Genetic analysis links high blood pressure and AFib

An estimated 12.1 million people in the United States will have AFib in 2030, according to the Centers for Disease Control and Prevention (CDC)Trusted Source. In 2018, AFib was the underlying cause for more than 25,800 deaths, per the CDC. In addition to causing an irregular heart rate, this condition can lead to lightheadedness, extreme fatigue, shortness of breath, and chest pain. AFib also increases the risk of stroke, accounting for about 1 in 7 strokes, according to the CDC. Because of how earlier studies were designed, though, the results didn’t provide a full picture of how these two conditions are related. Complicating things, both conditions share many of the same risk factors — including older age, obesity, diabetes, and inflammation — which could explain why high blood pressure and AFib often occur together. To gain a better understanding of how the two conditions are related, the authors of the new study examined genetic data from more than 1 million people of European ancestry. Their analysis suggests that when both conditions occur together, high blood pressure is likely the cause of AFib. This would mean that in many cases, AFib is preventable through medication and lifestyle changes that reduce high blood pressure. “Together with other [similar genetic] studies, our findings confirm the hypothesis that [AFib] is preventable,” wrote the authors in the new study. Shin said the size of this new study group was impressive. In addition, the use of genetic analysis to explore the link between high blood pressure and AFib — and to take into account other risk factors — was an “innovative” approach. However, Shin cautions that because participants included in the study were all of European descent, the results may not apply directly to other racial or ethnic groups.

Study fits with what’s known about AFib

Dr. David Stuhlmiller, of RWJBarnabas Health Emergency and Hospitalist Medicine Services and Robert Wood Johnson University Hospital Rahway, said the study makes sense medically, given what we know about the causes of AFib. “We understand that atrial fibrillation is caused by stretching of the chambers of the heart,” he said. This can stretch the muscles and disrupt the conduction of electrical signals through the heart. “Since hypertension stretches the muscle of the heart,” he said, “it naturally follows that hypertension may contribute to the development of atrial fibrillation.” However, Stuhlmiller said there are certain limitations to the study. One, researchers didn’t provide information on whether study participants were receiving treatment for high blood pressure with medications such as beta-blockers or angiotensin converting enzyme (ACE) inhibitors. By reducing blood pressure, these treatments could have reduced a person’s risk for developing AFib, which might have affected the results of the genetic analysis. Also, Stuhlmiller said the study would be more useful clinically if the authors had been able to show how much the blood pressure — both systolic and diastolic — would need to be lowered to reduce a person’s risk for AFib. High blood pressure isn’t just a risk factor of AFib. It’s also a major risk factor of heart disease and stroke. This makes managing high blood pressure an important health goal for anyone, but especially for people who already have AFib. “For those with AFib, it’s critically important to know that treating blood pressure — in addition to being physically active, treating sleep apnea, avoiding excess alcohol, and weight loss for those who are overweight — is a remarkably effective strategy for treating AFib,” Hurst said.