New-onset atrial fibrillation in adult critically ill patients: a scoping review

There are two approaches to the treatment of atrial fibrillation: one is cardioversion and treatment with antiarrhythmic drugs to maintain sinus rhythm, and the other is the use of rate-controlling drugs, allowing atrial fibrillation to persist. In both approaches, the use of anticoagulant drugs is recommended. We conducted a randomized, multicenter comparison of these two treatment strategies in patients with atrial fibrillation and a high risk of stroke or death. The primary end point was overall mortality. A total of 4060 patients (mean [+/-SD] age, 69.7+/-9.0 years) were enrolled in the study; 70.8 percent had a history of hypertension, and 38.2 percent had coronary artery disease. Of the 3311 patients with echocardiograms, the left atrium was enlarged in 64.7 percent and left ventricular function was depressed in 26.0 percent. There were 356 deaths among the patients assigned to rhythm-control therapy and 310 deaths among those assigned to rate-control therapy (mortality at five years, 23.8 percent and 21.3 percent, respectively; hazard ratio, 1.15 [95 percent confidence interval, 0.99 to 1.34]; P=0.08). More patients in the rhythm-control group than in the rate-control group were hospitalized, and there were more adverse drug effects in the rhythm-control group as well. In both groups, the majority of strokes occurred after warfarin had been stopped or when the international normalized ratio was subtherapeutic. Management of atrial fibrillation with the rhythm-control strategy offers no survival advantage over the rate-control strategy, and there are potential advantages, such as a lower risk of adverse drug effects, with the rate-control strategy. Anticoagulation should be continued in this group of high-risk patients. Copyright 2002 Massachusetts Medical Society

To describe the effect of atrial fibrillation on long-term morbidity and mortality. The Renfrew/Paisley Study surveyed 7052 men and 8354 women aged 45-64 years between 1972 and 1976. All hospitalizations and deaths occurring during the subsequent 20 years were analyzed by the presence or absence of atrial fibrillation at baseline. Lone atrial fibrillation was defined in the absence of other cardiovascular signs or symptoms. Cox proportional hazards models were used to adjust for age and cardiovascular conditions. After 20 years, 42 (89%) of the 47 women with atrial fibrillation had a cardiovascular event (death or hospitalization), compared with 2276 (27%) of the 8307 women without this arrhythmia. Among men, 35 (66%) of 53 with atrial fibrillation had an event, compared with 3151 (45%) of 6999 without atrial fibrillation. In women, atrial fibrillation was an independent predictor of cardiovascular events (rate ratio [RR] = 3.0; 95% confidence interval [CI]: 2.1-4.2), fatal or nonfatal strokes (RR = 3.2; 95% CI: 1.0-5.0), and heart failure (RR = 3.4; 95% CI: 1.9-6.2). The rate ratios among men were 1.8 (95% CI: 1.3-2.5) for cardiovascular events, 2.5 (95% CI: 1.3-4.8) for strokes, and 3.4 (95% CI: 1.7-6.8) for heart failure. Atrial fibrillation was an independent predictor of all-cause mortality in women (RR = 2.2; 95% CI: 1.5-3.2) and men (RR = 1.5; 95% CI: 1.2-2.2). However, lone atrial fibrillation (which occurred in 15 subjects) was not associated with a statistically significant increase in either cardiovascular events (RR = 1.5; 95% CI: 0.6-3.6) or mortality (RR = 1.8; 95% CI: 0.9-3.8). Atrial fibrillation is associated with an increased long-term risk of stroke, heart failure, and all-cause mortality, especially in women.

Maintenance of sinus rhythm is the main therapeutic goal in patients with atrial fibrillation. However, recurrences of atrial fibrillation and side effects of antiarrhythmic drugs offset the benefits of sinus rhythm. We hypothesized that ventricular rate control is not inferior to the maintenance of sinus rhythm for the treatment of atrial fibrillation. We randomly assigned 522 patients who had persistent atrial fibrillation after a previous electrical cardioversion to receive treatment aimed at rate control or rhythm control. Patients in the rate-control group received oral anticoagulant drugs and rate-slowing medication. Patients in the rhythm-control group underwent serial cardioversions and received antiarrhythmic drugs and oral anticoagulant drugs. The end point was a composite of death from cardiovascular causes, heart failure, thromboembolic complications, bleeding, implantation of a pacemaker, and severe adverse effects of drugs. After a mean (+/-SD) of 2.3+/-0.6 years, 39 percent of the 266 patients in the rhythm-control group had sinus rhythm, as compared with 10 percent of the 256 patients in the rate-control group. The primary end point occurred in 44 patients (17.2 percent) in the rate-control group and in 60 (22.6 percent) in the rhythm-control group. The 90 percent (two-sided) upper boundary of the absolute difference in the primary end point was 0.4 percent (the prespecified criterion for noninferiority was 10 percent or less). The distribution of the various components of the primary end point was similar in the rate-control and rhythm-control groups. Rate control is not inferior to rhythm control for the prevention of death and morbidity from cardiovascular causes and may be appropriate therapy in patients with a recurrence of persistent atrial fibrillation after electrical cardioversion. Copyright 2002 Massachusetts Medical Society