The 2026 AHA/ACC Pulmonary Embolism Guideline: Quick Review

Hi everyone. I thought it would be a good idea to go over the new um HACC pulmonary embolism guidelines that was just released earlier this year. So we're going to discuss not all the elements but at least those that can be a little bit related to acute hospital medicine or acute medicine. So let's start. I would like to start with this statement which I totally agree with. The diagnosis of PE is often challenging with less than 10% of patients evaluated for PE eventually being diagnosed with PE. So basically what they were saying is if you thought about PE in 10 patients you evaluated these 10 patients for PE only one of them probably is going to turn out to have PE which really shows you how challenging that could be and I cannot emphasize that more in the previous video I talked about chest pain. uh I mentioned pulmonary emibolism as one of the important diagnosis to think about of course and I just want to really bring that up again because I think it's very relevant. So chest pain is probably the most common symptom that people will think about PE when they see that symptom in their patients. Uh are also shortness of breath wheezes to some extent. If you have a patient with CBD exacerbation, as exacerbation or cardiaces, but you don't know why they have the exacerbation, think about PE unexplained upper abdominal pain. In few patient, if they have like lower lobe PE, they can present with upper abdominal pain and discomfort. Patient with unexplained vital signs, unexplained tachicardia, hypoxia, low gradede fever, hypotension. If it's another reason, think about PE. Cough and hemoptasis. Hemoptsis often referred to as one of the symptoms to look for in when you're like doing the scoring system for PE or DVT. Anex play or fall or alter mental status. Not not very common, but it's known. Um, unexplained exacerbation or heart failure. We've talked about that. and anxlained high BNB uh and or cardiac uh biomarkers and then usually normal chest X-ray. So this is kind of some of circumstances common and less common that maybe you need to think about pulmonary uh embolism. Now why is that? I also discussed this I think in uh some of the lectures about physical exam permanently the physical exam might not be very helpful right so so for example the likelihood ratio for having taken more than 30 per minute is only two which only mildly increases the clinical probability of the PE diagnosis tachicardia as well not very helpful left versus heave I don't know how many of us do that anymore new gallop mild mildly increases the probability by 22 to of likelihood ratios. Unilateral calf pain or swelling also not very high. So as as you can tell there's no single symptom or physical exam finding that really makes the probability very high and that's why we had all this scoring systems that can increase the probability up to six or seven or eight. And the new modality is point ultrasound and I talked about that in one of the videos. It also could be helpful at the bedside. It's specific if you can find the PE abnormalities in your exam but it has a low sensitivity meaning patient might have semi normal pocus exam but they still have polar embolism again signifying how challenging this diagnosis could be. So what tools you can use to make the diagnosis of PE. So basically clinical tool and laboratory tools right. So clinical decision tools that can incorporate assessment of clinical suspicion of PE with laboratory testing are recommended. Clinical suspicion basically four elements. What are the risk factors from history? What are the symptoms suggested of PE from history? Is physical exam helpful and the fourth one is you know can it detected with pockets point of care ultrasound the relatively new tool and then the laboratory testing is mostly the d-dimer testing right but also the guidelines suggest you think about lactate and cardc biomarkers mostly troponin for risk is stratassification. So when you're thinking about P most of the time you will need a D- dimer. Only maybe two situations based on these guidelines from what I read that you might not need the D- dimer. One is the clinical suspicion is very high more than 50% probability of having PE then in that case just go ahead and order the CT test because even if the Dimer is negative but you have high clinical suspicion the recommending recommendation is still to pursue the diagnosis of PE with the CT or VQ. And the second situation is when you have a very low probability of PE. In that case, for example, if you have like the eight questions of the perk tool, pulmonary embolism rule out criteria tool. If you have eight all the eight questions negative, the probability is very low and in that case you might not need the dimer. Just uh pursue other differential diagnosis. So how do you interpret the dimer? There's two ways based on the guidelines. The first one is the age adjusted dimer level. So basically you multiply the patient age by 10 and then anything above that is considered a positive test and then you can pursue the CTPa. So for example if you have a 60-year-old patient he has intermediate probability of PE. So you want to check the Dimer you checked it and it became back more than 600 nanog per milliliter then you go ahead and order the CT test. The other way uh is using the years algorithm criteria. you use is basically this is just a study that was published in the lens in 2017 that showed using this criteria three questions. If there are positive then you have a lower threshold for the level of dimer to check using CT and if um all the three are negative which are the clinical signs of DVT hemoptsis or PB PE being the most likely diagnosis. If these three are negative then you can have a higher a higher cutff uh basically th00and. So if none of these three are are present higher cut off is 1,000 nanog per milliliter. If one or more are positive then you can have a lower threshold for the dimer to test uh using the CT. So with this study they found that using this criteria the year's algorithm actually reduces the use of unnecessarily uh chest CT to check for pulmonary emolism and of course what test to order to make the diagnosis of P is basically the pulmonary angography uh CT scan right it's still the diagnostic test of choice even in pregnant patient the recommendation is to pursue a low radiation dose CTPA rather than lowd dose perfusion uh ctography and if you make the diagnosis of PE using the CTPA. Do you want to order a lower extremity venus duplex ultrasound? The recommendation is it's a plus 2B recommendation if you think that knowing the burden of the thrombosis. If the patient is having a DVT in addition to PE will make some changes in the diagnosis. For example, if the patient has clinical suspicion of P and it looks like really bad, then the patient might benefit from interventions like throbectomy or TPA, then you probably need to order a duplicate for sound as well. But at the end of the day, the management might be very similar. So when you order the CTPa, you're basically not just looking into the presence or absence of clot, but also look for effect of the clot on the or stress effect on the right side of the heart. Right? So the guidelines recommend that you look at the right ventricle over the left ventricle ratio to see if there's any right ventricular enlargement or stress or dysfunction. This is also can be uh evaluated better with a trans thoracic uh echo. So this is also recommended to do and there's certain element that you look at. So basically the whole idea is you again not just the presence of the clot but the effect of the clot on the hemodynamics of the patient uh including mostly the right side and this is probably why the point of character sound could be helpful because some of these element you can actually detect at the bedside by pocus. So for example the right ventricular size you can appreciate if it's enlarge or not. the systolic function as well the taps the tricuspid annual plane systolic excursion you can just do it visually or you can actually calculate it if you have more experience with focus mold sign if you're lucky and find this one also could be useful paradoxical septum motion is relatively easy to detect by bedside ultrasound and also the IVC a lot of uh pocus users may be familiar with that as well but again the more more information will be gained by looking at this element in the echo now Probably the biggest change in the guideline I would say is this this new clinical categories from to if you remember the previous guidelines they classified patient with pulmonary embolism based based on risk factors into low-risk pulmonary embolism patient submassive pulmonary embolism patient and massive pulmonary embolism patient those with hypo hypertension or with shock but this is not the case anymore they suggested this new classification or categories from A to and this is be basically to inform severity and prognosis. So basically the patient with the lowest risk of having complications or developing complication down the road a patient with a category A and category B. So patients with category A are those with subclinical pulmonary embolism meaning patient did not we did not really suspect B in this patient they're being evaluated for something else and we discovered that they have pulmonary embolism. So this is the lowest risk patients. B patient has some symptoms suggestive of pulmonary embolism but when you do the risk assessment tools for example the pulmonary embolism severity index is less than 85 or the simplified pulmonary embibism severity index of uh zero or the HTS score of zero out of 11 score is basically to detect patients who have can be treated as an outpatient if they have none of these 11 criteria these are lowest risk patient and they can be managed outpatient they don't need to be admitted to the hospital so ED The emergency medicine physician can use this tool to kind of send the patient outside. I would say probably very few patient in my experience again based on where where you practice. So this can also be I mean can subclassified into B1 and B2. B1 they have sub subsegmental PE single or multiple and P2 a little bit higher risk because they have more proximal non-subgmental pulmonary embolism. These two patients A and B probably can be either diagnosed in ED or manic as an outpatient or me maybe admitted just for overnight observation because there's the lowest risk. Now the highest risk patients at categories D and category. So these are the patient who have like hemodynamic instability maybe um the massive and some of the submassive PE in the old classification. So they have abnormal vital signs right. So uh category D is a patient with incant pulmonary failure. they're about to go into cardopulary failure further classified into D1 and D2. D1 they have transient hypotension D2 they have a normal tensive shock and this can be detected by having a high lactate or having uh what seems to be an eskeemic AKI. This kind of these tests can suggest hemodynamic or incibient cardopulmonary uh failure. So the recommendation is to take these test uh in these patients and another risk factor that they suggest to add is the R. So some patient might be D1R or D1 or D2R or D2 right. So R basically means they have a positive modifiers. They needed some supplemental oxygen to support their uh ventilation or oxygenation. So these are labeled as R and these are higher risk patients. Category E basically these are the patient with cardopulmonary failure. E1 they have uh recurrent or persistent with cardiogenic shock and E2 are refractory uh cardiogenic shock or uh cardiogenic arrest again with or without R. Now the one in between is category uh C and this is a patient who are symptomatic but they have a higher clinical uh severity score using uh the PCI or modified or simplified PSI or the they having one or more of the SCS scoring system. So they can be subclassified into C1 if they have normal right ventricle in the CTPa or echo and normal biomarkers the BNB or card troponin and that that's why these tests are recommended for uh risk stratification of these patients. The C2 patient they have abnormal right ventricle on CT or echo or two or more abnormal biomarkers and the C3 which is both abnormal the right ventricle function and size are abnormal or any of the parameters in the echo are abnormal and also they have an abnormal biomarkers abnormal BMP or abnormal cardropon with or without the R or the respiratory modifier. So these are the five categories. I think this is really kind of the major change that we have in this new guidelines that we didn't have before. So, what to do with this clinical categories? Um, I think they're really just trying to inform the physicians about the treatment because this is really what we're looking for, right? There's four options for medical treatment and there's four options for advanced therapy. So the four options for medical treatment include the direct oral anticoagulant and low molecular heperin and fraulated heperin and warfrain or comedian or vitamin K antagonist and the four advanced therapies thrombolyis or throbectomy be either systemic thrombolyis through uh ultral which is kind of the standard dose or low dose or catheter directed thrombolyis and throbectomy also has two options mechanical throctomy or surgical throctomy. So these are the four advanced therapies. So again the treatment and management will be based on this uh clinical categories and based on the risk factors right. So patient with uh category A and B this patient can be managed with an A dwak which is basically the medication of choice for pulmonary embolism uh based on these guidelines except in pregnancy dwax are not recommended just like warfrain. So the options you have in pregnancy uh is heperin. We'll talk about that. And then you assess this patient to see if they really need to be observed for overnight admission maybe or they can actually just be given the dwak and discharged from the emergency department or their place of diagnosis. So this is the lowest risk patients and then for patient who might need to be admitted maybe for observation or further workup to get the echo and other studies you can start them with dwac al also but also you can start them on bubble liquid heperin until you do their further risk assertification or management and one of the thing that we talked about that you might consider ordering is the cardiac biomarkers BMBB troponin lactate and then the echo also to evaluate the ventricular size and function. and also activating the per the pulmonary embolism response team which is a class one class one um recommendation. So now they really recommended that all hospitals that treat patient with permanism they have this system to kind of help the physicians decide on the management because sometime could be a little bit complicated. Now only patient with E2 you might consider unfraured heperin. Lomco hepin is preferred over a fracture hepin to the most part but for patient who are unstable and you think they might need some interruption of their treatment maybe the unfraracture hepin might be better but generally low microwave hepin is preferred and some patient of course who are like really sick they might need like emo management for oxygenation we're not going to talk about that and of course D2 to E2 patient might also need some hemodynamic support with those suppressors and or inotropic therapy now the advanced therapy option the thromboly the two thromboly options and the tooth from throb bacteria options these can be considered in patient from D1 to uh E2 categories this is kind of the highest risk patients and really the decision about these can be made by the perk uh per uh team and that's why the guidelines highly suggested that you know hospitals adopt uh this uh to help physicians work up this P patient and treat them as well so let's be a little bit more specific here. So, which DWAT to use? Uh, is there any preference over the four options we have for Dwak in general? I would say again, I think there's only one recent prior that had like head-to-head comparison uh between DWAX. I think they did it between Aexan and But to be honest, I think most of the time these are will be the two DWAC that will be mostly used by physicians. I usually prefer Aexiban. I put most all my patient just because of the data showing that it's um has lower bleeding risk. Reverend is a good option uh too. But you know to be more specific again we can go over specific situations that discusses this a little bit further. So for example if you have a patient that you need to do extended treatment you think they need anticagulation more than 3 to 6 months because they might be a little bit higher risk. So during this extended phase half dose epexiban 2.5 twice a day or half dose of roxiban 10 milligram daily is specifically recommended over a full dose regimens to reduce the risk of bleeding while maintaining efficacy. So you do the full dose in the first 3 to 6 months after that you can consider one of these dosages with these two medications. How a patient with obesity if they have a BMI more than 30. The guideline notes that Aexiban and Revoroxiban again may be superior to be superior in efficacy and safety when compared to Warframe. For patient with severe obesity BMI more than 50 still both Aexiban and Revoroxiban have been found to be equally safe and effective compared to Warframe. How about patient with chronic kidney disease? So du wax are recommended over vitamin K antagonist for mild to moderate CKD maybe state two or three but what about patient with severe CKD or patient hemodialysis the guidelines state that is uncertain if aexiban is better than vitamin uh K antagonist for reducing major bleeding in this patient population registry data kind of suggests that maybe aexiban is safe and efficacious as warpherine in this patient population but the data is kind of we don't have like really strong data for refer edoxiban or diabata in this patient but I personally also still prefer aexiban in patient with cd in chronic liver disease dwax specifically with mild talba or moderate talbetic impairment or chronic inner disease aexiban and riveroxan are still identified as safe alternative to warfrain due to to their lower incidence of major bleeding they're not really recommending in patient with advanced liver disease because of increased bleeding in this patient population patient with abnormal uterine bleeding AUB the guideline highlights difference differences in bleeding risk for women on antikagulus. So that gutran was found to be associated with a lower risk of bleeding in this patient population compared to warfrain. A pixaban shows no significant difference in this patient population compared to warfrain and foroxiban and and um redoxan they're actually shared with higher risk of bleeding for these patients. So maybe the gatin might be a good option for these patients. Again it's case by case determination. So just go over the medical history, liver function, kidney function, all the other risk for bleeding to determine which uh do what might be preferred. Talking about bleeding, the guideline didn't really specify any robust clinical tool or risk uh factor to assess the bleeding risk. Again it's case by case determination and some specific patient population that were specifically mentioned in the guideline including of course patient with CKD especially if they have severe advanced CKD and creating clearance less than 30 they have really increased risk of bleeding again for this patient population maybe a back event is too reasonable patient with primary or metastatic brain tumor they have higher baseline risk for intro hemorrhage of course so be careful with these patients patient with chronic liver disease again we mentioned that dwax in Cal A or B might be safe but with advanced kidney disease do watch generally might not be recommended and might be associated with high risk of bleeding. We talked about patient with different abnormally turn bleeding where dab dabby gapan is generally preferred. Uh aexaman is reasonable too. Now is there any situations where warfrain or chumine or vitamin K antagonist might be recommended over dwac? Yes. So for example patient with established antifphospholate syndrome especially those with like triple antibbody positive these generally have really high risk of thrombosis and duax might still be considered if they have like only one positive antibbody but generally if they're trivial positive orphan is generally preferred in patient with advanced CKD stage three or four oral disease it's really not very clear if aex bandan is better than comedian I would say still many physicians will still up to of Xavan in this patient population but you can consider warin as well. Breastfeeding DWAX are not recommended in breastfeeding patients and in this patient generally low molecular weight heperin or unfrured heperin are preferred with warfane as well. Patient with advanced liver disease calio class 6 class C use of dag general not recommended. So you can consider warin in these patient populations. If I intention about really high risk of bleeding maybe low miracle weight heperin is a better option. So if you decide to put your patient on low mer heperin when do you or when the guidelines suggest to for you to kind of take the activity to monitor the medication and make sure it's working by taking the anti- factor 10 level. So patient with severe uh CK when they have a creatin clear than 30 theory patient with extreme obesity as well in patient uh pregnant patient the benefit is not very clear but suggested to also monitor with antifactor 10A level also in critically ill patient also the benefit is uncertain. So a suggested monitoring protocol is to wait until the low moral heperin reaches steady state uh level that's usually typically after at least three doses and then take the peak level. The peak level is the one that's recommended over the cruff or random level and it's recommended to measure the peak level about 3 to four hours after the dose. How about IVC filters? The guideline did not really change much about it. Again there's very specific indications for IVC filters. The primary indications are there's absolute contraindication to anticagulation. Patient cannot get an anti-coagulation because of active bleeding or very high bleeding risk or the patient had recurrence despite being optimized on medical treatment and anticagulation. So the general recommendations again routine uses discouraged because you know they found that it's harmful and does not reduce recurrence and increase the risk of DVT in some patient. retrievable filters are preferred or more permanent filters unless specifically indicated and the time for retrieval is FDA kind of suggest that maybe between one to two months maybe after placement and this is to minimize the long-term complications like fracture or uh perforation and the guidelines really kind of recommend that structure follow-up is needed to make sure that these IBV IVC filters will be retrieved and removed and they suggested that the per uh protocol should help with that to make sure that this patient get their IVC filter removed in a timely fashion when their need for the IV filter is gone. How about if you have a patient with unprovoked pulmonary embolism when and how do you do like some testing to check for underlying cause? Why did this patient develop unprovoked PE? So cancer is a big one. You have to think about it. But the general recommendation is really just um age appropriate cancer screening. There's no recommendation to do like routine imaging or CT CT scan or PET in this patient. Just go with the appropriate history, physical exam and age guided recommendations by the general guidelines for cancer screening. It's strongly recommended that you do that upon followup. There is like about 40 to 10% of patient with unprotect PE who were found to have a underlying cancer within the first year after their PE event. What about thromophilia testing? So testing for genetic and acquired thrombophilia may be reasonable for patient without major reversal risk factors like younger patient and patient with family history of thrombosis. Although testing obviously does not alter the acute management of this patient but it can really help you assess the risk of needing lifelong treatment. Although I would say patient with unprovoked PE they really most likely would need a lifelong treatment anyways. But this resistification I think is still helpful for many patients especially talking about antroin deficiency, protein C deficiency and protein deficiency because they're linked to very higher recurrence risk. So it's reasonable to check those uh in certain patients. When do you test for these tendencies? So you can do the genetic and uh imu immunological testing like factor 5 lighten or prothroin gene mutations at any time because these are not affected by the acute event but the coagulation based test like antroin level protein C level and protein level these are affected by the acute event and it's re recommendation is not to test for those during the diagnosis of PE so delay testing until further time and further evaluation or if your patient tells you they need to travel whether in the future or like they have a history of PE in the past or they have like you know a recent PE. So generally for stable patients um early mobilization is preferred over uh bed rest. This is a class 2A recommendation for patient who had a history of PE and they have like a long whole travel like more than 5 hours. There's class 2A recommendation to use compression stocking during the travel time. If your patient had a history of PE and they want to travel so there's a suggestion it's a class uh 2A recommendation to consider one time prophylactic dose I never knew about this but it's it's there so something to think about depending on your discussion with your patient and for patient recovering from a acute PE especially if they're like a category 2C to E maybe it's reasonable to consider not to travel within the first four weeks this is kind of a class 2 recommendation for these patients. So again, it's case by case thing and it's all based on your discussion between you and your patient. So the last topic I want to discuss is if you have a patient who had confirmed PE, new PE and they have been taking the DWAK or you think they had been taking the DWAC what to do. So obviously investigate the contributing factors uh probably the most important thing first is really to kind of check adherance and compliance. So for example patient who are taking higher dose of reproduction than 15 or 20 milligram dosages they better take it with meals if they're not taking that maybe that's a contributing factor for them to developing up is there any other med drug interaction that is lowering the level of the dwack and contributing to medication being thoretic and that's why they developed pulmonary embolism so investigate that is there is any absorption issues so aexiban is less affected by biatic surgery for example but if they have surgery of like GI issues or malabsorption which could be contrib contributing factors. Uh is there any other underlying clinical risk that increases the risk of just having like really resistant thrombophilia like patient with active cancer or like triple antibbody positive antifosphilibid uh syndrome. So think about these conditions as well and if the patient is compliant or let's assume that the patient is not compliant. So just really do more patient education, do more frequent testing and follow up to make sure that the patient uh will be adhered to the medication and don't change the regimen if you think that the problem is that they're just not compliant. If for example a patient is taking the reduced dose aexiban or reveraxiban during the extended antioagulation time, maybe they just need a higher dose, not it's not necessarily to change them to another dwac. But um of course if the patient is compliant and they still develop a PE despite being an adequate dose then obviously it makes sense to try a different class of medications in this patient population. All right very good. So that's it. Um please let me know if you have any other questions or have any any comments about these guidelines. I hope it was uh useful and um hopefully to see you in next video. Thank you.