In patients who recently had an acute ischemic stroke, prolonged Holter monitoring identified significantly more cases of atrial fibrillation than standard care, a recent study found.
The open-label trial included patients in Germany who were 60 years or older when they presented with an acute ischemic stroke and sinus rhythm and no history of atrial fibrillation. The patients were randomized to 10 days of Holter EKG monitoring at baseline, 3 months, and 6 months (n=200) or standard care, including at least 24 hours of rhythm monitoring (n=198). Results were published online by The Lancet Neurology on Feb. 7.
After six months of follow-up, atrial fibrillation or flutter of at least 30 seconds had been detected in 14% of the monitoring group and 5% of the control group (difference, 9%; 95% CI, 3.4% to 14.5%; P=0.002). Researchers calculated a number needed to screen of 11. They concluded that the enhanced monitoring was better than standard care and should be considered in such patients if detection of atrial fibrillation would change medical management (e.g., initiation of anticoagulation).
Most atrial fibrillation cases (67%) were identified in the first 10-day monitoring period, the authors noted. This finding led them to propose a stepwise approach—all patients in whom the detection of atrial fibrillation would be of therapeutic relevance could receive seven to 10 days of monitoring beginning within the first days after stroke, and if results were negative, the decision to conduct additional monitoring would be based on patients' individual risk for atrial fibrillation. The authors noted that although the study was not powered for clinical endpoints, the monitored group had a lower rate of recurrent stroke and transient ischemic attack than the control group. The study was funded by a pharmaceutical company.
Although the study's results support potential benefits from monitoring, several questions about the relationship between atrial fibrillation and stroke remain unanswered, said an accompanying comment. It's not established whether cardiac arrhythmias detected after cerebral injury are the cause or consequence of strokes, and given the prevalence of atrial fibrillation in the general population, the prognostic significance of isolated and short-lasting atrial arrhythmias needs further investigation, according to the editorialist.