Exploring the Link Between Blood Fatty Acids and Cardiovascular Health Outcomes in the STRENGTH Study

Cardiovascular disease (CVD) is responsible for about 1 out of every 5 deaths in the US; that's over 700,000 people. Heart attacks and strokes make up the majority of deaths from CVD. Many research studies have been done to try to find new ways to lower people's chances of developing CVD. We believe that one of the safest ways to lower risk for CVD is to include more fish in your diet. Fish are rich in "omega-3 fatty acids." These are parts of the fat in fish, and they have been shown in many studies to be heart healthy. In addition to eating more fish, some doctors recommend that their patients take fish oil capsules which contain omega-3 in a more concentrated form, so even if people don't like fish, they can get more omega-3 in their diets by supplementation.
One large study, called the STRENGTH study, was done to see if a new type of omega-3 supplement, called Epanova, could help prevent heart problems. The study included about 13,000 people from 22 countries who were at high risk for heart disease. Half of the participants were given Epanova and the other half received corn oil (used as a neutral comparison). After 5 years, it turned out that there was no difference in the number of heart attacks or strokes between the two groups. As a result, the company behind the study decided not to continue with Epanova.
One of the unexpected findings in the STRENGTH study was that the chances of developing a condition called “atrial fibrillation (AF)” (AF is a heart rhythm problem where the upper and lower parts of the heart beat out of sync) was somewhat higher in the patients in the Epanova group compared with the control group. It is fairly common in older people, but nobody expected that fish oil – which has otherwise been seen as both safe and cardio-protective – might cause AF. This is an unsolved mystery from the STRENGTH study, and our goal is to dig more deeply into the data to try to figure out why this happened, and which patients were the most likely to develop AF while on omega-3.
To do this, we will look at the existing STRENGTH study data. We’ll identify the people who developed AF during the study and compare them with those who did not. We will look at factors like age, gender, medical history, medications, heart tests (like Electrocardiograms [ECGs]), and blood tests to see what differences might exist. Our goal is to help doctors figure out which patients might be at higher—or lower—risk of developing AF when taking fish oil supplements.
This has major medical implications because there are millions of people currently taking fish oil supplements for heart health, and if there really is some possible harmful effect, we need to know about it. Our proposal seeks access to the data from the STRENGTH study in order to answer this question.