The risk of myocardial infarction (MI) in the 90 days following testosterone therapy was 2 to 3 times greater in older men and in younger men with a history of heart disease, a study found.
There was no excess risk in younger men without such a history, the study noted.
Researchers conducted a cohort study of the risk of acute, non-fatal MI following testosterone therapy among nearly 56,000 patients in a commercial health care company’s database. They compared the incidence rate of MI in the 90 days following the prescription with the rate in the one year prior to the prescription (post/pre rates).
Researchers also looked at a comparison group of more than 167,000 men prescribed phosphodiesterase type 5 inhibitors (PDE5I; sildenafil or tadalafil), and compared testosterone therapy prescription post/pre rates with the PDE5I post/pre rates. Men receiving PDE5I prescriptions share some indications for prescription with testosterone therapy recipients, and the drug class is commonly prescribed to older men, does not have androgenic effects, and is not metabolized to other sex steroid hormones. Also, PDE5Is have not been associated with adverse cardiovascular events
Results appeared online Jan. 29 at PLOS One.
In all subjects, the post/pre rate ratio (RR) for testosterone therapy was 1.36 (95% CI, 1.03 to 1.81). In men aged 65 years and older, the RR was 2.19 (95% CI, 1.27 to 3.77) for testosterone therapy prescription and 1.15 (95% CI, 0.83 to 1.59) for PDE5I. The ratio of the rate ratios (RRR) for testosterone therapy prescription compared to PDE5I was 1.90 (95% CI, 1.04 to 3.49).
The RR for testosterone therapy prescription increased with age from 0.95 (95% CI, 0.54 to 1.67) for men less than 55 years to 3.43 (95% CI, 1.54 to 7.56) for those aged 75 years or older (Ptrend=0.03). No trend was seen for PDE5I (Ptrend=0.18). In men under age 65 years, excess risk was confined to those with a prior history of heart disease, with RRs of 2.90 (95% CI, 1.49 to 5.62) for testosterone therapy prescription and 1.40 (95% CI, 0.91 to 2.14) for PDE5I, and a RRR of 2.07 (95% CI, 1.05 to 4.11).
Researchers called the increased risk of MI in younger men with a history of heart disease a public health concern, as about 10% of the men in the study who were less than 65 years old and who had a testosterone therapy prescription had a history of heart disease.
“Given the rapidly increasing use of (testosterone therapy), the current results, along with other recent findings emphasize the urgency of the previous call for clinical trials adequately powered to assess the range of benefits and risks suggested for such therapy,” the authors wrote. “Until that time clinicians might be well advised to include serious cardiovascular events in their discussions with patients of potential risks, particularly for men with existing cardiovascular disease.”