Internal thoracic artery graft (ITAG): patency and functional status at rest and during dobutamine-stress echocardiography

FUNDAMENTO: A artéria torácica interna enxertada (ATIE) patente usualmente tem fração diastólica (FD)> 50% do fluxo. O estado funcional pode ser avaliado pelo índice de reserva coronariano (IRC). OBJETIVO: Avaliar, pela ecocardiografia e pelo Doppler em nível supraclavicular, a patência e o estado funcional da ATIE. MÉTODOS: Foram coletados prospectivamente e analisados os dados de 66 pacientes submetidos a ecocardiograma sob estresse com dobutamina (EED). O grupo I (GI) ocorreu com 49 ATIE sem estenose. No grupo II (GII) (10 ATIE) havia estenose significativa (> 50% e 50%, ocorreu em 49 ATIE (GI=40, GII=8 e GIII=1) no repouso e em 61 ATIE (GI=49, GII=10 e GIII=2) durante EED. Sensibilidade, especificidade, valor preditivo positivo (VPP), valor preditivo negativo (VPN) e acurácia foram, respectivamente, em repouso, 81%, 86% ,98%, 35 % e 82%; e no EED, 100%, 71%, 97%, 100% e 97%. As ATIE com FD>50% em repouso estavam patentes e as com FD1,8, isso ocorreu em 42 ATIE (39 do GI, 2 do GII e 1 GIII), verificando-se sensibilidade = 79%; especificidade = 85,7%; VPP = 94%; VPN = 59%; e acurácia = 80,9%. O IRC no GI foi maior (p=0,02) que em GII e GIII. CONCLUSÃO: Em nosso estudo, a avaliação não-invasiva da ATIE foi efetiva para verificar patência e estado funcional. BACKGROUND: The patent internal thoracic artery graft (ITAG) usually has a diastolic fraction (DF) > 50% of the flow. The functional assessment can be evaluated by the coronary reserve index (CRI). OBJECTIVE: The objective was to evaluate the patency and functional status of the ITAG through echocardiography and Doppler. METHODS: Data from sixty-six patients who underwent dobutamine-stress echocardiography (DSE) were prospectively collected and analyzed. Group I (GI) had 49 ITAG without stenosis, Group II (GII), 10 ITAG with significant stenosis (> 50% and 50%, it was observed in 49 ITAG (GI= 40, GII= 8 and GIII= 1) at rest and in 61 ITAG (GI=49, GII=10 and GIII=2) during DSE. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were respectively, 81%, 86%, 98%, 35% and 82%, and 100%, at rest and 71%, 97%, 100% and 97% in the DSE. The ITAG with DF>50% at rest were patent and the ones with DF1.8 for a good functional status, it was observed in 42 ITAG (39 from GI, 2 from GII and 1 from GIII), determining sensitivity=79%, specificity=85.7%, PPV=94%, NPV=59% and accuracy= 80.9%. The CRI in GI was higher (p= 0.02) than in GII or GIII. CONCLUSION: In our study, the non-invasive assessment of the ITAG was effective to verify the patency and the functional status.