Requirements: CT scans of the heart before and after the pulmonary embolism (PE)
Ventricular diameters were measured in a reformatted 4-chamber view as the maximum distance from the intervenricular septum to the endocardial border perpendicular to the long axis of the heart.
Parameters:
(1) right ventricular diameter prior to the PE
(2) left ventricular diameter prior to the PE
(3) right ventricular diameter after the PE
(4) left ventricular diameter after the PE
ratio of right to left ventricular diameter prior to the PE =
= (right ventricular diameter prior to the PE) / (left ventricular diameter prior to the PE)
ratio of right to left ventricular diameter after to the PE =
= (right ventricular diameter after to the PE) / (left ventricular diameter after to the PE)
interval change in the RV to LV ratio in percent =
= ((ratio after the PE) - (ratio before the PE)) / (ratio before the PE) * 100%
Interpretation:
• An interval increase > 18% had a hazard ratio of 19 for 30-day PE-related mortality.
• An interval increase > 15% had a hazard ratio of 7.2 for 30-day all cause mortality.
Performance:
• The interval increase performed better than a single RV/LV diameter ratio done after the PE since some patients have pre-existing conditions affecting the ratio.
Limitation:
• The patient needs a previous CT available.
