Despite Advanced Therapies, Mortality from Pulmonary Embolism Remains High

Journal Published on October 9, 2018

Originally published on The American Journal of Medicine

Key findings

72% of patients with massive pulmonary embolism (PE) received therapy beyond systemic anticoagulation within 7 days, compared with 35% of patients with submassive PE
Even so, the 90-day mortality rate was comparable to published reports at 41% for the sickest of patients with massive PE and 12% for those with submassive PE
Most deaths of patients with massive PE occurred in-hospital, whereas mortality risk persisted after discharge for submassive PE
Across the entire cohort, there was an independent association between the use of any advanced therapy and reduced mortality
While knowing which patients will benefit is hard, physicians should continue to consider escalating PE therapy beyond systemic anticoagulation

Research into the management of pulmonary embolism (PE) has not kept up with newer treatment techniques. For example, the effectiveness of catheter-directed lysis and endovascular clot retrieval is not well established, and few studies have assessed the outcomes of patients treated in the past 10 years.

To investigate contemporary practice patterns and event rates, researchers reviewed a prospective database of patients who presented to Massachusetts General Hospital with massive or submassive PE. They found that although advanced therapies are associated with improved survival, 90-day mortality rates remain high.

Ido Weinberg, MD, director, Vascular Medicine Fellowship, and colleagues detail their findings in The American Journal of Medicine, and conclude that physicians should continue to consider escalating therapy beyond systemic anticoagulation in those sicker PE patients.

The research team analyzed 338 patients, of whom 14% presented with massive PE (>15 minutes of hypotension or any period of pulselessness) and 86% presented with submassive PE (no hemodynamic compromise but had right ventricular dysfunction or evidence of myocardial injury). Follow-up data were recorded for up to one year.

The average age of the cohort was 63 years, 51% were male, 32% had malignancy, 22% had a recent surgery and 2.1% had a history of hypercoagulability. Interestingly, the patients with massive PE were similar to those with submassive PE in most respects.

Within seven days of presentation, 98% of all patients had received systemic anticoagulation and 38% had received any type of advanced therapy: inferior vena cava filter placement, systemic intravenous thrombolysis, catheter-directed thrombolysis, endovascular clot retrieval, extracorporeal membrane oxygenation and/or surgical embolectomy.

Patients with massive PE were significantly more likely than those with submassive PE to receive advanced therapy within seven days (72% vs 35%, < .01). Still, the 90-day mortality rate, the primary study outcome, was significantly higher for patients with massive PE than for those with submassive PE (41% vs 12%, < .01).

The risk of death among patients with massive PE was greatest during hospitalization. Patients alive 30 days after presenting with massive PE were likely to survive to 90 days. In contrast, among patients with submassive PE, the risk of death persisted for 90 days.

After multivariable adjustment, massive PE was associated with a 5.23-fold greater risk of death, compared with submassive PE (95% CI, 2.70–10.13; < .01).

Major bleeding was frequent, affecting 14% of all patients and 26% of those with massive PE. Bleeding occurred in part as a result of the use of advanced therapies, but even so, multivariable analysis showed that advanced therapy was associated with a 61% reduction in mortality among all patients (95% CI, 0.20–0.76; < .01).

The latter finding suggests, the researchers conclude, that physicians should continue to consider escalating therapy beyond systemic anticoagulation in the sickest of PE patients. They look forward to the development of risk stratification tools that would identify which patients with PE are most likely to benefit from various advanced therapies.