Mar 08, 2024 This Week in Cardiology Podcast

Plastics and heart disease, the MINT trial letters-to-the-editor and Bayes theorem, and Brugada syndrome are the topics John Mandrola, MD, discusses in this week’s podcast.
www.medscape.com/viewarticle/...
-- TRANSCRIPT --
In This Week’s Podcast
For the week ending March 8, 2024, John Mandrola, MD, comments on the following news and features stories: plastics and heart disease, the MINT trial letters-to-the-editor and Bayes theorem, and Brugada syndrome.
Plastics and Heart Disease
-Plastic Particles in Carotid Plaques Linked to CV Events
The New England Journal of Medicine (NEJM) published an observational study that explored potential linkage of microplastics and nanoplastics (from now on, I’ll refer to these just as plastics) and cardiac events.
This publication was a big event. Nearly 100 news sites have covered it. It’s all over social media. And I need not say how ubiquitous plastics are in our world.
The reason to explore the cardiac question is that a) plastics are ubiquitous, and b) numerous observational preclinical and animal studies have suggested links of plastics to potential cardiac issues.
The mechanisms are speculative but include oxidative stress, inflammation, and apoptosis in endothelial cells.
The many study authors from three centers in Italy, first author Dr. Raffaele Marfella, used an interesting design. They took resected plaque from patients who had undergone carotid endarterectomy (CEA) and assessed them for plastics using biophysics, such as electron microscopy.
These were all asymptomatic carotid lesions. (An aside could be why asymptomatic carotids should have CEA. It’s a good question. Some countries (the United States, for instance) do a lot of asymptomatic carotids, other countries do very few. We won’t get into that debate today.)
-The authors chose asymptomatic lesions to maximize the chances that patients survived the post-procedure period and to minimize interpatient variation in plaque phenotypes.
-They then followed 307 patients for future cardiac events. In all, 257 completed follow-up.
-They had two groups of patients: One group of 150 patients had plastics detected in carotid plaque and 107 patients had no plastics. The primary cardiac endpoint was a composite of myocardial infarction (MI), stroke, or death.
-The most common plastic found was polyethylene (58%); 12% of patients had measurable amounts of polyvinyl chloride. The electron microscopy pictures, which the authors shared in the paper, show jagged-edged foreign particles.
-Over 33 months, the main finding was that patients who had plastics detected were at higher risk for a primary end-point event than those in whom these substances were not detected (hazard ratio [HR], 4.53; 95% confidence interval [CI], 2.00 to 10.27; P 0.001).
-I know; it’s a huge effect size for a cardiac event. To support potential causality, the authors told us there were increased levels of four inflammatory markers in plastics-positive patients.
In sum, this observational, non-random comparison study combined biophysics with epidemiology.
As with many observational studies, there was an attempt to compare groups and assess causality. Of course, the authors say this was just an association; it cannot prove causality. But these words are just veneer. What they said in the conclusions was that patients with plastic detected had higher rates of events.
The NEJM also included an 80-reference review article and a scary editorial. That review included all the things that can be done to limit exposure to plastics.
The lead in the conclusion of the review article:
There is an urgent need for the clinical community to address the growing burden of exposure to EDCs, largely derived from petrochemicals, in order to prevent a broad range of associated health harms.
And then this:
In addition to counseling their patients, clinicians can be critical advocates for policy changes to both decarbonize and detoxify the economy in order to address the combined health threats of petrochemical-derived EDCs and climate change.
The editorialist, Dr. Philip Landrigan, wrote that:
The report by Marfella et al. provides evidence that microplastics and nanoplastics are associated with cardiovascular disease outcomes in humans.
And …
…the finding of microplastics and nanoplastics in plaque tissue is itself a breakthrough discovery that raises a series of urgent questions.
Transcript in its entirety can be found by clicking here: www.medscape.com/viewarticle/...