Apr 16, 2021 This Week in Cardiology Podcast

John M. Mandrola, MD


April 16, 2021

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 April 16, 2021, John Mandrola, MD comments on the following news and features stories.

COVID-19 Trends and Vaccine News

The United States seems in a plateau, but with a handful hotspots, Michigan most notably. The curve in the United Kingdom looks amazing and the New England Journal of Medicine published real-world data from Israel, showing that vaccinating rapidly and vaccinating the most vulnerable has dramatically beneficial effects. The sad news is the global rise in cases and deaths in India, Brazil, Turkey, some EU countries and Canada. Numerous friends tell me of a slow vaccine rollout in Canada, which is weird because it’s always seemed to me that the Canadian healthcare system is the most ideal.

Once again there was another big bad piece of vaccine news. The United States paused use of the Johnson & Johnson vaccine due to six severe clotting cases. This has dominated health news. All reports occurred among women between the ages of 18 and 48, and symptoms occurred 6 to 13 days after vaccination. From what I have read the reactions are similar to the other adenovirus-platform AstraZeneca vaccine mechanism—an atypical heparin-induced thrombocytopenia with thrombosis (HITT)-like issue. I don’t see patients with cerebral venous sinus thrombosis (CVST) but a hematologist told me it is terrible x 100. All of the Johnson & Johnson-related cases have also had thrombocytopenia.

Again, there are numbers to consider. As of taping this podcast there were six reports. Some news stories report this as six cases in 7 million does given, but I don’t think that is correct. Since all cases occurred in young women, a more accurate denominator would be the roughly 1.4 million doses of Johnson & Johnson vaccine given in this age group. That still seems like a very low incidence, but it’s likely the lower bound as the vaccine was only paused this week. Social media is full up with different policy takes on how to handle the rare but horrific complications. The utilitarian take is to continue giving the vaccine. For the podcast, I want to focus on individual decision-making because it resembles medical decisions.

Young people in this age category now have to balance the risk from COVID vs the risk for a life-threatening clotting cascade. I’m not foolish enough to try to figure the COVID-related risk of death or morbidity in a healthy woman. Suffice to say that both risks to a young and otherwise healthy woman are very low. Low enough for it be almost a wash, especially since in many countries, the mRNA vaccines will eventually become available.

My friend Vinay Prasad made a good point on Twitter regarding the psychology of individual decision making. It has to do with rolling dice. A vaccine is like one roll of the dice. But taking a chance on COVID is like two rolls--getting COVID and having something bad happen. Many will pick two rolls of the die in sequence.

There’s also degrees of stochasticity to consider, stochastic meaning randomly determined but not precisely predictable. Severe COVID is definitely stochastic, but even more stochastic, is the chance of CVST after a shot. A person will feel the risk from COVID is somewhat modifiable. They can be more careful, avoid crowds, wear a mask. But with the AstraZeneca or Johnson & Johnson vaccines, it is pure chance with CVST. You get the shot and you wait.

This news makes the podcast because rare but severe reactions of now two vaccines will have major implications globally as it slows the rate of vaccine uptake and will surely slow the ending of the pandemic and should allow for more rational discussion over vaccinating lower risk groups like children.


I want to make a correction on last week’s podcast. Thanks to Dr. Sacha Salzburg who pointed out that I mistakenly said in my concluding remarks on the CONVERGE trial that the Convergent procedure was open chest. It is not; it involves sub-xiphoid incisions and pericardial drains. Thanks for listening so closely.

Dr. Salzburg also wrote that minimally invasive SAVR (surgical aortic valve replacement) was common in Europe and that I should be more careful about citing anecdotes from my geography. Indeed, that is true. Going forward I will be mindful about qualifying any anecdotes as anecdotal.

If you want to leave a comment, and I hope you do, just go to the TWIC link at | Medscape Cardiology and click on comments. I really appreciate the feedback—good or bad.

Vitamin D Screening

JAMA published their latest recommendation against screening for vitamin D. It’s based on a recent systematic review of the benefits and harms of screening and of course early treatment for vitamin D deficiency in asymptomatic adults. The review found no studies that directly evaluated the benefits of screening for vitamin D deficiency.

The review did find 26 randomized control trials (RCTs) that evaluated the effectiveness of treatment of vitamin D deficiency with supplementation. "Among asymptomatic, community-dwelling populations with low vitamin D levels, the evidence suggests that treatment with vitamin D has no effect on mortality or the incidence of fractures, falls, depression, diabetes, cardiovascular disease, cancer, or adverse events," they concluded.

I realize vitamin D may seem tangential, but I cover this topic for three reasons: First, TWIC has great respect for the US Preventive Services Taskforce (USPSTF). The USPSTF is made up of 16 volunteer members who come from the fields of preventive medicine and primary care—generalists who are good at critical appraisal. Most are practicing clinicians. No human comes free of bias, but USPSTF gets pretty close. I see this group as a model for professional society guideline committees, which should have fewer content experts and more generalists with expertise in evidence review.

Second, just because a level of something is low and that low level is associated with worse outcomes, does not mean replacing it improves outcomes. The best analogy is HDL. High HDL generally associates with good outcomes, low HDL with bad outcomes, but no HDL raising agent has passed muster in a trial. To the learners who listen, always, and I mean always, be suspicious of doing things just because it makes sense. Medicine is replete with medical reversals of practices that were done because it made sense. PVC suppression after MI for instance.

Third, this podcast worries a lot about distraction and pill burden. The value in not doing things that don’t work is that you have more time for important stuff. And it is always good for adults to swallow fewer tablets.

Hold or Continue Anticoagulation before PCI?

JACC-Interventions has published an observational study from the SWEDEHEART registry looking at outcomes in two anticoagulation (AC) management strategies before unplanned percutaneous coronary intervention (PCI). This is an increasingly important question because more and more patients are treated with oral AC, usually for atrial fibrillation (AF).

Estimates indicate that about 10% of patients referred for PCI are taking oral AC. No RCTs address the ideal periprocedural strategy of anti-thrombotic meds. The first decision is obviously whether or not to continue the oral AC or interrupt the AC before PCI. Holding the AC may reduce the risk of bleeding as patients will not be on dual antiplatelet therapy and AC—so called triple therapy. But holding the AC also may increase the risk of stroke from AF as well as delay revascularization after an acute coronary syndrome (ACS).

European and American guidelines differ in their suggestions. The European Society of Cardiology (ESC) suggested uninterrupted strategy as the preferred approach, but a 2017 American Heart Association (AHA) statement says to discontinue oral AC (OAC).

Using the SWEDEHEART registry, first author Dimitrios Venetsanos and numerous colleagues compared the efficacy and safety of an uninterrupted OAC (U-OAC) vs interrupted OAC (I-OAC) strategy in patients on OAC who were undergoing an unplanned coronary angiography (CA) and PCI. Over a 12-year period (2005-2017) about 3300 patients had I-OAC and 3100 had U-OAC. This was not a randomized comparison, but the baseline characteristics were not terribly mismatched.

The authors used propensity matching to attempt to get more balance in the co-variates. Major adverse cardiac and cerebrovascular events (MACCE) occurred in 8.2% in both groups. The Kaplan Meier curves are superimposed. Major bleeds occurred in 5.6% vs 6.0% in patients treated with I-OAC versus U-OAC, respectively. The authors also found no significant interaction between the type of OAC on arrival (warfarin vs. direct OAC) in terms of MACCE; but more than 80% of both groups were on warfarin at presentation. As you would expect, length of hospital stay was longer with I-OAC strategy: 5 vs 4 days.

As the prevalence of AF increases, periprocedural decisions regarding oral AC will become an increasingly common issue. The best way to answer the question of U-OAC vs I-OAC is obviously with a trial. In fact, we have two pretty good trials in electrophysiology, BRUISE 1 and 2, which found no advantage to I-OAC before device implantation. So, it can be done.

But in the absence of RCT data, the SWEDEHEART registry data is something. I say this with great caution but this looks to be a notch above many observational studies. Yes, without randomization, there could be confounding; on the other hand, neither group looked better. The lack of major differences in baseline characteristics also suggests qualitatively at least two somewhat similar groups. The fact that most of these patients were on warfarin makes this data hard to extrapolate to the DOACs.

I think we can at least say this large real-world dataset suggests equipoise in the two strategies. To me, the U-OAC would seem the better default, the control arm if you will, mainly because it is the simpler, less intrusive strategy. U-OAC also results in shorter hospital stays, which is positive for costs and probably safety.

This podcast often warns about making causal inferences from non-randomized data, but this is better-than-average observational evidence, and it supports doing a pragmatic RCT like the BRUISE trials. MACCE and bleeding outcomes in such a high-risk group will occur mostly in the short-term and to me it wouldn’t be terribly costly trial to run.

A Superb Intervention at End of Life

While observational studies are not ideal for causal inference, they are very good for documenting trends in care. They can tell us what we are doing. The Journal of the American Heart Association published an observational study on the use of comfort care interventions after ischemic stroke.

First author Dr. Kristie Chu from the University of Texas and colleagues used the National Inpatient Survey from 2006 to 2015 to assess 10-year trends in the use of comfort after an ischemic stroke. This was a big sample of 4.2 million stroke encounters. In total 3.8% used comfort care intervention (CCI). And the good news is that CCI increased over time with a decreasing proportion of patients on comfort care dying in the hospital. Notable was that this increase in CCI occurred alongside the rise in interventional stroke care.

But there were some concerning trends—primarily disparities in use of CCI. Age was a barrier; less than half of the decedents under age 60 years received CCI while all those over the age of 90 received CCI. (Obviously, younger people will more often pursue life-prolonging care, but less than half of a group dying without palliative support is concerning).

Comfort care was also more common in White patients compared with other racial groups. This is consistent with previous studies showing that Black patients with serious illness have lower rates of advance care planning, palliative care use, and end‐of‐life discussions, with higher rates of life‐prolonging measures. There are many reasons these disparities exist, but since I consider CCI one of the most important things a doctor can do, I see this as a serious concern and a matter for much reflection.

The authors also observed geographic disparities, with the lowest rates of CCI in the Northeast and South, and the most in the West. Again, I don’t know why this would be, but variation in something this important also seems worthy of reflection.

I highlight this study because it emphasizes some of the most important notions in all of Medicine:

  • All our patients will die. While hope is often an important feeling to maintain it is definitely not a plan for end of life.

  • The Oath of Maimonides calls on doctors to look after the life and the death of our patients.

  • I loved the naming in this study. Calling the relief of suffering a comfort care intervention is perfect. It feels like the opposite of saying “going palliative” or “withdrawing care.”

Friends, if you remember one thing from this podcast, remember that the choice to pursue CCI at the end of life is simply to choose a different goal. In life-prolonging care the goal is to extend life; in comfort care, the goal is to relieve symptoms, thus to improve the quality of life. CCI never equates to giving up or withdrawing care. It is simply to change the goal to relief of symptoms and suffering—not only of the patient but also his or her loved ones. It is one of the most meaningful things we can do. And I wish I was better at it.


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