Prognostic importance of anaemia in patients with acute pulmonary embolism

Deep vein thrombosis symptoms and 30-day mortality in acute pulmonary embolism

BACKGROUND

In patients with acute symptomatic pulmonary embolism (PE), the presence of concomitant lower-limb deep vein thrombosis (DVT) has been associated with a higher mortality rate. The prognostic significance of DVT symptoms among these patients remains uncertain.

METHODS

We used the RIETE (Registro Informatizado de Enfermedad TromboEmbólica) registry to compare the 30-day mortality rate in patients with PE and concomitant lower-limb DVT, according to the presence or absence of DVT symptoms. Primary outcomes were all-cause death and PE-related death within the first 30 days.

RESULTS

Since March 2001 to June 2021, there were 17,742 patients with acute symptomatic PE and objectively proven concomitant lower-limb DVT. Of these, 11,984 (68%) had DVT symptoms. Most patients with or without DVT symptoms (82% vs. 81%) received low-molecular-weight heparin initially. Then, most (61% vs. 58%) switched to vitamin K antagonists. During the first 30 days of therapy, 497 patients with DVT symptoms (4.1%) and 164 (2.8%) with no DVT symptoms died (rate ratio [RR]: 1.48; 95%CI: 1.23-1.77). The rates of PE-related death were: 1.0% vs. 0.7%, respectively (RR: 1.50; 95%CI: 1.04-2.16). On multivariable analysis, patients with DVT symptoms were at increased risk for all-cause death (adjusted hazard ratio [aHR]: 1.49; 95%CI: 1.24-1.78), and PE-related death (aHR: 1.52; 95%CI: 1.05-2.20).

CONCLUSION

Among patients with acute symptomatic PE and concomitant lower-limb DVT, those with DVT symptoms had an increased all-cause and PE-related mortality within 30 days. Assessment of DVT symptoms would assist with risk stratification of these patients.

Effectiveness of Manchester Triage System in risk prioritisation of patients with pulmonary embolism who present dyspnoea, chest pain or collapse

BACKGROUND

Recognising patients with pulmonary embolism continues to be a clinical challenge. In the Emergency Department, up to 50% of patients with pulmonary embolism can be delayed or even misdiagnosed. The ability of a triage system to correctly prioritise suspected embolism in these patients is fundamental for determining diagnostic-therapeutic procedures.

AIM

To verify the effectiveness of the Manchester Triage System in risk prioritisation of patients with pulmonary embolism who present with dyspnoea, chest pain, or collapse.

METHODS

In this observational, retrospective, study the sensitivity, specificity, and positive and negative predictive values of the Manchester Triage System were calculated using the triage classification for these patients, and their established diagnoses. The analysis included baseline characteristics and triage evaluations.

RESULTS

During the two-year study period, 7055 patients were enrolled. Pulmonary embolism episodes were 2.1% of all cases, while severe pulmonary embolisms were 0.8%. The estimated specificity of the Manchester Triage System was 72.5% (CI 95%, 71.5-73.6), and the negative predictive value was 98.1% (CI 95%, 97.7-98.5). The results suggest that clinical characteristics leading to a high Manchester Triage System priority are similar to those characterising a pulmonary embolism episode.

CONCLUSIONS

Although pulmonary embolism is difficult to diagnose, the Manchester Triage System is an effective tool for prioritising patients with symptoms of this disease.

Impact of persistent anaemia on mortality in patients hospitalised with acute pulmonary embolism: an Australian retrospective observational study

OBJECTIVES

Anaemia is associated with increased mortality in acute pulmonary embolism (PE) patients. However, prior studies have not examined the prognostic impact of trends in plasma haemoglobin during admission. This study investigates the impact of changes in haemoglobin level on mortality during hospital stay in acute PE.

STUDY DESIGN

A retrospective observational study.

SETTING

Tertiary-referral centre in Australia.

PARTICIPANTS

Consecutive patients from 2000 to 2012 admitted with confirmed acute PE were identified from a dedicated PE database. Haemoglobin levels on days 1, 3-4, 5-6 and 7 of admission were retrieved. Patients without both baseline haemoglobin and subsequent haemoglobin levels were excluded (n=327), leaving 1099 patients as the study cohort. Anaemia was defined as haemoglobin <130 g/L for men and <120 g/L for women. There were 576 patients without anaemia throughout admission, 65 with transient anaemia (anaemic on day 1, but subsequently normalised during admission), 122 with acquired anaemia (normal on day 1 but developed anaemia during admission) and 336 with persistent anaemia. A total of 71 patients received blood transfusion during admission.

MAIN OUTCOME MEASURE

6-month mortality was tracked from a state-wide death database and analysed using multivariable modelling.

RESULTS

After adjusting for transfusion, patietns with persistent anaemia had a significantly increased 6-month mortality risk (adjusted HR 1.97, 95% CI 1.26 to 3.09, p=0.003) compared with patients without anaemia. There was no difference in mortality between patients with transient or acquired anaemia and patients without anaemia.

CONCLUSION

Among patients who had anaemia during their admission for acute PE, only the subgroup with persistent anaemia demonstrated worse outcomes.

Magnetic resonance angiography imaging of pulmonary embolism using agents with blood pool properties as an alternative to computed tomography to avoid radiation exposure

PURPOSE

To evaluate the feasibility and accuracy of a combined magnetic resonance angiography (MRA) - magnetic resonance venography (MRV) protocol using contrast agents with blood pool properties, gadofosveset trisodium and gadobenate dimeglumine, in the evaluation of pulmonary embolus (PE) and deep venous thrombosis (DVT) as compared to the standard clinical reference imaging modalities; computed tomography pulmonary angiography (CTPA) and color-coded Duplex ultrasound (DUS).

MATERIALS AND METHODS

This prospective clinical study recruited patients presenting to the emergency department with clinical suspicion for PE and scheduled for a clinically indicated CTPA. We performed both MRA of the chest for the evaluation of PE as well as MRV of the pelvis and thighs to evaluate for DVT using a single contrast injection. MRA-MRV data was compared to the clinical reference standard CTPA and DUS, respectively.

RESULTS

A total of 40 patients were recruited. The results on a per-patient basis comparing MRA to CTPA for pulmonary embolus yielded 100% sensitivity and 97% specificity. There was a small subset of patients that underwent clinical DUS to evaluate for DVT, which demonstrated a sensitivity and specificity of 100% for MRV.

CONCLUSIONS

This single-center, preliminary study using contrast agents with blood pool properties to perform a relatively rapid combined MRA-MRV exam to image for PE and above knee DVT shows potential as an alternative imaging choice to CTPA. Further large-scale, multicentre studies are warranted.

Red blood cell transfusion and outcomes in acute pulmonary embolism

BACKGROUND AND OBJECTIVE

Blood transfusion has been associated with adverse outcomes in certain conditions. This study investigates the prevalence and outcomes of red blood cell (RBC) transfusion in patients with acute pulmonary embolism (PE).

METHODS

Retrospective study of consecutive patients from 2000 to 2012 admitted to a tertiary hospital with a primary diagnosis of acute PE. Transfusion status during the hospital admission was ascertained. Mortality was tracked from a state-wide death database and analysed using multivariable modelling.

RESULTS

A total of 73 patients (5% of all patients admitted with PE) received RBC transfusion during their admission. These patients were significantly older, had more co-morbidities, worse haemodynamics, higher simplified pulmonary embolism severity index scores, and lower plasma sodium and haemoglobin (Hb) levels at admission. Unadjusted mortality for the transfused group was significantly higher at 30-day (19% vs 4%, P < 0.001) and 6-month (40% vs 10%, P < 0.001) follow-up. Multivariable modelling showed RBC transfusion to be a significant independent predictor of mortality at 30-day (odds ratio 3.06, 95% CI: 1.17-8.01, P = 0.02) and 6-month (hazard ratio (HR) 1.97, 95% CI: 1.12-3.46, P = 0.02). Sensitivity analysis confirmed that transfused patients had higher mortality than non-transfused patients in the subgroup of patients with Hb <100 g/L.

CONCLUSION

RBC transfusion in patients hospitalized with acute PE is rare and appears to be associated with increased risk of short- and long-term mortality, independent of Hb level on admission. This finding underscores the need for future randomized controlled studies on the impact of RBC transfusion in the management of patients admitted with acute PE. [Correction added on 4 May 2018, after first online publication: the word 'serum' was changed to 'plasma' throughout the article where appropriate.].

Magnetic Resonance Imaging of Pulmonary Embolism: Diagnostic Accuracy of Unenhanced MR and Influence in Mortality Rates

OBJECTIVES

We evaluated the diagnostic value for pulmonary embolism (PE) of the True fast imaging with steady-state precession (TrueFISP) MRI, a method that allows the visualization of pulmonary vasculature without breath holding or intravenous contrast.

METHODS

This is a prospective investigation including 93 patients with suspected PE. All patients underwent TrueFISP MRI after undergoing CT pulmonary angiography (CTPA). Two independent readers evaluated each MR study, and consensus was obtained. CTPA results were analysed by a third independent reviewer and these results served as the reference standard. A fourth radiologist was responsible for evaluating if lesions found on MRI for both analysis were the same and if these were the correspondent lesions on the CTPA. Sensitivity, specificity, predictive values and accuracy were calculated. Evidence for death from PE within the 1-year follow-up was also assessed.

RESULTS

Two patients could not undergo the real-time MRI and were excluded from the study. PE prevalence was 22%. During the 1-year follow-up period, eight patients died, whereas PE was responsible for 12.5% of cases. Between patients who developed PE, only 5% died due to this condition. There were no differences between MR and CT embolism detection in these subjects. MR sequences had a sensitivity of 85%, specificity was 98.6% and accuracy was 95.6%. Agreement between readers was high (κ= 0.87).

CONCLUSIONS

Compared with contrast-enhanced CT, unenhanced MR sequences demonstrate good accuracy and no differences in the mortality rates in 1 year were detected.

Clinical Features of Acute Massive Pulmonary Embolism Complicated by Radiofrequency Ablation: An Observational Study

Although pulmonary embolism (PE) complicated by radiofrequency catheter ablation (RFCA) is rare, it can be life-threatening. Our goal was to elucidate the clinical features of acute massive PE after RFCA. Of 2386 patients who underwent RFCA for supraventricular tachycardia or idiopathic ventricular arrhythmia, 4 patients (0.16%) whose cases were complicated by acute massive PE were examined. These 4 patients were female and middle-aged (range 43-52 years), and 2 of the 4 patients had iron-deficiency anemia and reactive thrombocytosis. Ablation in all patients was performed in the left heart via the right femoral arterial approach. All of the patients had a long-duration hemostasis procedure and bed rest following femoral arterial sheath removal after RFCA. All of the patients collapsed and lost consciousness during their &filig;rst attempt at walking after RFCA. The emergent electrocardiogram in 2 of the 4 patients revealed an S1Q3T3 pattern, 1 patient demonstrated new onset of right bundle-branch block (RBBB) and S1Q3 pattern and Qr pattern in V1, and the remaining patient had negative T waves in leads V1, V2, and III. The emergent echocardiogram revealed right ventricular hypokinesis and pulmonary hypertension in the 4 patients with acute PE after ablation. Although all of the patients initially experienced sinus tachycardia when they recovered consciousness, 2 of the 4 patients suddenly developed intense bradycardia and lost consciousness again, and these patients finally died (50% fatality rate). All of the patients were identi&filig;ed by CT pulmonary angiography or pulmonary angiography. Our report suggests that although acute massive PE is highly rare, there is a real and fatal risk in patients who experienced acute massive PE after RFCA. Particular attention should be paid to the first ambulation after RFCA. Acute PE should be strongly suspected when sudden loss of consciousness occurs upon mobilization after RFCA. The new onset of S1Q3T3 pattern, RBBB or T wave inversion in the right precordial leads, and early detection of echocardiographic right ventricular dysfunction may be useful for making an early diagnosis of acute PE after RFCA. Early ambulation after left-sided RFCA might be helpful to prevent the formation of deep venous thrombosis and subsequent PE.

Triage for suspected acute Pulmonary Embolism: Think before opening Pandora's Box

This is a review of the current strengths and weaknesses of the various imaging modalities available for the diagnosis of suspected non-massive Pulmonary Embolism (PE). Without careful consideration for the clinical presentation, and the timely application of clinical decision support (CDS) methodology, the current overutilization of imaging resources for this disease will continue. For a patient with a low clinical risk profile and a negative D-dimer there is no reason to consider further workup with imaging; as the negative predictive value in this scenario is the same as imaging. While the current efficacy and effectiveness data support the continued use of Computed Tomographic angiography (CTA) as the imaging golden standard for the diagnosis of PE; this test does have the unintended consequences of radiation exposure, possible overdiagnosis and overuse. There is a persistent lack of appreciation on the part of ordering physicians for the effectiveness of the alternatives to CTA (ventilation-perfusion imaging and contrast enhanced magnetic resonance angiography) in these patients. Careful use of standardized protocols for patient triage and the application of CDS will allow for a better use of imaging resources.

Prognostic value of red cell distribution width in patients with pulmonary embolism

Elevated red blood cell distribution width (RDW) has been associated with adverse outcomes of heart failure and pulmonary hypertension. A total of 702 consecutive patients with acute pulmonary embolism (PE) were evaluated. There was a graded increase in mortality rate with RDW quartiles of 5.8% in quartile I (≤13.6), 9.7% in quartile II (13.7%-14.5%), 13.1% in quartile III (14.6%-16.3%), and 20% in quartile IV (>16.3%; P < .001). Patients who died had higher baseline RDW values (16.1% [11.7-28.3] vs 14.5% [10.7-32.5]; P < .001). The optimal cutoff value of RDW for predicting in-hospital mortality was ≥15%. The area under the curve of mortality for RDW was 0.649 (confidence interval [CI]: 0.584-0.715); the negative predictive value was 93%. In multivariable regression analysis, RDW remained associated with an increased odds of death (odds ratio: 1.2, 95% CI: 1.1-1.4). High RDW level was an independent predictor of short-term mortality in PE. The RDW levels may provide a potential marker to predict outcome in patients with PE.

Clinical characteristics and outcomes of patients with clinically unsuspected pulmonary embolism versus patients with clinically suspected pulmonary embolism

BACKGROUND

The routine use of multidetector computed tomography has led to increased detection of unsuspected pulmonary embolism (UPE), with questionable benefit for diagnosis and treatment.

OBJECTIVE

The purpose of this work was to compare the clinical characteristics and prognosis of patients with UPE to patients with suspected PE (SPE).

METHODS

We retrospectively reviewed the charts of patients diagnosed with PE in a community-based university hospital between the years 2002 and 2007. UPE was defined as PE detected on CT scans performed for indications other than suspicion of PE. We compared patients with UPE to patients with SPE for differences in clinical features, electrocardiogram, imaging and echocardiographic findings. We also assessed the long-term outcomes using electronic patient records.

RESULTS

Of 500 patients with PE, 408 had SPE and 92 had UPE. Patients with UPE were similar to patients with SPE regarding age and sex distribution. Malignancy was more prevalent in UPE patients (39 vs. 23%, p < 0.0068). UPE patients had significantly less tachypnea (37 vs. 57%, p = 0.0005), dyspnea (47 vs. 87%, p < 0.0001), chest pain (19 vs. 42%, p < 0.0001) and hypoxemia (36 vs. 55%, p = 0.0011). Mortality was higher in UPE patients (70.3 vs. 53%, p = 0.0029). The hazard ratio after adjustment for confounders including age, sex and malignancy was 1.546 (95% CI: 1.139-2.099, p = 0.0052).

CONCLUSIONS

We suggest that UPE is more prevalent in patients with a malignancy and is associated with higher mortality despite a less severe clinical presentation. UPE may be a marker of poor prognosis.