Patent foramen ovale in patients with pulmonary embolism: A prognostic factor on CT pulmonary angiography?

BACKGROUND: Patent foramen ovale (PFO) in patients with acute pulmonary embolism (PE) represents a risk factor for mortality, but this has not been evaluated for CT pulmonary angiography (CTPA). The purpose of the present study was to assess the relationship between PFO and mortality in patients with acute PE diagnosed on CTPA. MATERIALS AND METHODS: This retrospective study included 268 adults [173 women, mean age 61 (range 22-98) years] diagnosed with acute PE on non-ECG-gated 64-slice CTPA in 2012 at our medical center. The images were reviewed for PFO by a panel of cardiothoracic radiologists with an average of 11 years of experience (range 1-25 years). CT signs of right heart strain and PE level were noted. Transthoracic echocardiograms (TTE), when available (n = 207), were reviewed for PFO by a cardiologist with subspecialty training in advanced imaging and with 3 years of experience. The main outcome was 30-day mortality. Fischer's exact test was utilized to compare mortality. RESULTS: PFO prevalence on CTPA was 22% (58/268) and 4% (9/207) on TTE. Overall 30-day mortality was 6% (16/268), 9% (5/58) for patients with PFO and 5% (11/210) for those without (p = 0.35). CT signs of right heart strain trended with higher mortality, but statistically significant only for hepatic vein contrast reflux [14% (6/44) vs 4% (10/224), p = 0.03]; right ventricular (RV) to left ventricular (LV) diameter ratio >1 [8% (13/156) vs RV:LV ≤ 1 3% (3/112), p = 0.07], septal bowing [10% (4/42) vs without 5% (12/226), p = 0.30]. CONCLUSION: PFO was demonstrated on CTPA in a proportion similar to the known population prevalence, while routine TTE was less sensitive. Mortality was non-significantly higher in patients with acute PE and PFO in this moderate-sized study. A larger study to answer this clinically important question is worthwhile.

Left heart chamber quantification in obese patients: how does larger body size affect echocardiographic measurements?

BACKGROUND: Accurate normalization of cardiac chamber size in the obese population is a challenge. The aim of this study was to develop and assess the performance of allometric models for scaling left heart chamber sizes, including left atrial anteroposterior dimension (LADAP), left atrial volume (LAV), left ventricular end-diastolic volume (LVEDV), and left ventricular end-diastolic dimension (LVEDD), in an obese population. METHODS: To normalize left heart chamber measurements (Y: LADAP, LAV, LVEDV, and LVEDD) to body size variables (X: height, weight, body mass index, and body surface area), both isometric models (Y = aX) and optimal allometric models (Y = aX(b)) were tested. A logarithmic transformation (LnY = Lna + b × LnX) and ordinary least squares linear regression was performed to estimate the allometric scaling exponents. Pearson's correlation coefficients were obtained for measured and indexed left chamber sizes using both isometric and allometric models against body size variables. Gender-specific allometric models were also derived as sensitivity analyses. RESULTS: A total of 717 healthy obese subjects were included in the analysis. The mean body surface area and body mass index were 2.3 m(2) and 42.2 kg/m(2), respectively. Measured LADAP, LAV, LVEDD, and LVEDV were positively correlated with body size variables. Allometric scaling of LADAP, LAV, LVEDD, and LVEDV showed stronger correlation with measured chamber sizes compared with isometric scaling. The overcorrection caused by isometric scaling significantly improved after allometric models were used. The sensitivity analysis showed no significant differences in scaling exponents between men and women. CONCLUSIONS: Normalizing cardiac chamber measurements with allometric scaling methods is superior to the use of isometric methods in removing the effects of body size and minimizing overcorrection in the obese population. Using an allometric model with height provides the most accurate results.