Estenose aórtica grave em pacientes assintomáticos - by Fábio Soares

Natural History of Very Severe Aortic Stenosis
Circulation 2010;121;151-156
Gerald Maurer Mundigler, Senta Graf, Jutta Bergler-Klein, Michael Grimm, Harald Gabriel and
Raphael Rosenhek, Robert Zilberszac, Michael Schemper, Martin Czerny, Gerald

Resumo: Esse estudo mostra que pacientes assintomáticos portadores de estenose aórtica (EAo) muito grave avaliada pela velocidade máxima de fluxo pela válvula aótica ([Vmáx] ≥5,0 m/s) têm mau prognóstico, alertando que o sintoma não deve ser considerado com critério essencial para a indicação cirúrgica desses pacientes.

Objetivo - Qual a evolução dos portadores de EAo assintomática grave que não são submetidos diretamente à troca de válvula aórtica (TVAo)?

Métodos: Estudo de coorte que incluiu consecutivamente 116 pacientes assintomáticos (57 mulheres; idade média 67 ± 16 anos) com EAo de alta gravidade ([Vmáx] ≥5,0 m/s) acompanhados de forma prospectiva (Vmáx média 5,37 ± 0,35m/s, área valvar aórtica [AVAo] 0,63 ± 0,12cm2).

Resultados: Durante seguimento médio de 41 meses (período interquartil 26-63 meses), houve 96 eventos (90 paciente tiveram indicação de TVAo e 6 mortes cardíacas). Ao final de 1, 2, 3, 4 e 6 anos de seguimento, a sobrevida livre de eventos foi de 64, 36, 25, 12 e 3%, respectivamente. A Vmáx, e não a AVAo, mostrou associação independente com a sobrevida livre de eventos. A sobrevida livre de eventos em 1, 2, 3 e 4 anos de seguimento foi de 44, 25, 11 e 4%, respectivamente, entre os paciente com Vmáx ≥5,5m/s, e de 76, 43, 33 e 17% para paciente com Vmáx entre 5 e 5,5m/s (p<0,0001). Houve 6 mortes cardíacas nos pacientes previamente assintomáticos (uma morte súbita, 4 por insuficiência cardíaca congestiva e uma por infarto agudo do miocárdio). Os pacientes com Vmáx inicial ≥5,5m/s tiveram uma probabilidade maior (52%) de apresentarem instalação súbita de sintomas graves (NYHA ou CCS >II) em relação àqueles com Vmáx entre 5 e 5,5m/s (27%, p=0,03).

Conclusão: Apesar de assintomáticos, os pacientes com EAo muito grave têm um péssimo prognóstico, com uma alta taxa de eventos e um risco de deterioração funcional rápida. A TVAo eletiva deve ser considerada nesses pacientes.

Valve Surgery for Asymptomatic Patients with Very Severe Aortic Stenosis

Journal Watch Cardiology May 19, 2010

Howard C. Herrmann, MD

Survival was significantly better after surgery than with conventional care in a nonrandomized study.

Current practice guidelines do not recommend aortic valve replacement (AVR) for asymptomatic patients with severe aortic stenosis (AS). However, advances in surgical techniques and prosthetic-valve technology prompted investigators in Korea to compare AVR with conventional care in this population. From 1996 to 2006, they enrolled 197 consecutive asymptomatic patients (mean age, 63; maximum age, 85) with very severe AS (mean peak aortic velocity 4.5 meters/second or mean transaortic pressure gradient 50 mm Hg); 61% had AS of bicuspid or rheumatic etiology. In consultation with their physicians, 95 patients chose conventional care and 102 chose AVR. Patients with left ventricular systolic dysfunction, mitral valve disease, or coronary artery disease were excluded. The researchers used propensity score matching to adjust for baseline differences.

No cases of operative mortality occurred. During a median follow-up of 4.1 years, no cardiac deaths occurred in the surgery group, and cardiac mortality was 19% in the conventional- care group. Significant predictors of cardiac mortality included male sex, aortic valve calcification, and aortic jet velocity 5 meters/second. The estimated actuarial survival rate at 6 years was significantly higher in the surgery group than in the conventional- care group (98% vs. 68%). During follow-up, symptoms developed in 59 conventional- care recipients (62%), 46 of whom then underwent surgery.

Comment: In this group of asymptomatic patients with very severe AS, those who underwent valve replacement had significantly lower cardiac and all-cause mortality than those who received conventional care. About half of the conventionally treated patients developed symptoms and required surgery within 6 years. Before practice guidelines are changed, these findings will need to be confirmed in a randomized trial, as well as in higher-risk patients and in patients with degenerative disease.