Testosterone Replacement and Heart Health — What the Evidence Actually Shows

Few clinical topics have been as distorted by incomplete evidence and media amplification as the relationship between testosterone replacement therapy and cardiovascular risk. The history is instructive: a poorly conducted trial in 2010 raised alarm; subsequent larger, better-designed research substantially corrected the picture. The fear persists long after the evidence moved on.

Where the concern originated

The Testosterone in Older Men with Mobility Limitations (TOM) trial, published in 2010, was stopped early after a higher rate of cardiovascular adverse events in the testosterone group. The trial had significant limitations: it enrolled elderly men with pre-existing cardiovascular risk factors, used higher-than-typical doses, and was too small to draw definitive conclusions. Despite these limitations, the signal it generated shaped prescribing caution and patient anxiety for years.

What larger and better-designed research shows

The TRAVERSE trial — a large, randomized, placebo-controlled trial with over 5,200 men specifically designed to evaluate cardiovascular outcomes — published its primary results in 2023. The findings: testosterone optimization was not associated with increased risk of major adverse cardiovascular events (MACE) in men with hypogonadism and elevated cardiovascular risk. Non-inferior to placebo on the primary endpoint.

The trial did find a higher rate of atrial fibrillation, pulmonary embolism, and acute kidney injury in the testosterone group — findings that warrant clinical attention and monitoring, particularly in higher-risk patients. These are not trivial signals; they inform risk-benefit discussions in appropriate patient populations.

What the meta-analytic evidence shows overall

Systematic reviews of testosterone therapy and cardiovascular outcomes have generally concluded that testosterone therapy, at physiological replacement doses, does not increase cardiovascular mortality in eugonadal men or in appropriately selected hypogonadal men. Some analyses suggest that low testosterone itself is a cardiovascular risk factor — that treating deficiency may be protective in the long run.

The complicating factor is that most cardiovascular outcome studies have focused on middle-aged to elderly men with significant comorbidities. The picture in younger men, women, and patients without pre-existing cardiovascular disease is less definitively studied.

The clinical approach to cardiovascular risk in testosterone therapy

At Revitalize and in evidence-based hormone therapy practice generally, cardiovascular risk assessment is integral to the comprehensive evaluation process:

Baseline cardiovascular status — existing diagnoses, family history, blood pressure, lipid profile — is reviewed before initiating therapy. Hematocrit is monitored because testosterone increases red blood cell production; significantly elevated hematocrit increases thrombosis risk and warrants dose adjustment. Patients with active cardiovascular disease, recent cardiac events, or very high cardiovascular risk require more conservative assessment and often close coordination with cardiology.

For most patients presenting for hormone optimization who do not have significant pre-existing cardiovascular disease, the current evidence does not support withholding testosterone therapy on cardiovascular grounds.

The risk of untreated low testosterone

This part of the conversation is underemphasized. Low testosterone is independently associated with increased all-cause mortality, cardiovascular disease risk, insulin resistance, and metabolic syndrome. The risk-benefit calculation for treatment involves weighing the risks of therapy against the risks of deficiency.

A patient with symptomatic hypogonadism who declines treatment is not choosing the low-risk option. They are choosing a different risk profile — one that includes the documented consequences of sustained testosterone deficiency.

What appropriate monitoring looks like

Testosterone therapy at physiological replacement doses requires monitoring, not avoidance. Standard protocol includes:

• Baseline labs before initiation
• Follow-up labs at 3-6 months after initiation to verify appropriate levels and monitor hematocrit, PSA (in men), and lipid panel
• Annual labs thereafter with clinical review
• Blood pressure monitoring
• Symptom and response assessment

This is not complicated. It is responsible clinical oversight that most patients find entirely manageable.