AF statistics from the real world

GENOA, ITALY. Atrial fibrillation (AF) is now considered epidemic and is one of the most important healthcare issues and a considerable contributor to overall healthcare expenditures. It is estimated that the worldwide prevalence of AF is about 1%, but only relatively sparse data is available as to how the condition is actually treated and how effective treatment is in the real world. A just-released study from the Italian College of General Practitioners and the Italian Association of Hospital Cardiologists aims to provide data in regard to the prevalence and treatment of AF in Italy.

In Italy every resident is registered with a general practitioner (GP) who cares for their patients and keeps track of their clinical history. Most GPs in Italy use standardized software to record patient data and thus extensive, directly comparable patient records are available for medical research. The present study involved 233 GPs and their 295,906 patients aged 15 years and older, of whom 6,036 (2%) had been diagnosed with AF during the previous 5 years. The GPs completed electronic questionnaires to provide detailed demographic and clinical characteristics of their AF patients and to detail their treatment protocols.

Amongst the 6036 patients with AF, 20.2% had the paroxysmal variety, 24.3% had persistent AF, and 55.5% were in permanent AF. The prevalence of AF was 0.16% in patients between the ages of 16 and 50 years, 9% in those aged 76 to 85 years, and 10.7% amongst those older than 85 years. AF was symptomatic despite therapy in 74.6% of patients and was associated with heart disease in 75%. Only 73 (1.2%) of AF patients were classified as having “lone” AF, oddly enough defined as AF without accompanying heart disease, hypertension, heart failure, chronic obstructive pulmonary disease, diabetes, renal failure, dementia, cerebrovascular disease, obesity, smoking, alcohol abuse, hyperthyroidism, and hypothyroidism – a select group indeed!

After extrapolating the data obtained in the study to the entire Italian population of the same age and gender, the prevalence of AF in Italy was determined to be 1.85%, which is substantially higher than previous estimates for the USA (California) of 0.9%, for China at 0.61%, and for Scotland at 0.94%. However, the Italian estimate is in line with prevalence in Iceland reported to be 1.9% in 2008.

Drug treatment protocols were fairly evenly split between rhythm control (44%) and rate control (55%). Beta-blockers and digoxin were the most commonly used rate control drugs, whilst amiodarone was the most commonly used rhythm control drug, followed by flecainide and propafenone. Catheter ablation was performed in only 174 patients (2.9%), mostly in cases of persistent AF. The GPs considered the procedure to be effective in only about 50% of cases – a much lower success rate than reported by centers actually performing ablation procedures. A total of 166 patients had a pacemaker installed with an unknown number undergoing AV node ablation as well. About 28% of patients on rhythm control drugs were also taking an oral anticoagulant (warfarin), whilst 60% of patients on rate control were doing so.
Zoni-Berisso, M, et al. Frequency, patient characteristics, treatment strategies, and resource usage of atrial fibrillation (from the Italian Survey of Atrial Fibrillation Management [ISAF] Study). American Journal of Cardiology, December 27, 2012 [Epub ahead of print]

Editor’s comment: This study confirms that the prevalence of AF may be far higher than estimated in previous studies and that current treatment modalities are ineffective in about 75% of patients.