Analysis of the correlation between body mass index and coronary flow reserve in patients with chest pain and no obstructive coronary artery disease / 中华内分泌代谢杂志

Objective:To explore the correlation between body mass index(BMI)and coronary flow reserve(CFR)in patients with chest pain and no obstructive coronary artery disease(NOCA).Methods:This study was a single-center retrospective cross-sectional study. Sixty-six patients with chest pain and NOCA on coronary angiography who underwent PET/CT quantitative myocardial blood flow measurements at TEDA International Cardiovascular Hospital were retrospectively analyzed from August 2018 to October 2019. Pearson correlation analysis and linear regression analysis were used to explore the correlation between BMI and CFR. Patients were divided into 2 groups according to CFR: coronary microvascular dysfunction(CMD)group(CFR<2.5)and control group(CFR≥2.5). Logistic regression analysis was applied to analyze the association of BMI with CMD.Results:The proportions of female, obesity, and overweight plus obesity in CMD group were higher than those in control group( P<0.05). The levels of BMI and low density lipoprotein-cholesterol(LDL-C)were higher in CMD group compared with control group( P<0.05). Pearson correlation analysis showed that CFR was linearly correlated with BMI( r=-0.45, P<0.01), which still existed after adjusted by confounding factors using linear regression model( r=-0.371, P<0.01). Logistic regression analysis showed that BMI was dependently associated with CMD after adjusted by gender, age, hypertension, diabetic mellitus, and LDL-C. The OR value of CMD was 4.46(95% CI 1.47-13.55, P<0.01)with BMI increased by 5 kg/m 2. Conclusion:In patients with chest pain and NOCA, higher BMI is an independent risk factor of CMD.

Value of absolute quantification of myocardial perfusion by PET in detecting coronary microvascular disease in patients with non-obstructive coronaries / 中华心血管病杂志

Objective: To compare the incidence of coronary microvascular disease (CMVD) between patients with non-obstructive and obstructive coronary arteries. Methods: We retrospectively analyzed 97 patients with angina pectoris, who underwent the absolute quantitative PET examination of myocardial perfusion and coronary anatomy examination within 90 days. All patients were divided into two groups: non-obstructive group (72 cases, no stenosis ≥50% in all three coronary arteries) and obstructive group (25 cases, at least one coronary stenosis ≥50%; and at least one coronary stenosis<50%). Quantitative parameters derived from PET including rest myocardial blood flow (RMBF), stress myocardial blood flow (SMBF), coronary flow reserve (CFR) and cardiovascular risk factors were compared between the two groups. CMVD was defined as CFR<2.90 and SMBF<2.17 ml·min(-1)·g(-1). Results: Incidence of CMVD was significant higher in the non-obstructive coronary arteries of the obstructive group than in the non-obstructive coronary arteries of non-obstructive group (47.1% (16/34) vs. 25.5% (55/216), χ(2)=6.738, P=0.009) while incidence of CMVD was similar between non-obstructive and obstructive patients ((44% (11/25) vs. 33.3% (24/72), χ(2)=0.915, P=0.339). RMBF ((0.83±0.14) ml·min(-1)·g(-1) vs. (0.82±0.17) ml·min(-1)·g(-1)), SMBF ((2.13±0.60) ml·min(-1)·g(-1) vs. (1.91±0.50) ml·min(-1)·g(-1)) and CFR (2.59±0.66 vs. 2.36±0.47) were similar between the two groups (all P>0.05). Conclusions: CMVD can occur in non-obstructive coronary arteries in both patients with non-occlusive coronary arteries and patients with obstructive coronary arteries. Prevalence of CMVD is significantly higher in patients with obstructive coronary arteries than in patients with non-obstructive coronary arteries. The CMVD severity is similar between the two groups.

Clinical value of non-invasive coronary flow reserve to evaluate the curative effect of percutaneous coronary intervention for patients with unstable angina pectoris / 中华超声影像学杂志

Objective To evaluate the value of non-invasive coronary flow reserve ( CFR ) for investigating the relationship between myocardial ischemia and coronary stenosis ,and the result after percutaneous coronary intervention ( PCI) in patients with unstable angina pectoris . Methods The rest blood flow spectrum and the maximum coronary diastolic blood flow spectrum were obtained respectively for 131 coronary artery lesions including the left anterior descending coronary artery ,the left circumflex coronary artery and the right coronary artery in 86 patients from the coronary artery flow imaging of transthoracic Doppler echocardiography ,then CFR was calculated . All patients were performed by coronary angiography . Patients with the rate of coronary stenosis > 70％ and CFR ≤ 2 .0 were treated by PCI . CFR was measured again at different intervals after PCI . Results ① As the degree of stenosis increased ,CFR decreased gradually .The coronary stenosis was negatively correlated with CFR ( r = - 0 .803 , P < 0 .001) . The sensitivity of CFR ≤ 2 .0 predicting coronary stenosis rate of more than 70％ was 82 .7％ ,the specificity was 87 .7％ . ② CFR of post-PCI was higher than that of per-PCI . With a follow-up of half a year ,CFR of all coronary arteries was greater than 2 .0(44/44) ,but restenosis occurred at one year after PCI in two left anterior descending coronary arteries . Conclusions Non-invasive CFR can evaluate the relationship between myocardial ischemia and coronary stenosis ,select indications for PCI and evaluate postoperative outcome for patients with unstable angina pectoris .

Efficacy of FFR-guided PCI in Coronary Artery Disease Patients With SYNTAX score≥33 Unsuitable for CABG: A Single-center Clinical Observation / 中国循环杂志

Objective: To observe the short- and long-term clinical outcomes of fraction flow reserve (FFR)-guided percutaneous coronary intervention (PCI) in coronary artery disease (CAD) patients with SYNTAX score≥33 unsuitable for coronary artery bypass grafting (CABG). Methods: A total of 117 CAD patients admitted in our hospital from 2012-01 to 2015-06 were enrolled. Since SYNTAX score≥33, EuroSCORE>6, the patients were unsuitable for CABG and treated in 2 groups: Medication group, n=20 and PCI group, during FFR-guided PCI procedure, patients received ROTA or IVUS according to physician's experience, n=97. All patients were followed-up for at least 12 months. Meanwhile, taking "coronary stent and bypass", "CABG and PCI" as key words, we searched relevant documents in VIP Chinese science and technology journal full-text database, WanFang medical database, ChinaNet and Chinese biomedical literature database from 2012-01-01 to 2015-12-31, patients' outcomes were compared with the above references to explore the clinical benefit. Results: ① PCI group and Medication group had similar SYNTAX score and EuroSCORE, P>0.05. The common pathogenesis was LAD involvement, chronic occlusion was 31.3% (5/16) in patients with partial revascularization.②PCI group had 18.6% (18/97) incidence of major adverse cardiac and cerebral events (MACCE), 2 patients died during follow-up period and 9 received revascularization; Medication group had 60% (12/20) incidence of MACCE, 3 patients died during follow-up period; the difference between 2 groups showed statistical meaning, P<0.05.③There were 22 relevant documents retrieved as comparison; in our research, PCI group had similar incidence of MACCE to the documents, P>0.05; Medication group had increased incidence of MACCE than the documents, P<0.05. Conclusion: FFR-guided PCI could bring clinical benefit in CAD patients with SYNTAX score≥33 unsuitable for CABG.

Coronary Flow Reserve in Non-Infarcted Myocardium Predicts Long-Term Clinical Outcomes in Patients Undergoing Percutaneous Coronary Intervention

PURPOSE: Coronary flow reserve (CFR) is recognized as an indicator of myocardial perfusion. The aim of this study was to assess the relationship between CFR in the non-infarcted myocardium and the incidence of major adverse cardiac events (MACEs). MATERIALS AND METHODS: 100 consecutive patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI) were enrolled in the present study, and divided into MACE and non-MACE groups according to the incidence of 12-month MACEs. Left ventricular function and CFR were analyzed using two-dimensional echocardiography and myocardial contrast echocardiography at one week after PCI. Cardiac troponin I levels were assayed to estimate peak concentrations thereof. RESULTS: The MACE group was associated with lower CFR, compared to the non-MACE group (2.41 vs. 2.77, p < 0.001). In the multivariable model, CFR in the non-infarcted myocardium was an independent predictor of 12-month MACE (hazard ratio: 0.093, 95% confidence interval: 0.020–0.426, p=0.002) after adjustment for baseline demographic and clinical characteristics. CONCLUSION: CFR in the non-infarcted myocardium is a useful marker for predicting 12-month MACEs in patients with AMI undergoing primary PCI.

Coronary microvascular resistance and its relevant factors in patients with moderate coronary stenosis and chest pain / 中华内科杂志

Objective To evaluate the impact of cardiovascular risk factors on index of microvascular resistance (IMR)and coronary flow reserve (CFR) and to explore the characteristics of IMR and CFR and the relationship between IMR and angiographic features in patients with intermediate coronary stenosis and chest pain.Methods Fractional flow reserve (FFR),CFR,and IMR were measured in patients who underwent invasive coronary angiography with 40％-70％ stenosis by visual assessment.All patients with FFR＞0.75 were enrolled and grouped with the cut-off points of IMR≥25 and CFR≤2.0.Patients with IMR≥25 were group H,including two sub-groups (high IMR-low CFR,group H1 and high IMR-high CFR,group H2),while those with IMR＜25 were group N.The thrombolysis in myocardial infarction (TIMI) frame were counted.Results A total of 34 patients with FFR＞0.75 were enrolled with 61.8％(21 cases) of males and 38.2％ (13 cases) of females.The mean age was (57.3±8.1) years old.High IMR accounted for 47.1％ of all cases.There was significant difference between group H and N in TIMI frame (33.0 vs.20.8,P=0.031).There were significant differences between group H1 and H2 in homocysteine (17.8 μmol/L vs.12.0 μmol/L,P=0.005) and IMRcorr (58.0 vs.36.1,P=0.002).IMRcorrwas correlated to TIMI frame (r=0.40,P=0.012) for all cases.The sensitivity and specificity of inferring IMR≥35.3 by TIMI frame were 0.75 and 0.65 (P=0.049) with TIMI frame over 40.5.Conclusions High IMR may be one of the reasons for chest pain in patients with intermediate coronary stenosis.There is no correlation between vascular risk factors and IMR or CFR,while there is positive correlation between TIMI frame and IMR.The specificity is 65％ for inferring IMR rise with TIMI frame over 40.5.

Impact of high serum Immunoglobulin E levels on the risk of atherosclerosis in humans

BACKGROUND: Epidemiological studies show that immunoglobulin E (IgE) levels were higher in subjects with acute coronary events. However, it is unknown if the increased IgE level is a marker of future coronary incidents and whether it may be regarded as a risk factor of an ischemic heart disease. OBJECTIVE: Our aim was to investigate the relationship between IgE levels and some atherosclerotic markers in patients without known atherosclerotic disease. METHODS: Fifty patients (mean age, 40.96 ± 10.8 years) with high serum IgE levels due to various conditions who did not display evidence of an atherosclerotic disease and 30 healthy control subjects (mean age, 47 ± 8.27 years) were included in the study. Atherosclerotic disease markers including adhesion molecules like vascular cell adhesion molecule-1, intercellular adhesion molecule-1, proinflammatory cytokines such as interleukin-6, endothelin-1, and systemic inflammatory markers such as high sensitivity C-reactive protein were determined by enzyme-linked immunosorbent assay (ELISA). Endothelial functions of the coronary arteries were determined by coronary flow reserve (CFR) measurements and carotid intima media thickness using transthoracic Doppler echocardiography.

Physiologic Evaluation of Microvascular Damage in Culprit Vessel After Successful Primary Percutaneous Coronary Intervention for ST-elevation Myocardial Infarction Patients

We investigated the importance of comprehensive physiologic assessment about culprit vessel in STEMI in estimating long-term clinical outcomes after complete revascularization. Comprehensive physiologic assessment provides additional information about microvascular function in coronary artery disease. This assessment includes three indices, fractional flow reserve (FFR), index of microcirculatory resistance (IMR) and coronary flow reserve (CFR). We have performed the comprehensive physiologic assessment in culprit vessels after successful primary PCI in STEMI patients. Both cases were thrombotic total occlusion in mid right coronary artery with inferior wall STEMI, successfully revascularized with stent implantation after thrombus suction. However, in post PCI physiologic assessment, one case showed overt microvascular damage. CFR was 1.1, and IMR was 75U, which was defined as a combined criterion of low CFR (<2.0) and high IMR (≥25U) in culprit vessel, but the other case showed 2.2 in CFR and 24U in IMR, which suggested no overt microvascular damage. Moreover, we can validate these findings by cardiac MR after primary PCI. Previous studies presented that the presence of overt microvascular damage was significantly associated with worse clinical outcome in patients with coronary artery disease. We suggest that comprehensive physiologic evaluation provides important information about the degree of microvascular damage and long-term clinical outcomes after complete revascularization in culprit vessel in STEMI.

Effects ofYiqi Shuxin Pills on Coronary Flow Reserve of Patients with Acute Coronary Syndrome in Coronary Angiography / 中国中医药信息杂志

Objective To observe the effects ofYiqi Shuxin Pills on the coronary flow reserve (CFR) of patients with acute coronary syndrome (ACS) in the coronary angiography (CAG); To discuss its relevant mechanism of action.Methods Totally 101 patients with ACS were divided into control group (49 cases) and treatment group (52 cases). Patients in the treatment group were treated with western therapy andYiqi Shuxin Pills, while patients in the control group were treated with western therapy only. After treated for 6 months, CAG was reviewed to compare the CFR in both groups before and after the treatment. The blood-stasis syndrome and qi-deficiency syndrome scores and the level of NO, ET-1, hs-CRP, sVCAM-1, P-selectin in blood of both groups before and after the treatment were observed.Results The blood-stasis syndrome and qi-deficiency syndrome scores in the treatment group were significantly lower than those in the control group (P<0.01); The levels of ET-1, hs-CRP, sVCAM-1, P-selectin were obviously reduced and NO obviously increased in treatment group than those of control group (P<0.05). The CFR in the treatment group was significantly better than that of control group, with statistical significance (P<0.05). ConclusionYiqi Shuxin Pills can improve the state of blood-stasis syndrome and qi-deficiency syndrome, improve vascular endothelial function, relieve inflammatory reaction, lower the expression of platelet, stabilize atherosclerotic plaque of coronary artery, and then improve the CFR of ACS patients in CAG.

Myocardial blood flow assessment with 82rubidium-PET imaging in patients with left bundle branch block

OBJECTIVES: Perfusion abnormalities are frequently seen in Single Photon Emission Computed Tomography (SPECT) when a left bundle branch block is present. A few studies have shown decreased coronary flow reserve in the left anterior descending territory, regardless of the presence of coronary artery disease. OBJECTIVE: We sought to investigate rubidium-82 (82Rb) positron emission tomography imaging in the assessment of myocardial blood flow and coronary flow reserve in patients with left bundle branch block. METHODS: Thirty-eight patients with left bundle branch block (GI), median age 63.5 years, 22 (58%) female, 12 with coronary artery disease (≥70%; GI-A) and 26 with no evidence of significant coronary artery disease (GI-B), underwent rest-dipyridamole stress 82Rb-positron emission tomography with absolute quantitative flow measurements using Cedars-Sinai software (mL/min/g). The relative myocardial perfusion and left ventricular ejection fraction were assessed in 17 segments. These parameters were compared with those obtained from 30 patients with normal 82Rb-positron emission tomography studies and without left bundle branch block (GII). RESULTS: Stress myocardial blood flow and coronary flow reserve were significantly lower in GI than in GII (p<0.05). The comparison of coronary flow reserve between GI-A and GI-B showed that it was different from the global coronary flow reserve (p<0.05) and the stress flow was significantly lower in the anterior than in the septal wall for both groups. Perfusion abnormalities were more prevalent in GI-A (p=0.06) and the left ventricular ejection fraction was not different between GI-A and GI-B, whereas it was lower in GI than in GII (p<0.001). CONCLUSION: The data confirm that patients with left bundle branch block had decreased myocardial blood flow and coronary flow reserve and coronary flow reserve assessed by 82Rb-positron emission tomography imaging may be useful in identifying coronary artery disease in patients with left bundle branch block.

Association of coronary flow reserve by dipyridamole technetium-99m sestamibi single photon emission computed tomography with perfusion findings and risk factors for coronary artery disease

BACKGROUND: Blunting of coronary flow reserve (CFR) may precede overt ischemia. The study aimed to correlate CFR with perfusion findings and risk factors for coronary artery disease (CAD).METHODS: Fifty-four consecutive patients underwent dipyridamole-rest technetium-99m sestamibi single photon emission computed tomography (SPECT) on two separate days. CFR was computed as the quotient of myocardial blood flow (MBF= global tissue perfusion divided by arterial input function) at stress and at rest.RESULTS: CFR was significantly lower in patients with abnormal perfusion vs normals (p=0.005). Reduced CFR was noted in 83% of patients with normal SPECT. Lower CFR was seen in hypertensive patients with left ventricular hypertrophy (LVH) compared to those without LVH (p=0.029); likewise in DM vs no DM (p=0.121). Independent predictors of reduced CFR were age and extent of ischemia. CONCLUSION: Abnormal perfusion is associated with reduced CFR. In those with normal perfusion, there is a high prevalence of reduced CFR, which may be attributed to the presence of risk factors for CAD and LVH.

Association between Cardiac Troponin Level and Coronary Flow Reserve in Patients without Coronary Artery Disease: Insight from a Thermodilution Technique Using an Intracoronary Pressure Wire

BACKGROUND AND OBJECTIVES: Cardiac troponins are associated with increased mortality, even among patients with no coronary artery disease. Elevated cardiac troponin levels are frequently observed in patients without significant coronary lesions, although the mechanism underlying this finding is unclear. The aim of our study was to evaluate the association between the levels of cardiac troponin and coronary flow reserve (CFR). SUBJECTS AND METHODS: We evaluated serum cardiac troponin-I in 19 patients (9 female; age 61.9+/-10.9 year-old). All patients had an ejection fraction >40% and angiographically normal coronary arteries. Simultaneous measurements of fractional flow reserve (FFR), the index of microcirculatory resistance (IMR), and CFR measurements using an intracoronary temperature- and pressure-sensing guidewire under basal conditions and during maximal hyperemia were performed in three vessels: the left anterior descending artery (LAD), left circumflex artery (LCX) and right coronary artery (RCA). RESULTS: All patients were followed for a median of 13 months. FFR, IMR, and CFR measurements were performed successfully in all subjects. Mean CFRs of LAD, LCX, and RCA were 1.98+/-1.20, 2.75+/-2.11, and 4.44+/-2.51, respectively. Mean IMRs of LAD, LCX and RCA were 33.28+/-18.78, 29.11+/-26.70, and 30.55+/-23.65, respectively. There was a poor correlation between CFR and troponin-I values in each vessel. In selecting the lowest value of CFR in each patient as the corresponding value, the lowest CFR was not associated with troponin-I levels (r=-0.219, p=0.367). CONCLUSION: In patients without significant coronary lesions, the correlation between CFR and troponin-I level was not significant using a thermodilution technique. Further study of a larger population with longer-term follow-up may be needed to more fully understand microvascular dysfunction.

Experiencia con Ecocardiograma de estrés dipiridamol y Reserva coronaria no invasiva: Comunicación preliminar / Dipyridamol Stress Echocardiography and Non-invasive Coronary Reserve: Preliminary report

Antecedentes: El Ecocardiograma de Estrés (EE) es una técnica ampliamente utilizada en el estudio de pacientes con Enfermedad Coronaria conocida o sospechada Recientemente se ha preconizado efectuar el test vasodilatador, método recomendado para evaluar no invasivamente la reserva de flujo coronario (RFC). Objetivos: Mostrar la experiencia preliminar con el EE Dipiridamol, con un seguimiento inicial, así como el estudio de la RFC en la porción distal de la arteria Descendente Anterior (ADA). Métodos: Se analizaron 164 pacientes (101 hombres, edad promedio 65 años) a los que se les efectuó un EE Dipiridamol entre Julio 2011 y Septiembre 2012, con una dosis de 0.84mg/kg en 6 minutos, que incluyó el estudio de RFC. Todos los pacientes completaron la prueba sin efectos secundarios significativos, y en un tiempo menor a 25 minutos. El seguimiento se hizo con miras a la aparición de eventos cardiovasculares mayores (revascularización, infarto al miocardio y muerte cardíaca). Resultados: EE resultó positivo para isquemia en 19 (21 por ciento) pacientes. En 19 (12 por ciento) el EE resultó alterado por motilidad parietal; 29 (15 por ciento) presentaron respuesta anormal en la RFC, con una coincidencia de 12 pacientes (7 por ciento) con ambos tipo de alteración; En 142 (88 por ciento) pacientes se logró medir la RFC en ADA. En 151 pacientes se obtuvo datos confiables del seguimiento, que fue en promedio 10 meses (6 a 18); entre estos, 10 pacientes tuvieron alguna revascularización. No hubo infartos ni fallecidos por causa cardio-vascular. Dado el corto período de seguimiento y baja incidencia de eventos, no se pudo establecer el valor predictivo del resultado de la prueba en esta muestra. Conclusiones: Esta experiencia permitió familiarizarse con la técnica del EE con Dipiridamol y estudiar en un alto porcentaje la RFC en la ADA. La técnica es segura y consume muy poco tiempo. Queda pendiente la determinación del valor predictivo de estos resultados en nuestras manos.

Background: Stress Echocardiography is a common technique in the study of patients with known or suspected Coronary artery disease (CAD). Recently the vasodilation test has been recommended for the non invasive study of Coronary Flow Reserve (CFR). Aim: to report our preliminary experience with Di-pyridamol Stress Echocardiography (DSE), an initial follow-up, and the study of CFR in the distal portion of the left anterior descending coronary artery (LAD). Methods: 164 consecutive patients (101 men, mean age 65) with suspected or known CAD underwent a high-dose DSE (0.84 mg/kg over 6 min) between July 2011 and September 2012. The test included a study of CFR. All patients completed the test within 25 min. Prospective follow-up regarding major adverse cardiovascular events(revascularization, cardiac mortality and infarction) was conducted for a mean of 10 months (range 6-18) Results: DSE was positive for ischemia in 34 (21 percent) patients, showed abnormal wall motion in 19 (12 percent), abnormal CFR in 29 (15 percent) , and both abnormalities in12 (7 percent). 142 patients (88 percent) had a normal CFR in the LAD. 151 patients were followed for a mean of 10 months (6 to 18). Ten of these patients required some type of revascularization. There were no myocardial infarctions or cardiac deaths. Due to the short follow up period and the low incidence of events, it was not possible to estimate the predictive value of abnormal CFR. Conclusion: The dipyridamol echo stress test with a study of coronary flow reserve is safe and brief. The predictive value for cardiac events remains to be determined.

Intervenciones coronarias percutáneas guiadas con medición de flujo de reserva coronario / Percutaneous coronary intervention guided by measurement of coronary flow reserve

Introducción: La revascularización de una estenosis coronaria que induce isquemia mejora el estatus funcional del paciente y su pronóstico. Por el contrario, la angioplastía de una lesión que no provoca isquemia puede implicar complicaciones sin beneficios. La medición de flujo de reserva coronario (FFR) es un índice del significado fisiopatológico de las estenosis coronarias. Objetivos: Comparar los eventos cardiovasculares adversos mayores (MACE) en pacientes en quienes la FFR permitió excluir una o más lesiones de angioplastia (Grupo FFR >0,75) con aquellos en que ésta obligó a la revascularización (grupo FFR < 0,75). Métodos: Estudio observacional en 74 pacientes derivados para angioplastía entre agosto de 2006 y julio de 2010. Se realizó medición de FFR con ade-nosina a lesiones de severidad intermedia (60-70 por ciento). Una FFR translesional <0,75 se consideró significativa para isquemia y subsidiaria de angioplastía. Se hizo un seguimiento de los MACE definidos como: muerte, infarto, necesidad de revascularización y/o presencia de angor. Resultados: 35 pacientes (47,3 por ciento) constituyeron el Grupo FFR >0,75, y en ellos disminuyó el porcentaje de lesiones múltiples angiográficamente significativas (dos o más vasos), desde un 51,4 por ciento (previo a la realización de FFR), a un 25,7 por ciento. En este grupo se utilizó un promedio de 0.7 stents por paciente, mientras que en el grupo FFR <0,75 (39 pacientes), este fue de 1.5 stents. Se efectuó un seguimiento promedio de 21,5 meses. Diecinueve pacientes (25,6 por ciento) desarrollaron MACE (28 eventos). No hubo fallecidos ni diferencias significativas en el análisis multifactorial en cuanto a infartos o angor, pero sí en la necesidad de nueva revascularización, siendo ésta significativamente mayor en el grupo FFR <0,75 (12,8 por ciento versus 2,9 por ciento, p=0,047). Conclusiones: La medición del FFR permite, en caso de descartar isquemia, disminuir la necesidad de angioplastías...

The treatment of coronary stenosis causing myocardial ischemia improves functional capacity and prognosis. Treatment of non-ischemia inducing coronary stenosis may lead to complications with no benefit to the patient Measurement of coronary flow reserve (CFR) may be used to assess the significance of coronary artery stenosis. Aim: To compare major adverse cardiovascular events (MACE) in patients with significant stenosis (CFR < 0.75), with those in which one or more stenosis was not significant (CFR > 0.75) and thus were not subjected to PTCA in the corresponding artery. Methods: 74 patients were included from August 2006 to July 2010. CFR was measured in lesions exhibiting 6070 percent stenosis, using adenosine. A value <0.75 was considered significant and led to PTCA. Patients were followed for death, myocardial infarction, revascularization and/or angina. Results: 35 patients (47 percent) constituted the >0.75 CFR group. After evaluation of CFR the number of significant coronary stenosis decreased from 51.4 percent to 25.7 percent. They received a mean of 0.7 stents per patient. On the other hand, in the group with CFR <0.75 (39 patients) the mean number of stents was 1.5. Patients were followed for a mean of 21.5 months. 28 MACE events were observed in 19 patients (25.6 percent). No deaths were observed. Multivariable analysis revealed no significant difference between groups regarding myocardial infarction or angina. The need for myocardial revascularization was greater in the CFR <0.75 group compared to the CFR >0.75 group (12.8 percent vs 2.9 percent, respectively, p=0.047). Conclusion: The exclusion of myocardial ischemia as inferred by a CFR >0.75 allowed a significantly lower number of PTCAs without increase in MACE at a medium term follow up. A greater number of revascularization procedures was required in patients with CFR <0.75, which is expected from the greater number of lesions subjected to PTCA.

Effects of adenosine on left coronary blood flow and flow reserve in mini-swine: a comparative study between different adenosine doses / 介入放射学杂志

Objective To compare the effects of different doses of adenosine(AD)on the left coronary blood flow(CBF)and left coronary flow reserve(CFR)in mini-swine.Methods By using Doppler flow wire and intracoronary ultrasound imaging catheter at the middle segment of LAD,coronary average peak flow velocity(APV)and lumen area were measured in 10 healthy mini-swines.CBF was calculated from the equation of 0.6 APV times 0.5 lumen area.Intracoronary bolus injection of different dose AD(12μg,18μg,24 μg and 36μg,separately)was used to induce maximal coronary hyperemic reaction.CFR was defined as the ratio of hyperemic CBF to resting CBF.Results Intracoronary bolus injection of 18μg AD level induced a maximal coronary vasodilation.Significant difference in the hyperemic CBF existed between 12 μg AD dose and 24μg or 36μg AD dose(P＜0.05).No significant difference in heart rate,blood pressure,rCBF and CFR was found among three different AD dose groups(18μg,24μg,and 36μg).Conclusion CBF and CFR in mini-swine can be effectively assessed by bolus injection of AD with the dose of(18～24)μg.

Detection of myocardial coronary flow reserve of syndrome X by real-time myocardial contrast echocardiography / 中华超声影像学杂志

Objective To evaluate myocardial coronary flow reserve of syndrom X by real-time myocardial contrast echocardiography(MCE). Methods Ten patients with syndrome X and seven normal subjects were involved in the study. Real-time MCE was performed with acoustic contrast SonoVue,and the peak video density (A), and re-turgor velocity of microvessel (β), and the product of A ×β of quiescent condition and after adenosin loading were detected,and also the coronary flow reserve (CFR, the ratio of A xβ circa-adenosin loading). Results There was no significant difference of A between syndrom X and contrast group in quiescent condition, the β and product of A x β of patients with syndrome X were lower than those of contrast group, the CFR of syndrome X was obviously less than that of contrast group.Conclusions Myocardial microvessel function is abnormal in syndrome X, real-time MCE is useful for evaluate myocardial coronary flow reserve.

Diagnosis of Coronary Restenosis Using Coronary Flow Reserve Measurements Obtained Through Transthoracic Doppler Echocardiography

BACKGROUND AND OBJECTIVES: Coronary flow reserve (CFR) decreases in the presence of significant coronary stenosis. Hence, CFR can be used for the detection of restenosis after percutaneous coronary intervention (PCI). However, because CFR can also be affected by other conditions such as endothelial dysfunction, microvascular damage, and left ventricular hypertrophy, the absolute value of CFR is not routinely used for detection of coronary restenosis. We hypothesized that changes in the value of CFR, rather than the absolute CFR value, are better correlated with restenosis in various clinical settings. SUBJECTS AND METHODS: We studied 99 patients (71 males/28 females, mean age 58+/-11 years) who underwent successful PCI of the left anterior descending artery. Pre-PCI diagnoses were as follows: 37 unstable angina, 35 stable angina, 27 acute myocardial infarction. CFR using transthoracic Doppler was measured at 48 hours after PCI and at the time of follow-up angiography (6.0+/-1.5 months later). Coronary flow velocity was measured in the distal left anterior descending artery with a 7 MHz transducer (HDI 5,000, Philips, The Netherlands) at baseline and during intravenous infusion of adenosine (140 microgram.kg(-1).min(-1)). Mean diastolic coronary flow velocities from at least three cardiac cycles were averaged. RESULTS: CFRs in 69 patients without restenosis were 2.55+/-0.99 at 48 hours after PCI and 2.93+/-1.00 at follow-up (p50% in diameter stenosis) decreased significantly from 2.70+/-1.01 at 48 hours after PCI to 1.98+/-0.91 at follow-up (p<0.001). There was a significant difference in CFR change (ratio of CFR(followup)/CFR(initial)) between the two groups. CFR change had a better receiver operating characteristics (ROC) curve than absolute CFR for prediction of restenosis [area under the curve (AUC) for absolute CFR=0.76, AUC for CFR change=0.82]. CONCLUSION: Restenosis after PCI leads to a significant decrease in CFR, even in the presence of variable baseline CFR values. Serial measurements of CFR can be used to detect restenosis after PCI.

Optimal Dosage and Method of Administration of Adenosine for Measuring the Coronary Flow Reserve and the Fractional Flow Reserve in Koreans

BACKGROUND AND OBJECTIVES: The achievement of maximal vasodilatation is mandatory for obtaining valid measurements of the coronary flow reserve (CFR) and the fractional flow reserve (FFR). Recent studies have indicated that an incremental dose or a high dose of adenosine is necessary to achieve maximal hyperemia. We performed this study to examine the response of the physiologic parameters to different doses and to different methods of administration of adenosine in Koreans. SUBJECTS AND METHODS: CFR: The CFR was measured in 25 consecutive patients with angiographically normal coronary arteries by using a Doppler wire. Three different doses (9, 18 and 36 microgram in the left coronary artery (LCA), and 6, 12 and 24 microgram in the right coronary artery (RCA)) of adenosine were used. FFR: In a phase I study, 102 consecutive patients with 188 intermediate lesions (160 LCA and 28 RCA lesions) underwent FFR measurements with using a pressure wire. Three different bolus doses (20, 40 and 80 microgram) were administered in an incremental fashion. In a phase II study, the hyperemic efficacy of 3 different doses of intracoronary (IC) infusion (180, 240 and 300 microgram/min) and of 3 methods of administration (IC infusion, intravenous infusion and IC bolus) were compared. RESULTS: CFR: The higher 2nd dose of adenosine had a tendency to achieve a higher CFR than the lower 1st dose. But when we increased the adenosine to more than 20 microgram (LCA 36 and RCA 24 microgram), there was a tendency towards obtaining a lower CFR than that obtained after the 2nd dose of adenosine (LCA: 2.78+/-0.71 vs. 2.66+/-0.60, p=0.055, RCA: 3.19+/-0.88 vs. 3.04+/-0.80, p=0.86). FFR: Phase I: The dose of adenosine that achieved maximal hyperemia was 51+/-16 microgram in the LCA and 35+/-20 microgram in the RCA. In 73 (46%) of the LCA lesions and 12 (42%) of the RCA lesions, a further reduction of the FFR occurred when a higher dose of adenosine was used (LCA>40 ug, RCA>20 microgram). Phase II: The FFR obtained after an IC bolus injection (0.83+/-0.06) was significantly higher than obtained with an IV infusion (0.79+/-0.07) and an IC (0.78+/-0.09) infusion (p<0.01). However, no difference in the FFR was observed for the IC and IV infusions. CONCLUSION: This study suggests that more than 20 microgram adenosine does not have an additive effect on measuring the CFR. Adenosine 40 microgram for the LAD and 20 microgram for the RCA seems to be optimal as a intracoronary bolus injection for measuring the FFR in most cases. However, for the patients with borderline FFR, a higher bolus adenosine dose or an adenosine continuous infusion may be necessary.

Fisiología coronaria y su utilidad para el cardiólogo intervencionista: Medición invasiva de la presión y flujo coronarios / Coronary physiology and its usefulness for the interventionist cardiologist: Invasive measurement of coronary flow-pressure

Una de las más importantes limitaciones de la angiografía coronaria es su incapacidad para determinar el impacto fisiológico de las estenosis coronarias moderadas. La medición de la presión y del flujo sanguíneo coronario nos brinda información valiosa que complementa la evaluación anatómica y facilitan la toma de decisiones en el laboratorio de cateterismo cardíaco. En esta revisión se discuten los conceptos fundamentales de la fisiología coronaria, así como la metodología y aplicación clínica de las técnicas de medición de presión y flujo coronarios.

One of the most important limitations of coronary angiography is the inability to characterize the physiological significance of an intermediate coronary stenosis. Measuring coronary blood flow and pressure provides unique information that complements anatomic evaluation and facilitates decision-making in the cardiac catheterization unit. This review discusses the fundamental concepts of coronary physiology, methodology, and clinical applications of coronary and flow measurements.

Evaluation of Myocardial Blood Flow and Coronary Flow Reserve Using Positron Emission Tomography / 대한핵의학회잡지

Positron emission tomography (PET) serves as a gold standard for noninvasive in vivo measurement of myocardial blood flow (MBF) and coronary flow reserve (CFR). CFR can be defined as the ratio of maximally vasodilated MBF over its basal flow. It is an important parameter for the evaluation of functional severity of coronary stenosis and prognositification in various diseases such as dilated cardiomyopathy. 13NH3, H215O, 82Rb are widely used radiopharmaceuticals for measuring MBF and CFR, This review introduces imaging techniques and its clinical utility. Cardiac application of PET and PET/CT is expected to be increased in near future.