Statin therapy in elderly patients with hypertension reduces the risk of new-onset atrial fibrillation (AF), according to results of a study presented May 9 during a poster session at the 33rd annual scientific sessions of the Heart Rhythm Society. The research team from Taiwan also found that the CHADS2 score could predict the preventive effect of statins in their study population.
Chen-Ying Hung, MD, a fellow at the Cardiovascular Center in Taichung Veterans General Hospital in Taichung, Taiwan, and colleagues pointed out that age and hypertension are high risk factors for AF. Consequently, management of hypertension—a modifiable risk factor—is critical for preventing new onset AF. They also noted that little is known about the effectiveness of statins on primary prevention of AF.
For the study, they enrolled patients 65 years or older who were identified as hypertensive in the National Health Insurance Research Institute (NHRI) database. They began with a sampling from 2000 to 2009 of one million patients, for a final total of 27,002 patients. Of that group, 8.9 percent were receiving statin therapy. Taiwan’s national health insurance program is 99 percent inclusive of the population, Hung and fellow researcher Tsu-Juey Wu, MD, PhD, a professor of National Yang-Ming University School of Medicine in Taipei, Taiwan, wrote by email before the presentation.
In the nine-year follow-up, they found 2,241 patients had experienced AF, as determined through claims data. Their analysis showed that statin users were younger (72.4 years vs. 73.4 years) and had a higher prevalence of ischemic heart disease, diabetes mellitus, stroke and chronic renal disease than non-users.
Overall, statin therapy reduced risk of AF by 19 percent, and the benefit of statin use was present in patients with or without a particular co-morbidity. Additionally, statin use was significantly effective in patients with CHADS2 scores of 2 or greater. But this benefit was not shown in hypertensive patients without other co-morbidities.
The researchers explained that the claims data did not capture either the duration of AF episodes or the types of AF. “Only patients with at least three consensus AF diagnoses at an outpatient department or at least one inpatient hospitalization AF diagnosis were identified,” Hung and Wu said. “This design may miss some paroxysmal AF, especially in those who did not seek a doctor's help, in both statin users and non-users.”
The claims data also did not distinguish the type of statin prescribed, but they said atorvastatin (Lipitor, Pfizer) was the most commonly used statin in Taiwan.
They concluded that their study showed that statin therapy reduces the risk of new onset AF in elderly patients, and that patients with a CHADS2 score of 2 or greater derived more benefits from the therapy than did those with a CHADS2 score of 1.
“This is the first study to explore the relationship between the AF protective effect of statins and the CHADS2 score,” they continued. “Further studies are needed to confirm this relationship before we can suggest using statins in patients with a high CHADS2 score for AF prevention.”