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

Prognostic value of pharmacologic stress echocardiography in diabetic and nondiabetic chest pain patients with intermediate-to-high threshold positive exercise electrocardiography

Aims: To compare the prognostic value of pharmacologic stress echocardiography in diabetic and nondiabetic patients with chest pain and intermediate-to-high threshold positive exercise electrocardiography. Materials and methods: 935 chest pain patients (131 diabetics) with ST-segment depression &#8805;1 mm on exercise electrocardiography at >75 watt workload underwent dipyridamole (n=786) or dobutamine (n=149) stress echocardiography and were followed-up for the occurence of hard (death, infarction) and major events (death, infarction, late revascularization). Results: During a median follow-up of 26 months, 158 events (51 deaths, 28 myocardial infarctions, and 79 late revascularizations) occurred: 34 in diabetics and 124 in nondiabetics (see Figure). Independent predictors of hard events were age, diabetes, and ischemia at stress echo. 5-year hard event rate was 24 % in patients with and 4 % in those without ischemia (p<0.0001). Independent predictors of major events were age, diabetes, hypercholesterolemia, smoking habit, antianginal therapy at the time of testing, and ischemia at stress echo. 5-year major event rate was 46 % in patients with and 7 % in those without ischemia (p<0.0001). Conclusions: Stress echocardiography is effective in risk stratifying diabetics and nondiabetics with intermediate-to-high threshold ischemic exercise electrocardiography. However, major event rate associated with a non ischemic test is similar in diabetics and nondiabetics during the first year of follow-up, and markedly increased in the former thereafter

Ventricular-Arterial coupling during dipyridamole stress

Background: The interaction of the heart with the systemic vasculature, termed ventricular-arterial coupling, is a central determinant of net cardiovascular performance in normal and pathological conditions. Ventricular and arterial elastance can be easily assessed by echocardiography, both at rest and during stress. Aim: To assess noninvasively left ventricular-arterial coupling in healthy and diseased subjects at rest and during dipyridamole (DIP) stress. Materials and methods: We enrolled 365 patients (63?16 years; 231 males) referred to stress echo lab: 131 "normals" (Nl); 86 patients with coronary artery disease, 68 with negative (CAD, SE -) and 18 with positive (CAD, SE+) stress echo; 148 with idiopathic dilated cardiomyopathy (DCM). In all, ventricular-arterial coupling was indexed by the ratio of ventricular force (Systolic Pressure/End-Systolic Volume index) to arterial elastance (EaI, ratio of end-systolic pressure by stroke volume). 2D echo (for ESV and stroke volume) and cuff sphygmomanometer (systolic pressure, multiplied x 0.90 to obtain end-systolic pressure) provided the raw measurements. Results: At rest, EaI was profoundly increased in DCM (6.3?4.4; p<.001 vs. all other groups: Nl=4?1.1; CAD, SE-=3.8?1; CAD SE+=4.2?1.3). DIP maximized ventricular-arterial coupling in normals. Residual vasodilatation and contractile reserve slightly increased cardiac efficiency in DCM and in CAD SE- pts. The CAD SE+ pts showed negative contractile reserve and the worse stress ventricular arterial coupling (see figure). Conclusions: Ventricular-arterial coupling was optimized by DIP in normals, and disrupted in CAD patients with stress induced ischemia. Effective arterial elastance is dramatically increased in DCM at rest and weakly responds to vasodilator stress

Coronary Flow Reserve During Dipyridamole Stress Echocardiography Predicts Mortality

ObjectivesThe goal of this study was to evaluate the ability of coronary flow reserve (CFR) over regional wall motion to predict mortality in patients with known or suspected coronary artery disease (CAD).BackgroundCFR evaluated using pulsed Doppler echocardiography testing on left anterior descending artery is the state-of-the-art method during vasodilatory stress echocardiography.MethodsIn a prospective, multicenter, observational study, we evaluated 4,313 patients (2,532 men; mean age 65 ± 11 years) with known (n = 1,547) or suspected (n = 2,766) CAD who underwent high-dose dipyridamole (0.84 mg/kg over 6 min) stress echocardiography with CFR evaluation of left coronary descending artery (LAD) by Doppler. Overall mortality was the only endpoint analyzed.ResultsStress echocardiography was positive for ischemia in 765 (18%) patients. Mean CFR was 2.35 ± 0.68. At individual patient analysis, 1,419 (33%) individuals had CFR ≤2. During a median follow-up of 19 months (1st quartile 8; 3rd quartile 36), 146 patients died. The 4-year mortality was markedly higher in subjects with CFR ≤2 than in those with CFR >2, both considering the group with ischemia (39% vs. 7%; p < 0.0001) and the group without ischemia at stress echocardiography (12% vs. 3%; p < 0.0001). At multivariable analysis, CFR on LAD ≤2 (hazard ratio [HR]: 3.31; 95% confidence interval [CI]: 2.29 to 4.78; p < 0.0001), ischemia at stress echocardiography (HR: 2.40, 95% CI: 1.65 to 3.48, p < 0.0001), left bundle branch block (HR: 2.26, 95% CI: 1.50 to 3.41; p < 0.0001), age (HR: 1.08, 95% CI: 1.06–1.10; p < 0.0001), resting wall motion score index (HR: 3.52, 95% CI: 2.38 to 5.21; p < 0.0001), male sex (HR: 1.74, 95% CI: 1.12 to 2.52; p = 0.003), and diabetes mellitus (HR: 1.47, 95% CI: 1.03 to 2.08; p = 0.03) were independent predictors of mortality.ConclusionsCFR on LAD is a strong and independent indicator of mortality, conferring additional prognostic value over wall motion analysis in patients with known or suspected CAD. A negative result on stress echocardiography with a normal CFR confers an annual risk of death <1% in both patient groups

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