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 marker

Cardiovascular risk prediction in the real world. The discouraging evidences coming from literature

Risk prediction plays a leading role in cardiovascular (CV) prevention. Thus, several risk charts have been developed in different Countries in the attempt to identify subjects at high risk who might benefit from more aggressive and early interventions. However despite the availability of several risk charts, they are underutilized in clinical practice. Indeed risk charts show main limitations: they estimate absolute, but not individual risk; their performance is affected by changes on the incidence of CV diseases; they do not take into account the duration of risk exposure, which is related to the progression of atherosclerosis. Moreover, risk estimate might be less accurate in younger, in women, and in the elderly. Addition of novel risk markers have substantially failed to improve risk charts' discrimination power. Imaging has recently gained relevance in CV risk stratification for its ability to detect subclinical atherosclerosis. Among imaging techniques coronary artery calcium score(CACS) emerged as the most powerful and independent predictor of CV events. Hence, a CACSbased screening strategy have been proposed in all asymptomatic middle-aged people. However since CACS it is still quite expensive and not-radiation free, it is not recommended by most scientific guidelines. Conversely, detecting subclinical organ damage (SOD) like LV hypertrophy, carotid plaque, renal failure, microalbuminuria or the metabolic syndrome in subjects at intermediate risk is pretty cost-effective yielding to reclassification of subjects into higher-risk strata. Thus, merging information coming from different tools (risk scores, biomarkers, and non-invasive imaging) individual risk might be better stratified saving costs. In the next future, an integrated, semi-automated, high-reproducible and inexpensive ultrasound approach could represent a key point to approach the individual risk

The non-invasive documentation of coronary microcirculation impairment: role of transthoracic echocardiography

Transthoracic Doppler echocardiographic-derived coronary flow reserve is an useful hemodynamic index to assess dysfunction of coronary microcirculation. Isolated coronary microvascular abnormalities are overt by reduced coronary flow reserve despite normal epicardial coronary arteries. These abnormalities may occur in several diseases (arterial hypertension, diabetes mellitus, hypercholesterolemia, syndrome X, aortic valve disease, hypertrophic cardiomyopathy and idiopathic dilated cardiomyopathy). The prognostic role of impaired microvascular coronary flow reserve has been shown unfavourable especially in hypertrophic or idiopathic dilated cardiomyopathies. Coronary flow reserve reduction may be reversible, for instance after regression of left ventricular hypertrophy subsequent to valve replacement in patients with aortic stenosis, after anti-hypertensive treatment or using cholesterol lowering drugs. Coronary flow reserve may increase by 30% or more after pharmacological therapy and achieve normal level >3.0. In contrast to other non invasive tools as positron emission tomography, very expensive and associated with radiation exposure, transthoracic Doppler-derived coronary flow reserve is equally non invasive but cheaper, very accessible and prone to a reliable exploration of coronary microvascular territories, otherwise not detectable by invasive coronary angiography, able to visualize only large epicardial arteries

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 wall motion and CFR both on left anterior descending (LAD) and right coronary artery (RCA). Methods: The study group comprised 460 patients with known or suspected coronary artery disease and negative stress echo by wall motion criteria. All underwent dipyridamole (up to 0.84 mg/kg over 6 minutes) stress echo with CFR evaluation of either LAD or RCA by Doppler, and were followed up for a median of 32 months. A CFR value of(2.0 was taken as abnormal. Results: CFR was abnormal in 174 patients (38%) (57 in LAD only, 48 in RCA only, and 69 in both LAD and RCA) and normal in 286 patients (62%). During follow-up, there were 77 cardiac events: 5 deaths, 44 acute coronary syndromes (6 STEMI, and 38 NSTEMI) and 28 late (.6 months from stress echo) revascularisations. CFR of (2.0 on LAD was the strongest multivariable predictor of either definite (death, acute coronary syndrome) and major (death, acute coronary syndrome, late revascularisation) events, followed by diabetes mellitus. Antiischaemic therapy at the time of testing and resting wall motion abnormality were also independently associated with major events. Preserved CFR in both LAD and RCA was associated with better (p,0.0001) definite and major event-free survival compared to abnormal CFR in one or both coronary vessels. Conclusion: CFR evaluation of either LAD or RCA allows the identification of distinct prognostic patterns. In particular, preserved CFR in both coronary vessels is highly predictive of a very favourable outcome, while reduced CFR in either coronary vessel, and especially on LAD, is a strong predictor of future cardiac events

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

Live 3-D stress echo: is beauty also a sign of intelligence?

Background: Last generation 3-D live stress echo has potential for adding "beauty" (seductive display) and also "intelligence" (unique quantitative information) to the robust, albeit qualitative, classic 2-D stress echo based on wall motion analysis. Aim: to assess feasibility of 3-D stress echo. Materials and methods: From May 2005, we enrolled 214 consecutive patients (age=64?11 years; 88 females) routinely screened for suspect coronary artery disease with dipyridamole (0.84 mg/kg in 6\u27) stress echo. Transthoracic echocardiography (2D, 3D and coronary flow reserve, CFR, by pulsed Doppler) was performed with commercially available systems (iE33) using phase array probes (1-5 and 3-8 MHz, S5-S8) and a matrix 3D probe for 3D-Live application. Each data set was analyzed with a dedicated software (3DQ, QLab - Advanced Ultrasound Quantification Software - vs. 4.1 and 4.2, Philips Electronics), including 3D volumes and dissynchrony index (DI), considered as the mean value of standard deviation of maximum time to systolic volume variation. Results: Interpretable 2D data were obtained in all pts (100 % feasibility), CFR data on left anterior descending artery in 185 pts (88 %) and 3D data in 151 pts (70 %). In the 48 pts with negative stress echo (for wall motion criteria) by 2D and 3D, 3D-DI decreased (rest=1.3?.8 vs. stress=.99?.54, p<.001): see figure. In patients with normal resting echo and positive stress echo, 3D-DI increased (rest= 4.5?1.9 vs. stress= 8.3?3.2, p<0.01). Last generation live 3D dipyridamole stress echo still suffers a feasibility gap vs. 2D and Doppler-CFR stress echo, but shows potential for adding substantial "beauty" (convincing display) and perhaps some extra-"intelligence" (quantitative support) to classic stress echo

Prognostic implication of coronary flow reserve in diabetic and nondiabetic patients with negative dipyridamole stress echo by wall motion criteria

Objectives: Aim of this prospective, multicenter, observational study was to assess the prognostic value of Doppler echocardiographic derived coronary flow reserve (CFR) in diabetic and nondiabetic patients with known or suspected coronary artery disease (CAD) and negative dipyridamole stress echo. Methods: The study group consisted of 1130 patients (207 diabetics) with known (n=418) or suspected (n=712) CAD and negative stress echo by wall motion criteria. All underwent dipyridamole (up to 0.84 mg/kg over 6\u27) echo with CFR evaluation of left anterior descending artery by Doppler. A value of CFR <2.0 was considered abnormal. Results: CFR was normal in 821 (63%) and abnormal in 309 (27%) patients. During a median follow-up of 16 months, 98 events (8 deaths, 24 STEMI, and 66 NSTEMI) occurred. In addition, 89 patients underwent revascularization and were censored. Multivariable prognostic indicators were abnormal CFR (HR=4.95; 95% CI=3.26-7.50; p<0.0001), antianginal therapy at the time of testing (HR=1.96; 95% CI=1.29-2.98; p=0.002), age (HR=1.02; 95% CI=1.00-1.04; p=0.02), and resting wall motion abnormalities (HR=1.50; 95% CI=1.00-2.25; p=0.05). The 36-month event rate was lower (p<0.0001) for either diabetics and nondiabetics with normal CFR as compard to diabetics and nondiabetics with abnormal CFR (Figure). Conclusion: CFR provides effective prognostic information in diabetic and nondiabetic patients with known or suspected CAD and negative dipyridamole stress echo. In particular, a reduced CFR is associated with worse outcome in both populations

Genetic stress echocardiography: role of A2a receptors polymorphism in modulating coronary flow reserve response in non-ischemic dilated cardiomyopathy

Background: Vasodilator stress imaging is based on coronary A2a receptor stimulation via endogenous adenosine (with dipyridamole administration), exogenous adenosine, or selective A2a receptor stimulation (with binodenoson).The recognized inter-individual variability in response to adenosine might be in part determined by genetic polymorphism in A2a adenosine receptors. Aim: to assess whether A2a receptor (263 C>T and 1976 C>T) polymorphism affects the coronary flow reserve (CFR) response in patients with non-ischemic dilated cardiomyopathy (DCM). Methods: we evaluated 44 DCM patients 34 males; age 62?9 years) by transthoracic dipyridamole (0.84 mg/kg) stress echocardiography. All patients had an ejection fraction <40% (mean 21.1?16.3%) and angiographically normal coronary arteries with NYHA class <3. CFR was assessed on left anterior descending coronary artery using Doppler as the ration of maximal peak vasodilation (dipyridamole) to rest diastolic flow velocity. All patients underwent peripheral blood sampling and A2a receptor genotyping with PCR and enzyme restriction analysis. Results: CFR was 2.1?0.6 (range=1.5-4). There was no correlation between CFR and 263 C>T variant of A2a gene. However, patients with 1976 TT genotype had significantly lower values from 1976 CC patients (p<0.05). The 7 patients omozygous for 1976 TT had an OR=8.8 (95% CI, 1-81, p=0.04) for abnormal CFR. Conclusion: In DCM patients 1976 C>T polymorphism of the adenosine A2A receptor gene may affect CFR response. In particular, the 1976-TT variant of A2a gene blunts the coronary vasodilatory response

Incremental value of contrast myocardial perfusion to detect intermediate versus severe coronary artery stenosis during stress-echocardiography

<p>Abstract</p> <p>Background</p> <p>We aimed to compare the incremental value of contrast myocardial perfusion imaging (MPI) for the detection of intermediate versus severe coronary artery stenosis during dipyridamole-atropine echocardiography (DASE).</p> <p>Wall motion (WM) assessment during stress-echocardiography demonstrates suboptimal sensitivity to detect coronary artery disease (CAD), particularly in patients with isolated intermediate (50%-70%) coronary stenosis.</p> <p>Methods</p> <p>We performed DASE with MPI in 150 patients with a suspected chest pain syndrome who were given clinical indication to coronary angiography.</p> <p>Results and discussion</p> <p>When CAD was defined as the presence of a ≥50% stenosis, the addition of MPI increased sensitivity (+30%) and decreased specificity (-14%), with a final increase in total diagnostic accuracy (+16%, p < 0.001). The addition of MPI data substantially increased the sensitivity to detect patients with isolated intermediate stenosis from 37% to 98% (p < 0.001); the incremental sensitivity was much lower in patients with severe stenosis, from 85% to 96% (p < 0.05), at the expense of a higher decrease in specificity and a final decrease in total diagnostic accuracy (-18%, p < 0.001).</p> <p>Conclusions</p> <p>The addition of MPI on top of WM analysis during DASE increases the diagnostic sensitivity to detect obstructive CAD, whatever its definition (≥50% or > 70% stenosis), but it is mainly driven by the sensitivity increase in the intermediate group (50%-70% stenosis).</p> <p>The total diagnostic accuracy increased only when defining CAD as ≥50% stenosis, since in patients with severe stenosis (> 70%) the decrease in specificity is not counterbalanced by the minor sensitivity increase.</p