Success rate of aspirin desensitization high in Asian patients with CVD

Aspirin desensitization achieves good success rates in Asian patients with cardiovascular diseases, helping those with hypersensitivities to nonsteroidal anti-inflammatory drugs (NSAIDs) develop temporary tolerance to aspirin, according to a recent Singapore study.

“[T]his study sought to shed light on the characteristics and outcomes of patients who underwent aspirin desensitization, as well as to identify risk factors associated with failure of the procedure,” the researchers said. “A large proportion of patients underwent aspirin desensitization successfully and were able to commence on long-term aspirin therapy.”

A retrospective review of records of 214 patients (mean age 59.3 years, 70.1 percent men) undergoing desensitization in the Singapore General Hospital showed that majority (65.9 percent) had documented hypersensitivity to aspirin. Angioedema was the most common reaction to NSAID, present in almost half of the cohort. [Asia Pac Allergy 2021;11:e20]

Overall, 97.2 percent (n=208) of the participants completed the aspirin desensitization process, while six patients dropped out due to hypersensitivities.

Success was defined in the study as completing desensitization without encountering significant hypersensitivity reactions. Participants who developed only minor reactions or who chose to not initiate long-term aspirin medication for reasons other than hypersensitivities were also deemed successful. In contrast, those who experienced sensitivity reactions that prevented aspirin therapy were said to have failed desensitization.

A total of 165 patients successfully achieved aspirin desensitization, resulting in a success rate of 77.1 percent. Of these, 151 commenced long-term aspirin therapy. Reasons for discontinuation included choosing to go for single antiplatelet therapy instead, as well as prioritizing other issues.

Among those who failed aspirin desensitization (n=57; 26.6 percent), angioedema was by far the most common hypersensitivity reaction, arising in 77.2 percent (n=44). This was followed distantly by rashes (n=10), respiratory symptoms (n=5), and itching (n=1).

Multivariate logistic regression analysis revealed that having an initial hypersensitivity reaction of angioedema increased the likelihood of failing the desensitization process by nearly six times (adjusted odds ratio [OR], 5.88, 95 percent confidence interval [CI], 2.60–13.30; p<0.05). Having atopic disease as a comorbidity was also a risk factor for failure (adjusted OR, 3.13, 95 percent CI, 1.16–8.42; p<0.05).

A subsequent risk analysis excluded patients with unknown reactions to NSAIDs or with side effects not indicative of hypersensitivity. Initial angioedema remained a strong predictor of failure (adjusted OR, 7.21, 95 percent CI, 1.94–26.71; p<0.05), though the effect of atopic disease was attenuated.

As the present study only drew on the experience of one hospital, “future research could involve the collaboration of various institutions, allowing investigators to access other institutions' databases as well as to explore risk factors that may be more generalizable to patients undergoing aspirin desensitization,” the researchers said.

“Developing an aspirin desensitization algorithm and studying the safety and efficacy of risk-stratification could also be potential topics for future studies to confirm the importance of risk-stratifying patients prior to aspirin desensitization,” they added.