Noninvasive assessment of significant right coronary artery stenosis based on coronary flow velocity reserve in the right coronary artery by transthoracic Doppler echocardiography

BACKGROUND: Coronary flow velocity reserve (CFVR) measured by transthoracic Doppler echocardiography (TTDE) has been reported to be useful for the noninvasive assessment of coronary stenosis in the left anterior descending artery. However, the measurement of CFVR in the right coronary artery by TTDE has not yet been validated in a clinical study. OBJECTIVE: The aim of this study was to evaluate whether CFVR by TTDE can detect significant stenosis in the right coronary artery. METHODS: We studied 50 patients who underwent coronary angiography. Coronary flow velocity in the posterior descending branch of the right coronary artery (PD) was measured by TTDE both at baseline and during hyperemia induced by the intravenous infusion of adenosine triphosphate. CFVR was calculated as the hyperemia/baseline (average diastolic peak velocity). RESULTS: Adequate spectral Doppler recordings in the PD were obtained in 36 patients including 26 patients who were given an echocardiographic contrast agent to improve Doppler spectral signals. The study population was divided into 2 groups with (Group A;n = 11) and without (Group B;n = 25) significant stenosis in the right coronary artery. CFVR in Group A was significantly smaller than that in Group B (1.6+/-0.3versus2.5+/-0.4; P < 0.0001). The sensitivity of a CFVR of <2.0 for predicting the presence of significant stenosis in the right coronary artery was 91%, and the specificity was 88%. CONCLUSIONS: The measurement of CFVR in the PD by TTDE is useful for the noninvasive assessment of significant stenosis in the right coronary artery.     

Effects of smoking on coronary blood flow velocity and coronary flow reserve assessed by transthoracic Doppler echocardiography

BACKGROUND: Smoking is a well-known risk factor for cardiovascular disease. Coronary blood flow velocity (CFV) can be measured directly with transthoracic Doppler echocardiography (TTDE) which is conducted immediately after smoking. PURPOSE: The purpose of this study was to evaluate the chronic and acute effects of smoking on coronary blood flow and coronary flow reserve (CFR) by the use of TTDE. METHODS: Healthy volunteers (11 smokers and 9 nonsmokers) with a mean age of 27 +/- 3 years were included. Smoking was abstained for at least 4 hours before the study. CFV was measured at the distal left anterior descending coronary artery by TTDE at baseline and during intravenous adenosine infusion (140 microg/kg per minute) in all participants. For smokers, CFV was measured immediately after consecutively smoking two cigarettes and during adenosine infusion. RESULTS: CFR and coronary vascular resistance index (CVRI) showed no significant difference between nonsmokers and smokers (CFR: 3.5 +/- 0.8 vs 3.6 +/- 0.6, P = ns, CVRI: 0.28 vs 0.28, P = ns) at baseline. CFR significantly decreased (3.6 +/- 0.6 to 2.8 +/- 0.7, P = 0.008) and CVRI markedly increased (0.28 to 0.35, P = 0.012) after smoking. CONCLUSION: After 4 hours of abstinence from smoking, CFR and CVRI in smokers were similar to those of nonsmokers. However, consecutively smoking two cigarettes acutely reduced CFR and increased CVRI. These findings suggested that smoking could reduce coronary blood flow immediately, even in healthy people.     

Noninvasive coronary flow velocity reserve measurement in the posterior descending coronary artery for detecting coronary stenosis in the right coronary artery using contrast-enhanced transthoracic Doppler echocardiography

BACKGROUND: Coronary flow velocity reserve (CFVR) measurement by transthoracic Doppler echocardiography (TTDE) has been found to be useful for assessing left anterior descending coronary artery (LAD) stenosis. However, this method has been restricted only for the LAD. The purpose of this study was to detect severe right coronary artery (RCA) stenosis by CFVR measurement using contrast-enhanced TTDE. METHODS: In 60 consecutive patients with angina pectoris (mean (SD) age: 60 (11), 18 women), coronary flow velocities in the RCA were recorded in the postero-descending coronary artery by contrast-enhanced TTDE at rest and during hyperemia induced by intravenous infusion of adenosine triphosphate (140 mcg/ml/kg). CFVR was calculated as the ratio of hyperemic to basal peak and mean diastolic flow velocity. CFVR measurements by TTDE were compared with the results of coronary angiography performed within 1 week. RESULTS: Coronary flow velocity was successfully recorded in 49 (82%) of the 60 patients with contrast agent. CFVR (mean (SD)) was 1.4 (0.4) in patients with, and 2.6 (0.6) in patients without significant stenosis in the RCA (%diameter stenosis > 75%, P < 0.001). Using the cutoff value 2.0 for CFVR in the RCA, its sensitivity and specificity in detecting significant stenosis in the RCA were 88% and 91%, respectively. CONCLUSION: CFVR measurement in the postero-descending coronary artery by contrast enhanced TTDE is a new, noninvasive method to detect significant stenosis in the RCA.     

Coronary flow reserve is supranormal in endurance athletes: an adenosine transthoracic echocardiographic study

OBJECTIVE—To compare coronary flow reserve in endurance athletes and healthy sedentary controls, using adenosine transthoracic echocardiography.
METHODS—29 male endurance athletes (mean (SD) age 27.3 (6.6) years, body mass index (BMI) 22.1 (1.9) kg/m²) and 23 male controls (age 27.2 (6.1) years, BMI 23.9 (2.6) kg/m²) with no coronary risk factors underwent transthoracic echocardiographic assessment of distal left anterior descending coronary artery (LAD) diameter and flow, both at rest and during intravenous adenosine infusion (140 µg/kg/min).
RESULTS—Distal LAD diameter and flow were adequately assessed in 19 controls (83%) and 26 athletes (90%). Distal LAD diameter in athletes (2.04 (0.25) mm) was not significantly greater than in sedentary controls (1.97 (0.27) mm). Per cent increase in LAD diameter following 400 µg sublingual nitrate was greater in the athletes than in the controls, at 14.1 (7.2)% v 8.8 (5.7)% (p < 0.01). Left ventricular mass index in athletes exceeded that of controls, at 130 (19) v 98 (14) g/m² (p < 0.01). Resting flow among the athletes (10.6 (3.1) ml/min; 4.4 (1.2) ml/min/100 g left ventricular mass) was less than in the controls (14.3 (3.6) ml/min; 8.2 (2.2) ml/min/100 g left ventricular mass) (both p < 0.01). Hyperaemic flow among the athletes (61.9 (17.8) ml/min) exceeded that of the controls (51.1 (14.6) ml/min; p = 0.02), but not when corrected for left ventricular mass (25.9 (5.6) v 28.5 (7.4) ml/min/100 g left ventricular mass; NS). Coronary flow reserve was therefore substantially greater in the athletes than in the controls, at 5.9 (1.0) v 3.7 (0.7) (p < 0.01).
CONCLUSIONS—Coronary flow reserve in endurance athletes is supranormal and endothelium independent vasodilatation is enhanced. Myocardial hypertrophy per se does not necessarily impair coronary flow reserve. Adenosine transthoracic echocardiography is a promising technique for the investigation of coronary flow reserve.


Keywords: coronary flow reserve; athlete; adenosine transthoracic echocardiography     

Coronary flow velocity reserve measurement in three major coronary arteries using transthoracic Doppler echocardiography

BACKGROUND: Measurement of the coronary flow velocity reserve (CFVR) by transthoracic Doppler echocardiography (TTDE) has been reported to be useful for the noninvasive assessment of significant coronary artery stenosis or myocardial ischemia. The purpose of this study was to evaluate the value of this method in three major coronary arteries for detecting myocardial ischemia in the clinical setting. METHODS: We studied 89 consecutive patients who were referred to our outpatient clinic because of chest pain. We measured CFVR using TTDE in three major coronary arteries. We defined CFVR<2.0 in at least one vessel as being positive for myocardial ischemia. The accuracy of CFVR measurements for detecting myocardial ischemia was determined in comparison with exercise thallium-201 (Tl-201) single photon emission computed tomography (SPECT) as a reference standard. RESULTS: CFVR in at least one vessel was successfully measured in 87 of 89 patients (98%). The sensitivity and specificity of CFVR<2.0 in at least one coronary vessel, in any of the coronary territories, was 86% and 89%, respectively. In terms of assessing myocardial ischemia in each coronary artery territory, the agreement between CFVR<2.0 and Tl-201 SPECT for the left anterior descending coronary artery, the posterior descending coronary artery, and the left circumflex coronary artery territories was 95%, 81%, and 73%, respectively. CONCLUSION: Noninvasive CFVR measurement by TTDE may be useful for detecting myocardial ischemia, as well as for identifying ischemic territories in the clinical setting.     

A warm footbath improves coronary flow reserve in patients with mild-to-moderate coronary artery disease

Backgrounds: Recent studies have shown that thermal therapy by means of warm waterbaths and sauna has beneficial effects in chronic heart failure. However, a comprehensive investigation of the hemodynamic effects of thermal vasodilation on coronary arteries has not been previously undertaken. In this study, we studied the effect of a warm footbath (WFB) on coronary arteries in patients with coronary artery disease (CAD), as well as any adverse effect. Methods: We studied 21 patients (33.3% men, mean age 60.8 ± 13.5 years) with CAD. Coronary flow Doppler examination of the left anterior descending coronary artery and coronary flow reserve (CFR) were performed and measured using adenosine before and after a WFB. Results: Systolic and diastolic blood pressure and heart rate did not change with the WFB. Mean velocity of diastolic coronary flow significantly increased (diastolic mean flow velocity: 18.3 ± 7.1 cm/sec initial, 21.5 ± 8.0 cm/sec follow‐up, P = 0.002) and CFR significantly improved (1.6 ± 0.4 vs. 2.2 ± 0.5, P < 0.001) after WFB. The WFB was well accepted and no relevant adverse effects were observed. The change of CFR after WFB correlated well with diastolic function (E’, r = 0.51, P = 0.031; E/E’, r =–0.675, P = 0.002). Conclusions: A WFB significantly improved CFR without any adverse effects in patients with mild‐to‐moderate CAD and can be applied with little risk of a coronary artery event if appropriately performed. (Echocardiography 2011;28:1119‐1124)     

Feasibility of measuring coronary flow velocity and reserve in the left anterior descending coronary artery by transthoracic Doppler echocardiography in a relatively obese American population

BACKGROUND: Transthoracic Doppler echocardiography (TTDE) assessment of coronary flow velocity reserve (CFVR) has been validated in Asian and European centers. This methodology has not gained acceptability in the United States due to the bias that coronary flow velocity (CFV) by TTDE might be difficult in an obese population with relatively poor acoustic windows. METHODS: Baseline CFV in the left anterior descending coronary artery (LAD) by TTDE was obtained in 67 nonselected American patients. A subset of 38/67 received adenosine infusion for measuring CFVR of the LAD. PURPOSE: The aim of this study was twofold: (1) to determine the feasibility of measuring CFV and CFVR in the LAD by TTDE in a relatively obese American population, and (2) to compare CFV and CFVR values in this population with those previously obtained in a group of Japanese patients. RESULTS: The mean body mass index (BMI) of the American population (28 +/- 6 kg/m2, range: 18-46 kg/m2) was significantly higher than that of the Japanese group (23 +/- 4 kg/m2, range: 15-37 kg/m2). Twenty-five American patients were classified as obese (BMI >30 kg/m2). Baseline CFV was obtained in 60/67 patients (feasibility: 90%) with a 10% need for intravenous contrast agent to enhance the delineation of the CFV envelope. The success rate in recording CFVR in American patients (92%) was nearly identical to that of a Japanese group (99%). The time-averaged peak diastolic coronary flow velocity increased from 15.6 +/- 5.5 cm/sec at baseline to 47.1 +/- 17.9 cm/sec during adenosine infusion, and CFVR was calculated to be 3.22 +/- 1.15 (range: 0.94-5.69). Intraobserver and interobserver variability for the CFV recording was 4.7 and 6.2%, respectively. CONCLUSIONS: These results suggest that the noninvasive measurement of CFV and CFVR of the LAD is feasible even in a relatively obese American population. Furthermore, the success rates for recording CFV and CFVR are similar to those measured in a Japanese population. This methodology has the potential to provide useful physiological information on the coronary circulation in American patients.     

Comparison of transesophageal coronary sinus and left anterior descending coronary artery doppler measurements for the assessment of coronary row reserve

Background: Currently used methods for assessment of coronary flow reserve are invasive and require extensive laboratory equipment. Recently, noninvasive assessment of coronary flow reserve by transesophageal Doppler evaluation of coronary sinus (CS) or left anterior descending coronary artery (LAD) flow has been proposed. Direct comparison between these two techniques is lacking. Methods: Doppler recordings of CS and LAD flow velocity were obtained before and after 0.6 mg/kg/5 min dipyridamole in 16 patients with significant stenosis of the LAD (Group A) and in 14 control patients (Group B). Flow recordings and all measurements were performed in a blinded manner. For assessment of coronary flow reserve, Doppler measurements after dipyridamole were divided by the respective baseline values. Results: Doppler studies of the CS and LAD were feasible in 30 of 30 (100%) and 23 of 30 (71%) patients, respectively. Analyzing the maximum flow velocities, coronary flow reserve in Groups A and B was 1.18 ± 0.28 and 1.68 ± 0.53 with CS recordings and 1.78 ± 0.83 and 2.51 ± 0.76 with LAD recordings, respectively. Analyzing the velocity time integrals, coronary flow reserve in Groups A and B was 1.53 ± 0.68 and 2.59 ± 0.74 with CS recordings and 1.77 ± 0.38 and 2.68 ± 0.93 with LAD recordings, respectively. Correlation between LAD and CS recordings was 0.69 (p<0.001), when coronary flow reserve was calculated from the velocity time integral and 0.68 (p<0.001) when the maximum flow velocities were used. Conclusion: Both transesophageal Doppler techniques might be useful for noninvasive assessment of coronary flow reserve.     

Live three-dimensional transthoracic echocardiographic assessment of coronary arteries

In the present study, we are illustrating some of the adult patients in whom live three-dimensional transthoracic echocardiography was found useful in assessing proximal and mid-coronary arteries.     

Simultaneous transesophageal Doppler assessment of coronary flow reserve in the left anterior descending artery and coronary sinus allows differentiation between proximal and non-proximal left anterior descending artery stenoses.

AIM AND METHODS: The role of simultaneous transesophageal Doppler assessment of coronary flow reserve (CFR) in the left anterior descending artery (LAD) and coronary sinus (CS) in the diagnostics of hemodynamically significant LAD stenoses of various localization was studied in 16 CAD patients with angiographically proven >50% stenotic atherosclerosis of the LAD (nine--in the proximal third, seven--in the mid and/or distal third) and 23 healthy volunteers (all men). Dipyridamole was used as a stress agent. The diastolic phase of coronary flow in the LAD and the antegrade phase of coronary flow in the CS were analyzed. CFR in the LAD and CS was calculated in two ways: one--as ratio of peak hyperemic flow velocity to the peak baseline blood flow velocity (CFR by Vp); two--as ratio of volume hyperemic blood flow velocity to the volume baseline blood flow velocity (CFR by VBF). The level of the CFR <2 in both ways of calculation was diagnosed as reduced. RESULTS: It was found that in CAD patients with LAD proximal stenosis the values of CFR in the LAD were significantly lower than those in healthy individuals by both Vp (1.87 +/- 0.43 and 3.54 +/- 0.82; P<0.001) and VBF (1.79 +/- 0.77 and 3.85 +/- 1.25; P<0.01). In proximal stenosis CFR in the LAD by Vp was significantly lower than that in non-proximal stenosis (1.87 +/- 0.43 and 3.31 +/- 1.44; P<0.05). Sensitivity and specificity of CFR <2 in the LAD by Vp in the diagnostics of LAD proximal stenosis were 56% and 97%, respectively; and CFR <2 in the LAD by VBF--89% and 93%, respectively. In CAD patients with both proximal and non-proximal LAD stenoses CFR in the CS by Vp was significantly lower than that in healthy volunteers and was 1.74 +/- 0.53, 1.63 +/- 0.30 and 2.56 +/- 0.87; P<0.05, respectively. Sensitivity and specificity of CFR <2 in the CS by Vp in the diagnostics of hemodynamically significant LAD stenoses were 75% and 70%, respectively. The values of CFR in the CS by VBF in CAD patients and healthy volunteers did not differ significantly. CONCLUSIONS: Thus, simultaneous evaluation of CFR in the LAD and CS makes it possible to diagnose hemodynamically significant LAD stenoses and to differentiate between proximal and non-proximal impairments.     

不同性别非冠状动脉阻塞性胸痛患者冠状动脉血流储备特点及影响因素研究

目的 探讨不同性别非冠状动脉阻塞性胸痛患者冠脉血流储备的特点及影响因素.方法 入选2011年10月至2017年9月于北京大学第三医院心内科就诊的302例影像学检查证实冠脉狭窄＜50％的胸痛患者,行经胸多普勒超声心动图测定冠状动脉左前降支的冠脉血流储备(CFR),比较男女性CFR特点.结果 研究对象平均年龄(60.1±9...     

Validation of noninvasive assessment of coronary flow velocity reserve in the right coronary artery. A comparison of transthoracic echocardiographic results with intracoronary Doppler flow wire measurements.

AIMS: Assessment of coronary flow velocity reserve (CFR) noninvasively using transthoracic Doppler echocardiography (TDE) is validated for the left anterior descending artery only. We evaluated the feasibility and reproducibility to assess CFR using TDE in the right coronary artery, and compared the results with intracoronary Doppler flow wire (DFW) measurements. METHODS AND RESULTS: Introduction of a modified apical 2-chamber view allows visualization of the posterior descending branch of the right coronary artery (RPD). 42 consecutive patients (31 men, mean age 61+/-10) with suspected coronary artery disease scheduled for coronary angiography underwent CFR assessment using TDE in fundamental imaging mode; the results were compared with DFW measurements. CFR could be taken noninvasively in 81% (34/42); in case of right dominant- or balanced coronary circulation type success rate was significantly higher (87%; 33/38) than in case of left dominant coronary circulation (25%; 1/4). Correlation between echocardiographically and intracoronary derived CFR results was significant (r=0.85, P<0.0001), as well as reproducibility (r=0.94, P<0.0001) and interobserver variability (r=0.78, P<0.0001). CONCLUSION: Coronary flow reserve assessed in the peripheral RCA by TDE concurs very closely with intracoronary Doppler flow wire CFR results. This new approach allows feasible, accurate and reproducible measurement of CFR in the RCA.     

Diagnostics of main coronary artery stenoses and occlusions: multiplane transoesophageal Doppler echocardiographic assessment.

AIM AND METHODS: The possibility of using multiplane transoesophageal echocardiography (TEE) and quantitative coronary angiography (QCA) in the diagnostics of stenotic atherosclerosis of the main coronary arteries in a comparative aspect were studied in 94 patients with coronary artery disease (men, mean age 52 +/- 7 years). Coronary arteries stenoses were calculated with Doppler echocardiography using a modified continuity equation: stenosis (%)=100 x(1-prestenotic VTI(d)/stenotic VTI(d)) where prestenotic VTI(d), (cm)=diastolic velocity integral in the prestenotic zone, and stenotic VTI(d), (cm)=in the trans-stenotic zone. RESULTS: High sensitivity and specificity of TEE in the diagnostics of stenotic and occlusive atherosclerosis of coronary arteries were revealed. They measured 88% and 98% for the left main coronary artery (LMCA), 97% and 67% for the left descending artery (LDA), 95% and 92% for the circumflex artery (CX), 83% and 97% for the right coronary artery (RCA), respectively. A high correlation was found between the results of TEE and QCA in the diagnostics of coronary stenoses which were made for the LMCA (r=0.82P <0.001), LDA (r=0.84, P<0.001), CX (r=0.85,P <0.001), and RCA (r=0.84, P<0.001). We developed Doppler echocardiography criteria for haemodynamically significant stenoses of coronary arteries (>50%) according to a peak diastolic velocity of the coronary blood flow, calculated as 1.4m.s(-1)for the LMCA, 0.9m.s(-1)for the LDA, and 1.1m.s(-1)for the CX. We determined Doppler echocardiography criteria of coronary arteries occlusions such as a 'break' of colour mapping, absence of Doppler spectrum and retrograde blood flow during late diastole. CONCLUSION: Transoesophageal Doppler evaluation of coronary blood flow with application of a modified continuity equation is an accurate, non-invasive method of coronary arteries stenoses diagnostics.     

应用经胸冠状动脉血流显像技术评价支架术前后冠脉血流储备

目的采用经胸多普勒超声心动图冠状动脉血流显像技术观察支架术前后冠状动脉血流速度的变化,评价其对冠状动脉血流储备（CFR）的影响。方法22例冠心病患者(男18例,女4例),平均年龄（53.2±6.7）岁。对狭窄的冠状动脉行经皮冠状动脉腔内成形术（PTCA）后各置入一枚支架。分别于木前、术后72h内采用经胸多普勒冠状动脉血流显像技术记录狭窄远端静息舒张期血流峰速(r-Vd)、注射潘生丁及等长握力实验时最大舒张期血流峰速(d-Vd)及CFR。结果22例患者行支架术均获成功,狭窄率由术前(83.5±8.9)%,降至术后(5.2±9)%(P<0.05)。20支冠脉获得理想多普勒频谱（检出率90.9％）;支架术后r-Vd较术前r-Vd有增加趋势,但无统计学意义;术后静脉注射潘生丁后最大d-Vd及CFR均较术前明显增加［（0.92±0.22)m/svs(0.52±0.18)m/s,2.94±1.16vs1.88±0.40,P均<0.01］。30％患者术后CFR仍<2.0,此组与CFR≥2.0患者组比较,支架术后r-Vd明显增高［(0.45±0.19)m/svs(0.27±0.12)m/s,P<0.05］。少数患者(约18%,4／22)术前出现心绞痛,头昏等不适,静注氨茶碱或(和)含化硝酸甘油可迅速缓解。结论支架术能明显增加冠状动脉血流储备。采用经胸多普勒冠脉血流显像技术结合潘生丁、握力试验是一可行的无创性评价冠心病患者冠脉血流储备及介入治疗疗效的新方法。     

Value of fractional flow reserve in making decisions about bypass surgery for equivocal left main coronary artery disease

OBJECTIVE—To investigate the value of coronary pressure derived fractional flow reserve (FFR) measurements in supporting decisions about medical or surgical treatment in patients with angiographically equivocal left main coronary artery stenosis.
DESIGN—A two centre prospective single cohort follow up study.
INTERVENTIONS—FFR of the left main coronary artery was determined in 54 consecutive patients with angiographically equivocal left main coronary artery disease. If FFR was 0.75, medical treatment was chosen; if FFR was < 0.75, surgical treatment was chosen.
MAIN OUTCOME MEASURES—Freedom from death, myocardial infarction, or any coronary revascularisation procedure.
RESULTS—In 24 patients (44%), FFR was 0.75 and medical treatment was chosen (medical group). In the remaining 30 patients (56%), FFR was < 0.75 and bypass surgery was performed (surgical group). Mean (SD) follow up was 29 (15) months (range 12-65 months). Survival among patients at three years of follow up was 100% in the medical group and 97% in the surgical group. Event-free survival was 76% in the medical group and 83% in the surgical group.
CONCLUSIONS—FFR supports decision making in equivocal left main coronary artery disease. If FFR is below 0.75, the decision for bypass surgery is supported. If FFR is above 0.75, a conservative approach is justified.


Keywords: coronary artery disease; left main coronary artery; fractional flow reserve; coronary artery bypass     

Live three-dimensional transthoracic echocardiographic assessment of anomalous origin of left coronary artery from the pulmonary artery

We describe live three-dimensional transthoracic echocardiographic (3DTTE) findings in a 52-year-old female who had previously undergone an aortopulmonary tunnel operation for anomalous origin of the left coronary artery (ACA) from the pulmonary artery. Three-dimensional transthoracic echocardiography clearly delineated the origin of the ACA from the posterolateral aspect of the main pulmonary artery just above the pulmonary valve, the surgically created tunnel, as well as a small defect in the tunnel near the aortic end communicating with the pulmonary artery.     

Reduced coronary flow reserve in the coronary sinus is a predictor of hemodynamically significant stenoses of the left coronary artery territory.

AIM AND METHODS: The role of transesophageal Doppler assessment of coronary flow reserve (CFR) in the coronary sinus (CS) in the diagnostics of significant left coronary artery (LCA) stenoses was studied in 65 CAD patients with angiographically proven >50% stenotic atherosclerosis of the LCA territory (38--with isolated left anterior descending artery (LAD) or left circumflex artery (Cx) stenosis; 27--with both LAD and Cx stenoses) and 31 healthy volunteers (all men). Dipyridamole was used as a stress agent. The antegrade phase of coronary flow in the CS moving into the right atrium was analysed. CFR in the CS was calculated in two ways: (1) as ratio of hyperemic to baseline peak antegrade flow velocity (CFRp); (2) as ratio of hyperemic to baseline volumetric blood flow velocity (CFRv). The level of CFR <2.0 in both ways of calculation was diagnosed as reduced. RESULTS: CAD patients compared with healthy volunteers had significantly lower CFRp (1.51+/-0.44 and 2.57+/-0.79; p<0.001) and CFRv (2.21+/-1.18 and 5.43+/-2.83; p < 0.001) in the CS. CFRp <2.0 in the CS was a predictor of significant stenoses of the LCA with sensitivity of 89% and specificity of 76%, while CFRv <2.0 was a predictor of significant stenoses of the LCA with sensitivity of 49% and specificity of 97%. CFRp <2.0 in the CS was registered in 96% of CAD patients with two-vessel lesion and in 84% of CAD patients with one-vessel lesion, while CFRv <2.0 in the CS was revealed in 85% of CAD patients with two-vessel lesion and only in 26% of CAD patients with one-vessel lesion. Sensitivity and specificity of CFRv <2.0 in the CS in the diagnostics of significant two-vessel lesion of the LCA were 85% and 84%, respectively. CONCLUSIONS: Thus, the reduced CFR in the CS is a sensitive and specific predictor of LCA stenoses. A decrease of both CFRp <2 and CFRv <2.0 in the CS is a predictor of significant two-vessel lesion of the LCA, while a decrease of only CFRp <2.0 in the CS is a predictor of significant one-vessel lesion of the LCA.     

无创血流储备分数测定对冠心病患者心肌缺血功能评估的临床进展

在中度病变的稳定型冠状动脉疾病(CAD)患者中,判断病变是否造成了冠状动脉远端血流动力学的显著改变(即心肌缺血),在制定临床决策中起着至关重要的作用。而在这些临界病变中,血流储备分数(FFR)测定是识别心肌缺血存在与否的金标准。近年来,随着计算机流体动力学(CFD)的发展,基于冠状动脉CT血管造影的无创性FFR(FFRCT)得以发展。本综述旨在通过阐述FFRCT的概念及应用原理,总结目前针对FFRCT技术的几项临床研究,说明其良好的诊断性能、临床实践进展、优点、局限性以及临床应用前景。