Jun 07, 2024 This Week in Cardiology Podcast

Cannabis and CV outcomes, post-CABG AF, embolic protection devices, emulation of randomization, and a preview heterogenous treatment effects are the topics John Mandrola, MD, covers this week.
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-TRANSCRIPT-
In This Week’s Podcast
For the week ending June 7, 2024 John Mandrola, MD, comments on the following news and features stories: Cannabis and cardiovascular (CV) outcomes, post-cardiac surgery atrial fibrillation (AF), embolic protection devices, emulation of randomization, and an preview of heterogenous treatment effects.
First, I want to offer huge thank you to Professor Andrew Clark and the British Cardiovascular Society (BCS) for inviting me to give the Paul Wood lecture at the BCS annual meeting on Monday.
Paul Wood practiced cardiology in the 1940s to 1960s. In 1950, he wrote what was then the definitive textbook in cardiology. It was 1000 pages by one author!
He became famous in Britian for his bedside skills, strong thinking, and lack of fear of speaking candidly.
He died at age 55 in 1962 of an acute coronary occlusion. When he saw his ECG, he called it "irreversible” and told his caregivers that he should not be resuscitated. He had ventricular fibrillation later that day.
I started my lecture by saying Dr Wood had a different problem than we have now. Dr Wood’s problem was that he did not have enough to do for his patients. One of his papers recommended treating angina by telling the patient to cut down to 10 cigarettes per day from 20 to 25.
Our problem now is that we have tons to do for (or to) our patients. The question is whether we should do these things. And that’s where evidence appraisal comes in.
So, I told stories about evidence appraisal - including many of the major mistakes we made as a field. One theme was how we are misled by overconfidence in observational studies.
I’ve been honing this lecture for months. There are good stories to tell about using evidence. It’s why I like doing this podcast.
Cannabis for Chronic Pain and CV Safety
- It Sure Looks Like Cannabis Is Bad for the Heart, Doesn't It?
- Cannabis Use Tied to Increased Cardiovascular Risk
- Medical Cannabis for Chronic Pain Tied to Arrhythmia Risk
There was a tale of two observational studies recently. One strong. One weak.
Dr. Anders Holt and his team led by Morten Lamberts at the University of Copenhagen have published a nice study of CV safety for medical cannabis use as a pain reliever.
This is an important topic to study, for multiple reasons:
- Chronic pain is a serious problem, not least because the relief of pain comes with the potential for adverse effects. Non-steroidal anti-inflammatory drugs have known CV and renal complications. The dependence issue with opioids surely is an even more serious complication. The utter tragedy of our US opioid crisis is under-appreciated.
- Second, cannabis is pharmacologically active and has CV effects. And there is little empirical data on its use.
- Third, as always, you’d want to have proper randomized controlled trials (RCTs) to really know how cannabis stacks up against other pain relievers, but there are no RCTs, and there are not likely to be any in the near future.
Observational data is going to be all we have with cannabis for a long while. Many countries have legalized medical uses of cannabis, Denmark included.
A recent JAMA Network Open paper, first author, Lillian Gelberg reports that in the UCLA system, nearly one in five people report cannabis use. Of those, about one-third meet criteria for cannabis use disorder.
Cannabis use is a big deal, and worthy of study.
The Danish paper:
The DANISH registry allows for high quality observational data. Part of the universal Danish healthcare system involves a national registry, which captures prescriptions filled as well as outcomes in all Danes that use the universal healthcare system.
When I was in Copenhagen, Dr. Lambert showed me the registry, and a bit about how it works. It’s an amazing resource for asking questions about associations, finding adverse effects of therapy, or describing temporal trends.
- Dr. Holt and his team identified patients (median age 59) with chronic pain who initiated a first-time treatment with medical cannabis between 2018 and 2021. They had about 5400 patients.
- They then matched these in a 1:5 ratio with 26,000 control patients who also had chronic pain. Matching also included age and sex.
- The two major outcomes of interest were arrhythmia of any sort and acute coronary syndrome (ACS).
- Diagnoses of pain included mostly musculoskeletal, but also cancer and neurologic pain. About one-third were unspecified.
- The 5400 patients who filled a cannabis prescription could have taken three different formulations - CBD alone, CBD/THC, or THC alone.
Transcript in its entirety can be found by clicking here: www.staging.me...