CHA2DS2‐VASc and PESI scores are associated with right ventricular dysfunction on computed tomography pulmonary angiography in patients with acute pulmonary thromboembolism

Abstract Background Accurate risk stratification is the most important step in the management of patients with acute pulmonary thromboembolism (PTE). Pulmonary embolism severity index (PESI) is a clinical tool for PTE risk stratification. CHA2DS2‐VASc score, a risk assessment tool in patients with atrial fibrillation, is recently considered for acute PTE. The presence of right ventricular (RV) dysfunction in imaging is more efficient in acute PTE risk evaluation. Hypothesis This study aims to evaluate the association between CHA2DS2‐VASc and PESI score and each of them with RV dysfunction on computed tomography pulmonary angiography (CTPA). Methods One hundred eighteen patients with a definite diagnosis of PTE were entered. The CHA2DS2‐VASc and PESI scores were calculated for all of them. RV dysfunction including an increase in RV to left ventricular diameter ratio, interventricular septal bowing, and reflux of contrast medium into the inferior vena cava was examined by CTPA. Results PESI and CHA2DS2‐VASc scores were significantly associated with RV dysfunction. In addition, different classes of PESI scores were correlated with RV dysfunction. Moreover, this study showed that the CHA2DS2‐VASc score and PESI score had a positive correlation. The area under the curve value for the CHA2DS2‐VASc score was 0.625 with 61.54% sensitivity and 60.0% specificity for predicting RV dysfunction while for PESI score was 0.635 with 66.7% sensitivity and 60.0% specificity. Conclusion This study showed that not only CHA2DS2‐VASc and PESI scores are positively correlated, but they are both associated with RV dysfunction diagnosed by CTPA. CHA2DS2‐VASc and PESI scores are able to predict RV dysfunction.


| INTRODUCTION
Acute pulmonary thromboembolism (PTE) is a life-threatening emergency that is responsible for nearly 200 000 deaths each year alone. 1 Acute PTE manifests with a broad spectrum of presentations from mild clinical features to severe life-threatening conditions and even death. The proper diagnostic approach and accurate risk stratification are essential for decreasing the morbidity and mortality rates of PTE. 2 In addition to making the diagnosis, the physician must decide the settings the patient should be managed and the best treatment that should be initiated. 3 Clinical evaluation and assessment of right ventricular (RV) size and function are two key components for risk stratification. 4 Computerized tomography pulmonary angiography (CTPA) is the choice method in the diagnosis of PTE with excellent sensitivity and specificity. Moreover, CTPA helps with evaluating the prognosis of patients with PTE. CTPA shows the fourchamber view of the heart and demonstrates RV dysfunction as an increase in RV to left ventricular (RV/LV) diameter ratio, interventricular septal bowing, and reflux of contrast medium into the inferior vena cava (IVC). 5,6 The European Society of Cardiology (ESC) guidelines recommend clinical, imaging, and laboratory evaluation of PTE severity, mainly related to the presence of RV dysfunction, to risk-stratify a patient with acute PTE more thoroughly. 7 The presence of RV dysfunction in imaging studies seems to act as an independent variable for predicting high mortality in acute PTE. 8,9 A recent study suggests that in the setting of acute PTE, which requires an accurate risk stratification tool, the presence of RV dysfunction alone is sufficient and superior for this purpose. 10  The pulmonary embolism severity index (PESI) specifies 11 features from history, demographics, and clinical findings and is a clinical risk stratification tool. Some studies suggest the association between the presence of RV dysfunction and PESI in patients diagnosed with PTE. 11,12 The CHA 2 DS 2 -VASc (C: congestive heart failure, H: hypertension, A: age of ≥75 years, D: diabetes mellitus, S: previous stroke, V: vascular disease, A: age between 65 and 74 years, Sc: female gender) has been shown as a useful clinical score to evaluate the thromboembolism risk and to administer the anticoagulant in patients diagnosed with nonvalvular atrial fibrillation. 13 The components of the CHA 2 DS 2 -VASc score are simple and practical. The CHA 2 DS 2 -VASc score has been considered for predicting the prognosis and mortality of coronary artery bypass grafting surgery and various cardiovascular diseases such as acute myocardial infarction and heart failure. 11,[13][14][15][16][17][18] It has been reported that a higher CHA 2 DS 2 -VASc score is associated with cardiovascular events such as ischemic stroke, thromboembolism, and death in patients without atrial fibrillation. [19][20][21] In a study in acute PTE patients with cardiac sinus rhythm, the CHA 2 DS 2 -VASc score has been suggested to provide further prognostic information besides the PESI score. 22 A recent study showed the association between CHA 2 DS 2 -VASc score and echocardiographic indices of RV dysfunction in patients with acute PTE. 23 In this study, we investigated the association of the CHA 2 DS 2 -VASc score with the PESI score, association and predictive values of PESI score and CHA 2 DS 2 -VASc for RV dysfunction on CTPA and assessed the correlation between different variables of these two scores and RV dysfunction.

| METHODS
This was a retrospective study that was conducted on patients over All CT scan images were acquired using a 16-section multidetector CT scanner based on the standard CTPA protocol for PTE and 20 s after injection of 100 ml contrast media at a rate of 5 ml/s. Careful evaluation of the CTPA images was made by an expert radiologist to detect signs of RV dysfunction by analyzing RV/LV diameter ratio, interventricular septal bowing and reflux of contrast medium into the IVC. LV and RV dimensions were measured exactly below the atrioventricular leaflets and defined as the distance between the endocardium of the septum with the ventricular wall.
Reflux of contrast medium was considered noticeable only when the reflux was seen into the IVC and hepatic veins. Diagnosis of RV dysfunction was based on the presence of at least one of these three criteria: (1) RV/LV diameter ratio ≥0.9; (2) bowing of interventricular septum; and (3) reflux of contrast medium into the IVC. 24 A clinician reviewed charts and scored PESI and CHA 2 DS 2 -VASc, blinded to patient outcomes. PESI score includes 11 features and is calculated by summing the patient's age in years (age > 80 years) and point assigned for each of the 10 variables as follows: 10 points for the male gender, 30 points for a history of malignancy, 10 points for a history of heart failure, 10 points for a history of chronic lung disease, 20 points for the presence of tachycardia (heart rate >109 beats/min), ALIREZAEI ET AL. | 225 30 points for systolic hypotension (systolic blood pressure <100 mmHg), 20 points for the presence of tachypnea (respiratory rate ≥30 breaths/min), 20 points for a temperature less than 36°C, 60 points for an altered mental status, and 20 points for arterial oxygen saturation less than 90%. According to the PESI score, patients were categorized into five classes including Class I (<65 points: very low risk), Class II (66-85 points: low risk), Class III (86-105 points: intermediate risk), Class IV (106-125 points: high risk), and Class V (>125 points: very high risk).
The CHA 2 DS 2 -VASc score was calculated for each patient as

| RESULTS
In this study, 118 patients including 60 (50.8%) males and 58 (49.2%) females were entered. The patients aged from 18 to 93 years old with a mean ± SD of 59.64 ± 20.6 years. The calculated PESI score was ranged from 27 to 283 with a mean ± SD of 106.5 ± 46.9. The prevalence of PESI score risk factors among patients showed that male gender, arterial O 2 saturation of less than 90%, and heart rate more than 109 beats/min were the most prevalent risk factors ( and 22 (28.2%) had three criteria of RV dysfunction. The mean of PESI score and CHA 2 DS 2 -VASc score in groups with and without RV dysfunction was evaluated and showed that both scores were significantly higher in patients with RV dysfunction. There was a statistically significant association between RV dysfunction and PESI score and also, CHA 2 DS 2 -VASc score (p = .023 and041, respectively).
Among RV dysfunction criteria, PESI score and CHA 2 DS 2 -VASc score were correlated with reflux of contrast medium into the IVC (p = .010 and <.0001, respectively) ( Table 2).
The distribution of PESI score among patients with classification into five classes is shown in Table 3. Most of the patients were in Class V (30.5%) and the least was in Class II (11.9%). Different classes of PESI score were associated with RV dysfunction, meaning that patients without RV dysfunction are seen in Class I more than patients with RV dysfunction, and patients with RV dysfunction are seen in higher classes of PESI score ( Table 3).
The analysis also showed that among the risk factors of PTE, male gender and heart rate more than 109 beats/min were significantly correlated with RV dysfunction (  Figure S1). radiologist for reading the CTPA and one observer calculating the scores and more observers might have increased the validity of our study. We hope further studies will draw definite conclusions.

| CONCLUSION
This study showed that not only CHA 2 DS 2 -VASc and PESI scores are positively correlated, but also they are both associated with RV dysfunction diagnosed by CTPA. CHA 2 DS 2 -VASc and PESI scores are able to predict RV dysfunction and are associated with reflux of contrast medium into the IVC among RV dysfunction criteria on CTPA. Further studies are required to define the role of the CHA 2 DS 2 -VASc score in acute PTE risk stratification.

ACKNOWLEDGMENTS
The authors of the present study sincerely thank all of the medical staff who cooperated with us for completion of this study. The results of this study was extracted from the specialist thesis, performed