I saw this study too. Here are my thoughts:
Interesting article that I read fully and my understanding is this: it's not that red meat is the culprit. It's when the carnatine found in red meat interacts with a specific type of gut bacteria...that gut bacteria metabolizes the carnatine to form TMAO which may be a biomarker for heart attacks.
More research needs to be done to determine which gut bacteria (there are millions if not billions, some healthy and some unhealthy) actually cause this reaction. My question is: does someone with a healthy gut (a very small slice of the American population) react the same way to carnatine intake? In one leg of the experiment they gave the patients a course of strong antibiotics that wiped out all of their gut bacteria (good and bad) and after that they showed no increase of TMAO in the blood after eating steak. So clearly its a certain gut bacteria that does this when it comes into contact with carnatine. Most Americans have totally unhealthy guts (due to overuse of antibiotics, diet, etc) that are abundant in bad bacteria (such as candida), and I wonder if that could be the reason for the reaction.
Additionally, my next question would be: Does the presence of TMAO in the blood alone (meaning without an inflammatory environment, and no other markers for cardio vascular disease or heart failure) indicate that someone is more likely to die of a heart attack? What about people who eat right (a paleo, anti-inflammatory diet), supplement to stave off inflammation, get good sleep, good exercise, and are able to successfully manage their stress levels? Those people would have no other factors other than some increase (MAYBE) in TMAO in their blood. Does that alone cause a heart attack.
My educated guess would be NO. But more research is needed to fully understand this. Personally, for me this changes nothing. I will still eat red meat as long as it comes from a high quality source (organic, grass fed) and I am keeping my inflammation levels low and staying generally healthy through good lifestyle choices.