Valvular heart disease guideline lowers intervention threshold, provides new disease classification

Issue: April 2014

The American College of Cardiology and American Heart Association have issued a new guideline for the management of patients with valvular heart disease, with recommendations that lower the threshold for intervention in certain patients and provide updated definitions of disease severity.

The guideline is the first on valvular heart disease since a focused update was issued in 2008. It incorporates newer therapies, most notably transcatheter aortic valve replacement, which was not approved in the United States until late 2011.

James D. Thomas, MD, FASE, FACC, FAHA, a member of the committee that wrote the document, told Cardiology Today that the threshold for intervention in some patients was lowered for several reasons.

James D. Thomas

“There has been a slight move toward earlier surgery or earlier intervention since over time our surgical interventions have gotten safer, we have more information on the natural history of these diseases, and we better understand the importance of intervening before there is deterioration in left ventricular function,” Thomas, from Cleveland Clinic and Case Western Reserve University, said. “For instance, in aortic stenosis, there are now more options for intervening in asymptomatic patients if they have really severe aortic stenosis, with valve gradients >100 mm Hg. Those are somewhat more liberal than they have been in the past.”

The document defines four stages of progression of valvular heart disease: Stage A includes patients with risk factors for valvular heart disease; Stage B includes patients with progressive valvular heart disease of mild to moderate severity and who are asymptomatic; Stage C includes asymptomatic patients who meet criteria for severe valvular heart disease; and Stage D includes patients with severe valvular heart disease who have developed symptoms.

New risk-assessment algorithm

The guideline contains a risk-assessment algorithm which can be applied to any patient under consideration for intervention. The algorithm combines the Society of Thoracic Surgeons Predicted Risk of Mortality (STS PROM), frailty indices, major organ system compromise and procedure-specific impediments.

Patients classified as low risk for surgery or intervention must meet all of the following criteria: STS PROM <4%; no frailty; no major organ system compromises; and no procedure-specific impediments.

Patients classified as intermediate risk have at least one of the following: STS PROM 4% to 8%; mild frailty based on one index; one major organ system compromise; and a possible procedure-specific impediment.

Patients classified as high risk have at least one of the following: STS PROM >8%; moderate to severe frailty based on at least two indices; no more than two major organ system compromises; and a possible procedure-specific impediment.

Patients who receive a prohibitive risk classification should not have surgery or intervention, according to the document. This classification includes the presence of at least one of the following: predicted >50% risk for death or major morbidity at 1 year after surgery; three or more major organ system compromises; and severe procedure-specific impediment.

The document also contains recommendations on which patients with valvular heart disease should receive surgery or intervention. The writing committee strongly recommended intervention for patients with severe high-gradient aortic stenosis (AS) who have symptoms by history or on exercise testing; asymptomatic patients with severe AS and LV ejection fraction <50%; and patients with severe AS who are undergoing cardiac surgery for other indications. The committee also identified five classes of patients in whom it is reasonable to perform surgery or intervention, and one class for whom it may be considered.

TAVR vs. surgery

In addition, the document classifies which patients are recommended for surgical aortic valve replacement (AVR) and which are recommended for TAVR.

Surgical AVR is strongly recommended for patients with an indication for AVR and who are classified as low or intermediate surgical risk. TAVR is strongly recommended for patients with an indication for AVR for AS who are classified as prohibitive surgical risk and have a predicted post-TAVR survival of more than 12 months.

TAVR is a reasonable alternative for patients with an indication for AVR but who are classified as high surgical risk, according to the document. However, the guideline states that TAVR has no benefit in patients for whom existing comorbidities would preclude the expected benefit from correction of AS.

Members of a heart valve team should collaborate on decisions regarding any candidate for TAVR or high-risk surgical AVR, the committee wrote. Further, it is reasonable for doctors to consult with or refer to a heart valve team on treatment options for asymptomatic patients with severe valvular heart disease; patients who may benefit from valve repair vs. valve replacement; and patients with multiple comorbidities for whom valve intervention is being considered, according to the document.

“The heart valve team needs to include clinical cardiologists, imaging cardiologists, cardiac surgeons, interventional cardiologists and cardiac anesthesiologists, and they all have to come together in the assessment of a patient to design the best therapy for that patient,” Thomas said. “For many patients, it’s still quite straightforward: If you have severe symptomatic aortic stenosis and you are a good surgical candidate, that remains a Class I indication for surgery, just as it has always been. But now that we have new therapeutic options like TAVR, that has required a more nuanced description of the clinical decision-making and requires a multidisciplinary team to come up with the best possible assessment.”

Thomas also said the new guideline contains a more sophisticated description of mitral regurgitation. “We have clearly separated out primary mitral regurgitation from secondary mitral regurgitation, with different indications for each,” he said. “The evidence base is much cleaner for primary mitral regurgitation, so there is a move toward a more liberal application of surgery in these patients as long as it is done in a center of excellent with a very high likelihood of successful valve repair. For secondary mitral regurgitation, the same volume of regurgitation may have greater impact on the patient than it would [in patients with] primary regurgitation, simply because of the poor LV function that goes along with that.”

The document was written by a committee co-chaired by Rick A. Nishimura, MD, MACC, FAHA, from Mayo Clinic, and Catherine Otto, MD, FACC, FAHA, from the University of Washington. It was simultaneously published online in Circulation and the Journal of the American College of Cardiology. – by Erik Swain

For more information:

Nishimura RA. Circulation. 2014;doi:10.1161/CIR.0000000000000031.

Nishimura RA. J Am Coll Cardiol. 2014;doi:10.1016/j.jacc.2014.02.536.

Disclosure: See the full statement for the relevant financial disclosures of the writing committee members and reviewers. Thomas reports no relevant financial disclosures.