Purpose: Recent studies based on echocardiography demonstrate that low volumes of the LA carry an increased risk of adverse outcome. Currently, there are no normal values of cardiac chambers` volumes on CTPA. The purpose of this study is to assess the volume ranges at which small left atrium (LA) according to computed tomography pulmonary angiography (CTPA) is associated with early adverse outcomes (critical state- e.g. shock or intubation during the same hospitalization, or mortality at 30-day), and their leading etiologies.
Methods: The cohort consisted of 752 consecutive patients who underwent CTPA during 2014, in whom pulmonary embolism (PE) was ruled out and had available body surface area data. Left atrial volumes were measured retrospectively using automatic four-chamber volumetric analysis (4CVA) software.Within this cohort, the study group consisted of patients within the lowest LA volume indices (LAVIs) quartile (
Results: LAVI volume of patients within the lower 25th LAVI percentiles was <28ml/m2while it was 28-43 43ml/m2in the control group.). Patients in the lowest 25th LAVI percentileswere younger (median age of 56 versus 72, p<0.001) and had less cardiovascular morbidities, while malignancies were less common in the control group. Patients within the lower 25th LAVI percentiles had an increased 30-day mortality risk (OR 2.1, 95% CI 1.1-4, p=0.028) compared to the IQR reference group. Further analyses showed additionalincreased30-day mortality in patients within the lowest 5th LAVI percentiles (OR 3.7, 95% CI 1.7-8.3,p=0.001) compared to the IQR controlgroup. After adjustment for baseline characteristics, the risk for 30-day mortality was 5.6 higher for patients within the lowest 5thLAVI percentile compared to the control group (OR 5.6, 95%CI 2.1-14.8,p=0.001).A critical state was noted ata higher rate for patients within the lowest 5th LAVI percentiles compared to the IQR reference group, although the difference was not statisticallysignificant. Among these patients, 92% of those who died within 30-day had a diagnosis of malignancy.
Conclusion: Individuals undergoing CTPA whose LAVI is within the lowest 25th percentiles are at an increased risk for short term mortality, this is further increased in individuals whose LAVI is withinthe lowest 5thpercentiles. The increased risk is mostly attributed to an underlying malignancy.
