Patients with low-risk blood clots may be better managed at home

Outpatient treatment appeared safe for select patients with acute pulmonary embolism with low risk for mortality, according a single-arm, prospective study.

No deaths or recurrent venous thromboembolism occurred among patients treated at home.

“Because of its high mortality rate, PE treatment historically included hospitalization for all patients,” Joseph Bledsoe, MD, research director in emergency medicine at Intermountain Medical Center, and colleagues wrote. “However, retrospective analysis has suggested a low PE mortality rate among select patients with PE treated on an outpatient basis, and patients with PE with a good prognosis are unlikely to benefit from inpatient care.”

Bledsoe and colleagues assessed 200 consecutive adults with acute low-risk PE from January 2013 to October 2016 across 5 EDs. Researchers used the Pulmonary Embolism Severity Index score, echocardiography and whole-leg compression ultrasound to confirm all participants had a low risk for mortality.

All patients underwent ED observation for 12 to 24 hours followed by outpatient management with FDA-approved anticoagulation.

Exclusion criteria included Pulmonary Embolism Severity Index score of 86 or higher, echocardiographic signs of right heart strain, deep vein thrombosis proximal to the popliteal vein, hypoxia, hypotension, hepatic or renal failure, contradiction to anticoagulation or another condition requiring hospital admission.

A composite of all-cause mortality, recurrent symptomatic VTE and major bleeding at 90 days served as the primary endpoint.

The composite outcome occurred in one patient, for a 90-day composite rate of 0.5% (95% CI, 0.02-2.36). One patient had major bleeding at day 61 after a traumatic thigh injury.

No patients experienced recurrent VTE or died during the 90-day follow-up period.

“We found a large subset of patients with blood clots who’d do well at home — in fact who probably did better at home,” Bledsoe said in a press release. “When patients are sent home vs. staying in the hospital, they’re at lower risk of getting another infection. It’s a lot less expensive, too.”

Within 7 days of enrollment, 19 patients (9.5%; 95% CI, 5-14) returned to the ED, with two admissions (1%; 95% CI, 0-2) to the hospital.

Within 30 days, 32 patients (16%; 95% CI, 11-21) returned to the ED, with five reported admissions (3%; 95% CI, 0-5) for events unrelated to their PE.

Of the 146 patients who completed a satisfaction survey at 90 days, 91% reported being highly satisfied with their ED care on their initial encounter. Additionally, 89% indicated a preference for outpatient management again should they experience another PE.

“Our findings show that if you appropriately risk stratify patients, there are a lot of people with blood clots who are safe to go home,” Bledsoe said.

The limitations of the study included the single-arm nature of the study design and implementation of the minimum 12-hour ED observation period, which may not be replicable in some hospitals.

“Our protocol consisted of a bundle of elements to select subjects for outpatient management; we cannot say which of the elements in our process (eg, use of the Pulmonary Embolism Severity Index score, echocardiography, bilateral lower extremity compression ultrasound, the minimum 12-hour observation period), alone or in combination, were associated with the very low rate of adverse outcome events we observed,” the researchers wrote. “Future research to optimize identification of patients with low-risk PE who are candidates for early discharge is needed.”

Questions remain about whether outpatient management for patients with low-risk PE is universally feasible and beneficial for patients, Samuel Z. Goldhaber, MD, FCCP, professor of medicine at Harvard Medical School, and director of the Brigham and Women’s Hospital VTE research group, wrote in an accompanying editorial.

“Despite these encouraging results, there remain some concerns that should be addressed,” he wrote. “Should the goals of PE hospitalization be limited to risk stratification and anticoagulation, with occasional use of advanced therapy for high-risk submassive or massive PE? Or, should hospitalization for PE also be the first step in providing a foundation for education about PE and discussion of the risk factors for PE and its potential long-term effects?” – by Cassie Homer

Disclosures: Bledsoe reports honoraria for participating in the Anticoagulation Forum and grant support from Allergan. Two researchers report grant support from Bristol-Myers Squibb. Goldhaber reports consultant roles with Agile, Bayer, Boehringer-Ingelheim, Bristol-Myers Squibb, Daiichi, Janssen, Portola and Soleno; and research support from BiO2 Medical, Boehringer-Ingelheim, Bristol-Myers Squibb, BTG EKOS, Daiichi, Janssen, the NHLBI and the Thrombosis Research Institute.