PracticeUpdate Cardiology June 2019

EDITOR’S PICKS 11

Early or Delayed Cardioversion in Recent- Onset Atrial Fibrillation

The New England Journal of Medicine Take-home message

• Patients in the emergency department (ED) with hemody- namically stable, recent-onset symptomatic atrial fibrillation were randomized to early cardioversion or a wait-and-see approach with delayed cardioversion if the atrial fibrillation did not resolve within 48 hours. The rate of sinus rhythm at 4 weeks was similar in the two groups, confirming the noninferiority of the wait-and-see approach. Conversion to sinus rhythm was seen in 69% of the delayed-cardiover- sion group within 48 hours and in a further 28% following delayed cardioversion. The rate of recurrence of atrial fibril- lationwithin 4weekswas 30% in the delayed-cardioversion group and 29% in the early-cardioversion group. • A wait-and-see approach was noninferior to early car- dioversion for the outcomes of return to sinus rhythm at 4 weeks among ED attendees with recent-onset, symptomatic atrial fibrillation. Abstract BACKGROUND Patients with recent-onset atrial fibrillation commonly undergo immediate restoration of sinus rhythm by pharmacologic or electrical cardioversion. However, whether immediate restoration of sinus rhythm is necessary is not known, since atrial fibrillation often terminates spontaneously. METHODS In a multicenter, randomized, open-label, noninferiority trial, we randomly assigned patients with hemodynamically stable, recent-onset (<36 hours), symptomatic atrial fibrillation in the emer- gency department to be treated with a wait-and-see approach (delayed-cardioversion group) or early cardioversion. The wait-and- see approach involved initial treatment with rate-control medication only and delayed cardioversion if the atrial fibrillation did not resolve within 48 hours. The primary end point was the presence of sinus rhythm at 4 weeks. Noninferiority would be shown if the lower limit of the 95% confidence interval for the between-group difference in the primary end point in percentage points was more than -10. RESULTS The presence of sinus rhythm at 4 weeks occurred in 193 of 212 patients (91%) in the delayed-cardioversion group and in 202 of 215 (94%) in the early-cardioversion group (between-group difference, -2.9 percentage points; 95% confidence interval [CI], -8.2 to 2.2; P=0.005 for noninferiority). In the delayed-cardioversion group, conversion to sinus rhythm within 48 hours occurred spontaneously in 150 of 218 patients (69%) and after delayed cardioversion in 61 patients (28%). In the early-cardioversion group, conversion to sinus rhythm occurred spontaneously before the initiation of cardioversion in 36 of 219 patients (16%) and after cardioversion in 171 patients (78%). Among the patients who completed remote monitoring during 4 weeks of follow-up, a recur- rence of atrial fibrillation occurred in 49 of 164 patients (30%) in the delayed-cardioversion group and in 50 of 171 (29%) in the early-car- dioversion group. Within 4 weeks after randomization, cardiovascular complications occurred in 10 patients and 8 patients, respectively. CONCLUSIONS In patients presenting to the emergency department with recent-onset, symptomatic atrial fibrillation, a wait-and-see approach was noninferior to early cardioversion in achieving a return to sinus rhythm at 4 weeks. Early or Delayed Cardioversion in Recent-Onset Atrial Fibrillation. N Engl J Med 2019 Mar 18;[EPub Ahead of Print], NAHA Pluymaekers, EAMP Dudink, JGLM Luermans, et al. www.practiceupdate.com/c/81402

hypothesized that increased influenza activity would be associated with an increase in hospitalizations for HF and MI among adults in the community. DESIGN, SETTING, AND PARTICIPANTS As part of the community surveillance component of the Atherosclerosis Risk in Communities (ARIC) study, a pop- ulation-based study with hospitalizations sampled from 4 US communities, data were collected from 451 588 adults aged 35 to 84 years residing in the ARIC communities from annual cross-sectional stratified random sam- ples of hospitalizations during October 2010 to September 2014. EXPOSURES Monthly influenza activity, defined as the percentage of patient visits to sentinel clinicians for influenza-like illness by state, as reported by the Centers for Disease Control and Prevention Surveillance Network. MAIN OUTCOMES AND MEASURES The monthly frequency of MI hospital- izations (n = 3541) and HF hospitalizations (n = 4321), collected through community surveillance and adjudicated as part of the ARIC Study. RESULTS Between October 2010 and September 2014, 2042 (47.3%) and 1599 (45.1%) of the sampled patients who were hospitalized for HF and MI, respectively, were women and 2391 (53.3%) and 2013 (57.4%) were white, respectively. A 5% monthly absolute increase in influenza activity was associated with a 24% increase in HF hospitalization rates, standard- ized to the total population in each community, within the same month after adjusting for region, season, race/ethnicity, sex, age, and number of MI/HF hospitalizations from the month before (incidence rate ratio, 1.24; 95% CI, 1.11-1.38; P< .001), while overall influenza activity was not signifi- cantly associated with MI hospitalizations (incidence rate ratio, 1.02; 95% CI, 0.90-1.17; P= .72). Influenza activity in the months before hospitaliza- tion was not associated with either outcome. Our model suggests that in a month with high influenza activity, approximately 19% of HF hospitaliza- tions (95% CI, 10%-28%) could be attributable to influenza. CONCLUSIONS AND RELEVANCE Influenza activity was temporally associated with an increase in HF hospitalizations across 4 influenza seasons. These data suggest that influenza may contribute to the risk of HF hospitaliza- tion in the general population. Association of Influenza-Like Illness Activity With Hospitalizations for Heart Failure: The Atherosclerosis Risk in Communities Study. JAMA Cardiol 2019 Mar 27;[EPub Ahead of Print], S Kytömaa, S Hegde, B Clag- gett, et al. www.practiceupdate.com/c/81652

VOL. 4 • NO. 2 • 2019