Evaluation Of Coronary Flow Reserve Research Articles

Role of cardiovascular imaging in systemic autoimmune diseases

Systemic autoimmune diseases are characterized by an excess of cardiovascular (CV) morbidity and mortality compared to the general population, mainly due to chronic inflammation that promotes the development of endothelial dysfunction and enhanced atherosclerosis. Early diagnosis of silent CV involvement is mandatory to improve the long term prognosis of these patients and CV imaging provides valuable information as a reliable diagnostic tool. Transthoracic echocardiography, with several applications (e.g. coronary flow reserve evaluation, tissue Doppler imaging, speckle tracking and the transesophageal approach), represents a first line evaluation, in association with biomarkers of endothelial dysfunction, such as asymmetric dimethylarginine. Nuclear medicine provides useful information on myocardial perfusion. The aim of this editorial is to provide a brief but complete review of the diagnostic tools available for screening and follow up of CV involvement in systemic autoimmune diseases.

Implication of the Continuous Prognostic Spectrum of Doppler Echocardiographic Derived Coronary Flow Reserve on Left Anterior Descending Artery

The additive prognostic value of coronary flow reserve (CFR) over regional wall motion has been established, but there is more than a binary (normal-abnormal) response in CFR, which can be continuously titrated. We assessed the prognostic value of quartiles of CFR, evaluated by transthoracic Doppler of the left anterior descending coronary artery (LAD), in patients with known or suspected coronary artery disease (CAD). One thousand six hundred twenty patients (1,006 men, 64 +/- 11 years of age) underwent dipyridamole (up to 0.84 mg/kg over 6 minutes) stress echocardiography with CFR evaluation of LAD by Doppler and coronary angiography. Patients were followed up for a median of 19 months. Mean CFR in the entire population was 2.25 +/- 0.65. Stress echocardiogram was positive for ischemia in 480 patients (30%). Obstructive (>or=70% vessel stenosis) CAD at angiography was present in 650 patients (40%). During follow-up, there were 298 events (42 deaths, 73 ST-elevation myocardial infarctions, and 183 non-ST-elevation myocardial infarctions). Patients (n = 399) undergoing revascularization were censored. With the Kaplan-Meier method, the first quartile of CFR (<or=1.80) was associated with a worse (p <0.0001) event rate than other quartiles in the entire population and in patients with no ischemia at stress echocardiography. Furthermore, the second quartile of CFR (1.81 to 2.16) was predictive of increased (p <0.0001) risk compared to the higher quartiles. In conclusion, Doppler echocardiographically derived CFR in LAD is a strong and independent prognostic predictor in patients with known or suspected CAD, but the spectrum of prognostic stratifications is expanded if the response is titrated according to a continuous scale rather than artificially dichotomized.

Prognostic correlates of combined coronary flow reserve assessment on left anterior descending and right coronary artery in patients with negative stress echocardiography by wall motion criteria

Aims:To assess the prognostic correlates of Doppler echocardiographically derived coronary flow reserve (CFR) on two coronaries in patients with negative stress echo. Vasodilator stress echocardiography allows dual imaging of regional...

Additive Prognostic Value of Coronary Flow Reserve in Patients With Chest Pain Syndrome and Normal or Near-Normal Coronary Arteries

In patients with angiographically normal coronary arteries and chest pain, pharmacologic stress echocardiography can identify a subgroup of patients with a less benign prognosis. Coronary flow reserve (CFR) in the left anterior descending artery (LAD) can currently be combined with wall motion analysis during vasodilator stress echocardiography. The aim of this study was to assess the prognostic value of CFR response in patients with normal coronary arteries and normal wall motion during stress. We selected 394 patients (171 men, 61 +/- 11 years of age) who underwent dipyridamole stress echocardiography (0.84 mg/kg over 6 minutes) with 2-dimensional echocardiography and CFR evaluation of the LAD by Doppler. All had angiographically nonsignificant (<50% quantitatively assessed) stenosis in any major vessel, normal left ventricular function (wall motion score index 1), and test negativity for conventional wall motion criteria. Images were independently read by a core laboratory for wall motion and a core laboratory for CFR. Mean CFR was 2.5 +/- 0.6 and 87 patients (22%) had an abnormal CFR <2. During a median follow-up of 51 months, 31 events occurred, namely 4 deaths and 27 nonfatal myocardial infarctions (3 ST-elevated myocardial infarctions and 24 non-ST-elevated myocardial infarctions). Kaplan-Meier survival estimates for hard events showed a better outcome for those patients with a normal CFR compared with those with an abnormal CFR (96% vs 55%, p = 0.001, at 48 months of follow-up). In conclusion, in patients with angiographically normal or near-normal coronary arteries and preserved at-rest regional and global left ventricular function at baseline and during stress, CFR adds incremental value to the prognostic stratification achieved with clinical and angiographic data.

Transthoracic Doppler ultrasound coronary flow reserve evaluation: preliminary insights into pathophysiology of Takotsubo cardiomyopathy

The aim of this study was to elucidate the role of coronary microvascular function in the pathophysiological scenario of Takotsubo cardiomyopathy. Noninvasive evaluations of coronary flow reserve through transthoracic Doppler ultrasound imaging of the left anterior descending coronary artery, a reliable marker of coronary microcirculation performance in the absence of epicardial coronary artery stenosis, were performed both in the acute and recovery phases of Takotsubo cardiomyopathy in consecutive patients strictly selected on the basis of absence of risk factors, concomitant diseases, or both impairing coronary microvascular function. Resting and hyperemic diastolic flow velocity tracings and corresponding velocity time integrals were obtained in seven consecutive patients, six of them women, aged 65-86 years (76 +/- 6.5) at admission and 23 +/- 4 days after, when left ventricular wall motion alterations recovered. In addiction, thrombolysis in myocardial infarction frame count of the two branches of the left coronary artery was evaluated on the cineangiogram obtained at admission. It was normal in both branches of the left coronary artery (left anterior descending, 30.6 +/- 8.79; circumflex, 23.4 +/- 2.96). In each patient, coronary flow reserve, calculated both on velocity time integrals (2.6 +/- 0.2) and average peak diastolic blood flow velocity (2.48 +/- 0.1) values, was in the normal range (>2.0) and did not significantly change when reevaluated in the recovery phase (2.55 +/- 0.1, 2.44 +/- 0.1). These data suggest that coronary microvascular function may not be impaired in Takotsubo patients when negative influences on coronary flow reserve by concomitant diseases and coronary risk factors are excluded. Its noninvasive evaluation with transthoracic Doppler ultrasound of the distal left anterior descending appears simple and useful in this type of patients.

Abstract 4234: Prognostic Implication of the Continuous Prognostic Spectrum of Coronary Flow Reserve in Patients with and without Angiographically Obstructive Coronary Artery Disease

Dual imaging of wall motion and coronary flow reserve (CFR) on left anterior descending (LAD) artery is now the state-of-the art technique for vasodilator stress echo. The additive prognostic value of CFR over regional wall motion has been established, but there is more than a binary (normal-abnormal ) response in CFR, which can be continuously titrated. Objectives. To assess the prognostic value of Doppler echocardiographic derived CFR in patients with and without angiographically obstructive coronary artery disease (CAD). 1244 patients (785 men, age 64±11 yy) with known or suspected CAD underwent dipyridamole (up to 0.84 mg/kg over 6′) stress echo with CFR evaluation of left anterior descending artery by Doppler and coronary angiography. Patients were followed-up for a median of 17 months. Mean CFR in the entire population was 2.25±0.64. During follow-up, there were 227 events (26 deaths, 55 STEMI, and 146 NSTEMI). Patients (n=384) undergoing revascularization were censored. Using the Kaplan-Meier method, the lowest quartile of CFR (&lt;1.80) was associated with a significantly (p&lt;0.0001) worst event rate than other quartiles (Figure ), both considering the group with (83 vs 53%, p&lt;0.0001) and without (53 vs 12%, p&lt;0.0001) obstructive CAD at angiography. CFR is a strong and independent prognostic predictor in patients with known or suspected CAD, but the spectrum of prognostic stratification is expanded if the response is titrated according to a continuous scale rather than artificially dichotomized.

Prognostic Implications of Coronary Flow Reserve on Left Anterior Descending Coronary Artery in Hypertrophic Cardiomyopathy

The aim of the study was to prospectively evaluate a cohort of patients with hypertrophic cardiomyopathy (HC) after coronary flow reserve (CFR) assessment of the left anterior descending coronary artery. Sixty-eight patients with HC (40 men, mean +/- SD 58 +/- 12 years of age) underwent dipyridamole (up to 0.84 mg/kg over 6 minutes) echocardiography with CFR evaluation of the left anterior descending coronary artery by Doppler. Seventy-four age- and gender-matched, apparently healthy subjects served as controls. A CFR value <2.0 was considered abnormal. CFR was decreased in patients with HC versus controls (2.12 +/- 0.39 vs 2.78 +/- 0.58, p <0.0001). CFR was abnormal in 26 of 39 symptomatic and in 5 of 29 asymptomatic patients with HC (67% vs 17%, p <0.0001). In addition, patients with HC with left ventricular obstruction had decreased CFR (p <0.0001) compared with those without obstruction. During follow-up (22 +/- 13 months), 27 events occurred: 1 sudden death, 1 nonfatal myocardial infarction, 4 cardioverter-defibrillator implantations, 6 hospitalizations for heart failure, 5 unstable anginas, 2 syncopes, and 8 atrial fibrillations. Three-year event rate was markedly higher in patients with abnormal than in those with normal CFR (79% vs 17%, p <0.0001). Events were more frequent in symptomatic than in asymptomatic patients (62% vs 10%, p <0.0001). However, the latter had a 10-fold increased risk of events in the presence of abnormal CFR (40% vs 4%, p = 0.02). In conclusion, mean CFR is markedly lower in patients with HC than in apparently healthy subjects. Abnormal CFR is a strong and independent predictor of outcome in patients with HC.

Stress Echocardiography Expert Consensus Statement--Executive Summary: European Association of Echocardiography (EAE) (a registered branch of the ESC)

Stress echocardiography is the combination of echocardiography with a physical, pharmacological, or electrical stress. The diagnostic endpoint for the detection of myocardial ischaemia is the induction of a transient worsening in regional function during stress. Stress echocardiography provides similar diagnostic and prognostic accuracy to radionuclide stress perfusion imaging, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. Among different stresses of comparable diagnostic and prognostic accuracy, semisupine exercise is the most used, dobutamine the best test for viability, and dipyridamole the safest and simplest pharmacological stress and the most suitable for combined wall motion coronary flow reserve assessment. The additional clinical benefit of myocardial perfusion contrast echocardiography and myocardial velocity imaging has been inconsistent to date, whereas the possibility of performing coronary flow reserve evaluation of the left anterior descending coronary artery by transthoracic Doppler echocardiography adds another potentially important dimension to stress echocardiography. New emerging fields of application taking advantage of the versatility of the technique are Doppler stress echo in valvular heart disease and in dilated cardiomyopathy. In spite of its dependence on the operator's training, stress echocardiography is today the best (most cost-effective and risk-effective) possible imaging choice to achieve the still elusive target of sustainable cardiac imaging in the field of non-invasive diagnosis of coronary artery disease. In 1935, Tennant and Wiggers1 demonstrated that coronary occlusion immediately resulted in instantaneous abnormality of wall motion. A large body of evidence2–5 recognized for the first time that transient dys-synergy was an early, sensitive, specific marker of transient ischaemia, clearly more accurate than ECG changes and pain. In European clinical practice,6–10 stress echo has been embedded in the legal and cultural framework of existing European laws and medical imaging referral guidelines. The …

The prognostic value of Doppler echocardiographic-derived coronary flow reserve is not affected by concomitant antiischemic therapy at the time of testing

When wall motion abnormality is the diagnostic end point, concomitant antiischemic therapy heavily modulates the prognostic value of dipyridamole echocardiography test (DET). A negative test result is less benign, and a positive test result is more malignant if performed under therapy. Recently, coronary flow reserve (CFR) was added to wall motion in dual imaging DET. The aim of the study was to determine whether antianginal medications affect the prognostic value of Doppler echocardiographic-derived CFR in patients with known or suspected coronary artery disease undergoing DET. In a prospective, multicenter, observational study, we evaluated 1,779 patients (1,072 males; 64 +/- 11 years) who underwent high-dose dipyridamole (0.84 mg/kg for 6 minutes) stress echo with CFR evaluation of left anterior descending (LAD) artery by Doppler. Seven hundred thirty-three (41%) patients were on antiischemic therapy at time of testing (nitrates and/or calcium antagonists and/or beta-blockers). Mean CFR was 2.3. +/- 0.6. At individual patient analysis, 1,141 patients had normal (CFR >2.0) and 638 had abnormal (CFR <or=2.0) CFR on LAD. During a median follow-up of 36 months, 263 events occurred as follows: 36 deaths and 59 ST-elevation myocardial infarctions (STEMIs) and 168 non-STEMIs (NSTEMIs). Survival was highest in patients with normal CFR and lowest in patients with abnormal CFR (87% vs 34%, P = .0001). Survival was comparable in patients with normal CFR on and off therapy and in patients with abnormal CFR on and off therapy. At multivariable analysis, hypertension (hazard ratio [HR] 1.5, 95% CI 1.0-1.9, P = .010), DET positivity for regional wall motion abnormalities (HR 5.7, 95% CI 4.3-7.4, P = .000), an abnormal CFR on LAD (HR 3.3, 95% CI 2.5-4.4, P = .000) were independent prognostic predictors of hard cardiac events. Ongoing antiischemic therapy at the time of testing does not modulate the prognostic value of Doppler echocardiographic-derived coronary flow reserve.

Prognostic value of coronary flow reserve and aortic distensibility indices in patients with suspected coronary artery disease

In recent studies it has been demonstrated that a reduced coronary flow reserve (CFR) is independently associated with a less benign long-term outcome. Aortic stiffness is one of the most important cardiovascular risk factors predicting cardiovascular morbidity and mortality. Vasodilator stress transesophageal echocardiography (TEE) is a suitable method to evaluate simultaneously CFR and elastic properties of the descending thoracic aorta. The aim of the present study was to assess the relative prognostic value of simultaneously measured CFR and aortic elastic properties by pulsed-wave Doppler TEE in patients with suspected or known coronary artery disease (CAD). The study comprised 157 in-hospital patients with chest pain. In all patients, stress TEE was used for the simultaneous evaluation of CFR and aortic distensibility indices [elastic modulus E(p) and Young's circumferential static elastic modulus E(s)]. During a mean follow-up of 48 +/- 8 months, 13 patients suffered cardiovascular death. By univariate analysis older age, diabetes mellitus, increased left ventricular (LV) end-diastolic diameter, increased LV mass index, lower LV ejection fraction, and lower CFR were significant predictors of cardiovascular survival. Multivariate regression analysis showed that only CFR (hazard ratio [HR] 10.31, P = 0.04), age (HR 1.20, P = 0.001), and increased left ventricular (LV) end-diastolic diameter (HR 1.14, P = 0.02) were independent predictors of cardiovascular survival. Only in the small number of patients without CAD and abnormal CFR aortic distensibility seemed to provide complementary prognostic information over CFR. In the majority of patients aortic distensibility did not offer complementary prognostic information to CFR during vasodilator stress TEE testing.

Factors predicting coronary flow reserve impairment in patients evaluated for chest pain: An ultrasound study

To evaluate the impact of multiple cardiovascular risk factors on coronary flow reserve (CFR) in a large patient population with acute chest pain referred for coronary angiography. Three hundred and ninety-four consecutive patients (mean age 59 +/- 10 years) were enrolled in the study. Blood flow velocity was measured, using transthoracic echocardiography, in the middle-distal tract of the left anterior descending coronary artery (LAD) at rest and during infusion of high-dose dipyridamole in 6 min. CFR was calculated as the ratio of hyperaemic to basal peak diastolic flow velocity. All patients underwent coronary angiography within 48-72 h of CFR evaluation and a LAD stenosis was considered significant for lumen diameter narrowing > or =70%. Out of 394 patients, 11 patients (3%) were excluded because of inadequate quality of the spectral Doppler envelope. In the group of 269 patients with LAD stenosis <70%, CFR was significantly reduced in 64 patients with >2 risk factors compared to 205 patients with < or =2 risk factors (2.24 +/- 0.48 vs. 2.52 +/- 0.53, P < 0.005). On multiple logistic regression analysis, age, hypertension and diabetes mellitus were related to reduced CFR. In 114 patients with significant LAD disease, CFR was not reduced in patients with multiple cardiovascular risk factors. On multiple logistic regression analysis, the percentages of stenosis and diabetes mellitus were independent determinants of CFR. In patients with acute chest pain, the occurrence of multiple cardiovascular risk factors adversely affected CFR in an additive manner, in absence of significant angiographic stenosis. Diabetes mellitus was a powerful coronary risk factor decreasing CFR both in patients with or without significant LAD disease.

Stress echocardiography expert consensus statement: European Association of Echocardiography (EAE) (a registered branch of the ESC)

Stress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. Among different stresses of comparable diagnostic and prognostic accuracy, semisupine exercise is the most used, dobutamine the best test for viability, and dipyridamole the safest and simplest pharmacological stress and the most suitable for combined wall motion coronary flow reserve assessment. The additional clinical benefit of myocardial perfusion contrast echocardiography and myocardial velocity imaging has been inconsistent to date, whereas the potential of adding - coronary flow reserve evaluation of left anterior descending coronary artery by transthoracic Doppler echocardiography adds another potentially important dimension to stress echocardiography. New emerging fields of application taking advantage from the versatility of the technique are Doppler stress echo in valvular heart disease and in dilated cardiomyopathy. In spite of its dependence upon operator's training, stress echocardiography is today the best (most cost-effective and risk-effective) possible imaging choice to achieve the still elusive target of sustainable cardiac imaging in the field of noninvasive diagnosis of coronary artery disease.

Transthoracic echocardiographic imaging of coronary arteries: tips, traps, and pitfalls

The aim of this paper is to highlight coronary investigation by transthoracic Doppler evaluation. This application has recently been introduced into clinical practice and has received enthusiastic feedback in terms of coronary flow reserve evaluation on left anterior coronary artery disease diagnosis. Such diagnosis represents the most important clinical application but has in itself some limitations regarding anatomical and technological knowledge. The purpose of this paper is to offer a didactic approach on how to investigate the different segments of left anterior and posterior descending coronary arteries by transthoracic ultrasound using different anatomical key structures .as markersWe will conclude by underlining that, nowadays, innovative technology allows complete evaluation of both major coronary arteries in many patients in a resting condition as well as during pharmacology stress-tests, but we often do not know it.

The additive prognostic value of wall motion abnormalities and coronary flow reserve during dipyridamole stress echo

The aim of the study was to evaluate the prognostic value of Doppler echocardiographic-derived coronary flow reserve (CFR) over regional wall motion in patients with known or suspected coronary artery disease (CAD) undergoing dipyridamole echocardiography test (DET). In a prospective, multicentre, observational study, we evaluated 1145 patients (702 males; 64 +/- 11 years) who underwent high-dose dipyridamole (0.84 mg/kg over 6 min) stress echo with CFR evaluation of LAD by Doppler. DET was positive for regional wall motion abnormalities in 291 (25%) and negative in 854 (74%) patients. Mean CFR was 2.2 +/- 0.5. At individual patient analysis 702 patients had normal (CFR > 2.0) and 443 had abnormal CFR on LAD. During a median follow-up of 27 months, 109 events occurred: 16 deaths, 17 non-fatal myocardial infarctions, 76 re-hospitalizations for unstable angina. The 30 months infarction-free survival showed the best outcome for those patients with negative DET by wall motion criteria and normal CFR and the worst outcome for patients with positive DET by wall motion and abnormal CFR (99 vs. 68%, P < 0.001). At multivariable analysis, CFR on LAD [hazard ratio (HR) 2.4, 95% CI 1.1-5.4, P = 0.030], medical therapy at time of testing (HR 2.8, 95% CI 1.2-6.6, P = 0.022), DET positivity for regional wall motion abnormalities (HR 3.6, 95% CI 1.5-8.7, P = 0.000), and angina on effort (HR 6.3, 95% CI 2.7-14.8, P = 0.000) were independent prognostic predictors of hard cardiac events. In patients with known or suspected CAD, DET result by wall motion criteria and CFR are additive and complementary for the identification of patients at risk of experiencing hard events.

Prognostic Value of Coronary Flow Reserve in Medically Treated Patients With Left Anterior Descending Coronary Disease With Stenosis 51% to 75% in Diameter

According to American College of Cardiology/American Heart Association/Society for Cardiovascular Angiography and Interventions 2005 guidelines on percutaneous intervention, intracoronary physiologic measurement in the assessment of effects of intermediate coronary stenoses in patients with anginal symptoms is a class IIa indication. This study assessed the additional prognostic value of Doppler echocardiographically derived coronary flow reserve (CFR) in patients with single-vessel disease and intermediate stenosis severity. We enrolled 86 patients (44 men; 66 +/- 10 years of age) with angiographically assessed single-vessel coronary artery disease of the left anterior descending coronary artery (LAD) with quantitatively assessed diameter stenosis severity 50% to 75%. All patients underwent dipyridamole (up to 0.84 mg/kg over 6 minutes) stress echocardiography with wall motion analysis by 2-dimensional echocardiography and CFR evaluation of the affected artery by Doppler. All patients were followed up for a median of 14 months (first quartile 10, third quartile 18) after diagnostic coronary angiography (without percutaneous intervention for a clinically driven decision). Mean diameter stenosis of the LAD was 58 +/- 10%. Mean CFR of the LAD was 2.09 +/- 0.5. Regional wall motion abnormality at peak stress was present in 17 patients. During follow-up, 24 events occurred: 6 nonfatal ST-elevation myocardial infarctions and 18 non-ST-elevation myocardial infarctions. Thirty-month spontaneous event-free survival was higher in patients with normal CFR and lower in patients with decreased CFR (86% vs 30%, p = 0.0001). At Cox analysis, a CFR <2 (hazard ratio 24.2, 95% confidence interval 3.2 to 179.7, p = 0.002) was the only independent prognostic predictor of outcome. In conclusion, in medically treated patients with single-vessel disease of intermediate severity, decreased CFR is associated with a worse outcome.

Additional Prognostic Value of Coronary Flow Reserve in Diabetic and Nondiabetic Patients With Negative Dipyridamole Stress Echocardiography by Wall Motion Criteria

The aim of this prospective, multicenter, observational study was to compare the prognostic value of Doppler echocardiographic-derived coronary flow reserve (CFR) in diabetic and nondiabetic patients with known or suspected coronary artery disease and negative dipyridamole stress echocardiography. The prognostic value of CFR in diabetic patients with negative stress echocardiography remains unknown. The study group consisted of 1,130 patients (207 diabetics) with known (n = 418) or suspected (n = 712) coronary artery disease and negative stress echocardiography by wall motion criteria. All underwent dipyridamole (up to 0.84 mg/kg over 6 min) echocardiography with CFR evaluation of left anterior descending artery by Doppler. A value of CFR < or =2.0 was considered abnormal. Coronary flow reserve was abnormal in 309 (27%) patients. During a median follow-up of 16 months, 98 events (8 deaths, 24 ST-segment elevation myocardial infarctions, and 66 non-ST-segment elevation myocardial infarctions) occurred. In addition, 101 patients underwent revascularization and were censored. Multivariable prognostic indicators were abnormal CFR (p < 0.0001), anti-ischemic therapy at the time of testing (p = 0.002), age (p = 0.02), and resting wall motion abnormality (p = 0.05). The event rate was markedly higher (p < 0.0001) for both diabetic and nondiabetic patients with abnormal CFR as compared with diabetic and nondiabetic patients with normal CFR. Of note, a preserved CFR off therapy identified diabetic and nondiabetic patients with better survival and comparable yearly event rates (2.2% vs. 2.0%, p = 0.80). Coronary flow reserve provides independent prognostic information in diabetic and nondiabetic patients with known or suspected coronary artery disease and negative dipyridamole stress echocardiography. In particular, a normal CFR off therapy is associated with better and similar survival in the 2 populations.

Transthoracic Echo-Doppler Assessment of Coronary Microvascular Function Late after Kawasaki Disease

The goal of this study was to demonstrate that Doppler transthoracic echocardiography (TTE) may represent a valuable tool for the noninvasive demonstration of coronary microvascular dysfunction in children with previous Kawasaki disease (KD) by the measurement of coronary flow reserve (CFR) during cold pressor test (CPT). Twenty-five children with previous KD (mean follow-up, 4.6 +/- 2.6 years) were included in the study-16 with no evidence of coronary artery lesions (CALs(-)) by TTE and 9 with coronary aneurysms (CALs(+)). Seventeen age-matched healthy subjects were also recruited. Diastolic peak velocity was measured by pulsed Doppler both at rest (DPV(Rest)) and during CPT (DPV(CPT)) in the anterior descending artery. CFR was calculated as DPV(CPT)/DPV(Rest). KD patients demonstrated significantly higher values of DPV(Rest) (0.21 +/- 0.05 vs 0.13 +/- 0.01 cm/sec, p < 0.0001) and DPV(CPT) (0.33 +/- 0.07 vs 0.27 +/- 0.03 cm/sec, p < 0.005). CFR was reduced in KD compared to control subjects (1.5 +/- 0.4 vs 2.1 +/- 0.2, p < 0.0001). CFR was decreased in a similar manner in both CALs(+) patients (1.4 +/- 0.4, p = 0.002 vs controls) and CALs(-) patients (1.6 +/- 0.4, p < 0.0001 vs controls). Doppler TTE at rest and during CPT may represent a valuable modality for CFR evaluation in children with a history of KD. CFR is significantly reduced in KD patients independently of the presence of CALs.

Reduced coronary flow reserve in young adults with renal transplant

Some degree of cardiovascular disease should be suspected in young adults who have been paediatric renal transplant recipients also if no systematic data collection is routinely performed in clinical setting. The aim of our work was to evaluate the degree of cardiovascular damage in these young patients, using a minimally invasive technique. We then evaluated coronary flow reserve (CFR) and carotid intima-media thickness (IMT) in 25 patients (13 males, median age 23.7 years). Coronary flow velocity on the left anterior descending coronary artery was assessed by transthoracic echocardiography, before and after dipyridamole, after standard echocardiography. CFR was compared with that of a small control group (n = 16; median age 25 yrs). In this relatively young sample, mean CFR was 2.8 +/- 0.6 (median 2.75), and half of the patients had reduced coronary reserve (P = 0.01). Mean IMT (0.48 +/- 0.08 mm) was only slightly, though significantly larger compared with the reference standard (P < 0.05) but was significantly thinner in normotensive than in hypertensive patients (0.42 +/- 0.06 vs 0.49 +/- 0.05 mm, P < 0.05). The time on dialysis prior to transplantation, hypertension and age at the time of CFR evaluation affect CFR. IMT did not correlate with CFR. CFR and IMT abnormalities are common in young transplant recipients, in spite of the fact that our paediatric population has much less of the atherosclerotic 'legacy' common to adult patients.

Noninvasive Evaluation of Flow Reserve in the Left Anterior Descending Coronary Artery in Patients With Cardiac Syndrome X

Data on coronary flow reserve (CFR) in patients with syndrome X are still controversial. Further, noninvasive evaluation of epicardial and microvascular flow reserves in these patients has never been performed. In 17 patients with syndrome X and in 17 age- and gender-matched control subjects, CFR in the mid left anterior descending coronary artery (LAD) was evaluated by transthoracic color and pulse-wave Doppler using a 7-mHz probe (Sequoia, Siemens). Peak diastolic LAD flow was calculated at rest and at peak adenosine (140 microg/kg/min intravenously in 90 seconds). Myocardial contrast echocardiography (MCE) was performed at rest and during adenosine use by real-time cadence pulse sequencing and intravenous SonoVue (Bracco; 5 ml at 1 ml/min) and microvascular blood volume (A), velocity (beta), and flow (Axbeta) by replenishing curves (y = A[1 - e(betat)]). CFR was measured by Doppler echocardiography as an adenosine/rest velocity ratio and by MCE as a microvascular volume, velocity, and flow adenosine/rest ratio. Compared with controls, patients with syndrome X demonstrated lower LAD CFR and velocity and flow microvascular flow reserves (p <0.01, <0.005, and <0.005, respectively). In patients with syndrome X, those with angina and ST-segment depression during adenosine testing had even lower LAD CFR and velocity and flow microvascular flow reserves compared with those with no symptoms (p <0.0001, <0.0001, and <0.005, respectively). LAD CFR demonstrated a significant linear correlation with velocity microvascular flow reserve (r = 0.92, p <0.0001) and flow microvascular flow reserve (r = 0.77, p <0.0001). In conclusion, CFR in the LAD, successfully evaluated by transthoracic Doppler echocardiography and MCE, is significantly decreased in patients with syndrome X and even more in those with angina pectoris and ST-segment depression during adenosine testing. Thus, noninvasive evaluation of CFR by echocardiography is feasible and provides information on the severity of microvascular impairment.

195 Evaluation of coronary flow reserve in young adults with renal transplant

195 Evaluation of coronary flow reserve in young adults with renal transplant