Aspirin Hypersensitivity Can be Managed in PCI Patients Without Switching Drugs

Aspirin hypersensitivity, though relatively infrequent, presents a challenge in some patients undergoing PCI that can be managed with effective and safe desensitization protocols, a review suggests. However, a survey shows that most physicians deal with the problem by avoiding aspirin altogether, a strategy with little supporting evidence.

The findings demonstrate that desensitization protocols allow most patients to leave the hospital on aspirin with a low risk of adverse reactions, Matteo Bianco, MD, of Azienda Ospedaliero-Universitaria San Luigi Gonzaga (Turin, Italy), and colleagues report in the January 2016 issue of Circulation: Cardiovascular Interventions.

Thus, they say, “desensitization should be the strategy to adopt in case of coronary artery disease and concomitant aspirin hypersensitivity, although randomized controlled trials should be performed to confirm the findings of our meta-analysis.”

Aspirin hypersensitivity is not very common, but it can lead to side effects including worsening respiratory tract disease, skin reactions, or anaphylaxis. The 2 main approaches to dealing with the issue are use of alternative drugs, which does not have strong support in the literature, and desensitization protocols.

To examine the efficacy and safety of desensitization, the authors reviewed 11 studies with a total of 283 patients. Overall, 2% of patients had aspirin allergy. The indication for PCI was stable angina in 44% and ACS in 55%.

One of the studies evaluated an IV protocol, which resulted in 98% of patients being discharged on aspirin (primary endpoint). No patients developed rash or angioedema.

The rest of the studies tested oral desensitization protocols, which carried a similarly high rate of efficacy. Protocols that involved fewer than 6 increases in aspirin dose had an efficacy rate of 95.83% and those that involved more than that were 95.89% effective. Rash was seen in about 2.6% of patients regardless of the type of oral protocol, but the rate of angioedema was higher for approaches that involved fewer than 6 dose escalations (3.43% vs 0%).

The authors hypothesize that the lower rate of adverse reactions with IV vs oral desensitization “is because of a more stable plasmatic level of aspirin if compared with oral administration. The latter is subjected to gastrointestinal absorption, which could lead to unpredictable plasmatic concentration of aspirin and to a less effective desensitization.”

Desensitization Underused?

In addition to searching the literature, the researchers also conducted an online survey of 100 interventional and clinical cardiologists, receiving responses from 86.

More than half (56%) of respondents said they manage aspirin hypersensitivity by changing the therapeutic regimen, most commonly by using clopidogrel monotherapy. “This choice, in particular in ACS subsets, is not supported by data and … could lead to stent thrombosis, early reinfarction, or bleedings,” the authors say.

Only 42% of survey takers said they used desensitization protocols, mostly oral strategies with initial doses ranging from 0.1 to 1 mg that were increased every 30 minutes to final doses of 75 to 100 mg. Anaphylaxis was reported in about 1% of cases and failure occurred in fewer than 20%.

Despite the low risk, “it is preferable to perform desensitization in a setting such as an intensive care unit to quickly manage adverse reactions,” the authors say. “The consultation of an immunologist specialist ... could be useful to set up a desensitization protocol at the beginning, but it is not routinely needed.”

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Source: 
Bianco M, Bernardi A, D’Ascenzo F, et al. Efficacy and safety of available protocols for aspirin hypersensitivity for patients undergoing percutaneous coronary intervention: a survey and systematic review. Circ Cardiovasc Interv. 2016;9:e002896.

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