The open-access study, published this week in Journal of the American Heart Association, found that people who used cannabis every day had 25 percent higher odds of having a heart attack and 42 percent higher odds of having a stroke compared with those who did not use cannabis at all.

And they found near-linear dose-responses, with more days of use per month associated with higher risk.

One common complicating factor is that people who use cannabis also often use tobacco products, which carry their own increased risk for cardiovascular disease.

Without tobacco use, the higher odds of heart attack and stroke persisted for people who used cannabis. For those without tobacco or e-cigarette use, only the higher odds of stroke remained.

The researchers also looked at age, another complicating factor. Heart disease can take years or decades to develop, but people who use cannabis tend to skew younger.

In all, the researchers concluded that "These data suggest that cannabis use may be a risk factor for cardiovascular disease and may be a risk factor for premature cardiovascular disease," they wrote.

About 74 percent of cannabis users in the study reported smoking cannabis, which could potentially increase the risk of cardiovascular disease much the same way as tobacco cigarettes—a result of inhaling particulate matter into the lungs. It's unclear if edible cannabis products would weaken the association seen in the study.

But, the authors note that there is a biologically plausible link between cannabis and cardiovascular disease.