New study: No increased risk of MI with testosterone

A recent large study has found no increased risk of heart attack in men undergoing testosterone replacement therapy.

The finding stands in contrast to earlier data linking TRT to a twofold to threefold increased risk of myocardial infarction in men younger than 65 years of age with pre-existing heart disease (PLOS ONE 2014; 29:e85805). In addition, a separate study evaluating the association between the use of testosterone therapy and all-cause mortality, myocardial infarction, and stroke among male veterans found that the proportion of patients experiencing events 3 years after coronary angiography was 19.9% in the no testosterone therapy group (average age, 64 years) and 25.7% in the testosterone therapy group (average age, 61 years), for an absolute risk difference of 5.8% (JAMA 2013; 310:1829-36).

Those studies, which have been the subject of widespread criticism, prompted the FDA to launch an investigation into the risk of cardiovascular events in men taking FDA-approved testosterone products.

The current study, which was published online in the Annals of Pharmacotherapy (July 2, 2014), evaluated 25,420 Medicare beneficiaries 66 years of age or older treated with intramuscular testosterone for up to 8 years. Men of the same age, race, Medicaid eligibility, and health status who did not receive testosterone therapy were used as a control group for comparison.

Using a Cox regression analysis that adjusted for demographic and clinical characteristics, the authors reported that receiving testosterone therapy was not associated with an increased risk of myocardial infarction (hazard ratio [HR]=0.84; 95% CI: 0.69-1.02).

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“The results of our study were that testosterone users did not have an increased risk of heart attack over the study period compared to testosterone nonusers,” said first author Jacques Baillargeon, PhD, of the University of Texas Medical Branch, Galveston in an online video. “However, large–scale, randomized clinical trials will provide more definitive evidence regarding these risks in the coming years.”

In addition, testosterone users with a higher probability of cardiovascular problems had a lower rate of heart attacks in comparison to equivalent patients who did not receive testosterone therapy (HR=0.69; 95% CI: 0.53-0.92).

Dr. Baillargeon explained that he and his colleagues conducted sensitivity analyses to ensure the robustness of the findings across a range of exposure thresholds, follow-up periods, and inclusion criteria.

“When we ran these analyses, we found that our major finding of no increased risk of heart attack in the testosterone user group persisted across all of these sensitivity analyses. This gave us confidence in the robustness of our findings,” Dr. Baillargeon said.

In related news, Upsher-Smith Laboratories, Inc. recently announced the launch of a generic formulation of its recently FDA-approved testosterone gel Vogelxo. The testosterone gel (1%) offers once-daily dosing, 24-hour coverage, and three configurations: unit-dose tubes, packets, and metered-dose pumps, Upsher-Smith Laboratories said in a press release.

Look for extensive coverage of the ongoing testosterone controversy in the August issue of Urology Times.