The use of mechanical thrombectomy (MT) was associated with reduced major adverse events in the short term and improved quality of life in the long term for pulmonary embolism (PE) patients with pulmonary hypertension (PH), based on data from 99 individuals.
The impact of MT on adverse events and long-term outcomes in PE patients with severe PH has not been well studied, wrote Kenneth Cho, MD, of Jefferson Einstein Montgomery Hospital, East Norriton, Pennsylvania, and colleagues.
In a study presented at the annual meeting of the Society for Interventional Radiology, the researchers reviewed 6-month outcome data after the use of MT in PE patients with severe PH. Data were taken from a prospective, multicenter registry (the FLASH registry) created to evaluate the safety and effectiveness of the FlowTriever System for medical thrombectomy in patients with severe PH, defined as systolic pulmonary artery pressure of at least 70 mmHg. The primary study endpoint was a composite score of major adverse events within 48 hours of treatment; patients were then followed for 6 months. A total of 83 patients completed the full study with a mean of approximately 204 days of follow-up. Most of the patients (92.9%) were considered intermediate-risk for PE, and 7.1% were high-risk.
Within 48 hours of MT, average systolic pulmonary artery pressure decreased significantly, from 78.9 mmHg to 60.9 mmHg (P < .0001). In addition, 74.2% of patients experienced resolution or reduced severity of PH. The rate of major adverse events was 3.1% within the first 48 hours.
Over the long-term follow-up, patients reported improvements in right ventricular/left ventricular ratio (RV/LV), RV systolic pressure, and RV function, which indicated lasting resolution of PH, the researchers noted.
At 6 months, patients also reported reductions in dyspnea and improvements in quality of life and experienced lower rates of all-cause mortality, chronic thromboembolic pulmonary hypertension, and chronic thromboembolic pulmonary vascular disease, the researchers wrote in their abstract.
Study limitations included the relatively small study population, but the results suggest short- and long-term benefits for patients with PE and severe PH after treatment with mechanical thrombectomy, the researchers concluded.
Data Refute Safety Concerns
The study is important because many clinicians believed that MT in PE patients with severe PH was unsafe, Cho said in an interview. "The decision was made to forego thrombectomy in these patients and manage their PE with only blood thinners or with clot-dissolving medications," he said. However, these medications have their own risks, ranging from poor outcomes to life-threatening bleeding, he added.
The current study assessed whether PE patients with severe PH had worse outcomes and therefore should be excluded from this treatment. The data demonstrate similar results in patients with and without severe PH, suggesting that severe PH is not a contraindication to undergoing MT in appropriate PE patients, Cho told Medscape Medical News. "In fact, patients with severe PH stand to benefit from this intervention via positive longer-term functional outcomes," he said.
Looking ahead, randomized, controlled clinical trials are needed to compare MT with anticoagulation and/or catheter-directed thrombolysis such as PE-TRACT, PEERLESS, and PEERLESS II in order to establish updated guidelines for the safest and most effective treatment of PE and improve patient outcomes, Cho said.
Concerns had been raised following the premarket approval trial (the FLARE trial) for the FlowTriever and other premarket trials about the safety of large-bore aspiration thrombectomy (LBAT) in patients with severe PH, said Robert A. Lookstein, MD, of the Icahn School of Medicine at Mount Sinai, New York City, in an interview.
"This presentation [at the meeting] was meant to address those concerns by reviewing the safety and clinical efficacy of those patients who were enrolled in the FLASH post-market registry," said Lookstein. The data seem to support the safety of this therapy in patients with severe PH, and the study is "a welcome contribution to the rapidly evolving scientific literature regarding the safety and efficacy of endovascular therapy for acute pulmonary embolism," he said.
The data suggest that, in experienced centers, LBAT may be offered to patients with severe PH, Lookstein told Medscape Medical News. More research is needed, but four prospective, randomized trials are underway (STORM-PE, Hi-PEITHO, PEERLESS 2, and PETRACT) to examine endovascular therapy for acute PE compared with anticoagulation alone.
"Many endovascular operators may choose to await the results of these trials to determine whether these devices are uniformly safe across the diverse populations that they are asked to potentially treat every day," Lookstein said.
The study received no outside funding. The researchers had no financial conflicts to disclose. Lookstein had no financial conflicts to disclose.