Zero-contrast intravascular ultrasound-guided percutaneous coronary intervention in a patient with high-risk iodinated contrast allergy: navigating in the dark through a brighter inner light

A 59-year-old patient was admitted with an inferior ST-elevation myocardial infarction and underwent primary percutaneous coronary intervention (PCI) to the right coronary artery. The patient also had residual severe disease of the mid-left anterior descending (LAD) artery in bifurcation with the first diagonal branch (Supplementary Video 1). During the index procedure, the patient developed anaphylactic shock to the contrast dye, with laryngeal spasm and hypotension. Subsequent evaluation by a specialist allergy physician confirmed IgE-mediated sensitization. {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Supplementary Video 1.","caption":"","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_ekj0f9gq"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} Following a positive stress echocardiography demonstrating anterolateral ischemia, the patient was scheduled for zero-iodine contrast intravascular ultrasound (IVUS) guided PCI, with the application of multiple contrast sparing techniques and tools as recently described [1], after receiving appropriate premedication with methylprednisolone and cetirizine. Initially, an IVUS evaluation of the diagonal branch was performed (Fig. 1a) to evaluate plaque morphology, proximal and distal landing zones, and to select the diameter and the length of the stent to implant. After plaque modification, stent implantation, and optimization, IVUS was used once again in conjunction with stent enhancement to evaluate the post-stenting result (Fig. 1b). The same stepwise approach was then used for the LAD artery (Fig. 1c,d). Despite the lack of suspected complications at the end of the procedure, a final injection of 4 mmol diluted gadolinium and 2 cc of diluted iodinated contrast were used to exclude potential clinically relevant complications (Fig. 1e, Supplementary Video 2, 3). {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Supplementary Video 2.","caption":"","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_gkzh8d3e"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} {"href":"Single Video Player","role":"media-player-id","content-type":"play-in-place","position":"float","orientation":"portrait","label":"Supplementary Video 3.","caption":"","object-id":[{"pub-id-type":"doi","id":""},{"pub-id-type":"other","content-type":"media-stream-id","id":"1_5l1jcl1y"},{"pub-id-type":"other","content-type":"media-source","id":"Kaltura"}]} Fig. 1: Procedural steps of the Zero-Contrast IVUS guided PCI of LAD and diagonal artery. (a) Morpho-anatomical LAD to diagonal intravascular evaluation. (b) Stent enhancement and IVUS evaluation after implant and optimization of a 18 mm long DES. (c) Morpho-anatomical LAD axis evaluation. (d) Stent enhancement and IVUS evaluation after implant and optimization of a 18 mm long DES. (e). Final sub-selective injections with diluted gadolinium (left) and diluted iodinated contrast (right) to exclude major complications. DES, drug eluting stent; IVUS, intravascular ultrasound; LAD, left anterior descending; PCI,percutaneous coronary intervention.This case demonstrates how contrast-sparing techniques and tools can be used to improve procedural safety and quality of PCI in patients with a history of severe allergic reactions to iodinated contrast media. Furthermore, it emphasizes how, especially in complex interventions, safety can be maintained for the duration of the procedure, and that a final contrast injection can still be performed to exclude major complications. Conflicts of interest There are no conflicts of interest.