Reconstructed 4-chamber views compared with axial imaging for assessment of right ventricular enlargement on CT pulmonary angiograms

Pulmonary arteries: imaging of pulmonary embolism and beyond

The pulmonary arteries are not just affected by thrombus. Various acquired and congenital conditions can also affect the pulmonary arteries. In this review we discuss cross sectional imaging modalities utilized for the imaging of the pulmonary arteries. Acquired pulmonary artery entities, including pulmonary artery sarcoma (PAS), vasculitis, aneurysm, and arteriovenous malformations, and congenital anomalies in adults, including proximal interruption of the pulmonary artery, pulmonary sling, pulmonary artery stenosis, and idiopathic dilatation of the pulmonary trunk, are also discussed. An awareness of these entities and their imaging findings is important for radiologists interpreting chest imaging.

Automated volumetric analysis of four cardiac chambers in pulmonary embolism

Identification of patients with acute pulmonary embolism (PE) who might be at risk of circulatory collapse by using a fast, automated system is highly desired. It was our objective to investigate whether automated cardiac volumetric analysis following computerised tomographic pulmonary angiography (CTPA) is useful to identify increased clot load and adverse prognosis in patients with acute PE. We retrospectively analysed a consecutive series of non-gated CTPA studies of 124 patients with acute PE and 43 controls. Right and left ventricular diameters (RV/LV) were measured on four-chamber view, while each cardiac chamber underwent automatic volumetric measurements. Findings were correlated to the pulmonary arterial obstruction index (PAOI). Outcome was expressed by admission to an intensive care unit (ICU) or mortality within 30 days. There was a significant positive correlation between the PAOI and the volumes of the right side cavities (r=0.25 for the atrium and r=0.49 for the ventricle), and between the right-to-left atrial and ventricular volume ratios (r=0.49 and r=0.57, respectively). Results for the combined outcome of mortality or ICU admission that fell in the upper tertile of the right atrial and right ventricular volumes yielded hazard ratios of 3.9 and 3.3, respectively, compared to those in the lower tertile. RV/LV diameter ratio did not correlate with outcome. In conclusion, adverse outcome and significant pulmonary clot load in patients with acute PE are associated with a volume shift towards right heart cavities, which correlates to prognosis better than the CT-measured RV/LV diameter ratio, suggesting the advantage of using fast fully automatic volumetric analysis to identify patients at risk.

Platelet-to-lymphocyte ratio as a novel marker of in-hospital and long-term adverse outcomes among patients with acute pulmonary embolism: A single center large-scale study

BACKGROUND

The interaction of platelets with leukocytes is a well-known process both in progression and prognosis of acute pulmonary embolism (PE). Recently, platelet to lymphocyte ratio (PLR) is emerged as an indirect inflammatory indicator which was shown to be associated with adverse cardiovascular events in various clinical conditions, including acute PE. However, the long-term prognostic value of PLR in acute PE has not been investigated thoroughly. Therefore, we aimed to assess the impact of PLR on both in-hospital and long-term adverse outcomes in acute PE.

METHODS

A total of 459 patients with definite diagnosis of acute PE between January 2009 and January 2016 were enrolled. On admission, blood sampling to calculate PLR and detailed clinical data were obtained. Patients were divided into tertiles according to the admission PLR levels. Simplified PE severity index (sPESI) score and computerized tomography (CT) based pulmonary artery obstruction index were calculated for each patient.

RESULTS

Mean sPESI score of the study population was 1.6. A total of 34 patients (7.4%) died during index hospitalization. At median 28.8months follow-up, all-cause mortality was observed in 81 patients (1.9%). Patients in the highest tertile of PLR revealed a higher rate of in-hospital adverse events including cardiogenic shock, the necessity for thrombolytic therapy and in-hospital mortality as well as long-term all-cause mortality. In multivariate analysis, the PLR was found to be a significant predictor of both in-hospital adverse events (OR: 1.588, 95% CI:1.116-2.154, p=0.004) and long-term all-cause mortality (OR:1.746, 95% CI:1.211-2.865, p=0.001).

CONCLUSIONS

The PLR, as a simple, inexpensive and available marker of inflammatory and prothrombotic status, seemed to be a novel predictor of in-hospital and long-term adverse outcomes in patients with acute PE.

CTA-derived left to right atrial size ratio distinguishes between pulmonary hypertension due to heart failure and idiopathic pulmonary arterial hypertension

BACKGROUND/OBJECTIVES

Assessing atrial sizes by routine non-gated CT-angiography (CTA) could be of value in discriminating between pulmonary hypertension (PH) due to heart failure with preserved ejection fraction (HFpEF) and idiopathic pulmonary arterial hypertension (IPAH). We aimed to determine how left (LA) and right atrial (RA) sizes on non-gated CTA can help discriminate between these patients.

METHODS AND RESULTS

In an initial study, CMR was used in 15 IPAH and 15 PH-HFpEF patients to determine LA- and RA size throughout the cardiac cycle. While significant variations were noted in LA size over the cardiac cycle, the calculated ratio of left over right atrial size (LA/RA ratio) remained stable in both groups and discriminated between PH-HFpEF and IPAH. In a second study, routine non-gated CTA was used to validate the diagnostic use of a LA/RA ratio in 95 consecutive treatment-naive patients with a final diagnosis of either IPAH (n=64) or PH-HFpEF (n=31). ROC analyses were conducted to determine the discriminative properties of atrial size parameters. On a transversal view, LA size was 19cm² (±5) in the IPAH group versus 27cm² (±6) in the PH-HFpEF group (p<0.001). CTA derived LA/RA ratio was significantly higher in PH-HFpEF patients compared to IPAH patients and had good discriminative abilities (AUC=0.833).

CONCLUSIONS

Assessing LA/RA size ratio by non-gated CTA allows for accurate discrimination between PH-HFpEF and IPAH patients. Because CTA is often available in the early diagnostic work-up, a LA/RA size ratio may guide clinical and diagnostic decision-making, even before invasive hemodynamic measurements.

Prognostic value of computed tomography in acute pulmonary thromboembolism

In addition to being the standard reference for the diagnosis of acute pulmonary thromboembolism, CT angiography of the pulmonary arteries can also provide valuable information about the patient's prognosis. Although which imaging findings are useful for prognosis remains controversial, signs of right ventricular dysfunction on CT are now included in clinical algorithms for the management of pulmonary thromboembolism. However, the optimal method for obtaining these measurements while maintaining a balance between the ease of use necessary to include their evaluation in our daily activity and the loss of precision in its predictive capacity remains to be determined. Moreover, other variables associated with pulmonary thromboembolism that often go unobserved can complement the prognostic information we can offer to clinicians. This review aims to clarify some of the more controversial aspects related to the prognostic value of CT in patients with pulmonary embolisms according to the available evidence. Knowing which variables are becoming more important in the prognosis, how to detect them, and why it is important to include them in our reports will help improve the management of patients with pulmonary embolism.

Fragmented QRS Complex Predicts In-Hospital Adverse Events and Long-Term Mortality in Patients with Acute Pulmonary Embolism

BACKGROUND

Electrocardiographic (ECG) abnormalities in pulmonary embolism (PE) are increasingly reported, and mounting data have recommended that ECG plays a crucial role in the prognostic assessment of PE patient population. However, there is scarce data on the prognostic importance of fragmented QRS (fQRS) on short- and long-term outcomes in patients with PE. Therefore, we aimed to investigate the prognostic role of fQRS in predicting in-hospital and long-term adverse outcomes in PE patients.

METHODS

A total of 249 patients (155 female, 66.2%; mean age, 66.0 ± 16.0) with the diagnosis of acute PE were enrolled and followed-up during median 24.8 months.

RESULTS

Compared with the fQRS (-) patient group, patients with fQRS showed higher rates of in-hospital adverse events including cardiogenic shock, the necessity of thrombolytic therapy, and in-hospital mortality as well as long-term all-cause mortality. In Kaplan-Meier survival analysis, during follow-up, all-cause mortality occurred more frequently in the fQRS (+) group (log-rank, P = 0.002). In multivariate Cox regression analysis, adjusted with other relevant parameters, the presence of fQRS were determined as an independent predictor of in-hospital adverse events (HR: 2.743, 95% CI: 1.267-5.937, P = 0.003) and long-term all-cause mortality (HR: 3.137, 95% CI: 1.824-6.840, P = 0.001).

CONCLUSIONS

The presence of fQRS complex, as a simple and feasible ECG marker, seems to be a novel predictor of in-hospital adverse events and long-term all-cause mortality in PE patient population. This parameter may utilize the identification of patients whom at higher risk for mortality and individualization of therapy.

Predicting pulmonary hypertension with standard computed tomography pulmonary angiography

The most common feature of pulmonary hypertension (PH) on computed tomography pulmonary angiography (CTPA) is an increased diameter-ratio of the pulmonary artery to the ascending aorta (PA/AA_AX). The aim of this study was to investigate whether combining PA/AA_AX measurements with ventricular measurements improves the predictive value of CTPA for precapillary PH. Three predicting models were analysed using baseline CTPA scans of 51 treatment naïve precapillary PH patients and 25 non-PH controls: model 1: PA/AA_AX only; model 2: PA/AA_AX combined with the ratio of the right ventricular and left ventricular diameter measured on the axial view (RV/LV_AX); model 3: PA/AA_AX combined with the RV/LV-ratio measured on a four chamber view (RV/LV_4CH). Prediction models were compared using multivariable binary logistic regression, ROC analyses and decision curve analyses (DCA). Multivariable binary logistic regression showed an improvement of the predictive value of model 2 (−2LL = 26.48) and 3 (−2LL = 21.03) compared to model 1 (−2LL = 21.03). ROC analyses showed significantly higher AUCs of model 2 and 3 compared to model 1 (p = 0.011 and p = 0.007, respectively). DCA showed an increased clinical benefit of model 2 and 3 compared to model 1. The predictive value of model 2 and 3 were almost equal. We found an optimal cut-off value for the RV/LV-ratio for predicting precapillary PH of RV/LV ≥ 1.20. The predictive value of CTPA for precapillary PH improves when ventricular and pulmonary artery measurements are combined. A PA/AA_AX ≥ 1 or a RV/LV_AX ≥ 1.20 needs further diagnostic evaluation to rule out or confirm the diagnosis.

A single imaging modality in the diagnosis, severity, and prognosis of pulmonary embolism

Introduction. This study aimed to investigate the currency of computerized tomography pulmonary angiography-based parameters as pulmonary artery obstruction index (PAOI), as well as right ventricular diameters for pulmonary embolism (PE) risk evaluation and prediction of mortality and intensive care unit (ICU) requirement. Materials and Methods. The study retrospectively enrolled 203 patients hospitalized with acute PE. PAOI was calculated according to Qanadli score. Results. Forty-three patients (23.9%) were hospitalized in the ICU. Nineteen patients (10.6%) died during the 30-day follow-up period. The optimal cutoff value of PAOI for PE 30th day mortality and ICU requirement were found as 36.5% in ROC curve analysis. The pulmonary artery systolic pressure had a significant positive correlation with right/left ventricular diameter ratio (r = 0.531, P < 0.001), PAOI (r = 0.296, P < 0.001), and pulmonary artery diameter (r = 0.659, P < 0.001). The patients with PAOI values higher than 36.5% have a 5.7-times increased risk of death. Conclusion. PAOI is a fast and promising parameter for risk assessment in patients with acute PE. With greater education of clinicians in this radiological scoring, a rapid assessment for diagnosis, clinical risk evaluation, and prognosis may be possible in emergency services without the need for echocardiography.

Relation of electrocardiographic changes in pulmonary embolism to right ventricular enlargement

The electrocardiographic (ECG) findings in patients with pulmonary embolism (PE) and no previous cardiopulmonary disease are well documented; however, investigation of the relation of ECG abnormalities to right ventricular (RV) enlargement has been limited. The purpose of the present investigation was to assess further the relation of ECG changes in acute PE to RV cavity enlargement (dilation). The records of patients hospitalized from January 2009 to December 2012 with acute PE and no previous cardiopulmonary disease were reviewed. A total of 289 patients were included. RV cavity enlargement was present in 141 patients (49%). Normal ECG findings were less prevalent in patients with PE and RV enlargement than those with PE and no RV enlargement (35 of 141 [25%] vs 56 of 148 [38%]; p = 0.02). One or more of the traditional ECG manifestations of acute cor pulmonale (S1Q3T3, complete right bundle branch block, P pulmonale, or right axis deviation) was found in 18 of 141 patients (13%) with RV enlargement and 13 of 148 (8.8%) with a normal size RV (p = NS). None of the ECG abnormalities was sensitive for RV enlargement. The specificity of P and QRS abnormalities was high. The positive predictive values were ≤83% or had wide 95% confidence intervals. The negative predictive values ranged from 50% to 61%. In conclusion, ECG findings were not useful for the detection or exclusion of RV cavity enlargement in patients with acute PE.

Short-term mortality in acute pulmonary embolism: clot burden and signs of right heart dysfunction at CT pulmonary angiography

PURPOSE

To assess the correlation between volumetric measurements of clot, semiquantitative clot burden indexes, and signs of right heart dysfunction at computed tomographic (CT) pulmonary angiography in patients with acute pulmonary embolism (PE) and to determine whether clot burden and signs of right heart dysfunction are associated with short-term mortality.

MATERIALS AND METHODS

This retrospective study was institutional review board approved and HIPAA compliant. CT pulmonary angiographic studies (January 2007 through December 2007) with findings positive for PE were retrieved. Two readers evaluated signs of right heart dysfunction at CT pulmonary angiography, measured clot volume using a dedicated software program, and assessed clot burden using semiquantitative scores (Qanadli and Mastora). Spearman rank coefficient was used to investigate correlation between clot burden measures and signs of right heart dysfunction. Uni- and multivariate analyses were used to test association between CT pulmonary angiographic findings and short-term mortality.

RESULTS

A total of 635 CT pulmonary angiographic studies from 635 patients (304 men, 331 women; mean age, 59 years) were included; 39 (6%) patients died within 30 days. Clot volume was strongly correlated with Qanadli score (ρ=0.841, P<.01) and Mastora score (ρ=0.863, P<.01) and moderately correlated (ρ=0.378, P<.01) with the ratio of right ventricle diameter to left ventricle diameter (RV/LV ratio). Among the pulmonary angiographic signs, only increase in RV/LV ratio (cut-off value, 1.0) was independently associated with short-term mortality in multivariate analysis.

CONCLUSION

Clot volume strongly correlated with semiquantitative CT scores of clot burden, and greater clot volume was associated with higher incidence of right heart dilatation. Increase in RV/LV ratio was associated with short-term mortality; however, measures of clot burden were not.

CT signs of right ventricular dysfunction: prognostic role in acute pulmonary embolism

OBJECTIVES

The purpose of this study was to compare the prognostic role of various computed tomography (CT) signs of right ventricular (RV) dysfunction, including 3-dimensional ventricular volume measurements, to predict adverse outcomes in patients with acute pulmonary embolism (PE).

BACKGROUND

Three-dimensional ventricular volume measurements based on chest CT have become feasible for routine clinical application; however, their prognostic role in patients with acute PE has not been assessed.

METHODS

We evaluated 260 patients with acute PE for the following CT signs of RV dysfunction obtained on routine chest CT: abnormal position of the interventricular septum, inferior vena cava contrast reflux, right ventricle diameter (RVD) to left ventricle diameter (LVD) ratio on axial sections and 4-chamber (4-CH) views, and 3-dimensional right ventricle volume (RVV) to left ventricle volume (LVV) ratio. Comorbidities and fatal and nonfatal adverse outcomes according to the MAPPET-3 (Management Strategies and Prognosis in Pulmonary Embolism Trial-3) criteria within 30 days were recorded.

RESULTS

Fifty-seven patients (21.9%) had adverse outcomes, including 20 patients (7.7%) who died within 30 days. An RVD(axial)/LVD(axial) ratio >1.0 was not predictive for adverse outcomes. On multivariate analysis (adjusting for comorbidities), abnormal position of the interventricular septum (hazard ratio [HR]: 2.07; p = 0.007), inferior vena cava contrast reflux (HR: 2.57; p = 0.001), RVD(4-CH)/LVD(4-CH) ratio >1.0 (HR: 2.51; p = 0.009), and RVV/LVV ratio >1.2 (HR: 4.04; p < 0.001) were predictive of adverse outcomes, whereas RVD(4-CH)/LVD(4-CH) ratio >1.0 (HR: 3.68; p = 0.039) and RVV/LVV ratio >1.2 (HR: 6.49; p = 0.005) were predictive of 30-day death.

CONCLUSIONS

Three-dimensional ventricular volume measurement on chest CT is a predictor of early death in patients with acute PE, independent of clinical risk factors and comorbidities. Abnormal position of the interventricular septum, inferior vena cava contrast reflux, and RVD(4-CH)/LVD(4-CH) ratio are predictive of adverse outcomes, whereas RVD(axial)/LVD(axial) ratio >1.0 is not.

Subjective assessment of right ventricle enlargement from computed tomography pulmonary angiography images

To retrospectively evaluate prognostic accuracy of subjective assessment of right ventricle (RV) enlargement on CT pulmonary angiography (CTPA) images in comparison with objective measures of RV enlargement in patients with acute pulmonary embolism (PE). For 200 consecutive patients with acute PE, two readers blinded to patient outcomes subjectively determined whether the maximum RV diameter was greater than that of the left ventricle (LV) using axial CTPA images. For the objective measurements, RV/LV diameter ratios were calculated using axial images and 4-chamber reformatted images. For all assessments, sensitivities and specificities for predicting PE-related death within 30-days and a composite outcome including PE-related death or the need for intensive therapies were compared. The agreement between two readers was 91.5% (kappa = 0.83) and all other assessments had pair-wise agreement over 75% (kappa = 0.53-0.72). There was no significant difference in sensitivity between the subjective and objective methods for predicting both outcomes. The specificity for subjective RV enlargement (55.4-67.7%) was significantly higher than objective measures (45.8-53.1%), except for the 4-chamber views where, for one reader, the specificity of the subjective evaluation was higher but did not reach statistical significance. Complex measurements of RV/LV diameter ratios may not be needed to maximize the prognostic value from CTPA. The radiologist who interprets the CTPA images should report RV enlargement when the RV diameter subjectively appears larger than the LV.

Non-severe pulmonary embolism: prognostic CT findings

The goal of this study was to retrospectively evaluate CT cardiovascular parameters and pulmonary artery clot load score as predictors of 3-month mortality in patients with clinically non-severe pulmonary embolism (PE). We included 226 CT positive for PE in hemodynamically stable patients (112 women; mean age 67.1 years ± 16.9). CT were independently reviewed by two observers. Results were compared with occurrence of death within 3 months using Cox regression. Twenty-four (10.6%) patients died, for whom 9 were considered to be due to PE. Interobserver agreement was moderate for the shape of interventricular septum (κ = 0.41), and for the ratio between the diameters of right and left ventricle (RV/LV) (κ = 0.76). Observers found no association between interventricular septum shape and death. A RV/LV diameter ratio >1 was predictive of death (OR, 3.83; p < 0.01) only when we also took into account the value of the embolic burden (< 40%). In a multivariate model, CT cardiovascular parameters were not associated with death. Concomitant lower limb DVT and comorbid conditions were important predictors of death. In clinically non-severe PE, a RV/LV diameter ratio >1 is predictive of death when the embolic burden is low (< 40%).