Is Medical Cannabis Hard on the Heart?

Medical cannabis use has steadily increased in the US as evidence continues to compound, demonstrating that it can treat a variety of conditions, such as seizures, mood disorders, and chronic pain. Chronic pain is a particularly attractive indication for medical cannabis, given the rising prevalence of this disorder and the desire by the healthcare community to limit opioid use.

Prior evidence has found that recreational cannabis use was associated with an increased risk of arrhythmia and acute coronary syndrome. While the data evaluating the cardiac safety of medical cannabis is very limited, prior reports have found an association between its use and increased heart rate and myocardial oxygen demand.

In this installment of Talking Therapeutics, we discuss a new study that aimed to address this gap in the literature concerning the cardiovascular safety of medical cannabis use.

Talking Point: Signal for Arrythmia Risk

The new study was a nationwide Danish analysis of 1.88 million chronic pain patients who were either using medical cannabis or other pain medications. Patients were extracted from 2018 through 2021, and the primary outcomes were the absolute risks of first-time arrhythmia (atrial fibrillation/flutter, conduction disorders, paroxysmal tachycardias, and ventricular arrhythmias) and the acute coronary syndrome was reported comparing medical cannabis use with no use.

Medical cannabis use was associated with an elevated risk of new-onset arrhythmia {180-day absolute risk: 0.8% [95% confidence interval (CI) 0.6%–1.1%]} compared with no use [180-day absolute risk: 0.4% (95% CI 0.3%–0.5%)]: a risk ratio of 2.07 (95% CI 1.34–2.80) and a 1-year risk ratio of 1.36 (95% CI 1.00–1.73). Fortunately, there was no associated risk for acute coronary syndrome identified.

Talking Point: Not a Death Blow for Medical Cannabis

No medication for chronic pain is without side effects. NSAIDs are quite cardiotoxic and have been linked to an increased risk for myocardial infarction and stroke, even with short-term use. Opioids carry the risk of physical dependence and addiction, among other side effects.

These signals for cardiovascular safety must be taken into account when recommending medical cannabis, but most patients can still safely use this treatment modality. Additional studies are also warranted to confirm the present study’s findings, especially in light of the relatively homogenous patient population that was studied.