My aortic valve is “blocked”
Do I need to go through surgery?
Aortic Stenosis (AS) is the obstruction of the LV outflow tract by calcification of the valve structures, associated or not with the fusion of the aortic valve valves. It is the most frequent acquired aortic valve disease and is present in 5% of the population over 75 years old. With population aging, we expect increase in incidence and importance in the upcoming decades. AS may also be secondary to bicuspid aortic valve and rheumatic fever. The latter is invariably associated with mitral valve disease, and despite the decrease in its incidence in developed countries, it is still frequent in Brazil and other countries in Latin America, leading to the involvement of younger patients.
Normal aortic valve area is 3 to 4 cm². The valve area should be reduced to 1/3 for symptoms to develop, which is why only an area < 1.0 cm² is considered as severe aortic stenosis. When aortic stenosis is severe and cardiac output is normal, the mean transvalvular gradient is generally > 40 mmHg. Surgical decisions are based on the presence or absence of symptoms; the valve area or the transvalvular gradient are generally not the primary determinants of the need for aortic valve replacement.
A long asymptomatic latent period allows low morbidity and mortality. It seems that the progression of aortic stenosis is faster in calcific degeneration than in congenital or rheumatic disease. Asymptomatic patients with severe AS, with normal left ventricular function, have good survival with risk of sudden death < 1% per year. After the onset of classic symptoms, heart failure, syncope or angina, 50% of patients die in 2, 3 and 5 years, respectively, if they remain on clinical treatment as shown in Figure 1. Therefore, patients with severe aortic stenosis need to be closely monitored and warned of possible symptoms indicating the need to seek medical help and the need for surgical treatment.
Figure 1 – Survival curve for Aortic Stenosis after symptom onset. Adapted from Ross and Braunwald. Circulation 1968.
AS is classified into stages A, B, C1, C2, D1, D2 and D3, according to the severity of echocardiographic parameters and symptoms, summarized in Table 1 below:
Generally speaking, according to the recommendations of current guidelines, patients classified as D1 and C2 and patients in stages C or D who undergo other cardiac surgery (revascularization surgery, for instance) have a precise surgical indication (Class I, B). The other situations must be detailed, and when there is a surgical contraindication (porcelain aorta, i.e.), remember the possibility of TAVR after discussion with the Heart Team.
- Symptomatic patients with significant AS, surgical treatment is essential due to the catastrophic outcome already demonstrated in other publications that support the current guidelines.
- In case of surgical contraindication, it is necessary to discuss with the Heart Team to assess the possibility of TAVR, a therapy based on the most recent publications (PARTNER II and III) and included in the most recent guidelines.
- Other situations must be detailed, individualized and decided upon after discussion with the Heart Team.
- Nishimura RA, Otto CM, Bonow RO, Carabello BA, Erwin JP, Fleisher LA, et al. 2017 AHA/ACC Focused Update of the 2014 AHA/ACC Guideline for the Management of Patients With Valvular Heart Disease: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Vol. 70, Journal of the American College of Cardiology. 2017. 252–289 p.
- Tarasoutchi F, Montera M, Ramos A, Sampaio R, Rosa V, Accorsi T, et al. Atualização Das Diretrizes Brasileiras De Valvopatias: Abordagem Das Lesões Anatomicamente Importantes. Arq Bras Cardiol. 2017;109(6).
- Ramaraj R, Sorrell VL. Degenerative aortic stenosis. Bmj. 2008;336(7643):550–5.