This study found that AF was not a frequent cause of death by heart failure or sudden cardiac arrest. However, the researchers identified AF as an important cause of stroke in HCM patients. Therefore, they recommend a low threshold for starting HCM patients on anti-coagulants following an initial AF episode.
Researchers in this study analyzed statistics from 1558 HCM patients, 20% of whom experienced AF. 74% experienced only sporadic episodes, while 26% went on to develop permanent AF.
At the time of publication, 91% of the 277 of the patients included in the sample were still alive and between the ages 49 and 75 years old.
According to an accompanying editorial by Italian HCM expert Dr. Paolo Spirito, the outlook for HCM patients with atrial fibrillation has improved over the last twenty years due to significant advances in HCM treatment over that time period such as ICD implantation and myectomy, along with aggressive anti-coagulation for atrial fibrillation patients.
Spirito also noted that it is difficult to predict whether a given HCM patient will go on to develop permanent Afib after a single episode since many will not. Additionally, permanent afib can be well tolerated when there is contemporaneous control of heart rate. Therefore, anti-arrhythmic medications, which can cause unpleasant side effects, may not be necessary for HCM patients with afib as long as anti-coagulation measures are taken.