DENVER — Hiatal hernia is associated with sharply increased risk of atrial fibrillation, according to a large Mayo Clinic study.
“The mechanism of the increased prevalence of atrial fibrillation in patients with hiatal hernia is not known but likely involves the direct mechanical effects of the hiatal hernia pressing on the left atrium or indirect effects through activation of the autonomic nervous system or inflammation,” Dr. Komandoor Srivathsan said at the meeting.
“Of course, it would be nice to show that if you treat the hiatal hernia with modified fundoplication, the atrial fibrillation rate goes down. We're looking into that now in our database. We should have the answer in the next 6 months,” added Dr. Srivathsan of the Mayo Clinic, Rochester, Minn.
The study was undertaken after he and his coinvestigators formed an impression that a disproportionate number of patients at the clinic's large-volume atrial ablation center had hiatal hernias on their preablation CT scans, echocardiography, or both. So the researchers used the Mlinic's electronic records identify the 111,429 adults diagnosed with hiatal hernia during 1976-2006. Among this group were 5,929 patients diagnosed with new-onset atrial fibrillation after they had already received a diagnosis of hiatal hernia.
For purposes of comparison, the investigators turned to published data on the Olmsted County and statewide Minnesota general populations. In this way, they determined that the prevalence of atrial fibrillation in men under age 55 with hiatal hernia was 13-fold greater than in the age-matched general population. Among women under age 55, atrial fibrillation was 15-fold more likely if they had a hiatal hernia.
Moreover, the prevalence of atrial fibrillation in men with hiatal hernia remained several-fold greater than in men without this abdominal defect up until about age 80. Among women, this remained the case even beyond age 80, Dr. Srivathsan continued.
Patients with hiatal hernia and atrial fibrillation were a mean of 73 years old at the time of their dual diagnosis, compared with 61 years for those with either diagnosis alone. The dual-diagnosis group had significantly more hypertension, diabetes, hyperlipidemia, coronary artery disease, heart failure, and sleep apnea.
The dual-diagnosis group had markedly worse long-term outcomes than did the general population. “One you have the combination, it seems to be a strong predictor of congestive heart failure,” the cardiologist observed.
Disclosures: Dr. Srivathsan reported no conflicts of interest.