Evidence for Left Atrial Volume Being an Indicator of Adverse Events in Patients With Acute Pulmonary Embolism: Retrospective Case-control Pilot Study.

Purpose: To assess the association between computed tomography pulmonary angiography (CTPA) atrial measurements and both 30-day pulmonary embolism (PE)-related adverse events and mortality, and non-PE-related mortality, and to identify the best predictors of these outcomes by comparing atrial measurements and widely used clinical and imaging variables.

Patients And Methods: Retrospective single-center pilot study. Acute PE patients diagnosed on CTPA who also had a transthoracic echocardiogram, electrocardiogram, and troponin T were included. CTPA left atrial (LA) and right atrial (RA) volume and short-axis diameter were measured and compared between outcome groups, along with right ventricular/left ventricular diameter ratio, interventricular septal bowing, tricuspid annular plane systolic excursion, electrocardiogram, and troponin T.

Results: A total of 350 patients. LA volume and diameter were associated with PE-related adverse events (P≤0.01). LA volume was the only atrial measurement associated with PE-related mortality (P=0.03), with no atrial measurements associated with non-PE-related mortality. Troponin was most associated with PE-related adverse events and mortality (both area under the curve [AUC]=0.77). On multivariate analysis, combination models did not greatly improve PE-related adverse events prediction compared with troponin alone. For PE-related mortality, the best models were the combination of troponin, age, and either LA volume (AUC=0.86) or diameter (AUC=0.87).

Conclusion: Among patients with acute PE, CTPA LA volume is the only imaging parameter associated with PE-related mortality and is the best imaging predictor of this outcome. Reduced CTPA LA volume and diameter, along with increased RA/LA volume and diameter ratios, are significantly associated with 30-day PE-related adverse events, but not with non-PE-related mortality.