Effectiveness of screening for atrial fibrillation and its determinants. A meta-analysis

Abstract

Background: Many atrial fibrillation patients eligible for oral anticoagulants are unaware of the presence of AF, and improved detection is necessary to facilitate thromboprophylaxis against stroke.

Objective: To assess the effectiveness of screening for AF compared to no screening and to compare efficacy outcomes of different screening strategies.

Materials and methods: Cochrane Central Register of Controlled Trials, EMBASE and MEDLINE from Jan 1, 2000 -Dec 31, 2015 were searched. Studies employing systematic or opportunistic screening and using ECG or pulse palpation in populations age ≥40 years were included. Data describing study and patient characteristics and number of patients with new AF were extracted. The outcome was the incidence of previously undiagnosed AF.

Results: We identified 25 unique (3 RCTs and 22 observational) studies (n = 88 786) from 14 countries. The incidence of newly detected AF due to screening was 1.5% (95% CI 1.1 to 1.8%). Systematic screening was more effective than opportunistic: 1.8% (95% CI 1.4 to 2.3%) vs. 1.1% (95% CI 0.6 to 1.6%), p<0.05, GP-led screening than community based: 1.9% (95% CI 1.4 to 2.4%) vs. 1.1% (95% CI 0.7 to 1.6%), p<0.05, and repeated heart rhythm measurements than isolated assessments of rhythm: 2.1% (95% CI 1.5-2.8) vs. 1.2% (95% CI 0.8-1.6), p<0.05. Only heart rhythm measurement frequency had statistical significance in a multivariate meta-regression model (p<0.05).

Conclusions: Active screening for AF, whether systematic or opportunistic, is effective beginning from 40 years of age. The organisation of screening process may be more important than technical solutions used for heart rhythm assessment.

Fig 1. Details of the study selection.

In total, 1056 articles were found. A primary screen of the abstracts resulted in the exclusion of 947 records. A further 82 were excluded based on the full-text review. This produced 27 articles that met inclusion criteria though representing 25 unique (3 RCTs and 22 observational) studies.

Fig 2. Meta-analysis of new AF incidence due to screening.

Three randomized trials and 22 observational studies were included. The total number of participants was 88 786. Heterogeneity was high at I2 = 95.13% (Q = 534, p<0.05). The incidence of newly detected AF was 1.5% (95% CI 1.1–1.8%). AF—atrial fibrillation.

Fig 3. Subgroup meta-analysis of new AF incidence according to setting.

New AF incidence was significantly higher in studies (n = 12) in which screening was performed in GP setting compared to studies in which screening was done in the community (n = 15): 1.9% (95% CI 1.4–2.4%) vs. 1.1% (95% CI 0.7–1.6%), p<0.05. AF—atrial fibrillation.

Fig 4. Subgroup meta-analysis of new AF incidence according to systematic vs. opportunistic screening.

New AF incidence was significantly higher in studies (n = 14) in which screening was organized in a systematic way in contrast to studies where it was opportunistic (n = 13): 1.8% (95% CI 1.4–2.3%) vs. 1.1% (95% CI 0.6–1.6%), p<0.05. AF—atrial fibrillation.

Fig 5. Subgroup meta-analysis of new AF incidence according to single vs. repeated screening.

New AF incidence was significantly higher in studies (n = 10) in which heart rhythm was measured repeatedly as opposed to studies with a single measurement performed (n = 17):: 2.1% (95% CI 1.5–2.8%) vs. 1.2% (95% CI 0.8–1.6%), p<0.05. AF—atrial fibrillation.

Fig 6. Funnel plot of newly identified AF.

Begg’s funnel plot of newly identified AF was asymmetric suggesting the presence of publication bias. Open circles represent the imputed sudies to adjust the analysis for the effect of potential publication bias. AF—atrial fibrillation.