TAVR Patients with Nickel Allergy (JACC Case Reports September 2025)-Article: TAVR Patients with Nickel Allergy

Article: TAVR Patients with Nickel Allergy

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This case series reports on seven patients with a history of nickel allergy who underwent transcatheter aortic valve replacement (TAVR), a common treatment for severe aortic stenosis often involving metal-frame prostheses containing nickel. Despite the concern about allergic reactions due to nickel's presence in valve alloys—primarily nitinol (50-55% nickel) and cobalt-chromium (with about 0.5% nickel)—none of the patients experienced significant allergic reactions during follow-up ranging from months to years. Preprocedural allergy evaluations, including patch testing or direct skin contact with valve fragments, showed variable results and no consistent correlation with clinical outcomes was observed, calling into question the routine utility of such testing.<br /><br />The seven cases varied in severity of nickel allergy and valve types used but all indicated favorable clinical outcomes without severe allergy symptoms attributable to the implanted devices. One patient developed a generalized rash two years postprocedure which resolved with steroids, while others remained asymptomatic even with documented nickel sensitivity. Notably, this report includes the largest known series of TAVR in patients with nickel allergy, contrasting with a singular previously reported case of severe allergic reaction after TAVR requiring valve explantation.<br /><br />The literature review highlights contradictory evidence concerning nickel hypersensitivity in vascular implants, with some endovascular devices demonstrating mild immunological responses and symptoms often called “device syndrome.” However, no long-term studies specifically address TAVR devices in this context. The authors emphasize that surface treatment and composition of valve metals mitigate nickel ion release and potential hypersensitivity.<br /><br />Current guidelines and FDA warnings advise caution or exclusion of patients with known significant nickel allergy from using nitinol-based devices, yet this series suggests TAVR can likely be performed safely in such patients. The study concludes that history of nickel allergy alone should not preclude TAVR but recommends further research to evaluate potential long-term hypersensitivity effects. The role of patch testing remains uncertain, and personalized clinical judgment is necessary.

Keywords

nickel allergy

transcatheter aortic valve replacement

TAVR

aortic stenosis

metal-frame prostheses

nitinol

cobalt-chromium alloy

allergic reactions

patch testing

device hypersensitivity