Improving Pulmonary Embolism Outcomes in Intermediate-Risk Patients: Krunal Patel, MD

Earlier intervention is beneficial for patients with pulmonary embolism (PE), even in those with intermediate risk, which highlights the need to update the current classification system to incorporate advanced therapies like mechanical thrombectomy, says Krunal Patel, MD, pulmonary and critical care fellow, Temple University Hospital.

This transcript was lightly edited; captions were auto-generated.

Transcript

What is the impact of time to mechanical thrombectomy specifically in intermediate-risk patients with PE, and how does this expand upon prior findings in high-risk populations?

We did a similar study at CHEST where we looked at the intermediate- and high-risk group. We saw that both the intermediate- and high-risk group had a stronger signal when we intervened on the patients in a sooner time frame. We did a cutoff of about 12 hours. Patients who were intervened within 12 hours, we classified them as short, and if patients were intervened after 12 hours, we classified them as a long group. We saw back then, when we did the study, that there was a signal for significant clinical improvement when they were intervened on sooner. I think most physicians will say that [for] high-risk patients, it's easy to say that we're going to intervene on them quicker. We wanted to see if the signal still remains if you just look at the intermediate-risk group.

The intermediate-risk group is kind of that hazy zone where we're still trying to figure out what to kind of necessarily do, how quickly to do it, and then what kind of interventions to use on these patients. For this study, we looked at just the intermediate-risk group patients, which came out to be about 735 patients, which was a good, significant sample size. Then, the short group came out to be about 30% of the patient cohort, and then the long group was about 70%. Even though we used the 12 hours as a cutoff, the short group had a median time frame of like 6 hours, and then the long group had a median time frame of 25 hours. There was a good, significant dichotomy between the 6- and 25-hour separation. We saw that the intermediate-risk patients, when they were intervened on quicker within the 12-hour period, with the average time being 6 hours, had better pulmonary artery pressures, had better RV:LV [right ventricle to left ventricle] ratio reductions at 48 hours, 30 days, and 6 months. Then, their walk tests, their walk distance was also significantly better at the 30-day and 6-month time frames. There's a signal that even in the intermediate-risk group, when you eliminate the high-risk, which is pretty easy, everyone kind of knows what to do with that cohort, the signal still persists even in the intermediate-risk group.

Your results suggest improved hemodynamic and functional outcomes with shorter time from hospital admission to mechanical thrombectomy. Can you explain the clinical significance of these improvements?

Clinical improvements are always great to have. I think every physician loves hemodynamics; it's a great way to have objective information. But then at the end of the day, what clinical improvements does the patient see? How is it improving their quality of life? This study was great because we looked at both, so we kind of satisfied both parties. The hemodynamics were definitely a lot better. You had the mean pulmonary artery pressure, systolic pulmonary artery pressure, which were significantly reduced when you intervened on patients in the shorter group rather than the longer group; the RV:LV ratio was also significantly better in the shorter group compared to the long group; and then on the clinical aspect, the patient aspect, their walk distances were greater too. You had that objective information, which the physicians love, the hemodynamics and everything, but then also on the patient side, the walk distance, which is a very great objective way to see what kind of clinical improvements the patients are seeing, also had a significant improvement as well.