Testosterone and Heart Health: What the TRAVERSE Trial Finally Proved

For over a decade, the cardiovascular safety of testosterone replacement therapy has been medicine's most contentious debate. Depending on which study you read, testosterone either causes heart attacks, prevents heart attacks, or has no effect whatsoever. Headlines seesawed. Patients were confused. Doctors were cautious to the point of withholding treatment from men who needed it.

Then the TRAVERSE trial published its results, and the fog finally lifted.

The Fear: Where It Came From

The testosterone-heart concern traces back to a few key events:

2010 — TOM Trial. A small study of elderly, frail men with significant comorbidities was stopped early due to more cardiovascular events in the testosterone group. The study had only 209 participants and wasn't designed to assess cardiovascular safety. But it raised the alarm.

2013 — Vigen et al. (JAMA). An observational study of veterans reported higher mortality and cardiovascular events in men who received testosterone. The study was later heavily criticized for methodological errors — including counting men as "testosterone-treated" even if they'd only filled one prescription. A correction was published, but the damage to public perception was done.

2014 — FDA Warning. The FDA required testosterone product labels to include a warning about possible cardiovascular risks. Importantly, this was a precautionary label based on signals, not confirmed causal evidence. The FDA simultaneously mandated that large-scale safety trials be conducted.

The result: TRT prescriptions declined. Many providers stopped prescribing testosterone to men with cardiovascular risk factors — the very population that needed the most evidence. And men with low testosterone and symptoms were left untreated due to theoretical risks.

The TRAVERSE Trial: The Answer

The TRAVERSE (Testosterone Replacement therapy for Assessment of long-term Vascular Events and efficacy ResponSE in hypogonadal men) trial was the study the FDA demanded. Here are the details:

Design: Multicenter, double-blind, randomized, placebo-controlled, non-inferiority trial

Population: 5,246 men aged 45-80 with hypogonadism (testosterone below 300 ng/dL) AND either established cardiovascular disease OR high cardiovascular risk (age 50+ with diabetes, dyslipidemia, hypertension, or other risk factors)

Intervention: 1.62% testosterone gel vs. placebo gel, titrated to maintain testosterone levels of 350-750 ng/dL

Follow-up: Median 33 months (some men followed up to 5+ years)

Primary outcome: First occurrence of a major adverse cardiovascular event (MACE) — cardiovascular death, non-fatal heart attack, or non-fatal stroke

Results:

• MACE occurred in 7.0% of the testosterone group vs. 7.3% of the placebo group
• Hazard ratio: 0.96 (95% CI: 0.78-1.17)
• The non-inferiority margin was met, meaning testosterone was proven to be not worse than placebo for cardiovascular events
• No signal of increased cardiovascular death, heart attack, or stroke

Translation: At replacement doses, testosterone therapy does not increase cardiovascular risk in men with hypogonadism — even in men who already have or are at high risk for cardiovascular disease.

What TRAVERSE Also Showed

Beyond the primary cardiovascular finding, TRAVERSE provided additional data:

Atrial fibrillation: A modest increase in atrial fibrillation was observed in the testosterone group (3.5% vs. 2.4%). This was a secondary finding and needs further study, but it suggests that men with existing AF risk factors should be monitored.

Pulmonary embolism: A small increase in pulmonary embolism events was observed (0.9% vs. 0.5%). This may be related to testosterone's effect on erythropoiesis (increased blood viscosity). Hematocrit monitoring remains important.

Bone fractures: Fewer fractures in the testosterone group, consistent with testosterone's known beneficial effect on bone mineral density.

Other outcomes: No significant differences in prostate cancer, prostate events, or acute kidney injury.

What This Means for Patients

If You're on TRT

You can be reassured that, at physiological replacement doses with appropriate monitoring, your cardiovascular risk is not increased by testosterone therapy. Continue your regular monitoring — but cardiovascular anxiety should no longer be a reason to stop treatment that's improving your quality of life.

If You Were Denied TRT Due to Cardiovascular Concerns

The evidence now supports reconsidering. If you have hypogonadism with symptoms and were told you couldn't have testosterone because of heart risk, that concern is no longer supported by the best available evidence. This is especially relevant for men with:

• Prior heart attack (stable, no acute event)
• Coronary artery disease
• Type 2 diabetes
• Metabolic syndrome
• Hypertension
• Dyslipidemia

At CORAL, Dr. Kim incorporates the TRAVERSE evidence into treatment decisions — meaning cardiovascular risk factors are assessed and monitored, but they are not automatic disqualifications for TRT when it's clinically indicated.

If You're Considering Starting TRT

The cardiovascular safety question should no longer be the barrier. The more important questions are:

• Do you have confirmed hypogonadism (two morning testosterone levels below 300 ng/dL)?
• Do you have symptoms attributable to low testosterone?
• Have other causes of your symptoms been ruled out?
• Are you aware of the other side effects and monitoring requirements (polycythemia, fertility impact, etc.)?

What TRAVERSE Didn't Study

Important limitations to understand:

Supraphysiologic doses were not studied. TRAVERSE maintained testosterone in the normal physiological range (350-750 ng/dL). Men using testosterone at bodybuilding doses (levels of 1,500+ ng/dL) cannot extrapolate these safety data to their use.

Younger men were underrepresented. The average TRAVERSE participant was 63 years old. The cardiovascular safety in men in their 20s and 30s using TRT may differ — though there's no specific evidence of harm in this group either.

Injectable testosterone was not studied. TRAVERSE used daily topical gel. Injectable testosterone (which creates supraphysiologic peaks) may have different cardiovascular effects, particularly through its greater impact on polycythemia.

Long-term (10+ year) safety data aren't available. TRAVERSE followed men for a median of 33 months. Very long-term safety remains extrapolated.

The Broader Context

Testosterone isn't a cardiovascular drug — it shouldn't be prescribed to protect your heart. But it also isn't a cardiovascular risk — it shouldn't be withheld because of outdated fear.

The real cardiovascular intervention for men with low testosterone is addressing the metabolic syndrome that often coexists with hypogonadism: weight management, exercise, blood pressure control, statin therapy when indicated, and smoking cessation. TRT may help with some of these indirectly (improved energy for exercise, modest improvements in body composition), but it's not a substitute for cardiovascular risk factor management.

Moving Forward

If testosterone therapy is on your radar — whether you're starting, continuing, or reconsidering — the cardiovascular evidence is now clear enough to make informed decisions. The conversation should focus on proper diagnosis, appropriate dosing, consistent monitoring, and individual risk assessment.

[Start a visit at coral.clinic/start](https://coral.clinic/start). Dr. Kim practices evidence-based TRT with the monitoring protocols that keep you safe, informed by the TRAVERSE data and ongoing updates to clinical guidelines.