Valvular heart disease: new evidence and updated guidelines

Following new evidence in recent years, updated guidelines have been published for the management of valvular heart disease (VHD) by the European Society of Cardiology (ESC) and European Association for Cardio-Thoracic Surgery (EACTS). Since the last iteration of the Guidelines, randomised trials on percutaneous interventional techniques and risk-stratification regarding timing of intervention in VHD have made new recommendations necessary. Following new evidence in recent years, updated guidelines have been published for the management of valvular heart disease (VHD) by the European Society of Cardiology (ESC) and European Association for Cardio-Thoracic Surgery (EACTS). Since the last iteration of the Guidelines, randomised trials on percutaneous interventional techniques and risk-stratification regarding timing of intervention in VHD have made new recommendations necessary.

ESC Chairperson, Professor Helmut Baumgartner said:

‘Since the 2012 Guidelines, a large amount of new data have accumulated, particularly in the field of catheter interventional treatment of valvular heart disease.’

Valvular heart disease

VHD is a leading cause of morbidity and mortality worldwide, and refers to conditions where the heart’s valves do not work properly (British Heart Foundation (BHF), 2017). This in turn can affect flow of blood to the heart. The estimated prevalence of VHD in developed countries is 2.5% (Lung and Vahanian, 2014). Causes of VHD can be congenital or acquired, with prevalence increasing markedly in those over 65 years of age (Lung and Vahanian, 2017).

Valve stenosis, or narrowing, refers to a valve that does not open fully, which will obstruct or restrict the flow of blood (BHF, 2017). As the heart has to pump harder in order to force the blood past the narrowing, it can put extra strain on the heart (BHF, 2017). By contrast, valve regurgitation, or leaky valve, concerns a valve that is not able to close properly, and so will allow blood to leak backwards (BHF, 2017). Again, this can put strain on the heart, but this is because the heart has to work harder to pump the required volume of blood (BHF, 2017). While many people may not experience any noticeable physical effects, commonly reported symptoms include:

• Breathlessness
• Swelling of the ankles and feet
• Fatigue (BHF, 2017).

Echocardiography

As was discussed in a recent issue of the British Journal of Cardiac Nursing, echocardiography is the gold standard to confirm a diagnosis of VHD, as well as to assess its severity and prognosis (Hall, 2017). It is also key to assess valve morphology and function, as well as to evalu¬ate the feasibility and indications of a specific intervention. Aortic stenosis is the most common VHD, leading to surgery or catheter intervention in Europe and the United States (US). Its growing prevalence is attributable to the ageing population. Echocardiography is used to:

• Confirm the presence of aortic stenosis
• Assess the degree of valve calcification, left-ventricle function and wall thickness
• Detect the presence of other associated valve disease or aortic pathology
• Provide prognostic information.

Baumgartner said:

‘In aortic stenosis, there have been five randomised clinical trials comparing surgical aortic valve replacement (SAVR) and transcatheter aortic valve implantation (TAVI) as well as large-scale registry data.’

The Guidelines strongly recommend early therapy in symptomatic patients with severe aortic stenosis. Exceptions are given to patients with severe comorbidities indicating a survival of less than a year, and patients in whom there are severe comorbidities, or their general condition at an advanced age make it unlikely that the intervention will improve their quality of life or survival.

SAVR and TAVI

SAVR is recommended in patients at low surgical risk, while TAVI is recommended in patients not suitable for surgery. For patients at increased surgical risk, the decision between SAVR and TAVI should be made by the heart team of surgeons and cardiologists, with TAVI being favoured in older patients suitable for transfemoral access.

The Guidelines stress that aortic valve interventions should only be performed in heart valve centres that include both cardiology and cardiac surgery on site. For asymptomatic patients, SAVR is indicated in those with severe aortic stenosis and systolic left-ventricular function not owing to another cause.

Baumgarter noted:

‘There is new evidence regarding predictors of outcome in asymptomatic patients with valvular heart disease and on antithrombotic therapy in this patient population among other innovations. This definitely required an update of management recom¬mendations.’

Baumgartner emphasised that risk score and age are not the only factors affecting the decision to use SAVR or TAVI:

‘The choice of surgical aortic valve replacement or transcatheter aortic valve implantation is not simply based on a risk score or age—the heart team must weigh the risks and benefits of both procedures, particularly in the intermediate risk situation. Discussion should include age, comorbidities, anatomy, and out¬comes of the centre for surgery and transcatheter intervention.’

Risk-stratification

Risk-stratification is an essential means of decision-making in this patient population in order to establish the risk of intervention compared with the expected natural history of VHD. The Guidelines call for the development of better risk-stratification tools, particularly for the decision between surgery and catheter intervention and for the avoidance of futile interventions.

In asymptomatic patients with VHD, studies suggest early surgery may improve outcomes. However, deciding when to intervene is controversial. For example, asymptomatic patients with aortic stenosis, who have pulmonary hypertension have been introduced into the criteria for being selected for surgery, following studies which showed it was a predictor of poor outcomes. But on the other hand, conflicting studies on the prognostic value of exercise echocardiographic parameters indicate the removal of asymptomatic patients with aortic stenosis and mitral regurgitation from the selection criteria.

Recommendations on the use of antithrombotic therapy have also been updated. Antithrombotic management should address effective control of modifiable risk factors for thromboembolism in addition to the prescription of antithrombotic drugs. The Guidelines state that there are now sufficient data to recommend non-vitamin K antagonist oral anticoagulants as an alternative to vitamin K antagonists in patients with atrial fibrillation who have aortic valve disease or mitral regurgitation. They do, however, point out that non-vitamin K antagonist oral anticoagulants remain contraindicated in patients with mechanical valves and in mitral stenosis.

Conclusion

These new Guidelines from ESC and EACTS represent a much-needed update on the management of VHD. They take into consideration new evidence on risk-stratification and the timing of intervention, as well as on percutaneous intervention techniques. They are aimed at both cardiologists and surgeons, and as Professor Volkmar Falk, EACTS Chairperson, highlights, it is important that both specialties follow the recommendations:

‘This is a joint guideline between cardiologists and surgeons. It is absolutely essential that both specialties follow the same recommendations because we are treating the same patients. Decisions in structural valve disease must be taken by a heart team of cardiologists and surgeons.’

References 

Baumgartner H, Falk V, Bax JJ et al. 2017. 2017 ESC/ EACTS Guidelines for the management of valvular heart disease. Eur Heart J. 2017;38(36):2739- 2791. https://doi.org/10.1093/eurheartj/ehx391

British Heart Foundation. Heart valve disease. 2017. http://tinyurl.com/yat7vjzt (accessed 15 December 2017)

Hall A. Suspected mitral valve disease: clinical assessment. Br J Cardiac Nurs. 2017;12(11):538- 546. https://doi.org/10.12968/bjca.2017.12.11.538

Lung B, Vahanian A. Epidemiology of acquired valvular heart disease. Can J Cardiol. 30(9):962-970. https://doi.org/10.1016/j.cjca.2014.03.022

Taken from British Journal of Cardiac Nursing, published December 2017.