A topic that was not addressed in the previous guideline was whether patients with a subsegmental PE should be treated. The guideline now suggests that patients with only subsegmental PE and no ultrasound-proven proximal DVT of the legs should undergo “clinical surveillance” rather than anticoagulation (grade 2C). Exceptions include patients at high risk for recurrent VTE (e.g., hospitalization, reduced mobility, active cancer, or irreversible VTE risk factors) and those with a low cardiopulmonary reserve or marked symptoms thought to be from PE. AT10 also states that patient preferences regarding anticoagulation treatment as well as the patient’s risk of bleeding should be taken into consideration. If the decision is made to not prescribe anticoagulation for subsegmental PE, patients should be advised to seek reevaluation if their symptoms persist or worsen.
The 2012 guideline included a new recommendation that patients with low-risk PE (typically defined by a low Pulmonary Embolism Severity Index [PESI] score) could be discharged “early” from the hospital. This recommendation has now been modified to state that patients with low-risk PE may be treated entirely at home. It is worth noting that outpatient management of low-risk PE has become much less complicated if using a DOAC, particularly rivaroxaban and apixaban as neither require initial treatment with parenteral anticoagulation.
AT10 has not changed the recommendation for which patients should receive thrombolytic therapy for treatment of PE. It recommends systemic thrombolytic therapy for patients with acute PE associated with hypotension (defined as systolic blood pressure less than 90 mmHg for 15 minutes) who are not at high risk for bleeding (grade 2B). Likewise, for patients with acute PE not associated with hypotension, the guideline recommends against systemic thrombolytics (grade 1B). If thrombolytics are implemented, AT10 favors systemic administration over catheter-directed thrombolysis (CDT) due to the higher-quality evidence available. However, the authors state that CDT may be preferred for patients at higher risk of bleeding and when local expertise is available. Lastly, catheter-assisted thrombus removal should be considered in patients with acute PE and hypotension who have a high bleeding risk, who have failed systemic thrombolytics, or who are in shock and likely to die before systemic thrombolytics become therapeutic.
Although no prospective trials have evaluated the management of patients with recurrent VTE events while on anticoagulation therapy, AT10 offers some guidance. After ensuring the patient truly had a recurrent VTE event while on therapeutic warfarin or compliant with a DOAC, the authors suggest switching to LMWH for at least one month (grade 2C). Furthermore, for patients who have a recurrent VTE event while compliant on long-term LMWH, the guideline suggests increasing the dose of LMWH by about one-quarter to one-third (grade 2C).
It is important to note that of the 54 recommendations included in the complete guideline update, only 20 were strong recommendations (grade 1), and none were based on high-quality evidence (level A). It is obvious that more research is needed in this field. Regardless, the ACCP antithrombotic guideline remains the authoritative source in VTE management and has a strong influence on practice behavior. With the recent addition of several newer anticoagulants, AT10 is particularly useful in helping providers understand when and when not to use them. The authors indicate that future iterations will be continually updated, describing them as “living guidelines.” The format of AT10 was designed to facilitate this method with the goal of having discrete topics discussed as new evidence becomes available.
Hospital Medicine Takeaways
Despite the lack of randomized and prospective clinical trials, the updated recommendations from AT10 provide important information on challenging VTE issues that the hospitalist can apply to most patients most of the time. Important updates include: