New Valve Guidelines Offer Staging, Risk-Scoring Advice

Shelley Wood

March 05, 2014

New guidelines released this week on the management of valvular heart disease in adults include recommendations for newer, less invasive therapies, plus provide a new system for classifying patient risks preprocedure[1].

According to cochair Dr Catherine Otto (University of Washington, Seattle), the American Heart Association (AHA)– and American College of Cardiology (ACC)–led document also reflects a shift toward intervening earlier in the course of the disease.

"Rather than discuss end-stage valve disease and how it should be treated, we talk about stages of valve disease like stages of heart failure," Otto explained to heartwire . "The idea here is that as we learn more about the [progression] of valve disease, we'd like to treat the patient over the course of the disease and hopefully prevent and treat comorbidities more closely."

The practice guidelines, the first since an update in 2008, were published on both the AHA and ACC websites and will appear in upcoming print journals.

The document spans all forms of acquired adult valve disease, offering recommendations for staging the disease, diagnosis, medical therapy, and interventions, both surgical and minimally invasive. Problems with prosthetic valves, diagnosing and treating infective endocarditis, and special considerations in the setting of pregnancy and cardiac and noncardiac surgery are also covered.

Staging for different diseases, in different valves, is broken down into four categories: at risk, progressive, asymptomatic severe, and symptomatic severe. Also new to the guidelines is a proposed risk-scoring system. In the past, Otto noted, surgeons and others have had to rely on the Society of Thoracic Surgeons (STS) score, which isn't well-suited to estimating risk in patients being considered for nonsurgical treatment, including less invasive transcatheter-valve procedures. The new guidelines thus suggest using STS plus three additional indicators: frailty (using accepted indices), major organ system compromise not to be improved postoperatively, and procedure-specific impediment.

That means there is no simple score that physicians can use to calculate risk, no "simple number that will tell us everything," Otto stressed. "We are emphasizing an individualized process and shared decision making."

US vs European Guidelines

Asked how the AHA/ACC guidelines differ from the European guidelines issued in 2012, Otto explained that the US document, at 234 pages (even the executive summary is 96 pages) is more comprehensive and detailed than the European document.

Like the European guidelines, transcatheter aortic-valve replacement (TAVR) is given a class I recommendation (level of evidence B) for high-risk patients with aortic stenosis who are not suitable candidates for surgical AVR and can be considered as a "reasonable alternative" to surgical AVR in patients suitable for surgery but at high surgical risk (class IIa [B] in both sets of guidelines). Both documents recommend against use of TAVR in patients at lower surgical risk. According to Otto, "surgery is still going to be the gold standard" in patients at intermediate surgical risk "until we get longevity data on the transcatheter valves. We just don't know long-term durability."

A transcatheter, device-based approach is also is also included in the new guidelines for the first time—a nod to the MitraClip (Abbott Vascular), which received FDA approval last year. According to the US guidelines, transcatheter mitral-valve repair may be considered for severely symptomatic patients with chronic severe primary mitral regurgitation (MR) (stage D) who have favorable anatomy and a reasonable life expectancy but who have a prohibitive surgical risk, a class IIb (B) recommendation. Recommendations on the MitraClip also debuted in the 2012 European guidance.

Both sets of guidelines emphasize the role of multidisciplinary teams and defines the important role of both heart-valve teams and heart-valve centers of excellence.

One point of divergence between the guidelines pertains to the timing of intervention in patients with asymptomatic mitral-valve disease and preserved LV function. In the AHA/ACC guidelines, mitral-valve repair is "reasonable" in this group, with a class IIa [level of evidence B] recommendation. In the European guidelines, however, surgery gets a class IIb recommendation.

"The timing of intervention always depends on the balance between the risk and durability of the procedure compared with the outcomes without intervention," Otto explained to heartwire . "For severe primary MR, natural-history studies show that patients will develop LV dilation and dysfunction as well as symptoms in the long term. The rationale for recommending surgery even in asymptomatic patients is that the risk of surgery is quite low in selected patients, there are more data on the excellent long-term durability of mitral-valve repair, and outcomes are better with intervention before onset of LV dilation, atrial fibrillation, or pulmonary hypertension. This conclusion is based on observational studies and on clinical expert opinion; however, as summarized in the online evidence tables, when we aggregated all the data, we considered that the evidence did support a level of evidence B recommendation."

As such, she clarified, earlier intervention in patients with mitral regurgitation would apply only to patients with:

  1. A repairable valve (>95% likelihood of a successful and durable repair without residual MR).

  2. A very low expected operative mortality (<1%).

  3. Valve repair planned for a heart-valve center of excellence.

"If these three conditions are not met, a more conservative approach is appropriate," she said.

Detailed conflict-of-interest information for guideline writers is provided in an online supplement .

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