AHA's 2017 overhaul of valvular heart disease guidelines, broken down

The American Heart Association (AHA) and American College of Cardiology (ACC) rolled out new guidelines for managing valvular heart disease (VHD) in 2017, marking the second overhaul of VHD recommendations in three years—a move attributable to “extensive new data” that have shaped the way clinicians treat valve disease.

The AHA/ACC guidelines released in 2014 were novel in that they identified stages of VHD and emphasized the importance of specific mechanisms of valvular disorders, Richard Matiasz, MD, and Vera H. Rigolin, MD, wrote in a review published in the Journal of the American Heart Association this month. The 2017 guidelines kept some of those changes and expanded upon them, Matiasz and Rigolin wrote, to include illuminating data from recent trials that have made a considerable impact in the world of VHD.

These are the recommendations and their latest changes, broken down.

Endocarditis prophylaxis

• What stayed the same: High-risk patients are still recommended for antibiotic prophylaxis as a treatment for endocarditis, but the evidence supporting that recommendation is growing weaker.
• What’s new: New evidence suggests endocarditis patients fitted with prosthetic materials like annuloplasty rings and chords post-cardiac treatment are at greater risk for infection and mortality. An emphasis was placed on maintaining oral hygiene to minimize seeding, and transcatheter aortic valve replacement (TAVR) patients are now included on the list of high-risk patients recommended for antibiotic prophylaxis.

Anticoagulation for atrial fibrillation with VHD

• What stayed the same: Atrial fibrillation (AFib) patients with mitral stenosis (MS) continue to be recommended for anticoagulation for stroke prophylaxis, and vitamin K antagonists (VKAs) continue to be the “agents of choice” for treating those with rheumatic MS with AFib.
• What’s new: The 2017 guidelines expanded the recommendation for anticoagulation to other valve disorder groups, including native aortic valve disease, tricuspid disease and mitral regurgitation. Direct oral anticoagulants (DOACs) trump VKAs as treatment options in the newest guidelines, and the CHA2DS2-VASc score was incorporated into the document in line with today’s AFib management guidelines.

Aortic stenosis

• What stayed the same: The latest recommendations still discuss percutaneous intervention as a viable option for AS treatment, and bicuspid, unicuspid and noncalcified valves remain excluded from general recommendations for TAVR.
• What’s new: The recommendation for TAVR in high- and prohibitive-risk patients is now class I, since evidence in recent years has pointed to TAVR as a reasonable alternative to SAVR in patients with severe AS and an immediate surgical risk. Extensive data from the PARTNER trials supported this change.

Mitral regurgitation

• What stayed the same: Just like in 2014, the 2017 guidelines underlined the importance of identifying the mechanism of MR, since management and treatment outcomes differ between chronic primary and secondary MR. The recognition of adverse outcomes found with lower effective regurgitant orifice in secondary MR was again emphasized.
• What’s new: Because the 2014 guidelines defined severe MR using a lower quantification threshold for secondary MR—which caused “a great deal of confusion,” Matiasz and Rigolin wrote—2017 quantification of MR severity was modified so both primary and secondary MR are graded in a similar way.

Primary MR

• What stayed the same: Almost everything. The majority of recommendations for surgical or percutaneous intervention for patients with chronic, severe primary MR remained intact.
• What’s new: A new recommendation outlines mitral valve surgery as a reasonable option for asymptomatic patients and preserved left ventricular size and function with a progressive increase in LV size or decrease in LV ejection fraction on serial imaging studies.

Secondary MR

• What stayed the same: Not much.
• What’s new: Rather than the 2014 recommendation to focus on treating the underlying cause of MR in secondary MR patients, the 2017 guidelines have added a class IIa recommendation to choose chordal-sparing MV replacement over annuloplasty with repair (though only in the case of chronic severe MR that persists despite goal-directed medical therapy). The new guidelines also explain the lack of “clear benefit” for repairing moderate MR in patients undergoing coronary artery bypass grafting.

Prosthetic valve choice

• What stayed the same: The importance of recognizing strengths and limitations of a variety of prosthetic valves, and discussing those options with the patient, remains important, and the patient discussion about the benefits of a bioprosthetic heart valve versus a mechanical heart valve stayed a class I indication.
• What’s new: New data have expanded the list of prosthetic valves to choose from, and transcatheter valve-in-valve procedures are now part of the patient-doctor conversation. The authors also stressed longer-term follow-up on patients with prosthetic valves.

Prosthetic valve antithrombotic therapy

• What stayed the same: Most recommendations, with a few exceptions.
• What’s new: The authors reiterated international normalized ratio (INR) ranges for anticoagulation in patients with mechanical hearts, with some minor shifts in recommended numbers. As TAVR became a more popular treatment mechanism, the guidelines also noted increased recognition of clinical and subclinical leaflet thrombus.

Bridging therapy for prosthetic valves

• What stayed the same: The AHA and ACC still recommend continuing anticoagulation for minor procedures, temporary interruption for bileaflet mechanical aortic valves without other risk factors and bridging with heparinoids for other patients with mechanical prosthesis.
• What’s new: In light of a recent study, the level of evidence for a handful of these claims was upgraded from C to B-NR.

Prosthetic valve thrombosis

• What stayed the same: The 2014 guidelines recognized challenges in this diagnosis, but medical management of valve thrombus was limited to recent onset of the disease or for right-sided thrombosis, and surgery was often the only option.
• What’s new: As thrombolytic therapy is incorporated increasingly into clinical practice, it’s being used as an alternative to surgery. The 2017 guidelines also suggest “urgent” therapy and multimodality imaging for thorough assessment of valve function, leaflet motion and assessing the presence and size of a thrombus.

Prosthetic valve stenosis and regurgitation

• What stayed the same: Surgery stayed a class I indication for operable patients with severe symptomatic prosthetic valve stenosis and for operable patients with MHV with intractable hemolysis or heart failure attributed to severe prosthetic or paraprosthetic regurgitation, and transcatheter-based therapies remained a potential treatment option for paravalvular regurgitation.
• What’s new: VKA treatment is now recommended for patients with suspected or confirmed BHV thrombosis who are hemodynamically stable and have no contraindications for anticoagulation.

Infective endocarditis

• What stayed the same: The 2014 recommendations for aggressive antibiotic therapy, early removal of devices and surgical consultation with consideration on the timing of surgery were left untouched.
• What’s new: The newest guidelines take into consideration the timing of operation in patients with IE who have suffered a stroke, leading to a recommendation that operation take place without delay in these patients.