Predictors of clinical outcome in acute pulmonary embolism: Correlation of CT pulmonary angiography with clinical, echocardiography and laboratory findings

Immediate cardiopulmonary responses to consecutive pulmonary embolism: a randomized, controlled, experimental study

BACKGROUND

Acute pulmonary embolism (PE) induces ventilation-perfusion mismatch and hypoxia and increases pulmonary pressure and right ventricular (RV) afterload, entailing potentially fatal RV failure within a short timeframe. Cardiopulmonary factors may respond differently to increased clot burden. We aimed to elucidate immediate cardiopulmonary responses during successive PE episodes in a porcine model.

METHODS

This was a randomized, controlled, blinded study of repeated measurements. Twelve pigs were randomly assigned to receive sham procedures or consecutive PEs every 15 min until doubling of mean pulmonary pressure. Cardiopulmonary assessments were conducted at 1, 2, 5, and 13 min after each PE using pressure-volume loops, invasive pressures, and arterial and mixed venous blood gas analyses. ANOVA and mixed-model statistical analyses were applied.

RESULTS

Pulmonary pressures increased after the initial PE administration (p < 0.0001), with a higher pulmonary pressure change compared to pressure change observed after the following PEs. Conversely, RV arterial elastance and pulmonary vascular resistance was not increased after the first PE, but after three PEs an increase was observed (p = 0.0103 and p = 0.0015, respectively). RV dilatation occurred following initial PEs, while RV ejection fraction declined after the third PE (p = 0.004). RV coupling exhibited a decreasing trend from the first PE (p = 0.095), despite increased mechanical work (p = 0.003). Ventilatory variables displayed more incremental changes with successive PEs.

CONCLUSION

In an experimental model of consecutive PE, RV afterload elevation and dysfunction manifested after the third PE, in contrast to pulmonary pressure that increased after the first PE. Ventilatory variables exhibited a more direct association with clot burden.

Evidence for Left Atrial Volume Being an Indicator of Adverse Events in Patients With Acute Pulmonary Embolism: Retrospective Case-control Pilot Study

PURPOSE

To assess the association between computed tomography pulmonary angiography (CTPA) atrial measurements and both 30-day pulmonary embolism (PE)-related adverse events and mortality, and non-PE-related mortality, and to identify the best predictors of these outcomes by comparing atrial measurements and widely used clinical and imaging variables.

PATIENTS AND METHODS

Retrospective single-center pilot study. Acute PE patients diagnosed on CTPA who also had a transthoracic echocardiogram, electrocardiogram, and troponin T were included. CTPA left atrial (LA) and right atrial (RA) volume and short-axis diameter were measured and compared between outcome groups, along with right ventricular/left ventricular diameter ratio, interventricular septal bowing, tricuspid annular plane systolic excursion, electrocardiogram, and troponin T.

RESULTS

A total of 350 patients. LA volume and diameter were associated with PE-related adverse events (P≤0.01). LA volume was the only atrial measurement associated with PE-related mortality (P=0.03), with no atrial measurements associated with non-PE-related mortality. Troponin was most associated with PE-related adverse events and mortality (both area under the curve [AUC]=0.77). On multivariate analysis, combination models did not greatly improve PE-related adverse events prediction compared with troponin alone. For PE-related mortality, the best models were the combination of troponin, age, and either LA volume (AUC=0.86) or diameter (AUC=0.87).

CONCLUSION

Among patients with acute PE, CTPA LA volume is the only imaging parameter associated with PE-related mortality and is the best imaging predictor of this outcome. Reduced CTPA LA volume and diameter, along with increased RA/LA volume and diameter ratios, are significantly associated with 30-day PE-related adverse events, but not with non-PE-related mortality.

Clinical and echocardiographic findings of patients with suspected acute pulmonary thromboembolism who underwent computed tomography pulmonary angiography

Background:

The aim of the study was to determine the correlation between clinical and echocardiographic findings and risk factors of patients with suspected acute pulmonary thromboembolism (PTE) who underwent computed tomography pulmonary angiography (CTPA).

Materials and Methods:

In this cross-sectional study, 310 hospitalized patients aged >18 years with high clinical suspicion of PTE referred to imaging center of our hospital from different wards for CTPA were enrolled. The frequency of different clinical presentations, risk factors, items of Wells’ criteria, and echocardiographic findings was compared in patients with and without PTE, which have been diagnosed according to the CTPA results.

Results:

PTE was diagnosed in 53 (17.1%) of patients with suspected PTE. From clinical manifestations, tachypnea, pleuritic chest pain, and edema of lower extremities were significantly more frequent among patients with PTE (P < 0.05). Major surgery was the risk factor which was significantly more prevalent among patients with PTE (P < 0.05). Frequency of all criteria of Wells’ criteria, except hemoptysis, was significantly higher in patients with PTE (P < 0.05). The frequency of all studied echocardiographic variables was significantly higher in patients with PTE (P < 0.05).

Conclusion:

It is suggested that we could use the results of this study for utilizing the diagnostic process of PTE in patients with highly clinical suspicion of PTE and providing more validated decision. Using the results of this study, we could identify high-risk patients and made appropriate risk assessment for better management of patients with suspected PTE as well as reduce the rate of unnecessary CTPA and its related adverse consequences.

Central Versus Peripheral Pulmonary Embolism: Analysis of the Impact on the Physiological Parameters and Long-term Survival

BACKGROUND

Studies aimed at assessing whether the emboli lodged in the central pulmonary arteries carry a worse prognosis than more peripheral emboli have yielded controversial results.

AIMS

To explore the impact on survival and long-term prognosis of central pulmonary embolism.

PATIENTS AND METHODS

Consecutive patients diagnosed with acute symptomatic pulmonary embolism by means of computed tomography (CT) angiography were evaluated at episode index and traced through the computed system of clinical recording and following-up. Central pulmonary embolism was diagnosed when thrombi were seen in the trunk or in the main pulmonary arteries and peripheral pulmonary embolism when segmental or subsegmental arteries were affected.

RESULTS

A total of 530 consecutive patients diagnosed with pulmonary embolism were evaluated; 255 patients had central pulmonary embolism and 275 patients had segmental or subsegmental pulmonary embolism. Patients with central pulmonary embolism were older, had higher plasma levels of N-terminal of the prohormone brain natriuretic peptide (NT-ProBNP), troponin I, D-dimer, alveolar-arterial gradient, and shock index (P < .001 for each one). Patients with central pulmonary embolism had an all-cause mortality of 40% while patients with segmental or subsegmental pulmonary embolism (PE) had an overall mortality of 27% and odds ratio of 1.81 [confidence interval (CI) 95% 1.16-1.9]. Survival was lower in patients with central PE than in patients with segmental or subsegmental pulmonary embolism, even after avoiding confounders (P = .018).

CONCLUSIONS

Apart from a greater impact on hemodynamics, gas exchange, and right ventricular dysfunction, central pulmonary embolism associates a shorter survival and an increased long-term mortality.

Diagnostic implications of computed tomography pulmonary angiography in patients with pulmonary embolism

INTRODUCTION:

Pulmonary embolism (PE) is a serious cardiovascular and pulmonary complication worldwide. We aimed to assess the implications of different computed tomography pulmonary angiography (CTPA) parameters in patients with acute PE.

METHODS:

A retrospective observational study to include patients presented with clinical suspicious of PE who underwent CTPA was conducted. Patients' demographics, clinical presentation, risk factors, laboratory investigations, management, and outcome were analyzed. Computed tomography findings included clot burden (Qanadli score [QS]) and right ventricular dysfunction (RVD) parameters.

RESULTS:

A total of 45 patients with radiologically confirmed diagnosis of PE were included in the study; of these patients, 8 (17.8%) died during the hospital course. Patients who died were 13 years older than those who survived, and the mortality rate was significantly higher in patients with cancer. The two groups were comparable for cardiovascular parameters. The mean clot burden (QS) was 19.5 ± 11.3 points and 53% of patients had QS >18 points. Obesity (52.4% vs. 12.5%; P = 0.01), hypertension (54.4% vs. 23.8%; P = 0.03), and median D-dimer levels (7.8 vs. 3.4; P = 0.03) were significantly higher in patients with QS >18. Among right ventricular (RV) dysfunction parameters, only higher RV/left ventricular (LV) ratio (P = 0.001) and bowing of interventricular septum (P = 0.001) were associated with higher QS. A significant positive correlation was found between RV short axis (r = 0.499, P = 0.001), RV/LV ratio (r = 0.592, P = 0.001), and pulmonary artery (PA) diameter (r = 0.301, P = 0.04) with the PA clot burden. Receiver operating characteristic curve for clot burden showed a cutoff value of 17.5 points to accurately predict RV dysfunction.

CONCLUSIONS:

Clot burden >18 is associated with RV dysfunction in patients with acute PE. Echocardiography and RVD parameters showed no correlation with in-hospital deaths. CTPA has clinicoradiological implications for risk stratification in PE patients. As the sample size is small, our findings warrant further larger prospective studies.

Predictive Value of Computed Tomography in Acute Pulmonary Embolism: Systematic Review and Meta-analysis

BACKGROUND

Many computed tomography (CT) parameters have been proposed as potential predictors of outcome in acute pulmonary embolism. We sought to summarize available evidence on the predictive value of CT severity parameters for short-term clinical outcome in pulmonary embolism.

METHODS

We searched PubMed and EMBASE through February 2014 for studies that reported on the association between CT parameters of acute pulmonary embolism severity and short-term (≤6 months) clinical outcome. Risk estimates for quantitative parameters of right ventricular (RV) dysfunction (abnormally increased RV/left ventricular [LV] diameter ratio on transverse sections and 4-chamber views), qualitative parameters of RV dysfunction (abnormal septal morphology and contrast reflux), thrombus load, and central thrombus location were derived using random effect regression analysis. Meta-regression analysis was performed to quantify and explain study heterogeneity.

RESULTS

A total of 49 studies with 13,162 patients with acute pulmonary embolism (median age of 61 years, 55.1% were women) who underwent diagnostic CT imaging were included in the analysis. An abnormally increased RV/LV diameter ratio measured on transverse sections was associated with an approximately 2.5-fold risk for all-cause mortality (pooled odds ratio [OR], 2.5; 95% confidence interval [CI], 1.8-3.5) and adverse outcome (OR, 2.3; 95% CI, 1.6-3.4) and a 5-fold risk for pulmonary embolism-related mortality (OR, 5.0; 95% CI, 2.7-9.2). Thrombus load (OR, 1.6, 95% CI, 0.7-3.9; P = .2896) and central location (OR, 1.7; 95% CI, 0.7-4.2; P = .2609) were not predictive for all-cause mortality, although both were associated with adverse clinical outcome.

CONCLUSIONS

Across all end points, the RV/LV diameter ratio on transverse CT sections has the strongest predictive value and most robust evidence base for adverse clinical outcomes in patients with acute pulmonary embolism.

Quantitative lung perfused blood volume imaging on dual-energy CT: capability for quantitative assessment of disease severity in patients with acute pulmonary thromboembolism

BACKGROUND

Regional iodine distribution assessment on dual-energy computed tomography (DECT) has been suggested as useful for management of acute pulmonary thromboembolism (APTE) patients. However, no reported studies have made a direct comparison between quantitatively assessed DECT and right-to-left ventricular (RV/LV) ratio on CT for differentiation of right heart dysfunction (RHD) from non-right heart dysfunction (NRHD) in APTE patients.

PURPOSE

To determine the capability of DECT for differentiation of RHD from NRHD in APTE patients.

MATERIAL AND METHODS

Thirteen APTE patients underwent DECT and echocardiography at onset of APTE. Patients were divided into RHD (n = 7) and NRHD (n = 6) groups based on echocardiography. A normalized lung perfused blood volume map was generated, and two kinds of overall perfusion (OP) index were determined, one placed over each lung field (OP index A) and as the average from six regions of interest (ROIs) placed over each lung field (OP index B). The heterogeneity index was also determined as the standard deviation for the six ROIs. RV/LV ratio evaluations were also performed. To assess differences between the two groups, each index was statistically compared with the Mann-Whitney U test. The receiver-operating curve-based positive test was then performed to determine the feasible threshold value for dividing patients into the two groups. Finally, differentiation capabilities of the indexes were compared using McNemar's test.

RESULTS

Significant differences between the two groups were found for both OP indexes and RV/LV ratio (P < 0.05). For each of the feasible threshold values, accuracy of each OP index with and without RV/LV ratio was better than that of the RV/LV ratio.

CONCLUSION

Quantitative DECT has good potential for differentiation of APTE patients with and without right heart dysfunction.

Outcome of pulmonary embolism and clinico-radiological predictors of mortality: Experience from a university hospital in Saudi Arabia

OBJECTIVES

The objective of this study is to determine the outcome of pulmonary embolism (PE) and the clinico-radiological predictors of mortality in a university hospital setting.

METHODS

A Prospective observational study conducted at King Khalid University Hospital, Riyadh Saudi Arabia between January 2009 and 2012. A total of 105 consecutive patients (49.9 ± 18.7 years) with PE diagnosed by computed tomography pulmonary angiography were followed until death or hospital discharge.

RESULTS

Overall in hospital mortality rate was 8.6%, which is lower than other international reports. Two-thirds of patients developed PE during the hospitalization. The most common risk factors were surgery (35.2%), obesity (34.3%) and immobility (30.5%). The localization of the embolus was central in 32.4%, lobar in 19% and distal in 48.6%. A total of 26 patients (25%) had evidence of right ventricular strain and 14 (13.3%) were hypotensive. Multivariate analysis revealed that heart failure (Beta = -0.53, P < 0.001), palpitation (Beta = -0.24, P = 0.014) and high respiratory rate (Beta = -0.211, P < 0.036) were significant predictors of mortality. There was no significant difference in the localization of the embolus or obstruction score between survivors and non-survivors.

CONCLUSION

The outcome of PE is improving; however, it remains an important risk factor for mortality in hospitalized patients. Congestive heart failure, tachypnea and tachycardia at presentation were associated with higher mortality. These factors need to be considered for risk stratification and management decisions of PE patients. Radiological quantification of clot burden was not a predictor of death.

Prognostic role of embolic burden assessed at computed tomography angiography in patients with acute pulmonary embolism: systematic review and meta-analysis

BACKGROUND

In patients with acute pulmonary embolism (PE), risk stratification is indicated for tailoring of both diagnostic strategies and acute treatment. Whether embolic burden assessed at computed tomography (CT) angiography has a role in risk stratification in these patients is debated.

OBJECTIVE

To systematically review and perform a meta-analysis to evaluate the role of CT-assessed burden associated with embolic obstruction and embolic localization in the prognostic stratification of patients with acute PE.

METHODS

We performed a systematic search in EMBASE and MEDLINE up until 30 June 2013. Studies reporting on the 30-day outcome of patients with confirmed PE and CT-assessed embolic burden were included. The study outcome was death.

RESULTS

Thirty studies reporting on the prognostic value of CT-assessed embolic burden met the inclusion criteria for this systematic review; of these, 19 were included in the meta-analysis. Five studies (2215 patients) were included in the analysis of localization: an association between embolus localization in the central arteries and 30-day mortality was found after heterogeneity was resolved (odds ratio [OR] 2.24, 95% confidence interval [CI] 1.29-3.89, I(2)  = 0%). No correlation was observed between obstruction index (according to the Qanadli scoring system) and 30-day mortality after heterogeneity was reduced (16 studies, 3884 patients, OR 1.22, 95% CI 0.99-1.51, I(2)  = 27%).

CONCLUSION

Localization of emboli assessed at CT angiography can be used for risk stratification in patients with acute PE. Moreover, no correlation was observed between obstruction index and prognosis.

Point of care cardiac ultrasound applications in the emergency department and intensive care unit--a review

The use of point of care echocardiography by non-cardiologist in acute care settings such as the emergency department (ED) or the intensive care unit (ICU) is very common. Unlike diagnostic echocardiography, the scope of such point of care exams is often restricted to address the clinical questions raised by the patient's differential diagnosis or chief complaint in order to inform immediate management decisions. In this article, an overview of the most common applications of this focused echocardiography in the ED and ICU is provided. This includes but is not limited to the evaluation of patients experiencing hypotension, cardiac arrest, cardiac trauma, chest pain and patients after cardiac surgery.

Pulmonary thromboembolism in an East African tertiary referral hospital

Pulmonary thromboembolism (PTE) is a frequent cause of mortality in Kenya, but its characteristics are hardly reported in Subsaharan Africa. To describe the pattern of PTE among black Africans, in a Kenyan referral hospital. Retrospective study at Kenyatta National Hospital (KNH), Nairobi, Kenya. Records of patients seen between January 2005 and December 2009 were examined for mode of diagnosis, comorbidities, age, gender, treatment and outcome. Data were analyzed using SPSS version 15.0 and are presented in tables and bar charts. One hundred and twenty-eight (60 male; 68 female) cases were analyzed. Diagnosis was made by clinical evaluation, a Well's score of >4.0, high D-dimer levels and ultrasound demonstration of a proximal deep venous thrombosis (DVT, 35.9%), lung spiral computer tomography (CT, 50%), multidetector CT (7.8%) and angiography (6.3%). Most frequent comorbidities included DVT (36%); hypertension (18.8%); pulmonary tuberculosis (PTB, 12.5%); HIV infection (10.9%), pueperium, diabetes mellitus and cigarette smoking (9.4% each). Mean age was 40.8 years (range 5-86 years) with a peak between 30 and 50 years. Over 46% of patients were aged 40 years and less. Male:female ratio was 1:1.13. All the patients were treated with anticoagulants and thrombolytics with only one having embolectomy. Ninety-two patients (71.9%) recovered, 18.8% of them with cor pulmonale, while 28.1% died. PTE is not uncommon in Kenya. It affects many individuals below 40 years without a gender bias, and carries high morbidity and mortality. Associated comorbidities include venous thrombosis, lifestyle conditions and communicable diseases. Control measures targeting both are recommended.