Índices fisiológicos não hiperêmicos ­ base teórica, aplicações clínicas e limitações / Non-hyperemic pressure ratios ­ theoretical basis, clinical applications, and limitations

A fisiologia coronariana tornou-se o padrão de tratamento para avaliar o significado funcional da doença aterosclerótica coronariana. Ela permite identificar isquemia miocárdica em nível de vaso, discriminar os padrões funcionais da doença aterosclerótica e orientar a necessidade de revascularização; complementar o planejamento da intervenção coronária percutânea e confirmar o sucesso funcional dessa última. Em uma edição anterior do Journal of Transcatheter Interventions, apresentamos uma revisão abrangente sobre o fluxo fracionado de reserva do miocárdio. Apesar do robusto corpo de evidências que apoiam seu uso, a aceitação clínica do fluxo fracionado de reserva é variável e excessivamente baixa em muitas áreas do mundo. O aumento percebido no tempo do procedimento, o uso de agentes hiperêmicos com seus correspondentes custos e desconforto do paciente, e a dificuldade de interpretação dos resultados em determinadas situações anatômicas contribuíram para a adoção limitada do método. A introdução do índice de fluxo instantâneo no período livre de ondas superou a maioria dessas limitações. Apoiada por uma validação técnica sólida e dados de desfechos clínicos, o índice de fluxo instantâneo no período livre de ondas recebeu as mesmas indicações clínicas que o fluxo fracionado de reserva nas recomendações mais recentes das diretrizes. Isso foi seguido pela introdução de outros índices pressóricos não hiperêmicos, já comercialmente disponíveis. Neste artigo, revisamos as bases fisiológicas que justificam o uso de índices pressóricos não hiperêmicos, sua validação técnica e clínica e dados de desfechos clínicos, além de discutirmos suas aplicações em situações anatômicas específicas, com exemplos de casos dos autores, sempre que aplicável.

Coronary physiology has become the standard of care to assess the functional significance of coronary atherosclerotic disease. It allows for identification of myocardial ischemia on a vessel level, discrimination of the functional patterns of atherosclerotic disease, guidance for the need of revascularization, complements the planning of percutaneous coronary intervention and verification of the functional success of percutaneous coronary intervention. On a previous issue of the Journal of Transcatheter Interventions, we presented a comprehensive review about fractional flow reserve. Despite the robust body of evidence supporting its use, the clinical use of fractional flow reserve is variable, and unreasonably low in many areas around the globe. The perceived increase in procedure time, the use of hyperemic agents with its related costs and patient discomfort, and difficulty in interpreting results in certain anatomical scenarios have contributed to the limited adoption of fractional flow reserve. The introduction of instantaneous wave-free ratio overcame most of these limitations. Supported by sound technical validation, and clinical outcomes data, instantaneous wave-free ratio received the same clinical indications as fractional flow reserve in the most recent guidelines recommendations. This was followed by the introduction of other non- hyperemic pressure ratios for commercial use. In the current manuscript we review the physiological basis that supports the use of non-hyperemic pressure ratios, their technical and clinical validation, clinical outcomes data, and discuss its applications on specific anatomic scenarios, with examples of cases from the authors, whenever applicable.

Research progress on image-based calculation of coronary artery fractional flow reserve / 生物医学工程学杂志

Coronary artery fractional flow reserve (FFR) is a critical physiological indicator for assessment of impaired blood flow caused by coronary artery stenosis. The wire-based invasive measurement of blood flow pressure gradient across stenosis is the gold standard for clinical measurement of FFR. However, it has the risk of vascular injury and requires the use of vasodilators, increasing the time and overall cost of interventional examination. Coronary imaging is playing an important role in clinical diagnosis of stenotic lesions, evaluation of severity of lesions, and planning of therapies. In recent years, the computation of FFR based on the physiological information of blood flow obtained from routinely collected coronary image data has become a research focus in this field. This technique reduces the cost of physiological assessment of coronary lesions and the use of pressure wires. It is beneficial to strengthen the physiological guidance in interventional therapy. In order to better understand this emerging technique, this paper highlights its implementation principle and diagnostic performance, analyzes practical problems and current challenges in clinical applications, and discusses possible future development.

Value of fractional flow reserve derived from coronary computed tomographic angiography and plaque quantitative analysis in predicting adverse outcomes of non-obstructive coronary heart disease / 中华危重病急救医学

OBJECTIVE@#To investigate the value of coronary computed tomographic angiography (CCTA)-based fractional flow reserve (CT-FFR) and plaque quantitative analysis in predicting adverse outcomes in patients with non-obstructive coronary heart disease (CAD).@*METHODS@#Clinical data of patients with non-obstructive CAD who underwent CCTA at the Affiliated Hospital of Jiangnan University from March 2014 to March 2018 were retrospectively analyzed and followed up, and the occurrence of major adverse cardiovascular event (MACE) was recorded. The patients were divided into MACE and non-MACE groups according to the occurrence of MACE. The clinical data, CCTA plaque characteristics including plaque length, stenosis degree, minimum lumen area, total plaque volume, non-calcified plaque volume, calcified plaque volume, plaque burden (PB) and remodelling index (RI), and CT-FFR were compared between the two groups. Multivaritate Cox proportional risk model was used to evaluate the relationship between clinical factors, CCTA parameters and MACE. The receiver operator characteristic curve (ROC curve) was used to assess the predictive power of outcome prediction model based on different CCTA parameters.@*RESULTS@#Finally 217 patients were included, of which 43 (19.8%) had MACE and 174 (80.2%) did not. The median follow-up interval was 24 (16, 30) months. The CCTA showed that patients in the MACE group had more severe stenosis than that in the non-MACE group [(44.3±3.8)% vs. (39.5±2.5)%], larger total plaque volume and non-calcified plaque volume [total plaque volume (mm3): 275.1 (197.1, 376.9), non-calcified plaque volume (mm3): 161.5 (114.5, 307.8) vs. 117.9 (77.7, 185.5)], PB and RI were larger [PB: 50.2% (42.1%, 54.8%) vs. 45.1% (38.2%, 51.7%), RI: 1.19 (0.93, 1.29) vs. 1.03 (0.90, 1.22)], CT-FFR value was lower [0.85 (0.80, 0.88) vs. 0.92 (0.87, 0.97)], and the differences were statistically significant (all P < 0.05). Cox regression analysis showed that non-calcified plaques volume [hazard ratio (HR) = 1.005. 95% confidence interval (95%CI) was 1.025-4.866], PB ≥ 50% (HR = 3.146, 95%CI was 1.443-6.906), RI ≥ 1.10 (HR = 2.223, 95%CI was 1.002-1.009) and CT-FFR ≤ 0.87 (HR = 2.615, 95%CI was 1.016-6.732) were independent predictors of MACE (all P < 0.05). The model based on CCTA stenosis degree+CT-FFR+quantitative plaque characteristics (including non-calcified plaque volume, RI, PB) [area under the ROC curve (AUC) = 0.91, 95%CI was 0.87-0.95] had significantly better predictive efficacy for adverse outcomes than the model based on CCTA stenosis degree (AUC = 0.63, 95%CI was 0.54-0.71) and the model based on CCTA stenosis degree+CT-FFR (AUC = 0.71, 95%CI was 0.63-0.79; both P < 0.01).@*CONCLUSIONS@#CT-FFR and plaque quantitative analysis based on CCTA are helpful in predicting adverse outcomes in patients with non-obstructive CAD. Non-calcified plaque volume, RI, PB and CT-FFR are important predictors of MACE. Compared with the prediction model based on stenosis degree and CT-FFR, the combined plaque quantitative index can significantly improve the prediction efficiency of adverse outcomes in patients with non-obstructive CAD.

Evaluación no invasiva de la significancia funcional de las lesiones coronarias mediante quantitative flow ratio (QFR): validación con reserva de flujo fraccional (FFR) / Functional significance of coronary artery lesions evaluated by quantitative flow ratio (QFR): a comparison fractional flow reserve (FFR)

RESUMEN: Introducción: La evaluación de lesiones coronarias mediante Reserva de Flujo Fraccional (FFR), es de elección para determinar su significancia funcional en el laboratorio de hemodinamia. La razón de flujo cuantitativo (Quantitative Flow Ratio, QFR) es una nueva técnica no invasiva para la evaluación de la significancia funcional de una estenosis coronaria, basada en el análisis de flujo a partir de la coronariografía diagnóstica, sin necesidad de hiperemia ni de la introducción de insumos adicionales. Objetivo: evaluar la correlación y valor predictivo del QFR comparado con FFR. Métodos: se seleccionaron arterias que contaban con medición de FFR realizados en nuestro centro y se analizó retrospectivamente el QFR a partir de las coronariografías de dichos estudios. Se excluyó lesiones de tronco y lesiones ostiales. La medición de FFR fue realizada con guía de presión ubicada distal al segmento afectado, mediante hiperemia con adenosina intracoronaria o intravenosa en infusión. Para el análisis de QFR se utilizan 2 proyecciones angiográficas ortogonales del vaso a interrogar con una separación de más de 25º entre ellas; ambas proyecciones deben coincidir en el eje para un correcto análisis. El análisis fue realizado por dos operadores, ciegos al resultado del FFR, utilizando el software QAngioXA (Medis ®, Netherland). Resultados: se analizaron 35 arterias, 57,1% Descendente Anterior (ADA), 20% Circunfleja (ACF) y 20% Derecha (ACD). El FFR promedio fue de 0,83±0,092 y 34,2% tuvieron como resultado un FFR ±0,80. El análisis retrospectivo del QFR se pudo realizar en 27 arterias; en las 8 restantes (22,9%) no fue posible su realización, ya sea por imágenes insuficientes o falta de perpendicularidad del segmento. El QFR promedio fue de 0,81±0,118. Hubo una buena correlación entre QFR y FFR (r =0,758; p0,8 pero QFR±0,8 en 3,7%; y FFR ±0,8 y QFR >0,8 en 3,7%. Así, el QFR tuvo una Sensibilidad: 90,9%, Especificidad: 93,8%; Valor Predictivo Positivo: 90,9%; Valor Predictivo Negativo: 93,8%; Likelihood Ratio Positivo: 14,55 y Likelihood Ratio Negativo: 0,1. La curva ROC mostró un área bajo curva: 0,923; 95% IC: 0,801-1,00. Conclusión: Los resultados del QFR en nuestra serie son similares a las mediciones de FFR. El uso de QFR podría ser una alternativa, rápida, económica y segura, en la evaluación fisiológica de lesiones coronarias. Se requieren mayores estudios clínicos para comprobar estos resultados.

ABSTRACT: Background: FFR is a gold standard used evaluate the severity of coronary artery lesions. QFR is a new non invasive technique for the same purpose based on the analysis of flow directly derived from routine coronary angiography, without additional intervention and with no induction of hyperemia. The aim was to compare the results obtained by QFR to those obtained by FFR in in terms of its predictive value. Method: Retrospective analysis of FFR measurements in routine coronary angiographic studies were compared to results obtained by means of QFR. Main left lesions were excluded. FFR was evaluated using pressure guides across the lesion under hyperemia induced by intracoronary or intravenous adenosine. Two orthogonal projections with no more than 25o difference between them were analyzed. The analysis was performed by two independent and operators blind to the results of FFR. The QAngioXA (Medis ®, Netherland) software was used in the analysis. Results: 35 coronary arteries were analyzed: LAD 57.1%, RCA 20.9%; Cx 20%. QFR was available for 27 arteries, the rest being discarded due to inadequate orientation of the artery. Mean QFR was 0.81 (SD 0.118). Mean difference between QFR and DD FFR was 0,04 (SD 0,006) (NS). Interobserver correlation was good (r=0.95, P 0.07). In only 7.4% of arteries there was a notable though not statistically significant difference between FFR and QFR, either due to under estimation or overestimation of lesion severity by QFR compared to FFR. Using FFR as a gold standard method QFR revealed sensitivity 90.9%, specificity 93.8%, The respective numbers for either positive or negative predictive values were the same. Area under the ROC curve was 0.923 (95% C.I. 0.01-1.00). Conclusion: this study reveals similar results of QFR compared to FFE in the estimation of coronary lesion severity. Given that QFR is a significantly less invasive and less expensive method than FFR, it may lead to an increased use of flow analysis in the determination of coronary artery lesion severity.

Performance Diagnóstica da FFR por Angiotomografia de Coronárias através de Software Baseado em Inteligência Artificial / Diagnostic Performance of a Machine Learning-Based CT-Derived FFR in Detecting Flow-Limiting Stenosis

Resumo Fundamento A quantificação não invasiva da reserva fracionada de fluxo miocárdico (FFR TC ) através de software baseado em inteligência artificial em versão mais atualizada e tomógrafo de última geração (384 cortes) apresenta elevada performance na detecção de isquemia coronariana. Objetivos Avaliar o desempenho diagnóstico da FFR TC na detecção de doença arterial coronariana (DAC) significativa em relação ao FFRi, em tomógrafos de gerações anteriores (128 e 256 cortes). Métodos Estudo retrospectivo com pacientes encaminhados à angiotomografia de artérias coronárias (TCC) e cateterismo (FFRi). Foram utilizados os tomógrafos Siemens Somatom Definition Flash (256 cortes) e AS+ (128 cortes). A FFR TC e a área luminal mínima (ALM) foram avaliadas em software (cFFR versão 3.0.0, Siemens Healthineers, Forchheim, Alemanha). DAC obstrutiva foi definida como TCC com redução luminal ≥50% e DAC funcionalmente obstrutiva como FFRi ≤0,8. Todos os valores de p reportados são bicaudais; e quando <0,05, foram considerados estatisticamente significativos. Resultados Noventa e três pacientes consecutivos (152 vasos) foram incluídos. Houve boa concordância entre FFR TC e FFRi, com mínima superestimação da FFR TC (viés: -0,02; limites de concordância: 0,14 a 0,09). Diferentes tomógrafos não modificaram a relação entre FFR TC e FFRi (p para interação = 0,73). A FFR TC demonstrou performance significativamente superior à classificação visual de estenose coronariana (AUC 0,93 vs. 0,61, p <0,001) e à ALM (AUC 0,93 vs. 0,75, p <0,001) reduzindo o número de casos falso-positivos. O melhor ponto de corte para a FFR TC utilizando um índice de Youden foi de 0,85 (sensiblidade, 87%; especificidade, 86%; VPP, 73%; NPV, 94%), com redução de falso-positivos. Conclusão FFR TC baseada em inteligência artificial, em tomógrafos de gerações anteriores (128 e 256 cortes), apresenta boa performance diagnóstica na detecção de DAC, podendo ser utilizada para reduzir procedimentos invasivos.

Abstract Background The non-invasive quantification of the fractional flow reserve (FFRCT) using a more recent version of an artificial intelligence-based software and latest generation CT scanner (384 slices) may show high performance to detect coronary ischemia. Objectives To evaluate the diagnostic performance of FFRCT for the detection of significant coronary artery disease (CAD) in contrast to invasive FFR (iFFR) using previous generation CT scanners (128 and 256- detector rows). Methods Retrospective study with patients referred to coronary artery CT angiography (CTA) and catheterization (iFFR) procedures. Siemens Somatom Definition Flash (256-detector rows) and AS+ (128-detector rows) CT scanners were used to acquire the images. The FFRCT and the minimal lumen area (MLA) were evaluated using a dedicated software (cFFR version 3.0.0, Siemens Healthineers, Forchheim, Germany). Obstructive CAD was defined as CTA lumen reduction ≥ 50%, and flow-limiting stenosis as iFFR ≤0.8. All reported P values are two-tailed, and when <0.05, they were considered statistically significant. Results Ninety-three consecutive patients (152 vessels) were included. There was good agreement between FFRCT and iFFR, with minimal FFRCT overestimation (bias: -0.02; limits of agreement:0.14-0.09). Different CT scanners did not modify the association between FFRCT and FFRi (p for interaction=0.73). The performance of FFRCT was significantly superior compared to the visual classification of coronary stenosis (AUC 0.93vs.0.61, p<0.001) and to MLA (AUC 0.93vs.0.75, p<0.001), reducing the number of false-positive cases. The optimal cut-off point for FFRCT using a Youden index was 0.85 (87% Sensitivity, 86% Specificity, 73% PPV, 94% NPV), with a reduction of false-positives. Conclusion Machine learning-based FFRCT using previous generation CT scanners (128 and 256-detector rows) shows good diagnostic performance for the detection of CAD, and can be used to reduce the number of invasive procedures.

Análise Comparativa do Padrão de Fluxo de Artérias Coronárias das Hipertrofias Miocárdicas Secundárias e por Mutação Sarcomérica / Comparative Analysis of the Coronary Arteries Flow Pattern in Secondary Myocardial Hypertrophies and by Sarcomeric Mutation

Fundamento: O fluxo coronariano com predomínio diastólico aumenta duas a cinco vezes na hiperemia, mediada por vasodilatação (reserva de fluxo coronariano), podendo, na hipertrofia, ocorrer isquemia relativa. Na hipertrofia secundária, o fluxo em repouso torna-se isquêmico pelo aumento da demanda. Na cardiomiopatia hipertrófica com fibrose perivascular, há funcionalização de vasos colaterais, para aumentar a irrigação dos segmentos hipertrofiados. Objetivo: Determinar o padrão do fluxo coronariano em pacientes com hipertrofia secundária e cardiomiopatia hipertrófica, avaliando a reserva de fluxo coronariano. Métodos: Avaliamos o fluxo coronariano em 34 pacientes com hipertrofia secundária, em 24 com cardiomiopatia hipertrófica e em 16 controles. A artéria descendente anterior foi detectada com Doppler transtorácico com calibração adequada do equipamento. Nos grupos controle e com hipertrofia secundária, foi calculada a reserva de fluxo coronariano com dipiridamol (0,84 mg/kg) endovenoso. O mesmo procedimento foi realizado em seis pacientes do grupo com cardiomiopatia hipertrófica, nos quais também foi avaliado o fluxo das colaterais da região hipertrófica. Os dados foram comparados por variância com significância de 5%. Resultados: Na hipertrofia secundária, houve aumento do índice de massa e, na cardiomiopatia hipertrófica, predominou o aumento da espessura relativa. A fração de ejeção e a disfunção diastólica foram maiores no grupo com cardiomiopatia hipertrófica. A reserva de fluxo coronariano foi menor no grupo com cardiomiopatia hipertrófica, sendo detectado, também, fluxo de colaterais com redução da reserva de fluxo coronariano. Conclusão: A análise da circulação coronariana com Doppler transtorácico é possível em indivíduos normais e hipertróficos. Pacientes com hipertrofia secundária e cardiomiopatia hipertrófica apresentam diminuição da reserva de fluxo coronariano, e aqueles com cardiomiopatia hipertrófica mostram fluxo de vasos colaterais dilatados observados na região hipertrófica, com diminuição da reserva de fluxo coronariano.(AU)

Background: Coronary flow with a diastolic predominance increases two to five times in hyperemia, mediated by vasodilation (coronary flow reserve, CFR) and, in hypertrophy, relative ischemia may occur. In secondary hypertrophy (LVH), the flow, normal at rest, becomes ischemic due to increased demand. In hypertrophic cardiomyopathy (HCM) with perivascular fibrosis, collateral vessels appear to increase the irrigation of hypertrophied segments. Objective: To determine the coronary flow pattern in patients with secondary hypertrophy and hypertrophic cardiomyopathy, evaluating the coronary flow reserve. Methods: Coronary flow was evaluated in 34 patients with secondary hypertrophy, 24 with hypertrophic cardiomyopathy and in 16 controls. The anterior descending artery was detected with transthoracic Doppler with adequate equipment calibration. In the hypertrophic cardiomyopathy group, the flow of collaterals from the hypertrophic region was evaluated. In the control and secondary hypertrophy groups and in six patients in the hypertrophic cardiomyopathy group, the intravenous dipyridamole (0.84 mg) coronary flow reserve was calculated. The data were compared by variance with a significance of 5%Results: In secondary hypertrophy there was an increase in mass index and blood pressure, and in hypertrophic cardiomyopathy an increase in relative thickness predominated. Ejection fraction and diastolic dysfunction were higher in the hypertrophic cardiomyopathy group. The coronary flow reserve was lower in the hypertrophic cardiomyopathy group, and flow of collaterals was also detected, with a reduction in the coronary flow reserve. Conclusion: the analysis of coronary circulation with transthoracic Doppler is possible in normal and hypertrophic individuals. Patients with secondary hypertrophy and hypertrophic cardiomyopathy have a decrease in the coronary flow reserve, and patients with hypertrophic cardiomyopathy show a hyper flow of dilated collateral vessels observed in the hypertrophic region, with a decrease in the coronary flow reserve.(AU)

Cut-off values of lesion and vessel quantitative flow ratio in de novo coronary lesion post-drug-coated balloon therapy predicting vessel restenosis at mid-term follow-up / 中华医学杂志(英文版)

BACKGROUND@#Drug-coated balloons (DCBs) have emerged as potential alternatives to drug-eluting stents in specific lesion subsets for de novo coronary lesions. Quantitative flow ratio (QFR) is a method based on the three-dimensional quantitative coronary angiography and contrast flow velocity during coronary angiography (CAG), obviating the need for an invasive fractional flow reserve procedural. This study aimed to assess the serial angiographic changes of de novo lesions post-DCB therapy and further explore the cut-off values of lesion and vessel QFR, which predict vessel restenosis (diameter stenosis [DS] ≥50%) at mid-term follow-up.@*METHODS@#The data of patients who underwent DCB therapy between January 2014 and December 2019 from the multicenter hospital were retrospectively collected for QFR analysis. From their QFR performances, which were analyzed by CAG images at follow-up, we divided them into two groups: group A, showing target vessel DS ≥50%, and group B, showing target vessel DS <50%. The median follow-up time was 287 days in group A and 227 days in group B. We compared the clinical characteristics, parameters during DCB therapy, and QFR performances, which were analyzed by CAG images between the two groups, in need to explore the cut-off value of lesion/vessel QFR which can predict vessel restenosis. Student's t test was used for the comparison of normally distributed continuous data, Mann-Whitney U test for the comparison of non-normally distributed continuous data, and receiver operating characteristic (ROC) curves for the evaluation of QFR performance which can predict vessel restenosis (DS ≥50%) at mid-term follow-up using the area under the curve (AUC).@*RESULTS@#A total of 112 patients with 112 target vessels were enrolled in this study. Group A had 41 patients, while group B had 71. Vessel QFR and lesion QFR were lower in group A than in group B post-DCB therapy, and the cut-off values of lesion QFR and vessel QFR in the ROC analysis to predict target vessel DS ≥50% post-DCB therapy were 0.905 (AUC, 0.741 [95% confidence interval, CI: 0.645, 0.837]; sensitivity, 0.817; specificity, 0.561; P < 0.001) and 0.890 (AUC, 0.796 [95% CI: 0.709, 0.882]; sensitivity, 0.746; specificity, 0.780; P < 0.001).@*CONCLUSIONS@#The cut-off values of lesion QFR and vessel QFR can assist in predicting the angiographic changes post-DCB therapy. When lesion/vessel QFR values are <0.905/0.890 post-DCB therapy, a higher risk of vessel restenosis is potentially predicted at follow-up.

Effects of Danhong Injection () on Peri-Procedural Myocardial Injury and Microcirculatory Resistance in Patients with Unstable Angina Undergoing Elective Percutaneous Coronary Intervention: A Pilot Randomized Study / 中国结合医学杂志

OBJECTIVE@#To evaluate the effect of Danhong Injection (, DH) on the index of microcirculatory resistance (IMR) and myocardial injury in patients with unstable angina undergoing elective percutaneous coronary intervention (PCI).@*METHODS@#Seventy-eight patients with unstable angina were randomly divided into DH group (39 cases) and the control group (39 cases) during elective PCI. Randomization was performed using a random-number table. The DH group received DH at a dosage of 40 mL (mixed with 250 mL saline, covered by a light-proof bag, intravenous drip) during PCI and daily for 7 consecutive days, while the control group only received the same dosage of saline. Both groups received standardized treatment. The IMR and fractional flow reserve (FFR) were measured at maximal hyperemia before and after PCI. Myocardial markers, including myoglobin, creatine kinase (CK), creatine kinase MB (CK-MB), and coronary troponin T (cTnT) values were measured at baseline and 24 h after PCI.@*RESULTS@#Among the 78 patients enrolled, the baseline and procedural characteristics were similar between the two groups. There was no significant difference in pre-PCI myocardial markers and coronary physiological indexes between the two groups. However, post-PCI CK and CK-MB levels in the DH group were significantly lower than those in the control group (111.97 ± 80.97 vs. 165.47 ± 102.99, P=0.013; 13.08 ± 6.90 vs. 19.75 ± 15.49, P=0.016). Post-PCI myoglobin and cTNT-positive tend to be lower in the DH group than in the control group but did not reach statistical significance (88.07 ± 52.36 vs. 108.13 ± 90.94, P=0.52; 2.56% vs.7.69%, P=0.065). Compared with the control group, the post-IMR levels of the DH group tended to decrease, but there was no statistical difference (20.73 ± 13.15 vs. 26.37 ± 12.31, P=0.05). There were no statistical differences in post-FFR in both groups. The peri-procedural myocardial injury of the DH group was significantly lower than that of the control group (2.56% vs. 15.38%, P=0.025). During the 30-d follow-up period, no major adverse cardiovascular events occurred in either group.@*CONCLUSION@#This study demonstrated benefit of DH in reducing myocardial injury and potential preserving microvascular function in patients with unstable angina undergoing elective PCI.

Estimación no invasiva de la reserva fraccional de flujo coronario (vFFR): Concepto y utilidad de una nueva herramienta para la detección de isquemia miocárdica en el arsenal de la cardiología intervencionista / Non-invasive estimation of the coronary flow fractional reserve (VFFR): concept and utility of a new tool for the detection of myocardial ischemia in the arsenal of interventional cardiology

[RESUMEN]: La reserva fraccional de flujo coronario o FFR es en la actualidad el estándar de oro para evaluar la gravedad de las estenosis coronarias. A pesar de evidencias indiscutibles la adopción en la práctica diaria ha sido muy limitada debido a diferentes motivos. El desarrollo de nuevas tecnologías como el FFR derivado del angiograma coronario o vFFR, un nuevo método basado en imágenes para calcular el FFR sin una cuerda de presión coronaria o un agente hiperémico, ayudaría a incrementar el uso de la fisiología coronaria en las salas de homodinamia. Aquí presentamos 4 casos de la primera experiencia con vFFR realizada en el Hospital de Alta Complejidad El Cruce - SAMIC - Dr. Néstor C. Kirchner.

[ABSTRACT]: Fractional flow reserve or FFR is currently the gold standard for assessing the severity of coronary stenosis. Despite indisputable evidence, adoption in daily practice has been very limited due to different reasons. The development of new technologies such as the FFR derived from coronary angiogram or vFFR, a new image-based method to calculate the FFR without a coronary pressure guidewire or a hyperemic agent, would help increase the use of coronary physiology in hemodynamic rooms. We present 4 cases from the first experience with vFFR carried out at the Hospital de Alta Complejidad El Cruce - SAMIC - Dr. Néstor C. Kirchner.

Manejo percutáneo de infarto con elevación del ST sin colocación de stent: reporte de un caso / Percutaneous management of ST elevation myocardial infarction without stent placement: a case report

Resumen Reportamos el caso de manejo percutáneo de un infarto agudo al miocardio utilizando una combinación atípica de estrategias cuyo resultado fue seguro y costoefectivo, que consistió en tromboaspiración, angioplastía con balón y utilización de la reserva fraccional de flujo para descartar la necesidad de colocación de stent.

Abstract Percutaneous management of ST elevation myocardial infarction without stent placement : a case report We herein report the case of percutaneous management of an acute myocardial infarction using an atypical combination of strategies whose outcome was safe and costeffective, which consisted of thrombus aspiration, balloon angioplasty and use of fractional flow reserve to rule out the need for stent placement.

Diagnostic Accuracy of a Novel On-site Virtual Fractional Flow Reserve Parallel Computing System

Research Progress in Fractional Flow Reserve / 中国医疗器械杂志

Coronary atherosclerotic heart disease is a heart disease caused by coronary artery stenosis or obstruction, resulting in myocardial ischemia, hypoxia or necrosis. Its examination methods include electrocardiogram, hematological examination, coronary CT, coronary angiography and intravascular imaging technology, etc. In recent years, blood Fractional Flow Reserve(FFR) has been widely used to measure the degree of coronary artery stenosis in the treatment of coronary heart disease. Based on the related literature at home and abroad, elaborated the FFR measurements of coronary artery stenosis degree background significance, basic principle and implementation method, on the basis of inductive expounds the FFR examination of clinical research and the advantages and disadvantages, at the same time a preliminary prospect on the development of technology of FFR iFR-the future instantaneous waveform ratio and the functional SYNTAX score has a broad space for development.

Beneficio económico en la utilización de reserva fraccional de flujo en lesiones coronarias intermedias y su impacto clínico a un año / Economic benefits of fractional flow reserve utilization on intermediate lesions and its clinical impact after one year-follow up

Resumen Antecedentes: La reserva de flujo fraccional (FFR) es una herramienta con evidencia demostrada para guiar las angioplastias coronarias. El reembolso por los sistemas de cobertura de salud es parcial o nulo a pesar de frecuentemente diferir la angioplastia. Nuestro objetivo fue determinar el beneficio económico de la utilización del FFR en la evaluación de lesiones intermedias, y evaluar asimismo puntos finales clínicos en el seguimiento a un año. Métodos: Estudio observacional prospectivo que incluyó una cohorte de pacientes consecutivos con lesiones coronarias intermedias, evaluadas con FFR, entre abril de 2013 y marzo de 2016. Para el análisis económico se evaluaron los recursos específicos utilizados para la realización del procedimiento. Se analizaron puntos finales clínicos (muerte cardiovascular, revascularización de la arteria objetivo e infarto agudo de miocardio) durante la internación y en el seguimiento a un año Resultados: Se incluyeron 222 lesiones en 151 pacientes consecutivos. Se registró FFR positivo en el 26.1% de las lesiones evaluadas. Se estimó que sin la utilización de FFR, 126 pacientes hubieran sido tratados con angioplastia transluminal coronaria y 25 con cirugía de revascularización miocárdica. El costo estimado con la utilización de FFR fue US$ 891,290.08, mientras que sin el mismo hubiera sido de US$ 1,557,352. Esto implicó un ahorro del 43% de los gastos. Se observaron una muerte de origen cardiovascular y dos reinternaciones en el grupo FFR positivo en el seguimiento a un año. Conclusiones: La revascularización de lesiones intermedias guiada por FFR resultó en un beneficio económico al reducir los costos generales sin resultar clínicamente perjudicial.

Abstract Background: Fractional flow reserve (FFR) is a proven technology for guiding percutaneous coronary intervention, but it is not reimbursed despite the fact that it frequently allows to defer revascularization. Our goal was to determine the economic benefit of FFR on intermediate lesions, as well as the clinical endpoints at 1 year follow up. Methods: Observational prospective study that included consecutive patients with intermediate lesions evaluated with FFR between April 2013 and March 2016. For the economic analysis we evaluated the specific resources used during the procedure. Clinical endpoints including cardiovascular death, target lesion revascularization and acute myocardial infarction, were followed up over a one-year period. Results: FFR was performed on 222 lesions in 151 consecutive patients. FFR was positive in 26.1% of the assessed lesions. The estimated total cost using FFR was US$ 891,290.08 while cost estimate without FFR was US$ 1,557,352, meaning 43% in cost savings. There was one cardiovascular death and two readmissions during follow up in the positive FFR group. Conclusions: FFR guided revascularization on intermediate coronary lesions resulted in an economic benefit by reducing overall costs without harming clinical outcomes.

Invasive Coronary Physiological Assessment in Symptomatic Middle-Aged Endurance Athletes

Despite the health benefits of routine exercise, coronary artery disease (CAD) is common among older competitive athletes and is an important cause of sudden cardiac death. Athletes with suspected or confirmed CAD routinely undergo conventional coronary angiography involving the performance of invasive coronary physiological assessment using the fractional flow reserve (FFR) or the instantaneous-wave free ratio (iFR). Data defining the role of invasive coronary physiological assessment, while robust in general clinical populations, are untested among older competitive athletes with CAD. The paper discusses the challenges and uncertainties surrounding the use of the FFR and iFR in this unique population with an emphasis on the need for future work to better define this approach

Diagnostic performance of qfr for the evaluation of intermediate coronary artery stenosis confirmed by fractional flow reserve

Abstract Introduction: Quantitative flow ratio (QFR) is a novel method enabling efficient computation of FFR from three-dimensional quantitative coronary angiography (3D QCA) and thrombolysis in myocardial infarction (TIMI) frame counting. We decided to perform a systematic review and quantitative meta-analysis of the literature to determine the correlation between the diagnosis of functionally significant stenosis obtained by QFR versus FFR and to determine the diagnostic accuracy of QFR for intermediate coronary artery stenosis. Methods: We searched PubMed, Embase, and Web of Science for studies concerning the diagnostic performance of QFR. Our meta-analysis was performed using the DerSimonian and Laird random effects model to determine sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR). The sROC was used to determine diagnostic test accuracy. Results: Nine studies consisting of 1175 vessels in 1047 patients were included in our study. The pooled sensitivity, specificity, LR+, LR-, and DOR for QFR were 0.89 (95% CI: 0.86-0.92), 0.88 (95% CI: 0.86-0.91), 6.86 (95% CI,: 5.22-9.02), 0.14 (95% CI: 0.10-0.21), and 53.05 (95% CI: 29.75-94.58), respectively. The area under the summary receiver operating characteristic (sROC) curve for QFR was 0.94. Conclusion: QFR is a simple, useful, and noninvasive modality for diagnosis of functional significance of intermediate coronary artery stenosis.

Clinical Outcomes and Cost-Effectiveness Analysis of FFR Compared with Angiography in Multivessel Disease Patient / Impacto Clínico e Custo-Efetividade da FFR em Comparação à Angiografia em Pacientes com Doenças Multiarteriais Submetidos à ICP

Abstract Background: In multivessel disease patients with moderate stenosis, fractional flow reserve (FFR) allows the analysis of the lesions and guides treatment, and could contribute to the cost-effectiveness (CE) of non-pharmacological stents (NPS). Objectives: To evaluate CE and clinical impact of FFR-guided versus angiography-guided angioplasty (ANGIO) in multivessel patients using NPS. Methods: Multivessel disease patients were prospectively randomized to FFR or ANGIO groups during a 5 year-period and followed for < 12 months. Outcomes measures were major adverse cardiac events (MACE), restenosis and CE. Results: We studied 69 patients, 47 (68.1%) men, aged 62.0 ± 9.0 years, 34 (49.2%) in FFR group and 53 (50.7%) in ANGIO group, with stable angina or acute coronary syndrome. In FFR, there were 26 patients with biarterial disease (76.5%) and 8 (23.5%) with triarterial disease, and in ANGIO, 24 (68.6%) with biarterial and 11 (31.4%) with triarterial disease. Twelve MACEs were observed - 3 deaths: 2 (5.8%) in FFR and 1 (2.8%) in ANGIO, 9 (13.0%) angina: 4(11.7%) in FFR and 5(14.2%) in ANGIO, 6 restenosis: 2(5.8%) in FFR and 4 (11.4%) in ANGIO. Angiography detected 87(53.0%) lesions in FFR, 39(23.7%) with PCI and 48(29.3%) with medical treatment; and 77 (47.0%) lesions in ANGIO, all treated with angioplasty. Thirty-nine (33.3%) stents were registered in FFR (0.45 ± 0.50 stents/lesion) and 78 (1.05 ± 0.22 stents/lesion) in ANGIO (p = 0.0001), 51.4% greater in ANGIO than FFR. CE analysis revealed a cost of BRL 5,045.97 BRL 5,430.60 in ANGIO and FFR, respectively. The difference of effectiveness was of 1.82%. Conclusion: FFR reduced the number of lesions treated and stents, and the need for target-lesion revascularization, with a CE comparable with that of angiography.

Resumo Fundamentos: Em pacientes multiarteriais e lesões moderadas, a reserva de fluxo fracionada (FFR) avalia cada lesão e direciona o tratamento, podendo ser útil no custo-efetividade (CE) de implante de stents não farmacológicos (SNF). Objetivos: Avaliar CE e impacto clínico da angioplastia + FFR versus angioplastia + angiografia (ANGIO), em multiarteriais, utilizando SNF. Métodos: pacientes com doença multiarteriais foram randomizados prospectivamente durante ±5 anos para FFR ou ANGIO, e acompanhados por até 12 meses. Foram avaliados eventos cardíacos maiores (ECAM), reestenose e CE. Resultados: foram incluídos 69 pacientes, 47(68,1%) homens, 34(49,2%) no FFR e 35(50,7%) no ANGIO, idade 62,0 ± 9,0 anos, com angina estável e Síndrome Coronariana Aguda estabilizada. No FFR, havia 26 com doença (76,5%) biarterial e 8 (23,5%) triarterial, e no grupo ANGIO, 24(68,6%) biarteriais e 11(31,4%) triarteriais. Ocorreram 12(17,3%) ECAM - 3(4,3%) óbitos: 2(5,8%) no FFR e 1(2,8%) no ANGIO, 9(13,0%) anginas, 4(11,7%) no FFR e 5(14,2%) no ANGIO, 6 reestenoses: 2(5,8%) no FFR e 4 (11,4%) no ANGIO. Angiografia detectou 87(53,0%) lesões no FFR, 39(23,7%) com ICP e 48(29,3%) com tratamento clínico; e 77(47,0%) lesões no ANGIO, todas submetidas à angioplastia. Quanto aos stents, registrou-se 39(33,3%) (0,45 ± 0,50 stents/lesão) no FFR e 78(66,6%) (1,05 ± 0,22 stents/lesão) no ANGIO (p = 0,0001); ANGIO utilizou 51,4% a mais que o FFR. Análise de CE revelou um custo de R$5045,97 e R$5.430,60 nos grupos ANGIO e FFR, respectivamente. A diferença de efetividade foi 1,82%. Conclusões: FFR diminuiu o número de lesões tratadas e de stents e necessidade de revascularização do vaso-alvo, com CE comparável ao da angiografia.