Diagnostic efficacy of ECG-derived ventricular gradient for the detection of chronic thromboembolic pulmonary hypertension in patients with acute pulmonary embolism

INTRODUCTION

Application of the chronic thromboembolic pulmonary hypertension (CTEPH) rule out criteria (manual electrocardiogram [ECG] reading and N-terminal pro-brain natriuretic peptide [NTproBNP] test) can rule out CTEPH in pulmonary embolism (PE) patients with persistent dyspnea (InShape II algorithm). Increased pulmonary pressure may also be identified using automated ECG-derived ventricular gradient optimized for right ventricular pressure overload (VG-RVPO).

METHOD

A predefined analysis of the InShape II study was performed. The diagnostic performance of the VG-RVPO for the detection of CTEPH and the incremental diagnostic value of the VG-RVPO as new rule-out criteria in the InShape II algorithm were evaluated.

RESULTS

60 patients were included; 5 (8.3%) were ultimately diagnosed with CTEPH. The mean baseline VG-RVPO (at time of PE diagnosis) was -18.12 mV·ms for CTEPH patients and - 21.57 mV·ms for non-CTEPH patients (mean difference 3.46 mV·ms [95%CI -29.03 to 35.94]). The VG-RVPO (after 3-6 months follow-up) normalized in patients with and without CTEPH, without a clear between-group difference (mean Δ VG-RVPO of -8.68 and - 8.42 mV·ms respectively; mean difference of -0.25 mV·ms, [95%CI -12.94 to 12.44]). The overall predictive accuracy of baseline VG-RVPO, follow-up RVPO and Δ VG-RVPO for CTEPH was moderate to poor (ROC AUC 0.611, 0.514 and 0.539, respectively). Up to 76% of the required echocardiograms could have been avoided with VG-RVPO criteria replacing the InShape II rule-out criteria, however at cost of missing up to 80% of the CTEPH diagnoses.

CONCLUSION

We could not demonstrate (additional) diagnostic value of VG-RVPO as standalone test or as on top of the InShape II algorithm.

Identification of chronic thromboembolic pulmonary hypertension on CTPAs performed for diagnosing acute pulmonary embolism depending on level of expertise

BACKGROUND

Expert reading often reveals radiological signs of chronic thromboembolic pulmonary hypertension (CTEPH) or chronic PE on computed tomography pulmonary angiography (CTPA) performed at the time of acute pulmonary embolism (PE) presentation preceding CTEPH. Little is known about the accuracy and reproducibility of CTPA reading by radiologists in training in this setting.

OBJECTIVES

To evaluate 1) whether signs of CTEPH or chronic PE are routinely reported on CTPA for suspected PE; and 2) whether CTEPH-non-expert readers achieve comparable predictive accuracy to CTEPH-expert radiologists after dedicated instruction.

METHODS

Original reports of CTPAs demonstrating acute PE in 50 patients whom ultimately developed CTEPH, and those of 50 PE who did not, were screened for documented signs of CTEPH. All scans were re-assessed by three CTEPH-expert readers and two CTEPH-non-expert readers (blinded and independently) for predefined signs and overall presence of CTEPH.

RESULTS

Signs of chronic PE were mentioned in the original reports of 14/50 cases (28%), while CTEPH-expert radiologists had recognized 44/50 (88%). Using a standardized definition (≥3 predefined radiological signs), moderate-to-good agreement was reached between CTEPH-non-expert readers and the experts' consensus (k-statistics 0.46; 0.61) at slightly lower sensitivities. The CTEPH-non-expert readers had moderate agreement on the presence of CTEPH (κ-statistic 0.38), but both correctly identified most cases (80% and 88%, respectively).

CONCLUSIONS

Concomitant signs of CTEPH were poorly documented in daily practice, while most CTEPH patients were identified by CTEPH-non-expert readers after dedicated instruction. These findings underline the feasibility of achieving earlier CTEPH diagnosis by assessing CTPAs more attentively.

Non-invasive early exclusion of chronic thromboembolic pulmonary hypertension after acute pulmonary embolism: the InShape II study

BACKGROUND

The current diagnostic delay of chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary embolism (PE) is unacceptably long, causing loss of quality-adjusted life years and excess mortality. Validated screening strategies for early CTEPH diagnosis are lacking. Echocardiographic screening among all PE survivors is associated with overdiagnosis and cost-ineffectiveness. We aimed to validate a simple screening strategy for excluding CTEPH early after acute PE, limiting the number of performed echocardiograms.

METHODS

In this prospective, international, multicentre management study, consecutive patients were managed according to a screening algorithm starting 3 months after acute PE to determine whether echocardiographic evaluation of pulmonary hypertension (PH) was indicated. If the 'CTEPH prediction score' indicated high pretest probability or matching symptoms were present, the 'CTEPH rule-out criteria' were applied, consisting of ECG reading and N-terminalpro-brain natriuretic peptide. Only if these results could not rule out possible PH, the patients were referred for echocardiography.

RESULTS

424 patients were included. Based on the algorithm, CTEPH was considered absent in 343 (81%) patients, leaving 81 patients (19%) referred for echocardiography. During 2-year follow-up, one patient in whom echocardiography was deemed unnecessary by the algorithm was diagnosed with CTEPH, reflecting an algorithm failure rate of 0.29% (95% CI 0% to 1.6%). Overall CTEPH incidence was 3.1% (13/424), of whom 10 patients were diagnosed within 4 months after the PE presentation.

CONCLUSIONS

The InShape II algorithm accurately excluded CTEPH, without the need for echocardiography in the overall majority of patients. CTEPH was identified early after acute PE, resulting in a substantially shorter diagnostic delay than in current practice.

Quality of initial anticoagulant treatment and risk of CTEPH after acute pulmonary embolism

BACKGROUND

The pathophysiology of chronic thromboembolic pulmonary hypertension (CTEPH) is not fully understood. Poor-quality anticoagulation may contribute to a higher risk of CTEPH after acute pulmonary embolism (PE), partly explaining the transition from acute PE to CTEPH. We assessed the association between the time in therapeutic range (TTR) of vitamin-K antagonist (VKA) treatment and incidence of CTEPH after a PE diagnosis.

METHODS

Case-control study in which the time spent in, under and above therapeutic range was calculated in 44 PE patients who were subsequently diagnosed with CTEPH (cases). Controls comprised 150 consecutive PE patients in whom echocardiograms two years later did not show pulmonary hypertension. All patients were treated with VKA for at least 6 months after the PE diagnosis. Time in (TTR), under and above range were calculated. Mean differences between cases and controls were estimated by linear regression.

RESULTS

Mean TTR during the initial 6-month treatment period was 72% in cases versus 78% in controls (mean difference -6%, 95%CI -12 to -0.1), mainly explained by more time above the therapeutic range in the cases. Mean difference of time under range was 0% (95%CI -6 to 7) and 2% (95CI% -3 to 7) during the first 3 and 6 months, respectively. In a multivariable model, adjusted odds ratios (ORs) for CTEPH were around unity considering different thresholds for 'poor anticoagulation', i.e. TTR <50%, <60% and <70%.

CONCLUSION

Subtherapeutic initial anticoagulation was not more prevalent among PE patients diagnosed with CTEPH than in those who did not develop CTEPH.

Differential impact of syncope on the prognosis of patients with acute pulmonary embolism: a systematic review and meta-analysis

Aims

Controversial reports exist in the literature regarding the prognostic role and therapeutic implications of syncope in patients with acute pulmonary embolism (PE). We conducted a systematic review and meta-analysis to investigate the association between syncope and short-term adverse outcomes, taking into account the presence or absence of haemodynamic compromise at acute PE presentation.

Methods and results

The literature search identified 1664 studies, 29 of which were included for a total of 21 956 patients with PE (n = 3706 with syncope). Syncope was associated with higher prevalence of haemodynamic instability [odds ratio (OR) 3.50; 95% confidence interval (CI) 2.67-4.58], as well as with echocardiographic signs of right ventricular (RV) dysfunction (OR 2.10; CI 1.60-2.77) at presentation. Patients with syncope had a higher risks of all-cause early (either in-hospital or within 30 days) death (OR 1.73; CI 1.22-2.47) and PE-related 30-day adverse outcomes (OR 2.00; CI 1.11-3.60). The absolute risk difference (95% CI) for all-cause death was +6% (+1% to +10%) in studies including unselected patients, but it was -1% (-2% to +1%) in studies restricted to normotensive patients. We observed no prognostic impact of syncope in studies with a lower score at formal quality assessment and in those conducted retrospectively.

Conclusion

Syncope as a manifestation of acute PE was associated with a higher prevalence of haemodynamic instability and RV dysfunction at presentation, and an elevated risk for early PE-related adverse outcomes. The association with an increased risk of early death appeared more prominent in studies including unselected patients, when compared with those focusing on normotensive patients only.

Fatal recurrent VTE after anticoagulant treatment for unprovoked VTE: a systematic review

Current guidelines recommend long-term anticoagulant therapy in patients with unprovoked venous thromboembolism (VTE). The risk of fatal recurrent VTE after treatment discontinuation (versus that of fatal bleeding during anticoagulation) is of particular relevance in the decision to continue or stop anticoagulation after the first 3 months. Our primary aim was to provide a point-estimate of the yearly rate of fatal recurrent VTE and VTE case-fatality rate in patients with unprovoked VTE after anticoagulation cessation. Data were extracted from both randomised controlled trials and observational studies published before May 1, 2017. The pooled fatality rates were calculated using a random-effects model. 18 studies with low-to-moderate bias were included in the primary analysis, totalling 6758 patients with a median (range) follow-up duration of 2.2 (1–5) years. After anticoagulation cessation, the weighted pooled rate of VTE recurrence was 6.3 (95% CI 5.4–7.3) per 100 patient-years and the weighted pooled rate of fatal recurrent VTE was 0.17 (95% CI 0.047–0.33) per 100 patient-years, for a case-fatality rate of 2.6% (95% CI 0.86–5.0). These numbers are a solid benchmark for comparison to the risks associated with long-term anticoagulation treatment for the decision on the optimal duration of treatment of patients with unprovoked VTE.

Healthcare utilization in chronic thromboembolic pulmonary hypertension after acute pulmonary embolism

Essentials Diagnostic delay of chronic thromboembolic pulmonary hypertension (CTEPH) is long. We explored healthcare utilisation of patients diagnosed with CTEPH after pulmonary embolism. A large number of physicians were consulted and test results were not always interpreted correctly. Better education and higher awareness of CTEPH may lead to faster diagnosis. SUMMARY: Background The median diagnostic delay of chronic thromboembolic pulmonary hypertension (CTEPH) is 14 months, which may affect prognosis. We aimed to explore the healthcare utilization of patients diagnosed with CTEPH after acute pulmonary embolism (PE), and to identify the causes of diagnostic delay. Methods We collected all data on patient symptoms, medical specialist referrals and ordered diagnostic tests to reconstruct the clinical pathways of 40 patients referred to the VU University Medical Center Amsterdam (VUMC, the Netherlands) for CTEPH treatment. Diagnostic delay was defined as the time between first symptom onset and referral to the VUMC. Correlations of patient-specific characteristics and diagnostic delay were evaluated. Results Patients consulted four (median) different physicians for a median of 13 (interquartile range [IQR] 10-18) consultations before the correct diagnosis was made. The median diagnostic delay was 21 months (IQR 12-49 months). Echocardiographic results suggestive of CTEPH were not always followed by an adequate work-up; most patients were not subjected to ventilation/perfusion scanning. Prior cardiopulmonary comorbidity and recurrent venous thromboembolism were predictors of a longer delay. Conclusion Healthcare utilization in patients before their final CTEPH diagnosis was far from optimal, contributing to a considerable diagnostic delay. Better education and higher awareness of CTEPH among PE caretakers may lead to faster diagnosis.

Sensitivity of a Simple Noninvasive Screening Algorithm for Chronic Thromboembolic Pulmonary Hypertension after Acute Pulmonary Embolism

Background  Recently, we constructed a noninvasive screening algorithm aiming at earlier chronic thromboembolic pulmonary hypertension (CTEPH) detection after acute pulmonary embolism (PE), consisting of a prediction score and combined electrocardiography (ECG)/N-terminal pro-brain natriuretic peptide (NT-proBNP) assessment. The aim of this study was to confirm the algorithm's sensitivity for CTEPH detection and to evaluate the reproducibility of its individual items. Methods  Two independent researchers calculated the prediction score in 54 consecutive patients with a history of acute PE and proven CTEPH based on clinical characteristics at PE diagnosis, and evaluated the ECG and NT-proBNP level assessed at the moment of CTEPH diagnosis. Interobserver agreement for the assessment of the prediction score, right-to-left ventricle (RV/LV) ratio measurement on computed tomography pulmonary angiography, as well as ECG reading was evaluated by calculating Cohen's kappa statistics. Results  Median time between PE diagnosis and presentation with CTEPH was 9 months (interquartile range: 5-15). The sensitivity of the algorithm was found to be 91% (95% confidence interval [CI]: 79-97%), indicating that 27 of 30 cases of CTEPH would have been detected when applying the screening algorithm to 1,000 random PE survivors with a 3% CTEPH incidence (projected negative predictive value: 99.7%; 95% CI: 99.1-99.9%). The interobserver agreement for calculating the prediction score, RV/LV ratio measurement, and ECG reading was excellent with a kappa of 0.96, 0.95, and 0.89, respectively. Conclusion  The algorithm had a high sensitivity of 91% and was highly reproducible. Prospective validation of the algorithm in consecutive PE patients is required before it can be used in clinical practice.

Accuracy and reproducibility of CT right-to-left ventricular diameter measurement in patients with acute pulmonary embolism

BACKGROUND

Right ventricular (RV) dysfunction caused by acute pulmonary embolism (PE) is associated with poor short- and long-term prognosis. RV dilatation as a proxy for RV dysfunction can be assessed by calculating the right-to-left ventricle diameter (RV/LV) ratio on standard computed tomography pulmonary angiography (CTPA) images. It is unknown whether dedicated training is required to accurately and reproducibly measure RV/LV ratio therefore we aimed to assess these parameters in residents in internal medicine without experience in CTPA reading.

METHODS

CTPA images of 100 patients with PE were assessed by three residents after single instruction, and one experienced thoracic radiologist. Maximum diameters were evaluated in the axial view by measuring the distance between the ventricular endocardium and the interventricular septum, perpendicular to the long axis of the heart. RV dilatation was defined as a ratio of ≥1.0. Interobserver accuracy and reproducibility was determined using Kappa statistics, Bland-Altman analysis and Spearman's rank correlation.

RESULTS

The kappa statistic for the presence of RV dilatation of the residents compared to the experienced radiologist ranged from 0.83-0.94. The average interobserver difference in calculated RV/LV ratio's (±SD) between the three residents was: -0.01 (SD0.11), 0.07 (SD0.14) and 0.06 (SD0.18) with an overall mean RV/LV diameter ratio of 1.04. In line with this, Spearman's rank correlation coefficients were 0.92, 0.88 and 0.85 respectively indicating very good correlation (p<0.01 for all).

CONCLUSION

After simple instruction, RV/LV diameter ratio assessment on CTPA images by clinical residents is accurate and reproducible, which is of help in identifying PE patients at risk.

Incidence of chronic thromboembolic pulmonary hypertension after acute pulmonary embolism: a contemporary view of the published literature

The incidence of chronic thromboembolic pulmonary hypertension (CTEPH) after pulmonary embolism (PE) is relevant for management decisions but is currently unknown.We performed a meta-analysis of studies including consecutive PE patients followed for CTEPH. Study cohorts were predefined as "all comers", "survivors" or "survivors without major comorbidities". CTEPH incidences were calculated using random effects models.We selected 16 studies totalling 4047 PE patients who were mostly followed up for >2-years. In 1186 all comers (two studies), the pooled CTEPH incidence was 0.56% (95% CI 0.1-1.0). In 999 survivors (four studies) CTEPH incidence was 3.2% (95% CI 2.0-4.4). In 1775 survivors without major comorbidities (nine studies), CTEPH incidence was 2.8% (95% CI 1.5-4.1). Both recurrent venous thromboembolism and unprovoked PE were significantly associated with a higher risk of CTEPH, with odds ratios of 3.2 (95% CI 1.7-5.9) and 4.1 (95% CI 2.1-8.2) respectively. The pooled CTEPH incidence in 12 studies that did not use right heart catheterisation as the diagnostic standard was 6.3% (95% CI 4.1-8.4).The 0.56% incidence in the all-comer group probably provides the best reflection of the incidence of CTEPH after PE on the population level. The ∼3% incidences in the survivor categories may be more relevant for daily clinical practice. Studies that assessed CTEPH diagnosis by tests other than right heart catheterisation provide overestimated CTEPH incidences.

[Cerebrospinal fluid ascites from a ventriculoperitoneal shunt]

BACKGROUND

In a patient with hydrocephalus, the placement of a ventriculoperitoneal shunt is the first treatment of choice. Cerebrospinal fluid ascites is a rare complication of a ventriculoperitoneal shunt, particularly a late complication which can arise more than two years after the implantation of the shunt.

CASE DESCRIPTION

We describe a 29-year-old woman who developed cerebrospinal fluid ascites 15 years after a ventriculoperitoneal shunt had been placed. She was referred due to abdominal pain. Ultrasound showed ascites and a CT scan showed free fluid in all of the abdominal compartments. The ascites disappeared after a ventriculoatrial shunt was placed.

CONCLUSION

This case demonstrates that cerebrospinal fluid ascites can occur as a late complication, years after the placement of a ventriculoperitoneal shunt.