PE on the Rise
Dr. Seth Bilazarian: Hi, Seth Bilazarian on theheart.org on Medscape for Practitioners' Corner. I want to reflect on pulmonary-embolism (PE) treatment and the PE response team (PERT) program that was developed at our community hospital and put it in perspective with regard to some exciting things that are happening nationally. I just attended the inaugural symposium run by Mass General Hospital (MGH) on pulmonary-embolism response treatment. This is an effort by the MGH group to create a strategy of collaboration, cooperation, and shared research protocols for the treatment of pulmonary embolism, both nationally and internationally. For many cardiologists, including myself, pulmonary embolism is one of those things that we fear. It's not in our core set of strengths in terms of treating patients, but it's really a significant problem.
The mortality for massive PE is 50%. It's the third most common acute cardiovascular event after myocardial infarction and stroke. One thing that is very important for physicians, cath labs, and hospitals to think about is that myocardial-infarction rates are in decline. Stroke rates have plateaued, but pulmonary-embolism rates have been increasing. In terms of where our work is going to come from, where we're going to be making an impact on patients, I think this is something really important to consider.
Death from PE is, of course, reduced by prompt diagnosis and treatment. The overall rate of case fatality in the Worcester DVT Study of patients with pulmonary embolism was 12% for low-risk, submassive, and massive DVTs. There's increasing awareness about pulmonary embolism, of course, through celebrities who have had pulmonary embolism. Chris Bosh of the Miami Heat is out for the season. There are several people, other famous people, including young athletes like Serena Williams, who've had pulmonary embolisms, several actors and actresses, ex-athletes. I was even reading a book recently of a famous US general whose wife died suddenly at a military hospital after having thyroid surgery. The account said that she had tachycardia and then died suddenly, presumably because of thyroid abnormalities. Of course, in retrospect, it probably was pulmonary embolism.
The MGH PERT strategy is something to be admired, but it can't be emulated in community hospitals in its entirety. The way they have put the program together is phenomenal. Physicians gather in a virtual meeting using GoToMeeting. A telephone call is placed, and people end up dialing in from cardiac surgery, vascular medicine, pulmonary critical care, the [medical intensive care unit] MICU, hematology, interventional cardiology, multiple fellows. There are five to 10 people on this call looking at CT-scan images and reviewing the case, making decisions about management for the patient, whether medical therapy, catheter-directed therapy, or surgical therapy.
PE Within Our Skill Set
Of course, most of us don't have those resources in a community hospital. There are more hospitals in the United States like the one I practice in than like Mass General. In our hospital, 14 months ago we have initiated a PERT program in which we have emulated the STEMI protocol. We encourage the emergency room to call us when there's a pulmonary embolism. The interventionalist is called and decisions are made whether catheter-directed thrombolysis is appropriate and reasonable.
I would encourage other clinical interventional cardiologists who might be listening to embrace this idea. I think the big impediment is a lack of training and experience with venous disease and right heart intervention in most cardiology departments. There's are very few cardiologists who have really taken this on. Sam Goldhaber of the Clotblog on Medscape is a notable exception, whose career has been largely dedicated to [deep venous thrombosis] DVT and PE. But for most practicing cardiologists, this is a new frontier. It's not a new disease, but we're beginning to realize that we have skills to offer to patients in terms of both our availability (particularly in the hospital in caring for patients), as well as our knowledge about the therapies that are used: anticoagulation, thrombolytic therapies, and, of course, the novel oral anticoagulants.
The other thing that cardiologists deal with—I know I have dealt with—is the humbling aspects of this disease. The diagnosis is frequently missed. Everyone has a patient in their history (if they've practiced as long as I have) in whom they missed the diagnosis before serious morbidity or even mortality. To me, that's more of a reason to embrace this, because we're less likely to miss it by having these protocols in place. The other factor is that it often involves young and healthy patients who are not in our cardiology practices. These patients are often in post–orthopedic surgery or on medical floors. And our typical technologies also are not the sensitive tools for diagnosing PE. Of course, CT scans are the primary diagnostic strategy.
Keys to Successful PERT Program
In our practice at Lawrence General Hospital, a community hospital with 189 beds, we have one cath lab and we have adopted this protocol 14 months ago and have had good success. Our lab is fairly willing to adopt new strategies. We took on radial first and have the Impella. I mention that because some of my colleagues who run community-hospital cath labs have told me they have difficulty implementing these strategies. That may have been part of our success. We went through the usual requirements for implementing any new technology in a community hospital: the pharmacy and therapeutics committee, ER, ICU committees. There's a financial assessment. There's the training of the cath-lab personnel, ICU staff for the postprocedure management. And then the training adoption of the PERT initiation; the emergency room requires a fair amount of training. I was surprised that the emergency department was open and enthusiastic about this. They view this as an important disease, and giving them a clear pathway with protocols where they can call a physician and know that the patient will be taken care of is something they very enthusiastically endorsed and adopted.
One impediment that I didn't anticipate is one of the critical aspects of pulmonary-embolism management and that is knowing that RV/LV ratio. It's not usually on the CT scan. Our radiologists were not doing that routinely on the CT angiogram, and to get them to do that consistently was somewhat difficult, but it's now become part of the protocol. Finally, the creation of border sets and the adoption of the electronic health record is also something that is required. We relied heavily on the expertise of others, and that's the great thing about this PERT symposium. We've been keeping a database of important characteristics, treatment, and outcomes of patients. We get an informal debrief after each case with nursing, technical staff, and industry representatives when we use catheter-directed thrombolysis. A PERT report goes out to all stakeholders (emergency department, intensive care units) in the management of the patient, how they presented. That's been a good way to keep people knowledgeable.
We followed a similar protocol that we've used for STEMI—we've had STEMI report cards, giving our door-to-balloon time. So we're able to give people in the hospital some information about our PERT program as to the way patients present and their outcomes. The tracking, as I mentioned, has been really helpful, and the streamlining of care outside of the emergency department for patients with pulmonary embolism is an important area where we should do better. It's similar to the issues we find with patients who have a STEMI in the hospital that doesn't happen in the emergency room; the pathways are not as easily coordinated when they're not in the emergency room.
More to Learn but Meanwhile Patients Can Benefit
There are many unanswered questions about the management of low-risk, submassive, and massive PE—which patient should get catheter-directed thrombolysis, what the main strategy should be. We're using a pretty simple strategy. A patient who has elevated biomarkers like troponin, BNP, who has an RV/LV ratio of greater than a 0.9, are generally considered for catheter-directed thrombolysis. We're using ultrasound-assisted catheter-directed thrombolysis by the Ekos company. The most recent patient I did has McConnell's sign, the very easy-to-see right ventricular free-wall issue that is basically severely hypokinetic in the mid wall and a preserved apex, and this patient had the largest RV/LV ratio (1.6) that we've had in our experience.
The RV improvement is really dramatic. We do the echocardiogram on the second day, and this patient had a really dramatic RV improvement with near normalization of the RV free wall. While there are many unanswered questions, participation in this PERT national symposium program and participating in a registry will help us understand going forward who the best patients to treat are and what doses of catheter-directed thrombolysis to use and will give us important information about a variety of other unknowns in this area, like inferior vena cava (IVC) filter use or the use of catheter-directed thrombolysis with or without ultrasound.
In summary, my experience at a community hospital using a pulmonary-embolism response team shows that it is feasible and rewarding for patients with submassive PE. The European Society of Cardiology divided the submassive group into low and high risk; high risk are patients who have both biomarker abnormalities and RV dysfunction or RV enlargement. Radiology adoption was a key element in having them report RV/LV ratios so we could quickly triage these patients. We use a STEMI model for activation we found to be safe, efficient, and effective. And it's been a very rewarding experience. Successful treatment is in the skill set of interventional cardiologists. It takes about 40 minutes for us to do a catheter-directed thrombolysis (right heart cath, bilateral pulmonary angiogram, and placement of catheters).
It's something that I think most interventional cardiologists would feel very comfortable with. The relief of chest pain, dyspnea, and markers, such as the RV function, is very rewarding. I would liken it to the dramatic improvement some patients get with primary PCI when they're having a STEMI or the relief patients get with medical management of acute pulmonary edema. I would strongly urge community-based interventional cardiologists to think about starting a PERT program. There are resources, as I mentioned, from the Mass General and elsewhere, and I think you'll find it very rewarding. I welcome your questions as a fellow community-hospital physician who has at least initially successfully adopted this. Thanks, until next time, I'm Seth Bilazarian.
Cite this: Pulmonary-Embolism Response Team: Not Just for the Big Boys - Medscape - Jun 15, 2015.