Robert P. Giugliano, MD, MSci, on Prescribing Anticoagulation Therapy

Prescribing the right anticoagulation therapy to the right patient is critical to the patient’s outcomes. Non-vitamin K oral anticoagulants (NOACs) have evolved since they first came on the market, with fewer reports of bleeding events and strokes in 2018. It is also important for cardiologists to monitor the therapy regimen and make changes when necessary.

Cardiology Consultant caught up with cardiologist Dr Robert Giugliano before his session at the Heart Rhythm Society’s Atrial Fibrillation (AFib) Forum to find out more about prescribing NOACs.

Robert P. Giugliano, MD, MSci, is a senior investigator in the TIMI Study Group; a staff physician in the Cardiovascular Division at Brigham and Women’s Hospital; and an associate professor of medicine at Harvard Medical School in Boston, Massachusetts.

Cardiology Consultant: What is your method for selecting the right anticoagulation therapy for the right patient?

Robert P. Giugliano: I assess the risk of thromboembolism vs bleeding to determine (1) who should be anticoagulated and (2) which treatment is best. For the latter, there are specific reasons why a NOAC should or should not be used, so those are easy. Deciding between NOACs is more nuanced, and the key factors include age, renal function, bleeding risk, patient preference for once vs twice daily, and potential drug-drug interactions, among others.

CARDIO CON: Which patients with AFib should receive anticoagulation therapy?

RPG: Patients with CHADS-VASc score 2 or higher, provided they are not having an active serious bleed. I often treat patients with a score of 1 but do discuss with them that the data are less certain.

CARDIO CON: Say one of your patients who is taking anticoagulation therapy presents to your office with a bleed. How do you alter the patient’s NOACs to ensure a lower risk for bleeding?

RPG: I first review the concomitant medications to make sure they are not taking aspirin, nonsteroidal anti-inflammatory drugs (NSAIDs) or other drugs that might increase the risk for bleeding (e.g., P-gp inhibitor, CYP 3A4 inhibitors—relevant for apixaban and rivaroxaban only). Then I assess some labs (complete blood cell count, platelet count, renal function). I review the dose of the anticoagulant to make sure it is appropriate for the patient’s renal function. Depending on the site and severity of the bleeding, I might consider other measures to prevent bleeding (e.g., add a proton-pump inhibitor to reduce the risk of gastrointestinal bleeding). I would then consider switching to one of the 2 NOACs with proven less major bleeding than warfarin (edoxaban, apixaban) rather than dabigatran or rivaroxaban. Lastly, I might consider lowering the dose of a NOAC.

CARDIO CON: Can you talk about an example of a challenging patient who may or may not have needed anticoagulation therapy? How did you come to the conclusion?

RPG: Earlier today I was consulted regarding a 93-year-old woman with recent-onset AFib who had fallen 1 month ago and sustained a subdural hematoma. She was not known to have AFib until she presented after the fall. Today, I just received the follow-up computed tomography scan results that showed completed resolution of the subdural hematoma. She deserved anticoagulation because of her high risk for stroke/embolism, but patients with recent intracranial hemorrhage have not been well studied. Because the bleeding had resolved, I decided to initiate therapy with a NOAC, as they have one-half the rate of intracranial bleeding compared with warfarin.

CARDIO CON: What other knowledge gaps exist amongst cardiologists when it comes to prescribing anticoagulation therapy?

RPG: A very common misconception is that the NOACs are all the same—they are not, and so I use them all in my attempt to select the best drug for each individual patient. 

Another misconception is that warfarin is “safer” because there are therapies to reverse the anticoagulant effect. Many health care providers are not aware that in the case of a life-threatening bleed in a patient on warfarin, the recommendations are to administer prothrombin-complex concentrates (and some guidelines also saw intravenous vitamin K, although that acts more slowly). With NOACs, we now have specific reversal agents (idaracizumab for dabigatran, andexanet alpha for the FXa inhibitors) that act quickly. Even if a patient were in a setting where the reversal agent was not available, the next line of therapy is the very same prothrombin-complex concentrates that are recommended for life-threatening bleeding events on warfarin. So, selecting warfarin because it can be reversed makes no sense.

A third misconception is related to the phrase “nonvalvular” AFib, which I feel is a misnomer. It is misleading, inaccurate, and confusing. In Europe and increasingly in the Americas and Asia, this term is no longer being used in the medical literature. What is really meant is AFib due to rheumatic mitral stenosis or mechanical heart valve, and this better describes patients who should receive warfarin instead of a NOAC.

CARDIO CON: What is the key takeaway from your session that cardiologists should keep top of mind?

RPG: In making decisions about anticoagulation in patients with AFib:

• Use the CHADS-VASc score to determine stroke risk and prescribe anticoagulation for those with a score of 2 or above (and strongly consider if the score = 1).
• Unless the patient has an absolute contraindication (e.g., mitral stenosis, mechanical heart valve, pregnancy), I would use a NOAC over warfarin.
• All NOACs are not the same—learn the differences between the 4 NOACs and select the best one that fits the patients’ profile.
• Involve the patient in the decision—what factors are important from the patient’s perspective?