Acute Pulmonary Embolism in Emergency Department Patients Despite Therapeutic Anticoagulation

CTEPH: A Kaiser Permanente Northern California Experience

INTRODUCTION

Chronic thromboembolic pulmonary hypertension (CTEPH) is a rare and life-threatening form of pulmonary hypertension and the only potentially curable form of the World Health Organization Pulmonary Hypertension classes. Thus, the prompt and accurate diagnosis of this condition is imperative. Despite widespread chronic symptoms following acute pulmonary embolism (PE), the condition is rarely considered, and an externally validated inexpensive diagnostic algorithm is lacking.

METHODS

A long-term, retrospective cohort study was conducted to assess the incidence of CTEPH following acute PE in a real-world study population. Additional data were collected regarding the practice patterns of diagnostic testing and imaging, particularly in patients with persistent or recurrent symptoms. Amongst diagnosed CTEPH patients, previously established risk factors were evaluated for degree of risk and commonly used diagnostic tests (electrocardiogram [ECG] right ventricular hypertrophy [RVH] pattern, B-type natriuretic peptide [BNP] elevations) employed during this period were evaluated and assessed for feasibility as screening tests. The study population was obtained from the MAPLE study cohort, comprised of patients presenting with acute PE in 21 community medical centers across the Kaiser Permanente Northern California system from January 2013 to April 2015. Diagnosis of CTEPH was confirmed via pulmonary vascular imaging (ventilation/perfusion [V/Q] scanning, computed tomography angiography, pulmonary angiography) and diagnostic right heart catheterization (RHC). Probable diagnoses were defined as a combination of suggestive echocardiographic and RHC findings. Additional inclusion criteria included age (≥18 years) with at least 2 years follow up and no previous diagnosis of CTEPH or PE during the prior 30 days.

RESULTS

There were 1973 patients who met inclusion criteria (mean age 62.4 years). Despite 75 % of patients developing symptoms consistent with CTEPH >3 months following acute PE, only 5.6 % of these symptomatic patients underwent V/Q scanning. There was overall a very low cumulative incidence of CTEPH (2.3 %), which was significantly higher amongst patients with symptoms compared to those without symptoms. When controlled for confounding in the multivariate analysis, only recurrent PE (HR 19.3, P < 0.001) and pulmonary artery systolic pressure >50 mmHg (HR 10.4, P < 0.001) were statistically significant predictors of CTEPH. Of the non-invasive diagnostic tests, ECG criteria for RVH were found to be poorly sensitive (2.6 %), but very specific (98.8 %) for CTEPH. Elevated levels of BNP alone were more sensitive than RVH ECG criteria (76.3 %) but poorly specific (44.4 %).

CONCLUSIONS

The diagnosis of CTEPH is uncommonly made following acute PE. Despite the frequency of persistent symptoms consistent with CTEPH following acute PE, the appropriate diagnostic work-up is rarely undertaken as evidenced in this cohort. This suggests that CTEPH is underappreciated and rarely considered, likely underestimating the true incidence in this cohort. Future studies are needed to elucidate the true prevalence of CTEPH and further investigate both the optimal diagnostic tools and timing of appropriate screening. These discoveries may help guide future development of diagnostic algorithms that can effectively rule out and accurately identify this potentially curable disease in a timely manner.

Rare Presentation of Deep Vein Thrombosis and Submassive Pulmonary Emboli Due to Hypercoagulable State With Supratherapeutic Anticoagulation

We present a case of an elderly male with multiple co-morbidities, including atrial fibrillation on warfarin and recently diagnosed left lower extremity deep vein thrombosis (DVT), who presented to the emergency department for dyspnea. He was found to be hypoxic and mildly hypotensive. He was diagnosed with submassive pulmonary emboli (PE) despite having a supratherapeutic international normalized ratio (INR). In this case report, the clinical presentation, diagnostic workup, and management of this patient are discussed.

Presyncope Is Associated with Intensive Care Unit Admission in Emergency Department Patients with Acute Pulmonary Embolism

INTRODUCTION

Syncope is common among emergency department (ED) patients with acute pulmonary embolism (PE) and indicates a higher acuity and worse prognosis than in patients without syncope. Whether presyncope carries the same prognostic implications has not been established. We compared incidence of intensive care unit (ICU) admission in three groups of ED PE patients: those with presyncope; syncope; and neither.

METHODS

This retrospective cohort study included all adults with acute, objectively confirmed PE in 21 community EDs from January 2013-April 2015. We combined electronic health record extraction with manual chart abstraction. We used chi-square test for univariate comparisons and performed multivariate analysis to evaluate associations between presyncope or syncope and ICU admission from the ED, reported as adjusted odds ratios (aOR) with 95% confidence intervals (CI).

RESULTS

Among 2996 PE patients, 82 (2.7%) had presyncope and 109 (3.6%) had syncope. ICU admission was similar between groups (presyncope 18.3% vs syncope 25.7%) and different than their non-syncope counterparts (either 22.5% vs neither 4.7%; p<0.0001). On multivariate analysis, both presyncope and syncope were independently associated with ICU admission, controlling for demographics, higher-risk PE Severity Index (PESI) class, ventilatory support, proximal clot location, and submassive and massive PE classification: presyncope, aOR 2.79 (95% CI, 1.40, 5.56); syncope, aOR 4.44 (95% CI 2.52, 7.80). These associations were only minimally affected when excluding massive PE from the model. There was no significant interaction between either syncope or presyncope and PESI, submassive or massive classification in predicting ICU admission.

CONCLUSION

Presyncope appears to carry similar strength of association with ICU admission as syncope in ED patients with acute PE. If this is confirmed, clinicians evaluating patients with acute PE may benefit from including presyncope in their calculus of risk assessment and site-of-care decision-making.

Massive Fatal Pulmonary Embolism While on Therapeutic Heparin Drip

Venous thromboembolism (VTE) includes deep venous thrombosis (DVT) and pulmonary embolism (PE). In this article, we present a case of a patient with an acute DVT who was treated with a therapeutic heparin drip, then developed syncope while in the hospital and found to have massive bilateral PEs. This case aims to arouse the medical staff’s awareness of the VTE diagnosis even if the patient is fully anticoagulated. We review the indications for DVT hospitalization, heparin infusion monitoring, risk factors for developing PE from DVT, mechanisms of developing PE from DVT while on therapeutic anticoagulation, and signs and treatment of massive PE.

Increasing Safe Outpatient Management of Emergency Department Patients With Pulmonary Embolism: A Controlled Pragmatic Trial

BACKGROUND

Many low-risk patients with acute pulmonary embolism (PE) in the emergency department (ED) are eligible for outpatient care but are hospitalized nonetheless. One impediment to home discharge is the difficulty of identifying which patients can safely forgo hospitalization.

OBJECTIVE

To evaluate the effect of an integrated electronic clinical decision support system (CDSS) to facilitate risk stratification and decision making at the site of care for patients with acute PE.

DESIGN

Controlled pragmatic trial. (ClinicalTrials.gov: NCT03601676).

SETTING

All 21 community EDs of an integrated health care delivery system (Kaiser Permanente Northern California).

PATIENTS

Adult ED patients with acute PE.

INTERVENTION

Ten intervention sites selected by convenience received a multidimensional technology and education intervention at month 9 of a 16-month study period (January 2014 to April 2015); the remaining 11 sites served as concurrent controls.

MEASUREMENTS

The primary outcome was discharge to home from either the ED or a short-term (<24-hour) outpatient observation unit based in the ED. Adverse outcomes included return visits for PE-related symptoms within 5 days and recurrent venous thromboembolism, major hemorrhage, and all-cause mortality within 30 days. A difference-in-differences approach was used to compare pre-post changes at intervention versus control sites, with adjustment for demographic and clinical characteristics.

RESULTS

Among 881 eligible patients diagnosed with PE at intervention sites and 822 at control sites, adjusted home discharge increased at intervention sites (17.4% pre- to 28.0% postintervention) without a concurrent increase at control sites (15.1% pre- and 14.5% postintervention). The difference-in-differences comparison was 11.3 percentage points (95% CI, 3.0 to 19.5 percentage points; P = 0.007). No increases were seen in 5-day return visits related to PE or in 30-day major adverse outcomes associated with CDSS implementation.

LIMITATION

Lack of random allocation.

CONCLUSION

Implementation and structured promotion of a CDSS to aid physicians in site-of-care decision making for ED patients with acute PE safely increased outpatient management.

PRIMARY FUNDING SOURCE

Garfield Memorial National Research Fund and The Permanente Medical Group Delivery Science and Physician Researcher Programs.