New practice guidelines for the management of patients with valvular heart disease (VHD) provide updated definitions of disease severity—categorizing four progressive stages from "at risk" to "symptomatic severe"—and lower the threshold for intervention in select patient populations.
Released today by the American College of Cardiology and the American Heart Association, the 2014 document further incorporates a more complex evaluation of interventional risk than the previous guideline and incorporates indications for newer catheter-based therapies.
The guideline was drafted by a committee including cardiologists, interventionalists, surgeons, and anesthesiologists, and is the first to be released on VHD since a focused update in 2008.
Among the document's most significant additions is the new classification of VHD stages. Created to help clinicians determine the optimal timing of intervention, the stages consider the degree of valve narrowing or leakage, the presence of symptoms, the response of the left and/or right ventricle to the valve lesion, and any change in heart rhythm.
The guideline also provides a proposed risk assessment that should be applied to all patients considered for intervention. Acknowledging that current scoring systems are useful but limited, the document's original assessment combines procedure-specific impediments, major organ system compromise, comorbidities, patient frailty, and the Society of Thoracic Surgeons predicted risk of mortality model. The risk scores—along with the specific risks and benefits—should be discussed with the patient in a shared decision-making process to determine the best therapy for the individual.
The guideline further addresses, for the first time, the use of transcatheter aortic valve replacement (TAVR). The introduction of TAVR and other new catheter-based therapies have made VHD management increasingly complex, as they have expanded patient options but increased the difficulty of discerning the risk–benefit ratio. The guideline thus provides separate recommendations on both the timing and choice of these new interventions.
Moreover, the new therapies now mandate a multidisciplinary approach to the diagnosis and management of VHD, said writing committee co-chair Catherine Otto, MD. In response, the guideline discusses both the Heart Valve Team and Heart Valve Centers of Excellence.
Treatment advances have also impacted interventional threshold. "Due to more knowledge regarding the natural history of untreated patients with severe VHD and better outcomes from surgery, we've lowered the threshold for operation to include more patients with asymptomatic severe valve disease," said Rick Nishimura, MD, writing committee co-chair and a consultant in the Division of Cardiovascular Diseases at Mayo Clinic. "Now, select patients with severe asymptomatic aortic stenosis and severe asymptomatic mitral regurgitation can be considered for intervention, depending on certain other factors, such as operative mortality and in the case of mitral regurgitation, the ability to achieve a durable valve repair."
Finally, the guideline includes formatting enhancements to facilitate their use at the point of care. Decision pathway diagrams have been incorporated, as have numerous summary tables. According to Otto, the new format will facilitate both greater clinical use and a more timely and efficient updating process.
"This VHD guideline was developed in a modular format that will allow the update or addition of individual recommendations based on the publication of new evidence," said Otto, a Professor of Medicine at the University of Washington Medical School and the Director of the UW Medical Center Heart Valve Clinic. "This novel approach to evidence-based guideline development will revolutionize the clinical impact of guideline recommendations, ensuring they are always current and allowing seamless integration with electronic medical record systems."