Purpose: Large numbers of non–gated CT pulmonary angiography (CTPA) examinations are currently done for pulmonary embolism (PE) diagnosis, which also contain imaging of the heart that is usually overlooked. Data regarding extreme values of each of the four cardiac chamber volumes of CTPA does not exist to date. The purpose of this study is to determine the extreme values of each cardiac chamber volume among patients undergoing CTPA without PE and their prognostic implications.
Methods: The cohort is a retrospective analysis of consecutive patients that underwent CTPA without PE during 1/2014-12/2015. All 4 Cardiac chambers (right atrium-RA, left atrium-LA, right ventricle-RV, left ventricle-LV) volumes, adjusted for body surface area (BSA) were calculated using automatic 4-chamber volumetric analysis software and the extreme volumes of each chamber (5th and 95th percentiles) according to gender were determined. Patients with extreme chambers` volumes (<5thor>95th percentiles) were compared to patients in the mid-IQR (25-75th percentiles) which was regarded as the control group.
Results: Out of 1985 patients, 1378 (575,41.7% males) without PE were included. Volume cut points were calculated for each cardiac chamber- LV(5th percentile ≤25.4 for males, ≤21.5 for females and 95th percentile ≥74.4 for males, ≥64.5 for females), LA(5th percentile ≤22.7 for males, ≤24.2 for females and 95th percentile ≥81.5 for males, ≥79.3 for females), RV(5th percentile ≤43.3 for males, ≤37.4 for females and 95th percentile ≥105.6 for males, ≥86.2 for females), RA(5th percentile ≤26.7 for males, ≤25.9 for females and 95th percentile ≥105.4 for males, ≥90.2 for females). Patients with extremely large RA had higher prevalence of atrial fibrillation (AF) (57.4% vs 3.9%), congestive heart failure (CHF) (23.5% vs. 4.5%) and lower prevalence of malignancy (8.8% vs. 13.4%). Conversely, patients with extremely small LA had significantly higher prevalence of malignancy (35.3% vs 14.7%) and lower rates of AF (0% vs. 4.2%) and CHF (1.5% vs. 5.8%). Patients with extremely large RA and extremely small LA had increased 30-day mortality (p<0.001). Patients with extremely small LA also had increased 3-year mortality (Hazard ratio (HR)= 2.8,p<0.001).
Conclusion: This is the first study to determine the extreme 5thpercentile of each cardiac chamber volume among large series of patients undergoing CTPA without PE. Our findings show that extreme values of LA and RA are associated with increased short and long-term mortality. Thus the use of non-gated CTPA volumetric analysis may contribute to fast patient` triaging by suggesting cardiac volume abnormalities associated with poor outcome.
