Nickel Allergy and Coronary Artery Stents

Should You Receive a Heart Stent After Angioplasty if You're Nickel Allergic?

Nickel allergy can cause reactions to coronary artery stents..

Background on Nickel Allergy and Coronary Artery Stents

Nickel allergy is extremely common, with some European studies showing 10% of women and 1% of men allergic to nickel. Symptoms of nickel allergy most often include skin rashes at the site of contact of nickel, called contact dermatitis. There are also reports of whole-body rashes after the consumption of nickel in certain foods, as well as after tongue piercings.
Joint replacements with nickel-containing artificial joints have resulted in chronic swelling, pain, itchy rashes and failure of the joint replacement in some people with nickel allergy.

Coronary artery disease is the leading cause of death in the United States. Balloon angioplasty has become a standard treatment for unstable coronary artery disease, especially in the setting of an acute heart attack, and is performed millions of times a year worldwide. Metal stents are commonly placed in the diseased portion of the coronary artery after balloon angioplasty to prevent the coronary artery from re-occluding. Unfortunately, metal stents are also prone to a process called in-stent restenosis, where inflammatory tissue resembling a scar forms within the metal stent, and can result in symptoms of worsening coronary artery disease. In-stent restenosis occurs in approximately 10-15% of people receiving coronary artery stents.

Coronary artery stents used in the United States are made of stainless steel, or alloys of cobalt, chromium and platinum. All of these stents contain at least some amount of nickel, chromium and/or molybdenum. Given that nickel allergy and in-stent restenosis are both very common, there is concern that nickel allergy might predispose to in-stent restenosis.

Therefore, there have been a number of studies performed to assess the relationship between nickel allergy and in-stent restenosis.

Does Nickel Allergy Predispose to Coronary Artery In-Stent Restenosis?

A few studies have suggested that people with nickel allergy (or allergy to other metals, such as chromium) are at increased risk of developing in-stent restenosis. These studies examined people with a history of in-stent restenosis, and found that the rate of nickel allergy was higher in those with a history of in-stent restenosis compared to those without. However, it is important to realize that many people with in-stent restenosis did not have nickel (or other metal) allergy, and therefore other causes were responsible for their condition.

Multiple other studies haven’t found an association between nickel allergy and in-stent restenosis. A large study published by researchers from Denmark in 2011 examined 149 patients who needed balloon angioplasty, and performed patch testing before coronary artery stent placement.

Approximately 14% of all patients developed in-stent restenosis, although less than 12% of those patients with nickel allergy developed in-stent restenosis. Therefore, having nickel allergy did not appear to increase the chance of having of developing in-stent restenosis.

Another study published in 2012 by researchers from Mayo Clinic examined 29 patients with nickel allergy, and compared them to 250 patients without nickel allergy. They found no increased risk of in-stent restenosis or any other complication from stent placement, even over a 4-year period of time after stent placement.

The bottom line: Studies are mixed as to whether or not people with metal allergies are at risk for in-stent restenosis after coronary artery stent placement. However, two recent large studies are reassuring that people with nickel allergy do not appear to be at increased risk for in-stent restenosis after receiving coronary artery stents. Some authors have suggested that if a person has already experienced in-stent restenosis, that patch testing for nickel allergy might be helpful to predict future episodes of in-stent restenosis if additional balloon angioplasty is planned. The decision on whether or not to place a stent in a person with nickel allergy should be made between the patient and his or her cardiologist.


Romero-Brufau S. Outcomes After Coronary Stent Implantation in Patients with Metal Allergy. Circ Cardiovasc Interv. 2012;5:220-6.

Aliagaoglu C. Relation of Nickel Allergy with In-Stent Restenosis in Patients Treated with Cobalt Chromium Stents. Ann Dermatol. 2012;24(4):426-9.

Thyssen JP. No Association Between Metal Allergy and Cardiac In-Stent Restenosis in Patients with Dermatitis – Results From a Linkage Study. Contact Dermatitis. 2011;64(3):138-41.

Hillen U. Evaluation of Metal Allergies in Patients with Coronary Stents. Contact Dermatitis. 2002;47:353-6.

Koster R. Nickel and Molybdenum Contact Allergies in Patients with Coronary In-Stent Restenosis. Lancet. 2000;356:1895-8.

DISCLAIMER: The information contained in this site is for educational purposes only, and should not be used as a substitute for personal care by a licensed physician. Please see your physician for diagnosis and treatment of any concerning symptoms or medical condition.

Continue Reading