Efficacy of transesophageal echocardiography-guided cardioversion of patients with atrial fibrillation at 6 months: a randomized controlled trial.

BACKGROUND: Electrical cardioversion in patients with atrial fibrillation (AF) is associated with an increased risk of stroke. We compared a transesophageal echocardiography (TEE)-guided strategy with a conventional strategy in patients with AF > 2 days' duration undergoing electrical cardioversion over a 6-month follow-up. METHODS: The ACUTE study was a multicenter, randomized, clinical trial, with 1222 patients. Six-month follow-up was available in 1034 patients (85%), 525 in the TEE group and 509 in the conventional group. The primary composite end points were cerebrovascular accident, transient ischemic attack, and peripheral embolism at 6 months, which was a prespecified time point. Secondary end points were hemorrhage, mortality, and sinus rhythm. RESULTS: At 6 months, there was no difference in composite embolic events between the TEE group and the conventional group (10 [2%] vs 4 [0.8%]; risk ratio (RR) 2.47, 95% CI 0.78-7.88; P = .11). However, the hemorrhagic rate was significantly lower in the TEE group (23 [4.4%] vs 38 [7.5%]; RR 0.58, 96% CI 0.35-0.97; P = .04). There was no difference between the 2 treatment groups in all-cause mortality (21 [4%] vs 14 [2.8%]; RR 1.48, 95% CI 0.76-2.92; P = .25) and in the occurrence of normal sinus rhythm between the 2 groups (305 [62.2%] vs 280 [58.1%]; P = .51). Sinus rhythm at 6 months was more common in the TEE-guided group, in those patients who had direct current cardioversion (238 [62.5%] vs 151 [53.9%]; P = .03). CONCLUSION: The TEE-guided strategy may be considered a clinically effective alternative to a conventional anticoagulation strategy for patients with AF of > 2 days' duration undergoing electrical cardioversion over a 6-month period.

Utility of transesophageal echocardiography in identification of thrombogenic milieu in patients with atrial fibrillation (an ACUTE ancillary study).

The ACUTE trial randomly assigned patients who had atrial fibrillation (AF) of >2 days' duration to a transesophageal echocardiographically guided or a conventional strategy before cardioversion. In the 571 patients who underwent transesophageal echocardiography (TEE) in the ACUTE trial, we assessed the relative predictive value of baseline data derived by history, transthoracic echocardiography, and TEE for prediction of thrombus and adjudicated embolism (thromboembolism) as a composite end point. TEE was performed at 70 centers in 571 patients, 549 in the transesophageal echocardiographically guided group and 22 crossovers in the conventional group. Six patients (1.1%) who had embolism and 79 (13.8%) who had thrombi were identified in this group. Thrombus was completely resolved in 76.5% of patients who had repeat transesophageal echocardiographic procedures after 31.7 +/- 7.5 days of anticoagulation. For patients who had embolic events, none had a transesophageal echocardiographically identified thrombus; 5 of 6 (83.3%) had >/=1 transesophageal echocardiographic risk factors (including spontaneous echocardiographic contrast, aortic atheroma, patent foramen ovale, atrial septal aneurysm, mitral valve strands), and 4 of 6 (66.66%) had subtherapeutic anticoagulation or no anticoagulation. Clinical, transthoracic echocardiographic, and transesophageal echocardiographic risk factors contributed significantly to the prediction of composite thrombus/embolism. However, transesophageal echocardiographic thromboembolic risk factors were the strongest predictors of thromboembolism and provided statistically significant incremental value (chi-square 38.0, p <0.001) for identification of risk. Thus, in addition to thrombus identification, TEE has significant incremental value in the identification of patients who had high thromboembolic risk. In conclusion, this study supports the role of TEE and anticoagulation monitoring in patients who have atrial fibrillation and is useful for identifying thromboembolic risk factors.

Impact of cardioversion strategy on functional capacity in patients with atrial fibrillation: the Assessment of Cardioversion Using Transesophageal Echocardiography (ACUTE) study.

BACKGROUND: The ACUTE Trial studied a transesophageal echocardiography (TEE)-guided strategy compared with a conventional strategy for management of patients with atrial fibrillation undergoing direct current cardioversion. The primary aim was to determine if patient functional capacity, measured by the Duke Activity Status Index (DASI), would differ between treatment strategies. METHODS: The DASI was self-administered at study enrollment and at 8-week follow-up in 1074 (88%) of 1222 total patients. Clinical outcomes associated with enrollment DASI scores and change in follow-up DASI scores were reviewed. RESULTS: There was no difference between the TEE-guided (n = 544) and conventional treatment (n = 530) groups for mean baseline and 8-week DASI scores, adjusting for baseline; however, patients who improved their DASI score were more likely to be in the TEE-guided group (P = .03). Pooled group data showed that the higher the enrollment DASI score, the more it tended to be positively related to maintenance of sinus rhythm (P = .06) at 8 weeks. The lower the enrollment DASI score, the more it was predictive of death (P = .03) and bleeding (P = .01) within 8 weeks. Patients with congestive heart failure (CHF) at enrollment showed greater improvement in DASI scores at 8 weeks compared with patients without CHF (DASI Delta 45.9% vs 31.6%, P < .001). CONCLUSIONS: There was no difference in DASI scores between treatment groups. However, TEE-guided treatment was a predictor of improved DASI at follow-up, and subgroup analysis showed that patients with CHF did show improvement in functional capacity with cardioversion.

Spontaneous conversion of patients with atrial fibrillation scheduled for electrical cardioversion: an ACUTE trial ancillary study.

OBJECTIVES: This study was designed to determine the characteristics and outcomes of spontaneous conversion (SC) to sinus rhythm (SR) in patients with atrial fibrillation (AF) of more than two days. BACKGROUND: The Assessment of Cardioversion Using Transesophageal Echocardiography (ACUTE) multicenter study was a prospective trial in which transesophageal echocardiography (TEE)-guided treatment was compared with conventional anticoagulation treatment for the management of patients with AF >2 days undergoing direct current cardioversion (DCC). In an ancillary analysis, we evaluated the baseline and outcome data in patients who underwent SC to SR before scheduled DCC. METHODS: We identified 1,041 patients for this analysis after excluding patients on pre-existing antiarrhythmic agents. Patients with SC in the TEE-guided and conventional groups were first compared then pooled and compared with non-spontaneous conversion (No-SC) patients. RESULTS: Overall, 167 of 1,041 (16%) patients underwent SC, with twice as many in the conventional compared with the TEE-guided group (110/523 [21%] vs. 57/518 [11%]; p < 0.001). When compared with No-SC patients, a higher proportion of SC patients maintained SR at eight weeks (87.2% vs. 48.9%, p < 0.001), without statistically significant differences in bleeding, thromboembolism or mortality. Multivariate predictors of SC were shorter duration of AF, New York Heart Association (NYHA) functional class 1 or 2, smaller left atrial size, and absence of left atrial spontaneous echo contrast. CONCLUSIONS: Spontaneous conversion was associated with shorter duration of AF, lower NYHA class, smaller left atrial size, and absence of left atrial spontaneous echo contrast. There was a better SR outcome in the SR group, but no differences in the other clinical end points. The conventional treatment strategy allowed greater opportunity for SC. In the absence of favorable predictors of SC, the TEE-guided approach should be considered.

Bleeding complications in patients with atrial fibrillation undergoing cardioversion randomized to transesophageal echocardiographically guided and conventional anticoagulation therapies.

In a multicenter randomized trial, we studied a transesophageal echocardiography (TEE) guided strategy with short-term anticoagulation compared with a conventional strategy for patients with atrial fibrillation >2 days' duration and undergoing cardioversion. Composite major and minor bleeding was a predetermined secondary end point of the study. The objective of the study was to assess the incidence, location, and predictors of bleeding in the 2 treatment groups. A total of 1,222 patients were assigned to a TEE guided or conventional strategy and followed over 8 weeks. We present data on major and minor adjudicated bleeding complications for the 2 study groups during the 8-week study period. Composite major and minor bleeding complications occurred in 51 of 1,222 patients (4.2%) and were significantly lower in the TEE guided group compared with the conventional group (2.9 vs 5.5%, p = 0.025). The TEE group had fewer cancellations of cardioversion as a result of bleeding (0% vs 0.7%, p = 0.003). Major (n = 14) and minor (n = 38) bleeding complications were predominantly gastrointestinal (71.4% and 31.6%, respectively) and were associated with warfarin use. Predictors of bleeding included patient age, conventional group assignment, inpatient status, and functional status. Thus, composite major and minor bleeding complications occurred in 4.2% of the 1,222 patients and were significantly lower in the TEE guided group compared with the conventional group. Treatment variables affecting length of anticoagulant therapy in the conventional arm combined with advancing age and functional status are important concerns in patients who undergo cardioversion of atrial fibrillation.