ADT and the Risk of Major Adverse Cardiovascular Events - Episode 2
Dipti Gupta, MD, MPH: It is important to understand the role of androgens in cardiovascular health and well-being before dwelling into the pathophysiology of ADT [androgen deprivation therapy] and its effect on cardiovascular risk. So it turns out that androgens have a significant cardioprotective effect. In the 1990s, there were a multitude of studies that looked at the role of androgens as coronary vasodilators. So if you inject it intracoronary, testosterone led to coronary dilatation. In men with established coronary artery disease, testosterone, when given, prolongs the time to ischemic ST depression on treadmill testing. Furthermore, testosterone helps with plaque stabilization by inhibiting platelet aggregation and promoting fibrinolysis and clot degradation.
As we all know, testosterone also has favorable effects on body composition. It helps improve and increase lean body weight. Meaning it helps to gain muscle mass, which also improves insulin sensitivity. Last but not the least, we know studies have shown that men have shorter QT interval compared with women. In an NHANES study of greater than 700 participants, the higher the testosterone level, the shorter the QT interval. Now, even though we don’t know the clinical ramifications of this finding, we do know that prolonged QT is anti-arrhythmic. So we can speculate that shorter QT intervals probably lend anti-arrhythmic properties.
We can almost assume, and we already know, that there are a lot of shared risk factors between prostate cancer and cardiovascular disease—by virtue of risk factors, as well as age, as well as the demographic. So at an addition to that, some of the therapies—including androgen deprivation that is used for prostate cancer—often tend to have cardiotoxic effects. We’ll talk about that a little bit more in the future, but because of all those reasons, it is not surprising that cardiovascular mortality, the big cause of mortality in patients with prostate cancer, in most studies has shown that it trails prostate cancer mortality by only a little bit. So it’s a significant amount of patients with prostate cancer who actually die of cardiovascular reasons, not of prostate cancer itself.
Transcript Edited for Clarity