Use the NICE Heart Valve Disease Guideline to Drive Improvements in Cardiac Pathways

Dr James D Newton Assesses the Key Recommendations for Cardiologists in the NICE Guideline on Valvular Heart Disease, and Outlines How it can Provide a Roadmap for Improved Care 

The Need for a Guideline

The majority of heart valve disease is secondary to degeneration and deterioration in valve function with time¹—so perhaps it is no surprise that around 13% of adults aged more than 75 years have moderate or severe valve disease.² Population modelling predicts that in the next 25 years, the number of people aged above 85 years in England will double to more than 2.6 million.³ Therefore, the prevalence of heart valve disease will increase proportionately. Furthermore, due to increasing age, patients are more likely to have complex comorbidities alongside their heart valve disease.⁴ Landmark developments in transcatheter strategies mean that the range of potential treatments continues to increase, and NICE has published Heart valve disease presenting in adults: investigation and management (NICE Guideline [NG] 208),⁵ which provides evidence-based recommendations on when to refer patients with valve disease for assessment, and which treatments are appropriate. The guideline also aims to help healthcare professionals improve the quality of care and services, ensure equity of access to treatment, and support local commissioners in delivering appropriate investigations and treatment options.⁵

Importance of Timely Referral

Patients are frequently referred late with severe symptoms and advanced consequences of their heart valve disease, limiting their prognosis and potential treatment options.⁶ The guideline recommends urgent specialist assessment within 2 weeks (including an echocardiogram) for patients with a systolic murmur who report exertional syncope, and an urgent referral to be considered for patients with a murmur and New York Heart Association (NYHA) class III or IV breathlessness, or easily provoked angina.⁵ Secondary care will need to develop clear pathways for urgent referrals to ensure timely diagnosis and treatment for these high-risk patients.

Pharmacological Management

Heart valve disease is a mechanical problem, with one or more valves influencing cardiac function. There is a very limited role for medical therapy as definitive management for patients with symptomatic heart valve disease. There is evidence for benefit of beta-blocker therapy in patients with mitral stenosis, as reducing the heart rate and maintaining sinus rhythm reduces the impact of the stenosis on cardiac output.⁷ However, mitral stenosis is a rare lesion in the UK⁸ and, in my experience, typically presents in younger patients^5,9 compared to the much more common scenario of patients with aortic stenosis and mitral regurgitation.¹⁰

For the management of heart failure in people with heart valve disease and left ventricular dysfunction, the guideline (NG208) directs readers to NG106, Chronic heart failure in adults: diagnosis and management.¹¹ NG106 recommends the use of diuretic therapy, beta blockade, and ACE inhibition. Notably, however, the chronic heart failure guideline (NG106) advises avoidance of ACE inhibitors in patients with suspected valve disease until assessed by a specialist,¹¹ given the potential for harm if administered to patients with severe aortic stenosis.¹² For patients with severe valve disease and symptoms who have normal left ventricular function there are no recommendations on the use of medical therapy. This reflects the lack of clinical trials looking at medical therapy in this group of patients.

Risk Stratification and Decision-Making

All patients with severe valve disease and symptoms should be considered for definitive intervention with conventional cardiac surgery to repair or replace a diseased heart valve; this is the primary option for the majority.⁵ To facilitate decision-making, the estimated risk of mortality for each patient should be calculated using the European System for Cardiac Operative Risk Evaluation II (EuroSCORE II) system.¹³ This system was developed using several risk factors, including the main risk factors listed in Box 1. High-risk patients are considered for alternative treatments, typically transcatheter therapies.

Frailty and comorbidities are challenges that are frequently encountered in the decision-making process for treatment of heart valve disease. However, the absence of reliable objective assessments of mobility, or the ability to recover from the physical impact of a sternotomy and cardiopulmonary bypass, limit their inclusion in formal risk scores.

Notably, the impact of age-related cognitive decline or other memory problems, frequently encountered in patients with degenerate valve disease,¹⁴ are not directly considered in the guideline.

The NICE guideline also recommends a full and tailored discussion with each patient to consider:⁵

• Short- and long-term benefits to quality of life
• Durability of the implanted valve
• Procedural risk
• Route and type of access—conventional sternotomy, minimally invasive, transcatheter
• Need for other cardiac procedures.

Individual patient characteristics and preferences should also be considered, and the NICE guidance on shared decision making followed.¹⁵

Which Asymptomatic Patients Should be Referred for Intervention?

Although most patients referred for surgical or transcatheter treatment will have symptoms, there are specific scenarios when an asymptomatic patient should be considered for treatment.

Asymptomatic patients with severe aortic stenosis should be referred for intervention if they have any of the following:⁵

• Very severe stenosis—defined as a peak velocity of more than 5 m/s or an estimated valve area of less than 0.6 cm² on echocardiography
• Impaired left ventricular systolic function—defined as an ejection fraction of less than 55% on echocardiography
• Natriuretic peptide levels greater than twice the upper limit of normal
• Symptoms provoked by exercise testing.

Asymptomatic patients with severe aortic regurgitation should be referred for intervention if they have any of the following:⁵

• Impaired left ventricular systolic function—defined as an ejection fraction of less than 55% on echocardiography
• Evidence of significant left ventricular dilation—defined as an end systolic diameter of more than 50 mm (or more than 24 mm/m² when indexed to body surface area).

Asymptomatic patients with severe mitral regurgitation due to primary valve degeneration who have suitable anatomy for treatment should be referred for intervention if they have any of the following:⁵

• Impaired left ventricular systolic function—defined as an ejection fraction of less than 60% on echocardiography
• Evidence of significant left ventricular dilation—defined as an end systolic diameter of more than 45 mm (or more than 22 mm/m² when indexed to body surface area)
• An increase in the estimated right ventricular systolic pressure to more than 60 mmHg during exercise echocardiography.

Additional criteria for the consideration of intervention include the presence of atrial fibrillation, or estimated right ventricular systolic pressure of more than 50 mmHg during resting echocardiography, although no detail on the nature and duration of the atrial fibrillation is provided.⁵

When are Additional Investigations Required?

Symptomatic patients with impaired left ventricular function and suspected severe aortic stenosis but who have low resting gradients at echocardiography should be referred for dobutamine stress echocardiography, and then referred for intervention if severe stenosis is proven, which is defined as:⁵

• A mean gradient increasing to more than 40 mmHg with dobutamine stress
• An estimated aortic valve area less than 1.0 cm² during increased flow.

Cardiac computerised tomography is also mentioned as an adjunctive assessment of aortic stenosis severity by deriving the valve calcium score, although no guidance on the relevant cut-off for severe stenosis is recommended.⁵

Choice of Intervention

Aortic Stenosis

Symptomatic aortic stenosis should be treated by cardiac surgery unless a patient is judged to be inoperable or at high surgical risk, as defined by a EuroSCORE II score of more than 8%.⁵

Transcatheter aortic valve implantation (TAVI) is not cost-effective in patients at intermediate (EuroSCORE II 4–8%) and low risk (EuroSCORE II less than 4%), but it is cost effective for people at high risk for surgery. The guideline recommends TAVI in suitable patients with non-bicuspid severe AS who are at high surgical risk, or if surgery is unsuitable.⁵

NICE recommend that TAVI is also considered in:⁵

• All patients at high risk of mortality or morbidity after cardiac surgery (defined as a EuroSCORE II risk of more than 8%)
• Patients with other risk factors for poor outcomes such as increased infection risk
• All patients expected to have unacceptably strenuous and prolonged recovery from surgery due to frailty, mobility problems, or musculoskeletal conditions
• All patients with low life expectancy because of age or life-limiting comorbidities.

Mitral Regurgitation

Surgical mitral valve repair by sternotomy or minimally invasive surgery should be offered to symptomatic patients with severe primary mitral regurgitation, or surgical mitral valve replacement for those with valve anatomy unsuitable for valve repair.⁵

Transcatheter edge-to-edge repair should be considered in patients with severe primary mitral regurgitation and symptoms who are unsuitable for surgical mitral valve repair, based on their surgical risk.⁵

Secondary mitral regurgitation due to ventricular or atrial enlargement in the absence of mitral leaflet degeneration should be managed medically, although edge-to-edge repair should be considered for patients who remain symptomatic despite medical therapy.⁵ If patients with secondary mitral regurgitation have an additional indication for cardiac surgery, such as surgical coronary artery disease, then mitral repair or replacement should be considered.⁵

The advice to consider transcatheter edge-to-edge repair for patients who have symptomatic severe secondary mitral regurgitation despite medical therapy is at odds with current NHS commissioning policy, which only recognises edge-to-edge repair in primary mitral regurgitation.¹⁶

Anticoagulation and Antiplatelet Therapy

The NICE guideline recommends the use of a single antiplatelet agent in patients with TAVI valves. If people have other indications for anticoagulation or antiplatelet therapy, such as atrial fibrillation, the relevant NICE guideline should be followed.⁵ The guideline does not make any recommendation on the role of anticoagulation for the treatment of bioprosthetic valve thrombosis.

Monitoring Patients Not Yet Appropriate for Intervention

The guideline recommends at least annual review with an echocardiogram for patients with asymptomatic severe valve disease who do not yet meet criteria for intervention, and that echocardiographic assessment after 3–5 years be considered for patients with mild aortic or mitral stenosis.⁵

Psychological Support and Tailored Information

The guideline stresses the need for providing appropriate information to the patient and recommends an expert point of contact for advice between appointments.⁵ The need for additional psychological support once valve disease is diagnosed is also highlighted.⁵ Patients should be provided with information about:⁵

• Expected progression and prognosis of the valve disease
• Need for intervention and the type of intervention
• Pregnancy, if appropriate
• Effects of other conditions on long-term outcomes
• Rehabilitation and long-term outcomes
• Access to palliative care, if appropriate.

Comparison With the EACTS/ESC Guideline

The 2021 European Association for Cardio-Thoracic Surgery and European Society of Cardiology (EACTS/ESC) guideline for the management of valvular heart disease¹⁷ has important additions and differences to the NICE guidance. NICE recommends medical therapy only for patients with severe secondary mitral regurgitation, as evidence suggests transcatheter edge-to-edge repair is not cost-effective.⁵ The EACTS/ESC guideline recommends that transcatheter edge-to-edge repair should be considered in patients with persistent symptoms, despite guideline-directed medical therapy and pacemaker treatment when appropriate.¹⁷ The EACTS/ESC guidelines also provide useful recommendations on the prosthesis type for patients undergoing cardiac surgery;¹⁷ the NICE guideline makes no such recommendation.

A strong theme in the EACTS/ESC guideline is the role of an active and collaborative ‘Heart Team’ assessing patients in a heart valve centre, with clear recommendations on the optimal requirements for the team and centre.¹⁷ Although the NICE guideline provides a definition of a multidisciplinary team, it does not provide details of a specific approach or what a specialist centre should include.⁵

Potential Barriers to Implementation in Secondary Care

The guideline outlines how the recommendations might affect practice, and therefore, where change will be required:⁵

• Pregnancy—specialised support for women with valve disease is not widely available
• Embedding revised indications for intervention in asymptomatic patients, noting the change in the cut off of ejection fraction for aortic stenosis from 50% to 55%, and the role of brain natriuretic peptide
• Increase in rates of surgery for aortic stenosis if all patients, at low or intermediate risk, are referred for surgical intervention
• Increase in referrals for mitral valve edge-to-edge repair
• Reduction in the use of routine anticoagulation after biological valve implantation
• Need for psychological support and access to specialist advice for all patients.

Conclusion

The NICE guideline, Heart valve disease presenting in adults: investigation and management,⁵provides a roadmap to improved care for patients with heart valve disease in England, and should ensure better access to treatment options for all patients. This, along with robust information, psychological support, and tailored decision-making, will help to drive improvements in the diagnosis, assessment, and timely referral of adults with valve disease.

Secondary care providers will need to assess the impact of these guidelines on their practice and referral pathways, and to develop solutions that deliver the recommendations. Any changes will need to be balanced with those recommended by the Cardiology Getting It Right First Time (GIRFT) Programme National Speciality Report,¹⁸ and NHS England commissioning policies.¹⁹

Finally, all patients should be actively involved in decision-making about the choice of intervention for heart valve disease. Recommending sternotomy and surgical valve replacement to an intermediate or low surgical risk patient with aortic stenosis who may prefer a faster recovery with a transcatheter approach—a procedure that is not cost effective—will present an increasing challenge for surgeons and cardiologists.

Dr James D Newton

Consultant Cardiologist, John Radcliffe Hospital, Oxford