Oct 2, 2020 This Week in Cardiology Podcast

John M. Mandrola, MD


October 02, 2020

Please note that the text below is not a full transcript and has not been copyedited. For more insight and commentary on these stories, subscribe to the This Week in Cardiology podcast.

In This Week’s Podcast

For the week ending October 2, 2020, John Mandrola, MD comments on the following news and features stories.

The EXCEL Trial (Again)

EXCEL, the largest RCT of percutaneous coronary interventions (PCI) vs coronary artery bypass graft (CABG) for patients with left main coronary artery disease (CAD) cannot seem to avoid controversy. The controversy centers on three basic issues: rates of death and MI, and selective publishing. The controversy is detailed in a news article by Steve Stiles and a column by me.

Now, 4 years after the original paper, the EXCEL authors have published a complicated analysis in which they attempt to correlate periprocedural MI as defined by a) the protocol-defined way that depends greatly on enzymes, or b) the UDMI in the PCI and CABG arms with future cardiovascular and all-cause death.

They find that the protocol definition correlates with future death with a similar hazard in both the PCI and CABG arm. But the UDMI (significantly) predicts future cardiac death only after CABG but not PCI. Their conclusion is that UDMI is not a fair or useful thing to measure while their protocol’s definition of MI is.

Along with this new paper, The Journal of the American College of Cardiology (JACC) published an editorial that helps counter the authors contention. Dr. Donald Cutlip had to delve deep into the Appendix to show that the significance of the correlations were statistically quite precarious. I outline the details in my column.

The specific message is that CABG is clearly the superior treatment for patients with left main coronary artery disease. But the general lesson is that these are famous and highly prolific authors who have influenced guidelines in numerous areas of interventional and structural cardiology. Many of them have financial relationships with stent makers. They clearly had this important prespecified data (MI per UDMI) that looked bad for PCI; they chose not to publish it (twice); they called it fake when someone else published it; and then 4 years on, they publish essentially the same data dressed up in a complex analysis using multivariate regressions.

If this mess isn’t sorted out, trust in clinical science diminishes. While I greatly respect Dr. Fuster, I disagree with his assessment that this paper settles the controversy.

Vitamin D and COVID-19 Science

Medscape has a feature article from Dr. Alok Patel, a pediatric hospitalist, who urges doctors to be louder about fake COVID cures. He is right and it’s a good feature. But Dr. Patel’s focus on the most egregious fake cures and conspiracy hoaxes reminds me of us electrophysiologists trying to treat a disease caused by scar (atrial fibrillation) by creating more scar: it misses the upstream causes.

I would submit that what is being laid bare in the pandemic are the results of widespread hubris and long-standing scientific overreach. Think about it: week after week, even before the pandemic, but surely worse during the pandemic, medical publishing offers up studies that will bring pageviews.

A few weeks ago, a terribly flawed paper on cardiac MRI after COVID brought unnecessary fear to the public, but was a smashing success for the journal, because it brought hundreds and thousands of pageviews and will surely bring tons of citations. Yet is a broken study.

Now, a retrospective chart review in a few hundred patients in Diabetes Care purports to show diabetic patients who are well enough to be on an oral diabetes medicine have fewer COVID-19 complications than diabetic patients sick enough to be on insulin. This is lunacy. Of course, sicker people do worse with COVID.

Another example is Vitamin D. Recent studies correlate Vitamin D with COVID-19: Low Vitamin D is bad; normal Vitamin D is protective. Instead of leaping to causal claims about Vitamin D and COVID-19, what we ought to do is teach the public the lesson of Vitamin D that has been obvious for years: Low Vitamin D levels are associated with bad outcomes, but every single RCT that studies replacing Vitamin D with pills has failed to show benefit.

The conclusion is obvious: almost all patients with low Vitamin D have low levels because they are too sick to go out and play in the sun. The diseases and conditions that makes them too sick to go out and play are what makes them have worse outcomes—you can’t replace that with a pill.

The obvious solution is to not incentivize the publishing of howlers. Like AF, the solution is upstream.

Time-Restricted Eating

Dr Ethan Weiss and colleagues at University of California San Francisco did something remarkable—they conducted an RCT in nutrition science. They studied the weight loss effects of time-restricted eating vs a standard diet of three structured meals. It was an app-based study and both groups got reminders about eating time. The short story is that in this RCT of 100+ overweight volunteers, time-restricted eating did not work. Both groups lost a few pounds but there was no difference between groups. They also found no difference in lipids, insulin, and cardiometabolic markers such as blood pressure.

There was a suggestion that those in the time-restricted eating group may have lost more lean mass than fat mass—that is a cautionary finding. One phrase in the conclusion is particularly important: Time-restricted eating, in the absence of other interventions, is not more effective in weight loss than eating throughout the day.

This makes perfect sense. Time-restricted eating probably causes weight loss because it reduces calories. But so does being mindful about your intake eating regular meals. So I think the crew from UCSF has not proven that time-restricted eating is not useful. Instead, they have shown that time-restricted eating alone is no better than motivated mindful attention to eating three healthy meals a day.


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