Informação da revista
Vol. 32. Núm. 1.
Páginas 7-13 (Janeiro 2013)
Partilhar
Partilhar
Baixar PDF
Mais opções do artigo
Visitas
8677
Vol. 32. Núm. 1.
Páginas 7-13 (Janeiro 2013)
Original article
Open Access
One-shot diagnostic and prognostic assessment in intermediate- to high-risk acute pulmonary embolism: The role of multidetector computed tomography
Angiografia pulmonar por tomografia computadorizada em doentes com tromboembolia pumonar de médio a alto risco: avaliação diagnóstica e prognóstica num só exame
Visitas
8677
Rui Baptistaa,b,
Autor para correspondência
ruibaptista@gmail.com

Corresponding author.
, Inês Santiagoc, Elisabete Jorgea,b, Rogério Teixeiraa,b, Paulo Mendesa, Luís Curvo-Semedod, Graça Castroa, Pedro Monteiroa,b, Filipe Caseiro-Alvesb,d, Luís A. Providênciaa,b
a Cardiology Unit, Hospitais da Universidade de Coimbra, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
b Faculty of Medicine, University of Coimbra, Coimbra, Portugal
c Radiology Department, Hospital Infante D. Pedro, Aveiro, Portugal
d Radiology Unit, Hospitais da Universidade de Coimbra, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
Conteúdo relacionado
Rev Port Cardiol. 2013;32:15-710.1016/j.repc.2012.10.003
Daniel Ferreira
Este item recebeu

Under a Creative Commons license
Informação do artigo
Resume
Texto Completo
Bibliografia
Baixar PDF
Estatísticas
Tabelas (4)
Table 1. Clinical characteristics and laboratory variables at initial diagnosis.
Table 2. Symptoms, risk factors and diagnostic test data at diagnosis.
Table 3. Main computer tomography pulmonary angiography findings.
Table 4. Correlations of clinical, laboratory and echocardiographic data with MDCT parameters.
Mostrar maisMostrar menos
Abstract
Introduction

Contrast-enhanced multidetector computed tomography (MDCT) is useful for the diagnosis of pulmonary embolism (PE). However, current guidelines do not support its use for risk assessment in acute PE patients.

Objectives

We compared the prognostic impact of MDCT-derived indices regarding medium-term mortality in a population of intermediate- to high-risk PE patients, mostly treated by thrombolysis.

Methods

Thirty-nine consecutive patients admitted to an intensive care unit with acute PE were studied. All patients had a pulmonary MDCT on admission to the emergency room as part of the diagnostic algorithm. We assessed the following MDCT variables: right ventricular/left ventricular diameter (RV/LV) ratio, arterial obstruction index, pulmonary artery-to-aorta diameter ratio and azygos vein diameter. A 33-month follow-up was performed.

Results

Mean age was 59.1±19.6 years, with 80% of patients receiving thrombolysis. Follow-up all-cause mortality was 12.8%. Of the MDCT-derived variables, only the RV/LV ratio had significant predictive value, being higher in patients who suffered the endpoint (1.6±0.5 vs. 1.9±0.4, p=0.046). Patients with an RV/LV ratio ≥1.8 had 11-fold higher medium-term all-cause mortality (3.8% vs. 38.8%, p<0.001). Regarding this endpoint, the c-statistic was 0.78 (95% CI, 0.60–0.96) for RV/LV ratio and calibration was good (goodness-of-fit p=0.594). No other radiological index was predictive of mortality.

Conclusions

MDCT gives the possibility, in a single imaging procedure, of diagnosing and assessing the prognosis of patients with intermediate- to high-risk PE. Although further studies are needed, the simple-to-calculate RV/LV ratio has good discrimination and calibration for predicting poorer outcomes in patients with acute PE.

Keywords:
Pulmonary embolism
Prognosis
Right ventricular dysfunction
Thrombolysis
Multidetector computed tomography
Contrast
Resumo
Introdução

A angiografia pulmonar por tomografia computadorizada com contraste (angio-TC) é recomendada para o diagnóstico mas não para a estratificação de risco em doentes com tromboembolia pulmonar (TEP).

Objectivos

Determinar o impacto prognóstico a médio-prazo de vários índices radiológicos obtidos na angio-TC em doentes com TEP de médio a alto risco, a maioria tratados com fibrinólise.

Métodos

Estudaram-se 39 doentes admitidos numa unidade de cuidados intensivos por TEP, todos com angio-TC prévia realizada na urgência e seguiram-se durante 33 meses. Mediram-se as seguintes variáveis: razão entre os diâmetros do ventrículo direito e ventrículo esquerdo (índice VD/VE), índice de obstrução arterial, razão ente os diâmetros da artéria pulmonar e aorta e diâmetro da veia ázigos.

Resultados

A idade média foi de 59,1 ± 19,6 anos; 80% dos doentes foram tratados com fibrinólise. Durante o período de seguimento clínico, a mortalidade foi 12,8%. Das variáveis analisadas, apenas o índice VD/VE demonstrou valor preditivo, sendo significativamente mais elevado nos doentes que faleceram (1,6 ± 0,5 versus 1,9 ± 0,4, p=0,046). Os doentes com um índice VD/VE ≥ 1,8 tiveram uma incidência 11 vezes superior de mortalidade a médio prazo (3,8% versus 38,8%, p < 0,001). Relativamente a este endpoint, o c-statistic foi de 0,78 (95% IC 0,60–0,96) e a calibração elevada (goodness-of-fit p=0,594). Nenhum outro índice radiológico demonstrou associação com a mortalidade.

Conclusões

A angio-TC permite num único exame, em doentes de médio e alto risco, diagnosticar e estratificar o risco da TEP. Apesar de serem necessários mais estudos, o índice VD/VE pode identificar doentes com pior prognóstico após uma TEP.

Palavras-chave:
Tromboembolia pulmonar
Prognóstico
Disfunção ventricular direita
Trombólise
Tomografia computadorizada
Contraste
Texto Completo
Introduction

Pulmonary embolism (PE) ranges from asymptomatic forms to life-threatening massive arterial pulmonary bed obstruction and may be responsible for up to 15% of all in-hospital deaths.1 Mortality is thought to be caused in part by right ventricular (RV) pressure overload resulting in RV dilatation and dysfunction (RVD), ischemia with ensuing failure and ultimately death.2

PE can be difficult to diagnose and risk stratification is paramount, in order to choose the best therapeutic option for each patient.3,4 Contrast-enhanced multidetector computed tomography (MDCT) is currently the gold standard for diagnosing PE and has a growing role in risk stratification. Recent evidence has confirmed the good correlation between echocardiography and MDCT-derived indices of RVD and the ratio of right ventricular to left ventricular (RV/LV) short-axis diameters has emerged as the most accurate sign of RVD.5,6 Also, the extent of PE (the thrombus burden in the pulmonary bed) has been proposed as an important parameter for predicting RVD and death.7–9 At the same time, the number of patients with low-risk PE is increasing, due to the lower threshold of clinical suspicion and greater availability of diagnostic techniques.10

However, the majority of studies assessing RV/LV ratios exclude the most severe patients from MDCT analysis, particularly hemodynamically unstable patients. This is reflected by the low mean RV/LV ratios reported in the literature, ranging from 1.15,11 to 1.32.12,13 Moreover, the proportion of patients undergoing thrombolytic therapy in these studies was also low.

Our aim was to compare the prognostic impact of various MDCT-derived RVD indices on medium-term mortality in a population of intermediate- to high-risk PE patients, most of them treated by thrombolysis.

MethodsPatient population

We retrospectively studied all patients with intermediate- to high-risk PE admitted to the intensive care unit of our department between November 2005 and July 2008. The diagnosis of PE was confirmed by 4- or 64-detector MDCT in all patients. The clinical severity of pulmonary embolism was stratified using the system proposed by the ESC guidelines.3 All patients had intermediate- (positive troponin I and/or RV dilatation/dysfunction on echocardiogram) or high-risk PE (shock, defined by systolic blood pressure <90 mmHg). Medical records of patients who were eligible for the study were reviewed by two of the authors, who were not involved in MDCT reporting. Clinical data was collected prospectively, including demographic, clinical, laboratory and echocardiographic data. We assessed a medium-term endpoint of all-cause mortality, and in-hospital clinical deterioration – a composite of in-hospital death, need for mechanical ventilation, inotrope usage and rethrombolysis – was also assessed. The protocol was reviewed by the institutional board. The population was divided into two groups, classified by survival status at follow-up (alive or deceased).

Therapeutic protocol

Decisions on treatment were the responsibility of the attending physician. The indications for thrombolytic therapy were hypotension, severe hypoxemia, evidence of RV dysfunction on transthoracic echocardiography and evidence of severe pulmonary thrombus burden. Thirty-three (84.6%) patients underwent thrombolysis with alteplase (Actilyse®, Boehringer Ingelheim Pharma, Germany) followed by a continuous intravenous infusion of heparin. No patient underwent surgical or catheter-based embolectomy. Mean follow-up was three years and survival status was available for 97.4% of patients.

Transthoracic echocardiography

Bedside standard two-dimensional echocardiography was performed by the on-call cardiologist with a portable Aloka® echocardiograph and was available in 30 patients (77%). Pulmonary artery systolic pressure (PASP) was derived from the right atrioventricular pressure gradient using peak velocity of tricuspid regurgitation with continuous wave Doppler in apical four-chamber view and the modified Bernoulli equation. Right atrial pressure was considered equal to 5 mmHg or 10 mmHg according to whether or not the inferior vena cava collapsed during inspiration, respectively.

Contrast-enhanced multidetector computed tomography

All MDCT examinations were performed during patient stay in the emergency department by the on-call radiologist. Images were obtained on either a 4-slice or a 64-slice multidetector CT scanner during inspiratory breath holding when possible or during quiet breathing if the patient was short of breath. For patients on mechanical ventilation, ventilation was manually suspended in deep inspiration. Intravenous injection of contrast medium (80 ml of iodinated contrast material with a concentration of 400 mg/ml, at a rate of 3.5–5 ml/s) was started using a bolus tracking device, when attenuation of blood in the main pulmonary artery reached 100 Hounsfield units (HU) for the 4-slice MDCT and 180 HU for the 64-slice MDCT scanners, respectively.

Caudocranial helical acquisition was obtained with a collimation of 0.625–1.25 mm and a pitch of 0.9–1.5. Acquisition time was 0.5 s per rotation and tube current was modulated between 100 and 700 mA and 100 and 140 kV. The z-axis coverage started 2 cm below the diaphragm and extended up to the upper part of the aortic arch, enabling visualization of the heart and pulmonary arteries up to the subsegmental level. Images were immediately analyzed by the on-call radiologist, who diagnosed PE based on the presence of pulmonary arterial filling defects.

Offline image analysis

All MDCT scans were retrospectively reviewed by two independent radiologists (with 4 and 13 years of experience, respectively) who were blinded to clinical data, results of echocardiography and outcomes. The readers scored pulmonary arterial thrombus load using the system proposed by Mastora et al.7 The widths of the ventricular chambers were evaluated based on a single axial image obtained at the plane of maximal visualization of the ventricular chambers, which was typically at the level of the mitral valve. Axes were measured in diastole on a single transverse scan perpendicular to the long axis of the heart and were defined as the largest distance between the inner aspect of the interventricular septum and the ventricular free wall.14 The right ventricle was considered dilated if the right ventricular chamber was wider than the left ventricular chamber along the short axis.

Vascular measurements for the diameters of the pulmonary artery, aorta and azygos vein were also obtained used adjusted multiplanar images in the plane perpendicular to the long axis of the vessel being considered and were acquired using electronic calipers. The pulmonary artery was measured near its branching, the aorta at the middle third of its ascending portion and the azygos vein where it faced the right tracheal wall.

Statistical analysis

All variables were tested for normality using the Kolmogorov-Smirnov test. If normal, values are presented as mean values ± standard deviation. If the distribution was skewed, values are presented as medians, first and third quartiles. Correlations were analyzed with the Pearson correlation. Results are presented as coefficients of correlation (r). The area under the receiver operating characteristic curve (AUROC) was used for discrimination; this provides a measure of overall accuracy that is independent of the decision criterion. The criterion value with the highest accuracy is the value with the minimum false negative and false positive results at the same time. Statistical analyses were performed using SPSS 13.0® software (Chicago, Illinois). AUROC analysis was performed using MedCalc® software version 6.12 (MedCalc, Mariakerke, Belgium).

ResultsClinical data

A total of 39 consecutive patients admitted to our intensive care unit with an MDCT-confirmed diagnosis of PE were studied. All MDCT parameters were assessable in all patients. Baseline characteristics are presented in Table 1. Mean age was 59.1±19.6 years (range 22–85 years), with a majority of females (53.8%). Body mass index was high, with a mean value of 29.2±4.2 kg/m2. No differences were found in mean blood pressure or heart rate between the groups; similarly, no differences were found between groups regarding arterial blood gases, blood glucose, troponin I, estimated glomerular filtration rate or C-reactive protein on admission. D-dimers were higher in patients who died than in surviving patients (16.3±6.8 vs. 6.8±5.2 μg/l, p=0.02).

Table 1.

Clinical characteristics and laboratory variables at initial diagnosis.

  Total(n=39)  Survivors(n=34)  Deceased(n=5) 
Age, years  59.1±19.6  56.0±19.0  80.3±3.9  0.001 
Body mass index, kg/m2  29.2±4.2  29.1±4.3  29.8±4  NS 
Mean arterial pressure, mmHg  90.5±13.4  91.9±13.4  81.5±9.9  NS 
Heart rate, bpm  97±19.3  97.6±18.8  92.4±24.4  NS 
O2 partial pressure, mmHg  63.8±18.8  64.7±20  58.4±6.9  NS 
CO2 partial pressure, mmHg  32.6±5.7  32.8±5.9  30.9±4.9  NS 
D-dimers, μg/l  7.9±6.1  6.8±5.2  16.3±6.8  0.02 
Blood glucose, mg/dl  158.9±66.6  159.1±67.6  157.8±67.1  NS 
Troponin I, ng/ml  0.2±0.3  0.2±0.3  0.1±0.1  NS 
eGFR, ml/min/m2  71.9±22.9  74.3±22.3  55.7±22.7  NS 
C-reactive protein, mg/dl  3.9±3.9  4±4.1  3.1±2.1  NS 

bpm: beats per minute; eGFR: estimated glomerular filtration rate by the Modification in Diet in Renal Disease equation.

Clinical data are presented in Table 2. Most patients presented with dyspnea (69.2%), followed by chest pain (51.3%). Almost one third suffered syncope (30.8%). The most common risk factor for PE was recent major surgery (20.5%), closely followed by neoplasia (17.9%) and a prior thromboembolic event (17.9%). A typical S1Q3T3 pattern on the surface ECG was found in 23.1% of patients and in 28.2% right ventricular strain was present. The bedside echocardiogram documented mean PASP of 56.6±17.0 mmHg, with no significant differences between groups. Regarding treatment, more than 80% of patients underwent thrombolysis (82.4 vs. 100%, p=0.307). Five percent of these were high-risk patients according to the ESC guidelines, with hemodynamic instability, while 95% were in the intermediate-risk stratum.

Table 2.

Symptoms, risk factors and diagnostic test data at diagnosis.

  Total(n=39)  Survivors(n=34)  Deceased(n=5) 
Symptoms, n (%)
Dyspnea  27 (69.2)  24 (70.6)  3 (60.0)  NS 
Chest pain  20 (51.3)  19 (55.9)  1 (20.0)  NS 
Cough  4 (10.3)  4 (11.8)  0 (0.0)  – 
Syncope  12 (30.8)  9 (26.5)  3 (60.0)  NS 
Risk factors, n (%)
Recent major surgery  8 (20.5)  7 (20.6)  1 (20.0)  NS 
Neoplasia  7 (17.9)  7 (20.6)  1 (17.9)  NS 
Prior pulmonary embolism/DVT  7 (17.9)  1 (20.6)  0 (0.0)  – 
Diagnostic tests, n (%)
Electrocardiogram         
S1Q3T3 pattern  9 (23.1)  8 (23.5)  1 (20.0)  NS 
Inverted T waves in V1–V3  11 (28.2)  9 (26.5)  2 (40.0)  NS 
Echocardiogram         
PASP, mmHg  56.6 ± 17.0  55.7 ± 15.1  64.0 ± 36.8  NS 

DVT: deep vein thrombosis; PASP: pulmonary artery systolic pressure.

Outcomes

There were five deaths, three of them in-hospital (7.7%). None was due to bleeding complications. Median time to death was six days (range 1–40 days). The in-hospital combined endpoint of clinical deterioration occurred in 10.3% of patients. During the three-year medium-term follow-up, all-cause mortality was 12.8%.

Quantitative measurements

Results of the MDCT variables are shown in Table 3. Reflecting the overall severity of the population, the arterial obstruction index was over 40% in 71.8% of patients, with a mean of 49.4±16.9%. Although this index correlated significantly with age, heart rate, troponin I and RV/LV ratio (Table 4), it was not predictive of medium-term mortality. This high arterial obstruction index was accompanied by a very high mean RV/LV ratio of 1.7±0.5. This variable differed significantly between the groups, with higher values in patients who died during follow-up (2.0±0.4 vs. 1.6±0.5, p=0.046). None of the other radiological variables correlated significantly with mortality. Patients who underwent thrombolysis had similar RV/LV ratios to patients not receiving thrombolysis (1.6±0.7 vs. 1.7±0.5, p=0.407).

Table 3.

Main computer tomography pulmonary angiography findings.

  Total(n=39)  Survivors(n=34)  Deceased(n=5) 
Arterial obstruction index  49.4±16.9  49.2±17.9  51.1±8.6  NS 
Obstruction ≥40%, n (%)  28 (71.8)  23 (67.6)  5 (100.0)  NS 
RV diameter, cm  5.3±0.8  5.3±0.8  5.3±0.5  NS 
LV diameter, cm  3.5±0.9  3.6±0.9  3.1±0.7  NS 
RV/LV ratio  1.7±0.5  1.6±0.5  2.0±0.4  0.046 
PA diameter, cm  3.1±0.4  3.1±0.4  3.2±0.3  NS 
Aortic diameter, cm  3.3±0.5  3.3±0.5  3.5±0.1  NS 
PA/aortic diameter, cm  0.9±0.2  0.9±0.2  0.9±0.1  NS 
Azygos vein diameter, cm  1.1±0.3  1.1±0.3  0.9±0.2  NS 

LV: left ventricle; PA: pulmonary artery; RV: right ventricle.

Table 4.

Correlations of clinical, laboratory and echocardiographic data with MDCT parameters.

  Arterial obstruction indexRV/LV ratio
  Pearson coefficient  Pearson coefficient 
Age, years  0.373  0.019  0.353  0.027 
Heart rate, bpm  0.432  0.006  0.366  0.022 
Troponin I, ng/ml  0.446  0.012  0.315  0.085 
PASP, mmHg  0.318  0.106  0.238  0.232 

bpm: beats per minute; PASP: pulmonary artery systolic pressure.

On AUROC analysis, the best RV/LV ratio cut-off to predict medium-term mortality in this intermediate- to high-risk PE population was 1.81, with a c-statistic of 0.78 (95% confidence interval [CI], 0.60–0.96). Patients with an RV/LV ratio of more than 1.8 had 11-fold higher mortality than patients with RV/LV ratio <1.8 (3.8% vs. 38.8%, p<0.001). This compares with an established risk marker in PE, troponin I, which, in our population, yielded a c-statistic of 0.66 (95% CI, 0.34–0.97) for medium-term mortality.

Sensitivity and specificity (95% CI) of RV enlargement on MDCT for predicting death during follow-up were 80.0% and 76.5%, respectively. Negative and positive predictive values of RV enlargement on MDCT for medium-term all-cause mortality were 96.3% (95% CI, 81.0–99.9%) and 33.3% (95% CI, 9.9–65.1%), respectively. The RV/LV ratio had good calibration (Hosmer-Lemeshow test, p=0.594).

Discussion

The results of our study suggest than in this severely ill, intermediate- to high-risk PE population, only RV/LV ratio had the ability to predict medium-term mortality. Other radiological parameters, including azygos vein diameter, aortic diameter, pulmonary artery diameter and arterial obstruction index, showed no correlation with the endpoint of interest. Analysis of the data on survivors and non-survivors clearly demonstrated a significant difference in mean RV/LV ratios between these groups.

Follow-up all-cause mortality was 12.8%, similar to the rate seen in larger studies, suggesting that our sample is a representative cohort of PE patients. However, most studies report short-term (usually 30–90-day) mortality,11,13 whereas we report three-year follow-up data.

Although echocardiography has long been recognized as a rapid, non-invasive and sensitive method for demonstrating RVD in acute PE patients, it is not routinely performed due to its limited availability in emergency rooms and poor image quality in some patients. As MDCT has become the favored diagnostic method in acute PE, its emergence as a diagnostic tool that can simultaneously risk-stratify the patient is of great value. Arterial obstruction index and RV/LV ratio are the most extensively studied prognostic variables in patients with PE. The current literature is not clear regarding the association of radiological indices of PE severity and morbidity and mortality, especially in predicting long-term outcomes. Moreover, most studies only include patients with less severe forms of PE, a fact that is highlighted by the low arterial obstruction and RV/LV indices reported.5,11,12 Two studies focused only on MDCT findings in massive PE, using different definitions. Ocak et al. studied three patients with massive PE and concluded that reduced left atrial and pulmonary vein diameters were important findings on MDCT.15 Lim et al. reported data on 14 patients with acute massive PE, concluding that MDCT identified patients with right ventricular dysfunction with high sensitivity and specificity, a finding of relevance in hospitals without echocardiography available around the clock.7

One question that arises is why arterial obstruction index (or PA thrombus load) was not associated with mortality. Although correlated with troponin increase and RV/LV ratio in this intermediate- to high-risk population, it did not predict RV failure or death. Our results are in agreement with those of Collomb et al.16 and Ghaye et al.,14 supporting the idea that the most important prognostic factor is how the RV responds to the sudden increase in pulmonary vascular resistance and not the extent of the thrombus burden in the pulmonary bed. Several authors suggest that it is uncoupling of RV resources from the pulmonary arterial load, rather than obstruction, that causes RV failure.17,18 This is further evidence that fixed variables, such as obstruction index and pulmonary systolic pressure, are unable to predict morbidity, as they do not reflect RV-PA coupling. Added to the fact that calculation of the arterial obstruction index is difficult and time-consuming, the effectiveness of this index in the acute setting remains to be proven.

The RV/LV ratio, in contrast, reflects RV volume and pressure overload and thus reflects the pathophysiological processes leading to heart failure and death. Leftward shifting of the interventricular septum leads to impairment of left ventricular distensibility and pericardial constraint, limiting left ventricular filling and cardiac output. At the same time, acute RV dilatation aggravates tricuspid regurgitation, itself worsening RV performance. Several reports5,6,14,19,20 and a meta-analysis13 suggest that an RV/LV ratio >1.0 (or 0.9 in reconstructed four-chamber views) is a strong prognostic marker in patients with acute PE. Although there is some evidence that reconstructed four-chamber views may be superior to axial views for the identification of high-risk patients,19 several studies have found robust prognostic value using standard axial acquisitions to calculate the RV/LV ratio.11,12,20

In a large retrospective series of 431 patients, 30-day mortality was 15.6% in patients with RV enlargement (reconstructed four-chamber views), defined as RV/LV ratio >0.9 on MDCT, compared to 7.7% in those without this finding.6 In the above-mentioned meta-analysis of two studies (with two different RV/LV ratio thresholds, 1.5 and 1.0) including 191 normotensive patients with PE, a 58% (95% CI, 51–65%) overall negative and a 57% positive (95% CI, 49–64%) value of RV dilatation were reported on MDCT for predicting early death, yielding a relative risk for in-hospital mortality of 2.28 (95% CI, 0.9–5.9).13 Our study extends these findings to a population of severely ill patients (all with RV/LV ratio >1.0) and demonstrates that patients with RV/LV ratio >1.8 have an 11-fold higher risk of mortality during medium-term follow-up. These results are comparable to those reported by Ghuysen et al.,14 in which patients with a mean RV/LV ratio of 1.52 had a mortality of 25%.

To date, no study has demonstrated a clear benefit of thrombolysis over an anticoagulation-only strategy in intermediate-risk patients,3 although a multicenter trial is currently underway to assess the value of thrombolysis in these patients.21 The majority of our population underwent thrombolysis, due to the extensive thrombus burden (72% of patients with >50% arterial obstruction index), severe RV dilatation and elevated markers of myocardial necrosis in most patients. An elevated RV/LV ratio may identify high-risk patients who will benefit most from thrombolysis. However, the low positive predictive value of the RV/LV ratio may preclude its use to justify treatment escalation.

Our study is limited by its retrospective design and the small number of patients. Moreover, due to the characteristics of the population, selected in an emergency room setting, significant heterogeneity among patients, particularly regarding comorbidities, cannot be excluded. However, this reflects the actual population referred to our hospital with suspected or confirmed PE. The echocardiograms were not performed by the same operator and hence we do not provide quantitative data on chamber dimensions or RV function. Although the MDCT scans were immediately interpreted by the on-call radiologist, all exams were thoroughly reviewed by two radiologists who were blinded to outcomes and to echocardiography results, who confirmed the diagnosis of PE in all patients. The high usage of thrombolytic therapy may have influenced the mortality results. None of the MDCT scans were ECG-gated.

In conclusion, in this selected intermediate- to high-risk PE population with markers of severe right ventricular dysfunction, most of whom were treated with thrombolysis, only the MDCT-derived RV/LV ratio was predictive of medium-term death. Regular reporting of this parameter by the radiologist, jointly with the diagnosis of PE, may help the attending physician to risk-stratify PE patients.

Ethical disclosuresProtection of human and animal subjects

The authors declare that no experiments were performed on humans or animals for this study.

Confidentiality of data

The authors declare that they have followed the protocols of their work center on the publication of patient data and that all the patients included in the study received sufficient information and gave their written informed consent to participate in the study.

Right to privacy and informed consent

The authors declare that no patient data appear in this article.

Conflicts of interest

The authors have no conflicts of interest to declare.

References
[1]
S. Konstantinides.
Clinical practice. Acute pulmonary embolism.
N Engl J Med, 359 (2008), pp. 2804-2813
[2]
V.F. Tapson.
Acute pulmonary embolism.
N Engl J Med, 358 (2008), pp. 1037-1052
[3]
A. Torbicki, A. Perrier, S. Konstantinides, et al.
Guidelines on the diagnosis and management of acute pulmonary embolism: the Task Force for the Diagnosis and Management of Acute Pulmonary Embolism of the European Society of Cardiology (ESC).
Eur Heart J, 29 (2008), pp. 2276-2315
[4]
R. Martins.
The potential of new and old biomarkers for risk stratification in pulmonary embolism.
Rev Port Cardiol, 30 (2011), pp. 887-889
[5]
R.W. van der Meer, P.M. Pattynama, M.J. van Strijen, et al.
Right ventricular dysfunction and pulmonary obstruction index at helical CT: prediction of clinical outcome during 3-month follow-up in patients with acute pulmonary embolism.
Radiology, 235 (2005), pp. 798-803
[6]
U.J. Schoepf, N. Kucher, F. Kipfmueller, et al.
Right ventricular enlargement on chest computed tomography: a predictor of early death in acute pulmonary embolism.
Circulation, 110 (2004), pp. 3276-3280
[7]
I. Mastora, M. Remy-Jardin, P. Masson, et al.
Severity of acute pulmonary embolism: evaluation of a new spiral CT angiographic score in correlation with echocardiographic data.
Eur Radiol, 13 (2003), pp. 29-35
[8]
S.D. Qanadli, M. El Hajjam, A. Vieillard-Baron, et al.
New CT index to quantify arterial obstruction in pulmonary embolism: comparison with angiographic index and echocardiography.
AJR Am J Roentgenol, 176 (2001), pp. 1415-1420
[9]
W. Ghanima, M. Abdelnoor, L.O. Holmen, et al.
The association between the proximal extension of the clot and the severity of pulmonary embolism (PE): a proposal for a new radiological score for PE.
J Intern Med, 261 (2007), pp. 74-81
[10]
R.A. Douma, H.M. Hofstee, C. Schaefer-Prokop, et al.
Comparison of 4- and 64-slice CT scanning in the diagnosis of pulmonary embolism.
Thromb Haemost, 103 (2010), pp. 242-246
[11]
C. Becattini, G. Agnelli, M.C. Vedovati, et al.
Multidetector computed tomography for acute pulmonary embolism: diagnosis and risk stratification in a single test.
Eur Heart J, 32 (2011), pp. 1657-1663
[12]
A. Ghuysen, B. Ghaye, V. Willems, et al.
Computed tomographic pulmonary angiography and prognostic significance in patients with acute pulmonary embolism.
Thorax, 60 (2005), pp. 956-961
[13]
O. Sanchez, L. Trinquart, I. Colombet, et al.
Prognostic value of right ventricular dysfunction in patients with haemodynamically stable pulmonary embolism: a systematic review.
Eur Heart J, 29 (2008), pp. 1569-1577
[14]
B. Ghaye, A. Ghuysen, V. Willems, et al.
Severe pulmonary embolism: pulmonary artery clot load scores and cardiovascular parameters as predictors of mortality.
Radiology, 239 (2006), pp. 884-891
[15]
I. Ocak, C. Fuhrman.
CT angiography findings of the left atrium and right ventricle in patients with massive pulmonary embolism.
AJR Am J Roentgenol, 191 (2008), pp. 1072-1076
[16]
D. Collomb, P.J. Paramelle, O. Calaque, et al.
Severity assessment of acute pulmonary embolism: evaluation using helical CT.
Eur Radiol, 13 (2003), pp. 1508-1514
[17]
A. Ghuysen, B. Lambermont, J.M. Dogne, et al.
Effect of BM-573 [N-terbutyl-N′-[2-(4′-methylphenylamino)-5-nitro-benzenesulfonyl]urea], a dual thromboxane synthase inhibitor and thromboxane receptor antagonist, in a porcine model of acute pulmonary embolism.
J Pharmacol Exp Ther, 310 (2004), pp. 964-972
[18]
P.R. Fourie, A.R. Coetzee, C.T. Bolliger.
Pulmonary artery compliance: its role in right ventricular-arterial coupling.
Cardiovasc Res, 26 (1992), pp. 839-844
[19]
R. Quiroz, N. Kucher, U.J. Schoepf, et al.
Right ventricular enlargement on chest computed tomography: prognostic role in acute pulmonary embolism.
Circulation, 109 (2004), pp. 2401-2404
[20]
K.E. Lim, C.Y. Chan, P.H. Chu, et al.
Right ventricular dysfunction secondary to acute massive pulmonary embolism detected by helical computed tomography pulmonary angiography.
Clin Imaging, 29 (2005), pp. 16-21
[21]
G. Meyer.
The PEITHO study: for a clarification of the indications for the fibrinolytic treatment of pulmonary embolism.
Rev Pneumol Clin, 64 (2008), pp. 326-327
Copyright © 2012. Sociedade Portuguesa de Cardiologia
Idiomas
Revista Portuguesa de Cardiologia
Opções de artigo
Ferramentas
en pt

Are you a health professional able to prescribe or dispense drugs?

Você é um profissional de saúde habilitado a prescrever ou dispensar medicamentos

Ao assinalar que é «Profissional de Saúde», declara conhecer e aceitar que a responsável pelo tratamento dos dados pessoais dos utilizadores da página de internet da Revista Portuguesa de Cardiologia (RPC), é esta entidade, com sede no Campo Grande, n.º 28, 13.º, 1700-093 Lisboa, com os telefones 217 970 685 e 217 817 630, fax 217 931 095 e com o endereço de correio eletrónico revista@spc.pt. Declaro para todos os fins, que assumo inteira responsabilidade pela veracidade e exatidão da afirmação aqui fornecida.