ECMO for COVID; Heart Attack Treatment in High-Income Countries; Screen for COPD?

Allergies & Asthma

TTHealthWatch is a weekly podcast from Texas Tech. In it, Elizabeth Tracey, director of electronic media for Johns Hopkins Medicine in Baltimore, and Rick Lange, MD, president of the Texas Tech University Health Sciences Center in El Paso, look at the top medical stories of the week.

This week’s topics include use of ECMO in people with COVID, variations in treatment of heart attack in high-income countries, variations in excess mortality during COVID, and screening for COPD.

Program notes:

0:40 ECMO in people with COVID

1:40 844 patients on ECMO

2:40 Bias toward who gets on ECMO

3:30 Treatment after heart attack in 6 high-income countries

4:30 Death within 1 year of admission

5:30 No country excelled in all of the outcomes

6:00 Excess mortality from external causes during COVID

7:00 17,000 additional fatalities

8:02 Ethnic groups with higher rates of poverty

9:00 Screening for chronic obstructive pulmonary disease

10:01 Can treatment improve quality of life

11:36 End

Transcript:

Elizabeth Tracey: During COVID, how was excess mortality experienced by minorities?

Rick Lange, MD: How does treatment of heart attack vary across high-income countries?

Elizabeth: What’s the impact of ECMO, extracorporeal membrane oxygenation, in people with COVID-19?

Rick: And should we be screening for COPD in people without symptoms?

Elizabeth: That’s what we’re talking about this week on TT HealthWatch, your weekly look at the medical headlines from Texas Tech University Health Sciences Center in El Paso. I’m Elizabeth Tracey, a Baltimore-based medical journalist.

Rick: And I’m Rick Lange, president of Texas Tech University Health Sciences Center in El Paso, where I’m also dean of the Paul L. Foster School of Medicine.

Elizabeth: Rick, I’m going to turn right to the BMJ. This is a look at ECMO, extracorporeal membrane oxygenation, in people with acute COVID-19. This is something, of course, that lots and lots of people — I have seen many patients who have been on this during the pandemic and this is a pretty exhaustive look, to this point at least, of what is the impact of ECMO and should we try to expand resources in that direction for more people?

This is a study that looks at data from a lot of different places: 30 countries, 5 continents, 7,300+ adults admitted to the ICU with either clinically suspected or laboratory-confirmed SARS-CoV-2 infection. They used ECMO in some of these folks when their oxygen saturation dropped and then they compared that with conventional mechanical ventilation without ECMO. Their primary outcome measure was hospital mortality within 60 days of admission.

844 of them, or 11.5%, were put on ECMO. They found that ECMO was most effective in those patients who were younger than 65 years of age and also were put on ECMO during their first — like at the beginning, rather than later on in their clinical course.

The more trouble you had with your oxygen level, the less likely you were to really benefit from ECMO, especially as time went on. ECMO, of course, is a very intensive and very expensive intervention to employ, and trying to determine who really is going to best be able to benefit from that is important.

Rick: For those individuals that may not be familiar with ECMO, for people that have severe lung injury, as occurs in this particular case due to COVID, and can’t get oxygen into their blood, it takes the blood from the patient, it routes it through a machine in which oxygen can be supplied to the blood, and it’s returned to the patient.

Here is the major issue I have with this particular study. As you mentioned, it’s observational and there is already a bias towards who would get on ECMO. If you think the person is so sick they may not benefit from it, they wouldn’t get on it, and hence they would fall into that category that have mechanical ventilation, and they would do poorly.

There is no mention in this particular trial of the two groups how they compared, those who were on ECMO versus those that weren’t on ECMO, in terms of their comorbidities and other similarities or disparities. This is, in my opinion, a hypothesis-generating study. It doesn’t prove that ECMO is beneficial, but suggests that it may be and we need to compare comparable groups.

Now, you’re right. If you are going to try something like this, you might think, “Gosh, it would be the people that would be most likely to tolerate it — those under the age of 65 or those that are started on it early.” But, again, this particular study because it isn’t a randomized trial really doesn’t answer the question in my mind.

Elizabeth: More to come. Which of yours would you like to turn to?

Rick: Well, since we are in the BMJ, let’s talk about the other study: the variation in revascularisation, percutaneous coronary intervention, or bypass surgery, and outcomes in individuals that presented with an acute heart attack in six different high-income countries.

This was a cross-sectional study that looked at how people did in the United States, in two provinces in Canada, England, the Netherlands, Israel, and Taiwan. It looked at people over the age of 66 that were admitted with a heart attack over a period of about 7 years from 2011 to 2017.

You’d think that if treatment was known and you had a high-income country, they would all have very similar types of treatment. What we found is that there is a huge variation from country to country. For example, percutaneous coronary intervention ranged from 37% in England to 79% in Canada and 72% in United States. Same thing when you looked at bypass surgery — it was about three times more likely to happen in the United States than in Netherlands. Then when we looked at mortality, death within 1 year of admission ranged from 19% in the Netherlands to 28% in the United States, and even 32% in Taiwan.

Unfortunately, this study doesn’t tell us why there is such a huge variation in use of these procedures, or why there is a difference in mortality. But what you can see from this study is that the use of procedures doesn’t improve mortality.

What are we missing in this? We are missing the patient-level information. Were the people in the U.S. sicker? Do they have bigger heart attacks? Or do they have more underlying conditions and that’s why they ended up not having a better outcome? All we can conclude from this particular study is there is a huge disparity even among high-income countries. Of all the countries, the U.S. had the shortest hospital stay and the lowest readmission rate. Unfortunately, it didn’t translate to a lower mortality in the U.S. population.

Elizabeth: Right. Isn’t that interesting, especially as we are moving toward this globalization? Certainly information and training in all of these procedures is available globally.

Rick: Yeah. There is no particular country that excelled in all of the outcomes.

Elizabeth: All right, so if you were addressing this, what would you say? Would you say that this is a call toward a need for more comprehensive data and standardization?

Rick: Well, either some countries are underutilizing some procedures or some countries are overutilizing them. What can we learn from these countries that have the lowest mortality?

Elizabeth: Very good point. Let’s turn to JAMA Internal Medicine and this is addressing the issue of what they call excess mortality from external causes during the COVID-19 pandemic and how those are related to racial and ethnic disparities.

We already know that there were profound racial and ethnic disparities in COVID-19 deaths during the pandemic, but these are taking a look at other things. They use something that I was unfamiliar with and I don’t know if you knew about this particular database. It’s called the Wide-ranging Online Data for Epidemiologic Research, so called WONDER, and I’m going to call it that if I use that again. It’s a database from the CDC to look during the pandemic how many additional fatalities did we find and were they related to this racial and ethnic bent that we’re looking at in so many other areas right now.

They cite that there is a couple of public health crises that are going on in addition to COVID-19. Those are the opioid overdose epidemic and structural racism. There were more than 17,000 additional fatalities from these external causes. These external causes: homicide, suicide, transportation, and drug overdoses from March through December 2020. Black individuals — highest estimated excess homicide deaths per capita, overall external causes highest among American Indians and Alaska Natives, lower than expected suicide deaths. With regard to excess transportation fatalities, we only saw those among Black individuals.

Rick: They estimated these excess mortalities by comparing death data from 2015 to February of 2020. Then they looked at it after COVID and compared those two time periods. That’s how they accounted for excess deaths. Trying to tie this either to COVID or structural racism is a little bit more difficult. I’m not saying that it couldn’t be due to it, but these are again relationships and it doesn’t actually prove causality.

Elizabeth: Oh, yeah. Well, I don’t think there is any question about that. But there is also no question about the fact that these ethnic groups experience higher rates of poverty, unemployment, housing instability, food insecurity, and decreased access to healthcare, or simply choose not to access healthcare, as we have also talked about during the pandemic.

Rick: Right. But we have talked before about with regard to opioid and drug overdose is that that has particularly hit Caucasians, for example. It’s one of the few reasons why the lifespan over the last several years has decreased. That’s due to opioid overdose. There are clearly structural issues that need to be addressed to provide health equitably across all races and all ethnicities. There is no question about that. Whenever there is a stress in the system — as occurs with COVID or any type of economic stress — it actually exacerbates these.

Elizabeth: Yeah. Then, finally a look at your last one and that’s in JAMA.

Rick: This is talking about screening for chronic obstructive pulmonary disease or what we call emphysema, which still remains one of the leading causes of death in the United States. It’s known that about three-fourths of individuals with COPD actually remain undiagnosed. The predisposing factors for COPD are very clear. It’s cigarette smoking and exposure to environmental smoke or inhalants.

In 2016, the United States Preventive Services Task Force reviewed the question: Should we be screening for COPD in people without symptoms? They said that there was no evidence that screening in asymptomatic adults resulted in improved outcomes. That was 2016. Fast forward 6 years later, they look at the additional data and it’s centered around three questions: whether the screening for COPD improved health-related quality of life, or did it reduce morbidity or mortality in asymptomatic individuals. The answer was, there is no data that shows that.

The second question was whether the treatment of mild to moderate COPD in these asymptomatic individuals could improve quality of life or reduce morbidity or mortality. Unfortunately, there is no evidence that treating these individuals, even if you could find out who they were, we don’t have any evidence that the treatment actually improves outcome.

The third question is, are there any adverse effects of treating COPD in these people that are asymptomatic, and there is some observational data that suggests that putting some of these people on medications may actually lead to harm.

Elizabeth: I’m guessing that at some point there is going to be some kind of molecular markers that are going to show us that somebody is headed in that direction and it’s potentially possible that screening that way might be helpful.

Rick: The screening will only be helpful if we have a treatment that changes the overall outcome. We know what the primary recommendations are. It’s to stop cigarette smoking and to prevent exposure to inhalants. By the way, that should occur whether or not someone has COPD because that puts those individuals at risk for COPD.

Elizabeth: We can say, of course, that everyone should quit smoking.

Rick: Yeah, and there is no question about that. Again, we are not talking about people that have cough. We’re not talking about people that have frequent bronchitis. These are oftentimes early symptoms of COPD and those individuals should be screened, because we know that if they have those symptoms, the treatments can delay or decrease the number of exacerbations and also decrease the decline in lung function. Those individuals’ symptoms should actually be evaluated.

Elizabeth: OK. On that note then, that’s a look at this week’s medical headlines from Texas Tech. I’m Elizabeth Tracey.

Rick: And I’m Rick Lange. Y’all listen up and make healthy choices.

Leave a Reply

Your email address will not be published. Required fields are marked *