Care of patients with acute pulmonary emboli: a clinical review with cardiovascular focus

Catheter-directed Thrombolysis for Intermediate-Risk Pulmonary Embolism

Intermediate-risk pulmonary embolism is common and carries a risk of progression to hemodynamic collapse and death. Catheter-directed thrombolysis is an increasingly used treatment option, based largely on the assumptions that it is more efficacious than anticoagulation alone and safer than systemic thrombolysis. In this review, we critically analyze the published data regarding catheter-directed thrombolysis for the treatment of intermediate-risk pulmonary embolism. Catheter-directed thrombolysis reduces right heart strain and lowers pulmonary artery pressures more quickly than anticoagulation alone. The mortality for patients with intermediate-risk pulmonary embolism treated with catheter-directed thrombolysis is low, between 0% and 4%. However, similarly low mortality is seen with anticoagulation alone. Catheter-directed thrombolysis appears to be safer than systemic thrombolysis, and procedural complications are uncommon. Bleeding risk appears to be slightly higher than with anticoagulation alone. Randomized, controlled trials are needed to compare the efficacy and safety of catheter-directed thrombolysis versus anticoagulation for intermediate-risk pulmonary embolism. There is no evidence that catheter-directed thrombolysis decreases the incidence of chronic thromboembolic pulmonary hypertension. There is no evidence from clinical studies that ultrasound-assisted thrombolysis is more effective or safer than standard catheter-directed thrombolysis.

Role of D-dimer Assays in the Diagnostic Evaluation of Pulmonary Embolism

The diagnosis of pulmonary embolism (PE) remains challenging despite the evolution of well-validated clinical algorithms over the past few decades, largely because of nonspecific clinical features altering clinician suspicion. D-dimer is a simple noninvasive test that is an essential part of the diagnostic algorithm but is often deemed to be of little value in patients who are elderly or have other comorbidities. We describe a case of an elderly man who presented with clinical features and initial imaging consistent with pneumonia and a positive D-dimer test. Adherence to the suggested diagnostic algorithm and obtaining chest imaging, however, prevented what could have been a catastrophic missed diagnosis of PE. We review existing evidence on the importance of suspecting PE in the presence of alternative diagnosis and explore the literature on the association between the magnitude of D-dimer and the diagnosis of PE.

Analysis of National Trends in Admissions for Pulmonary Embolism

BACKGROUND

Pulmonary embolism (PE) remains a significant cause of hospital admission and health-care costs. Estimates of PE incidence came from the 1990s, and data are limited to describe trends in hospital admissions for PE over the past decade.

METHODS

We analyzed Nationwide Inpatient Sample data from 1993 to 2012 to identify patients admitted with PE. We included admissions with International Classification of Diseases, 9th revision, codes listing PE as the principal diagnosis as well as admissions with PE listed secondary to principal diagnoses of respiratory failure or DVT. Massive PE was defined by mechanical ventilation, vasopressors, or nonseptic shock. Outcomes included hospital lengths of stay, adjusted charges, and all-cause hospital mortality. Linear regression was used to analyze changes over time.

RESULTS

Admissions for PE increased from 23 per 100,000 in 1993 to 65 per 100,000 in 2012 (P < .001). The percent of admissions meeting criteria for massive PE decreased (5.3% to 4.4%, P = .002), but the absolute number of admissions for massive PE increased (from 1.5 to 2.8 per 100,000, P < .001). Median length of stay decreased from 8 (interquartile range [IQR], 6-11) to 4 (IQR, 3-6) days (P < .001). Adjusted hospital charges increased from $16,475 (IQR, $10,748-$26,211) in 1993 to $25,728 (IQR, $15,505-$44,493) in 2012 (P < .001). All-cause hospital mortality decreased from 7.1% to 3.2% (P < .001), but population-adjusted deaths during admission for PE increased from 1.6 to 2.1 per 100,000 (P < .001).

CONCLUSIONS

Total admissions and hospital charges for PE have increased over the past two decades. However, the population-adjusted admission rate has increased disproportionately to the incidence of patients with severe PE. We hypothesize that these findings reflect a concerning national movement toward more admissions of less severe PE.