For Screening for Atrial Fibrillation, the Pulse Is the Thing

BIRMINGHAM, England, Aug. 3 -- When seeking to reduce the risk of stroke in older patients by screening for atrial fibrillation, a pulse-based system is an effective approach, found researchers here.

In a multicenter study, a British team found that "opportunistic" screening by an irregular pulse, followed by electrocardiography if needed, was as effective as systematic population screening and more sensitive than non-systematic case finding.

"This finding suggests that routine electrocardiography within this population is unnecessary for the detection of atrial fibrillation as long as healthcare professionals are conscientious about feeling the pulse," F.D. Richard Hobbs, M.B., Ch.B., of the University of Birmingham, and colleagues, reported in BMJ Online First.

The two screening strategies were similar in detecting atrial fibrillation and both were almost 60% better than non-systematic case finding.

The cluster randomized trial, conducted at 50 primary care centers in England, included 14,802 patients, 65 or older, with further randomization to the two intervention practices. Screening took place over 12 months from October 2001 to February 2003.

The detection rate of new cases of atrial fibrillation was 1.63% a year in both intervention practices and 1.04% in control practices (difference 0.59%, 95% confidence interval 0.20% to 0.98%).

Systematic and opportunistic screening by pulse-taking detected similar numbers of new cases (1.62% and 1.64%, difference 0.02%, ?0.5% to 0.5%).

In the opportunistic screening group, there were 75 new cases of atrial fibrillation and 74 new cases in the systematic screening group.

Of 1,940 patients (75%) who returned a questionnaire and had electrocardiography in either group, almost all thought screening was important and said they had received sufficient information before screening.

The study had certain limitations, the investigators noted. The findings were complicated by the fact that the control population had a higher prevalence of atrial fibrillation at baseline, assumed to be a random finding, although it had to be accounted for in the analysis.

The data could not directly suggest how often screening should take place, the researchers wrote.

Also, they said, still to be determined is how antithrombotic treatment of incident cases can affect the cost-effectiveness of any screening program inasmuch as treatment would be started earlier, but outcomes might differ.

As the detection rates were essentially identical for the two methods, the more labor intensive, costly, and intrusive approach with systematic screening cannot be justified, Dr. Hobbs said.

Furthermore, systematic screening was much less acceptable to patients overall, with more than 20% positively declining the offer and more than 26% not responding.