Asymptomatic Pulmonary Embolism after Ablation.

BACKGROUND: Pulmonary embolism (PE) is a life-threatening event with a broad presentation spectrum ranging from asymptomatic cases to sudden cardiac arrest. It is unclear if right atrial emboli cause PE in patients with atrial fibrillation (AF) or if mild PE itself increases right cardiac pressure provoking AF.

OBJECTIVE: To determine the incidence and predictors of asymptomatic PE in patients undergoing AF ablation.

METHOD AND RESULTS: Patients (n = 93) were screened and those with previous or current symptomatic PE or venous thromboembolism, pulmonary hypertension, increased right heart pressures detected on echocardiography, a history of stroke, transient ischemic attack, coagulopathy or cancer and inappropriate contrast for the evaluation of pulmonary arterial tree were excluded. The remaining AF patients (n = 71) underwent guided ablation controlled with 3-dimensional, left atrial and pulmonary venous computed tomography. The asymptomatic PE was defined by using the modified Miller score by 2 independent assessors in 6 patients. Univariate logistic regression showed that age (OR: 1.094, 95% CI 1.007-1.188, p = 0.033), diabetes (OR: 12.000, 95% CI 1.902-75.716, p = 0.008), CHA2DS2-VASc score (OR: 2.800, 95% CI 1.304-6.013, p = 0.008), and pulmonary artery diameter (OR: 1.221, 95% CI 1.033-1.444, p = 0.019) were significantly associated with PE. However, multivariate analysis revealed that the CHA2DS2-VASc score (p = 0.047) remained the exclusive significant predictor for asymptomatic PE.

CONCLUSION: The incidence of random asymptomatic PE in AF patients is high (>8%). The CHA2DS2-VASc score can predict silent PE. Since patients with a high CHA2DS2-VASc score are already anticoagulated, our results do not change clinical practice but are noteworthy in terms of the cause-effect relationship between AF and PE.