Authors’ contributions
The authors of this study participated in the conception and design of the research, data collection, data analysis and interpretation, statistical analysis, manuscript writing and critical review. No funding was received in support of this study.
Conflict of interest
The authors have declared that they have no conflict of interest.
Coronary computed tomography angiography is a noninvasive anatomic test for the diagnosis of coronary artery disease. The coronary fractional flow reserve is the gold standard method to determine if coronary stenosis is hemodynamically significant but requires an invasive procedure. Fractional flow reserve measurement by tomography is a new method to determine the hemodynamic significance of coronary luminal reduction.
To compare the accuracy of the invasive fractional flow reserve with the fractional flow reserve measurement by tomography.
Patients submitted to invasive coronary computed tomography angiography and fractional flow reserve were included in the study. Flow-restricted stenosis was defined by fractional flow reserve measurement by tomography and fractional flow reserve ≤ 0.8, and anatomically significant coronary artery disease was defined as stenosis ≥ 50%. Diagnostic performance of fractional flow reserve measurement by tomography and stenosis by coronary computed tomography angiography was accessed with invasive fractional flow reserve as the gold standard.
Among the patients, 33% had fractional flow reserve ≤0.8. There was no significant difference between the fractional flow reserve measurement by tomography and fractional flow reserve averages (0.87 versus 0.84; p = 0.4). The correlation between the values of the methods was r = 0.77, and concordance was moderate (k = 0.54). When fractional flow reserve ≤ 0.75 was analyzed, the concordance between the methods was absolute. The sensitivity, specificity, positive predictive value and negative predictive value of fractional flow reserve measurement by tomography were, respectively, 50%, 100%, 100% and 75%, for the threshold of 0.8. The mean difference between fractional flow reserve and fractional flow reserve measurement by tomography was -0.033 (95%CI -0.072-0.007), with concordance limits between -0.176 and -0.1111.
Fractional flow reserve measurement by tomography is a new method with high diagnostic performance in the detection of hemodynamically significant coronary stenoses and significantly elevates the specificity of the isolated coronary computed tomography angiography.
A angiotomografia de coronárias é um teste anatômico não invasivo para diagnóstico de doença arterial coronariana. A reserva de fluxo fracionado coronariano é o método padrão-ouro para determinar se a estenose coronariana é hemodinamicamente significativa e requer procedimento invasivo. A mensuração da reserva de fluxo fracionado por tomografia é um novo método para determinar a significância hemodinâmica da redução luminal coronária.
Comparar a acurácia da reserva de fluxo fracionado invasiva com a reserva de fluxo fracionado por tomografia.
Pacientes submetidos à angiotomografia de coronárias e à reserva de fluxo fracionado invasiva foram incluídos neste estudo. Estenose com limitação de fluxo foi definida por reserva de fluxo fracionado por tomografia e reserva de fluxo fracionado ≤ 0,8. Doença arterial coronariana anatomicamente significativa foi definida por estenose ≥ 50%. O desempenho da reserva de fluxo fracionado por tomografia e da estenose pela angiotomografia de coronárias foi acessado com a reserva de fluxo fracionado invasiva como padrão-ouro.
Dentre os pacientes, 33% tinham reserva de fluxo fracionado ≤ 0,8. Não houve diferença significativa entre as médias de reserva de fluxo fracionado por tomografia e reserva de fluxo fracionado (0,87 versus 0,84; p=0,4). A correlação entre os valores dos métodos foi r = 0,77, com concordância moderada (k=0,54). Quando analisada a reserva de fluxo fracionado ≤ 0,75, a concordância entre os métodos foi absoluta. Sensibilidade, especificidade, valor preditivo positivo e negativo da reserva de fluxo fracionado por tomografia foram, respectivamente, 50%, 100%, 100% e 75%, para o limiar de 0,8. A média da diferença entre reserva de fluxo fracionado e reserva de fluxo fracionado por tomografia foi de -0,033 (IC95% -0,072-0,007), com limites de concordância entre -0,176 e -0,111.
A reserva de fluxo fracionado por tomografia é um novo método, com alto desempenho diagnóstico na detecção de estenoses coronárias hemodinamicamente significativas, e eleva significativamente a especificidade da angiotomografia de coronárias isolada.