A new study raises questions about whether men who take testosterone replacement therapy are actually at risk of testosterone heart attack side effects.

At the University of Texas, doctors analyzed the records of more than 6,000 patients and found there was little correlation or none at all between a myocardial infarction and the use of testosterone injections. However, there are two key caveats to keep in mind when analyzing these results.

One is that the researchers solely focused on injectable therapies. However most of these low-T lawsuits revolve around the use of creams and gels, which were not analyzed over the course of the trial. Therefore it is unclear whether the delivery mechanism could play a role in the possibility of developing stroke, heart attack or other related testosterone side effects.

Additional factors that several studies in New York City, with a similarly large patient population, noted that a key risk factor for AndroGel side effects was a previous history of heart problems. It’s not clear just how many men may be at risk, even if they have no prior history.

According to the Centers for Disease Control, half of the men who died suddenly of heart disease had no previous symptoms. Moreover, the risk factors for heart disease are present in half of all men including diabetes, poor diet, physical inactivity, and excessive weight. Therefore it is unclear how many men may have undiagnosed problems that could cause a heart attack.

Compounding that, according to many low-T lawsuits, is the question of whether the testosterone replacement therapy products are even necessary. A recent study indicated that just a fraction of men who received prescriptions for medications linked to AndroGel side effects even received hormone tests.