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Practical Cardiology editorial advisory board member Brett Nowlan, MD, compiled a top 5 list of studies he thought were noteworthy from ESC Congress 2021 and offers his perspective on why he chose each study.
Ahead of ESC Congress 2021, Practical Cardiology reached out to advisory board member Brett Nowlan, MD, a noninvasive cardiologist and board-certified lipidologist at a private practice in Connecticut, to take part in our coverage of the annual meeting. Nowlan’s personal experience provides a unique perspective on data from the ESC’s annual meeting. A practicing cardiologist in the US, Nowlan spent the early portion of his life, including attending medical school, in South Africa. With this additional perspective, Nowlan compiled a list and created a video detailing his picks for the top 5 studies from ESC Congress 2021.
Hello, my name is Brett Nowlan and I am a noninvasive cardiologist and lipidologist. I'm the Director for preventative cardiology and director for men's cardiovascular health at Hartford Healthcare in Connecticut. I'm also the Assistant Professor of Internal Medicine at the Frank Neto School of Medicine.
We've just wrapped up the European Society of Cardiology Congress 2021 and I'd like to share 5 trials and studies which I found interesting or provocative and give you some of my thoughts on these.
The first is the LOOP study. So, this addressed the issue of screening at-risk people for atrial fibrillation using implantable loop recorders and this was published in The Lancet. Now, this did not specifically or exclusively include people who had suffered a prior stroke. All of the patients included were over 70 years of age, and had at least one risk factor for stroke, including hypertension, diabetes, or heart failure or a prior stroke. The primary outcome was the end point of stroke or systemic arterial embolization. So, about 6000 patients were studied and a significant atrial fibrillation episode was defined as 6 minutes in duration or longer. In the loop recorded group, atrial fibrillation was diagnosed in about 32% of participants versus 12% in the standard of care group. Similarly, oral anticoagulation was initiated in about 30% of the patients in the implantable loop recorder group, compared to about 13% of the participants in the standard of care group. Not really surprising.
What was surprising was the lack of clear clinical benefit. So, when stroke was looked at or cardiovascular death or any cause death, there was actually not a statistical difference between the 2 groups. Now, I think this is a very interesting trial because we have all unwittingly embarked on a massive similar experiment with all of our patients who are now wearing smartwatches, which can detect atrial fibrillation. The loop trial should really give us pause in terms of how we respond to this proactively demonstrated or detected atrial fibrillation. Clearly, we do not have it clear as to which patients actually derive benefit from receiving anticoagulation in that setting.
The next study of interest to me was the IAMI study or the Influenza Vaccine after Myocardial Infarction study. This was a multicenter trial looking at 2500 patients, who presented primarily with an ST-elevation myocardial infarction, or a non-ST-elevation myocardial infarction during the influenza season. They were randomized to receive the influenza vaccine or placebo within 72 hours of intervention.
At 12 months of follow-up, there was a reduction in all-cause death, there was an absolute risk reduction of 2.0%. Cardiovascular death also showed an absolute risk reduction of 1.8%. Those results are great, but you should realize that they're actually diluted because about 13% of the patients crossed over from placebo to vaccine and only about 58% of patients who intended to be enrolled were enrolled because this trial was stopped early due to the COVID-19 pandemic. So, I like this trial because it underscores the benefit in the value of vaccines And it also highlights the negative effect of inflammatory viral infections on cardiovascular risk.
My third study of interest is the SSaSS trial or the China Salt Substitute and Stroke Study, which was published in the New England Journal of Medicine. This was an open-label study of 21,000 rural patients in China, who either had a history of stroke or who were older than 60 years of age and had a history of hypertension. The intervention studied was a salt substitute, which was 75% sodium chloride and 25% potassium chloride, and that was compared to using salt which was 100% sodium chloride. The outcomes studied were stroke, major adverse cardiovascular events, all-cause death, and hyperkalemia.
So, after a mean follow-up of 4.7 years, stroke was reduced by 14%, major adverse cardiovascular events was reduced by 13%, and all-cause death was reduced by 12%. All of this was without a statistically significant increase in hyperkalemia. I think this is a great example of a practical, real-world, simple lifestyle intervention showing translation into major cardiovascular benefits and was essentially risk-free.
Something that did not make me happy at all was the abstracts presented regarding the association between saturated fatty acids from different dietary sources and cardiovascular disease risk. This story has been widely disseminated across the internet and social media. This, to me, is an example of many things that are flawed in dietary sites.
So, this study looked at 114,000 people in the United Kingdom without cardiovascular disease and it asked them to report their dietary intake for 2 periods of 24 hours. That was presumed to be their diet for the next 8.5 years. Then, cardiovascular outcomes were gathered by chart reviews and correlations, not causations, were drawn from this data.
Now, using this obviously limited dietary data and using just observational correlations with multivariate corrections, the data showed the following: number 1, there was no association between total saturated fat intake and cardiovascular disease outcomes. Number 2, there was no association between meat-derived saturated fats and cardiovascular outcomes when one corrected for BMI. Number 3, there was no association between dairy-derived saturated fat and cardiovascular outcomes when correcting for BMI. And number 4, there was no association between processed food-derived saturated fat and cardiovascular outcomes. However, this was not the stated conclusion. The stated conclusion was saturated fatty acids from meat was associated with a higher risk of total cardiovascular disease and ischemic heart disease, while saturated fatty acid from dairy was associated with lower risk of ischemic heart disease, although BMI seem to account for a large proportion of these associations. BMI, not the saturated fat. Randomized controlled trials are needed to confirm whether replacing saturated fatty acids from meat by carbohydrates from whole grain or fruit and vegetables may be beneficial in reducing stroke risk. The researcher and colleagues recommend that patients follow the dietary guidelines recommendation to consume less than 10% of daily energy from saturated fat.
Why? The data did not show that. Of course, now, headlines streaming around the world from the study include "Are all saturated fats equally bad for the heart?", "Saturated fat from meat maybe worse for your heart than other foods,", and “Eating saturated fat increases risk of heart disease". So, the conclusions and these headlines are not what the data showed. The suggestion for a plate replacing saturated fatty acids by whole grains, fruit, and vegetables was studied in the largest ever randomized dietary trial, the Woman's Health Initiative, and this intervention showed absolutely no benefit in any measured outcome, including cardiovascular outcomes, including stroke.
Like I said, this trial highlights to me the problems with dietary science. where we are often clinging on to these recommendations that are not based in good data. It's hard to get good data in this arena, but we have to be honest about the data and we have to apply the same scrutiny of data to dietary science that we do to medication science. We would never accept this if it were a medication and then draw the same conclusions, but enough ranting about diet.