regular user of contrast, often for emergent procedures. In the cath lab, there are no feasible alternatives for the use of contrast during coronary angiography. This is especially problematic for emergency, lifesaving, primary percutaneous coronary interventions (PCI). The only option in the cath lab is to minimize the volume of contrast using fewer views and injections, biplane imaging, intravascular ultrasound, etc. Theoretically, thrombolytics could be used as an alternative to primary PCI for patients with ST-elevation myocardial infarction, but that seems unlikely to be adopted.

IV contrast is also used for most cardiac electrophysiology (EP) procedures—although fortunately with relatively low volumes. For example, it is now common practice that 5-10 cc of contrast are used to perform an upper extremity venogram to guide vascular access for transvenous axillary lead implantations. Contrast injections using slightly higher volumes are used to opacify the left atrial appendage (LAA) during left atrial appendage closure (LAAC) procedures, the pulmonary veins (PVs) during pulmonary vein isolation (PVI) procedures (particularly during cryoballoon PVI when assessing for occlusion), and the coronary sinus during implantation of pacing leads to deliver cardiac resynchronization. Included here is a table with some thoughts on ways to reduce the use of contrast for these procedures in the EP lab.

It is hard to explain how hospitals were so caught off guard by a sudden worldwide radiographic contrast shortage. It is also hard to explain how a primary contrast supplier in the United States was so dependent on a single production source. One can only hope that no patients will be harmed by this contrast shortage, and that efforts such as those above will be sufficient to ride out the storm. Perhaps some of these strategies to minimize the use of IV contrast in the EP lab will be adopted in the long term to reduce the overall use of contrast and radiation exposure in the future. 

Bradley P. Knight, MD, FACC, FHRS

Editor-in-Chief, EP Lab Digest

Disclosures: Dr Knight reports that he has served as a consultant, speaker, investigator, and/or has received EP fellowship grant support from Abbott, AtriCure, Baylis Medical, Biosense Webster, Biotronik, Boston Scientific, CVRx, Medtronic, Philips, and Sanofi. He has no equity or ownership in any of these companies.

References

1. Ali F, Mangi MA, Rehman H, Kaluski. Use of carbon dioxide as an intravascular contrast agent: a review of current literature. World J Cardiol. 2017;9(9):715-722. doi:10.4330/wjc.v9.i9.715

2. United States Food & Drug Administration. FDA Drug Safety Communication: FDA warns that gadolinium-based contrast agents (GBCAs) are retained in the body; requires new class warnings. Published May 16, 2018. Accessed May 11, 2022. https://www.fda.gov/drugs/drug-safety-and-availability/fda-drug-safety-communication-fda-warns-gadolinium-based-contrast-agents-gbcas-are-retained-body

3. Squara F, Tomi J, Scarlatti D, et al. Self-taught axillary vein access without venography for pacemaker implantation: prospective randomized comparison with the cephalic vein access. EP Europace. 2017;19(12):2001-2006. https://doi.org/10.1093/europace/euw363

4. Seto AH, Jolly A, Salcedo J. Ultrasound-guided venous access for pacemakers and defibrillators. J Cardiovasc Electrophysiol. 2013;24(3):370-374. doi:10.1111/jce.12005

5. Alkhouli M, Chaker Z, Alqahtani F, Raslan S, Raybuck B. Outcomes of routine intracardiac echocardiography to guide left atrial appendage occlusion. JACC Clin Electrophysiol. 2020;6(4):393-400. doi:10.1016/j.jacep.2019.11.014

6. Cauti FM, Solimene F, Stabile G, et al. Occlusion tool software for pulmonary vein occlusion verification in atrial fibrillation cryoballoon ablation. Pacing Clin Electrophysiol. 2021;44(1):63-70. doi:10.1111/pace.14130

7. Kosmidou J, Wooden S, Jones B, et al. Direct pressure monitoring accurately predicts pulmonary vein occlusion during cryoballoon ablation. J Vis Exp. 2013;(72):50247. doi:10.3791/50247