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

Dobutamine-induced myocardial ischemia and ST-segment elevation in collateral-dependent myocardium

In patients with obstructive coronary artery disease, electrocardiographic (ECG) ST-segment elevation (STE) is frequently seen during dobutamine stress echocardiography (DSE) in leads overlying previous transmural left ventricular (LV) myocardial infarction. The mechanism of occasional STE during DSE in LV region with inducible myocardial ischemia and no previous myocardial infarction has not been well delineated. We retrospectively identified 28 adults (age 51 to 83 years [69 ± 8]; 82% men) with STE (>1 mm at ≥80 ms after J point in ≥2 contiguous leads without pathologic Q waves) and inducible myocardial ischemia in the same territory during DSE. STE occurred in inferior (n = 16), inferolateral (n = 8), anterior (n = 1), lateral (n = 2), or anterolateral (n = 1) leads and was associated with ischemic symptoms in 17 patients (61%). Inducible LV wall motion abnormality developed in LV segments corresponding to ECG STE in all patients. Coronary arteriography (within 1 week of the index DSE) showed severe luminal narrowing in the major epicardial coronary artery supplying the region with DSE STE and ischemia (90% to 99% in 9 patients [32%] and 100% in 19 patients [68%]). The ischemic region was supplied by ipsilateral (n = 4 [14%]), contralateral (n = 21 [75%]), or both ipsilateral and contralateral (n = 3 [11%]) collateral branches. In conclusion, dobutamine-induced ECG STE in LV segments with normal baseline wall motion is a highly reliable marker of viable collateral-dependent myocardium.

End-systolic elastance and ventricular-arterial coupling reserve predict cardiac events in patients with negative stress echocardiography

Background. A maximal negative stress echo identifies a low-risk subset for coronary events. However, the potentially prognostically relevant information on cardiovascular hemodynamics for heart-failure-related events is unsettled. Aim of this study was to assess the prognostic value of stress-induced variation in cardiovascular hemodynamics in patients with negative stress echocardiography. Methods. We enrolled 891 patients (593 males mean age 63 ± 12, ejection fraction 48 ± 17%), with negative (exercise 172, dipyridamole 482, and dobutamine 237) stress echocardiography result. During stress we assessed left ventricular end-systolic elastance index (E_LVI), ventricular arterial coupling (VAC) indexed by the ratio of the E_LVI to arterial elastance index (E_aI), systemic vascular resistance (SVR), and pressure-volume area (PVA). Changes from rest to peak stress (reserve) were tested as predictors of main outcome measures: combined death and heart failure hospitalization. Results. During a median followup of 19 months (interquartile range 8–36), 50 deaths and 84 hospitalization occurred. Receiver-operating-characteristic curves identified as best predictors E_LVI reserve for exercise (AUC = 0.871) and dobutamine (AUC = 0.848) and VAC reserve (AUC = 0.696) for dipyridamole. Conclusions. Patients with negative stress echocardiography may experience an adverse outcome, which can be identified by assessment of E_LVI reserve and VAC reserve during stress echo.

Transplant of stunned donor hearts rescued by pharmacological stress echocardiography: a "proof of concept" report

Background

Due to the shortage of donor hearts, the criteria for acceptance have been considerably expanded. Hearts with regional or global left ventricular dysfunction are excluded from donation, but stress echo might be useful to identify patients with reversible wall motion abnormalities, potentially eligible for donation.

Methods

Six marginal candidate donors (mean age, 40 ± 13 years; three men) were enrolled. Resting echocardiography showed in all subjects a LV ejection fraction ≥ 45% (mean 51 ± 5%), but multiple risk factors were present. All donors had either global or discrete wall motion abnormalities: Wall Motion Score Index (WMSI) rest = 1.33 ± 0.25. Stress echocardiography was performed with the dipyridamole high dose of 0.84 mg/kg given over 6 min.

Results

The stress echo results were abnormal in three donors (WMSI rest = 1.51 ± 0.19 vs peak = 1.41 ± 0.30). These hearts were excluded from donation and cardiac pathology verification was available in two cases of confirmed LV myocardial fibrosis and/or severe coronary stenosis. The remaining three hearts improved during stress (WMSI rest = 1.15 ± 0.13 vs peak = 1.04 ± 0.06) and were transplanted uneventfully. Recipients (three males, mean age 53 ± 4 years) underwent post-TX coronary angiography, IVUS and endomyocardial biopsies. No recipient had primary graft failure, and all showed normal coronary angiography and normal LV function (EF = 57 ± 6%; WMSI = 1 ± 0) at 1-month post-TX. The recipients were alive at 12-month median follow-up.

Conclusions

Dipyridamole stress echo performed in brain-dead potential donors with LV resting global or discrete wall motion abnormalities identifies hearts with severe morphologic abnormalities excluded from donation (with fixed response during stress echo) from hearts eligible for donation, showing improvement in regional wall motion during stress (viability response) and normal function and coronary anatomy following transplantation.

Clinical applications of exercise stress echocardiography in the treadmill with upright evaluation during and after exercise

Exercise stress echocardiography is the most frequently used stress test in our laboratory. Exercise echocardiography is used mainly in the study of patients with coronary artery disease. However, the technique is increasingly being used to study other diseases. In our centre, we use an original methodology, published by us in 2000, in which we evaluate heart function during exercise in the treadmill. After the exercise, patients are maintained in orthostatic position when appropriate or lying down in left lateral decubitus for further evaluation. Since this method seems to increase the quality and the quantity of information obtained in so many clinical arenas, we now present a detailed review of this methodology and its applications.

Inducible myocardial ischemia and outcomes in patients with coronary artery disease and left ventricular dysfunction

OBJECTIVES

The study objectives were to test the hypotheses that ischemia during stress testing has prognostic value and identifies those patients with coronary artery disease (CAD) with left ventricular (LV) dysfunction who derive the greatest benefit from coronary artery bypass grafting (CABG) compared with medical therapy.

BACKGROUND

The clinical significance of stress-induced ischemia in patients with CAD and moderately to severely reduced LV ejection fraction (EF) is largely unknown.

METHODS

The STICH (Surgical Treatment for IsChemic Heart Failure) trial randomized patients with CAD and EF ≤35% to CABG or medical therapy. In the current study, we assessed the outcomes of those STICH patients who underwent a radionuclide (RN) stress test or a dobutamine stress echocardiogram (DSE). A test was considered positive for ischemia by RN testing if the summed difference score (difference in tracer activity between stress and rest) was ≥4 or if ≥2 of 16 segments were ischemic during DSE. Clinical endpoints were assessed by intention to treat during a median follow-up of 56 months.

RESULTS

Of the 399 study patients (51 women, mean EF 26 ± 8%), 197 were randomized to CABG and 202 were randomized to medical therapy. Myocardial ischemia was induced during stress testing in 256 patients (64% of the study population). Patients with and without ischemia were similar in age, multivessel CAD, previous myocardial infarction, LV EF, LV volumes, and treatment allocation (all p = NS). There was no difference between patients with and without ischemia in all-cause mortality (hazard ratio: 1.08; 95% confidence interval: 0.77 to 1.50; p = 0.66), cardiovascular mortality, or all-cause mortality plus cardiovascular hospitalization. There was no interaction between ischemia and treatment for any clinical endpoint.

CONCLUSIONS

In CAD with severe LV dysfunction, inducible myocardial ischemia does not identify patients with worse prognosis or those with greater benefit from CABG over optimal medical therapy. (Comparison of Surgical and Medical Treatment for Congestive Heart Failure and Coronary Artery Disease [STICH]; NCT00023595).

Low-dose sodium nitrite attenuates myocardial ischemia and vascular ischemia-reperfusion injury in human models

OBJECTIVES

The aim of this study was to assess the potential benefits of inorganic nitrite in 2 clinical models: stress-induced myocardial ischemia and whole-arm ischemia-reperfusion.

BACKGROUND

Inorganic nitrite, traditionally considered a relatively inert metabolite of nitric oxide, may exert vasomodulatory and vasoprotective effects. Despite promising results from animal models, few have shown effectiveness in human model systems, and none have fully translated to the clinical setting.

METHODS

In 10 patients with inducible myocardial ischemia, saline and low-dose sodium nitrite (NaNO₂) (1.5 μmol/min for 20 min) were administered in a double-blind fashion during dobutamine stress echocardiography, at separate visits and in a random order; long-axis myocardial function was quantified by peak systolic velocity (Vs) and strain rate (SR) responses. In 19 healthy subjects, flow-mediated dilation was assessed before and after whole-arm ischemia-reperfusion; nitrite was given before ischemia or during reperfusion.

RESULTS

Comparing saline and nitrite infusions, Vs and SR at peak dobutamine increased in regions exhibiting ischemia (Vs from 9.5 ± 0.5 cm/s to 12.4 ± 0.6 cm/s, SR from -2.0 ± 0.2 s(-1) to -2.8 ± 0.3 s(-1)), whereas they did not change in normally functioning regions (Vs from 12.6 ± 0.4 cm/s to 12.6 ± 0.6 cm/s, SR from -2.6 ± 0.3 s(-1) to -2.3 ± 0.1 s(-1)) (p < 0.001, analysis of variance). With NaNO2, the increment of Vs (normalized for increase in heart rate) increased only in poorly functioning myocardial regions (+122%, p < 0.001). Peak flow-mediated dilation decreased by 43% after ischemia-reperfusion when subjects received only saline (6.8 ± 0.7% vs. 3.9 ± 0.7%, p < 0.01); administration of NaNO2 before ischemia prevented this decrease in flow-mediated dilation (5.9 ± 0.7% vs. 5.2 ± 0.5%, p = NS), whereas administration during reperfusion did not.

CONCLUSIONS

Low-dose NaNO₂ improves functional responses in ischemic myocardium but has no effect on normal regions. Low-dose NaNO₂ protects against vascular ischemia-reperfusion injury only when it is given before the onset of ischemia.

Are measures of left ventricular systolic performance during low dose dobutamine stress echocardiograms repeatable over time?

To establish the test-retest reliability and the normal dose-response relationship of echocardiographic measures of Left Ventricular (LV) contractile function to low dose dobutamine stress in healthy individuals. Thirty healthy volunteers (23 males, 7 females) with an average age of 38 ± 13 years underwent dobutamine stress echocardiography (DSE) (at successive doses of 0, 5, 10, and 20 mcg/kg/min) on two occasions, separated by 14 days. Ejection fraction (EF) was determined from 2D echocardiographic measures of left ventricular (LV) end diastolic and end systolic volumes. Longitudinal strain (S) and strain rate (SR) were measured using 2D speckle tracking analysis from three consecutive cardiac cycles. The Intraclass Correlation Coefficient (ICC) and the Coefficient of Variation (CV) were calculated to assess reliability and variability of the study population's EF, S, and SR responses to increasing doses of dobutamine. Left ventricular S and EF gradually increased with low doses of dobutamine but reached a plateau between 10 and 20 mcg/kg/min. Strain rate, however, gradually increases with each increasing dose of dobutamine. These responses were replicated on Day 2 with a high degree of reliability as determined from the ICC and low variability as determined from the CV, which fell within acceptable limits (<10 %). Left ventricular EF, S and SR can be measured during DSE with a high degree of test-retest reliability, and may be of clinical value when serial follow up of DSE measures of LV performance is indicated over time.

Resolution of angina pectoris and improvement of the coronary flow reserve after ranolazine treatment in a woman with isolated impaired coronary microcirculation

In a 61-year-old woman with well controlled arterial hypertension, hypercholesterolemia, and smoke and suffering from recurrent angina pectoris despite angiographically normal epicardial coronary vessels and maximal therapy, the replacement of nitrates with novel antiangina drug ranolazine, after 6-month therapy, induced a complete relief of angina and a relevant rising of the transthoracic Doppler-derived coronary flow reserve (CFR). The present clinical case underlines therefore how in patients with chronic ischemic heart disease without epicardial coronary stenosis ranolazine can induce an improvement till the complete solution of the angina symptoms and a substantial increase of CFR as expression of the enhancement of the microvascular coronary function. The improvement of both symptoms and coronary microvascular function is strictly linked to the mechanism of action of the drug. Ranolazine induces in fact a reduction of the intracellular late sodium current that leads to a reduction of the intracellular calcium concentration thus producing a better myocardial diastolic relaxation process which in its turns enhances the myocardial perfusion. The ranolazine acts therefore as a lusitropic drug that improves the diastolic dysfunction and the segmental ischemia thus affecting one of the first steps of the ischemic cascade.

Imagining the future of diagnostic imaging

Cardiovascular imaging has become essential to achieving a better understanding of cardiovascular diseases. Due to the advent of new technology and the refinement of existing technologies, imaging's role has extended into the biological, functional, and hemodynamic diagnosis of multiple pathophysiologic processes. Current and future trends in cardiovascular imaging will focus on improving early diagnosis of vascular disease, so as to be able to promote cardiovascular health, and on its development as a useful tool in clinical decision-making. Imaging is also increasingly used to quantify the effect of novel therapies. The rapid development of molecular imaging and fusion imaging techniques improves our understanding of cardiovascular processes from the molecular and cellular points of view and makes it possible to design and test new preventive interventions. The proliferation and integration of imaging techniques in different clinical areas and their role in "translational imaging" plays an important part in the implementation of personalized therapeutic and preventive management strategies for patients with cardiovascular disease.

Mental stress-induced ischemia in patients with coronary artery disease: echocardiographic characteristics and relation to exercise-induced ischemia

OBJECTIVE

The aims of this study were to investigate the incidence and parameters associated with myocardial ischemia during mental stress (MS) as measured by echocardiography and to evaluate the relation between MS-induced and exercise-induced myocardial ischemia.

METHODS

Study participants were 79 patients (63 men; mean [M] [standard deviation {SD}] age = 52 [8] years) with angiographically confirmed coronary artery disease and previous positive exercise test result. The MS protocol consisted of mental arithmetic and anger recall task. The patients performed a treadmill exercise test 15 to 20 minutes after the MS task. Data of post-MS exercise were compared with previous exercise stress test results.

RESULTS

The frequency of echocardiographic abnormalities was 35% in response to the mental arithmetic task, compared with 61% with anger recall and 96% with exercise (p < .001, exercise versus MS). Electrocardiogram abnormalities and chest pain were substantially less common during MS than were echocardiographic abnormalities. Independent predictors of MS-induced myocardial ischemia were: wall motion score index at rest (p = .02), peak systolic blood pressure (p = .005), and increase in rate-pressure product (p = .004) during MS. The duration of exercise stress test was significantly shorter (p < .001) when MS preceded the exercise and in the case of earlier exercise (M [SD] = 4.4 [1.9] versus 6.7 [2.2] minutes for patients positive on MS and 5.7 [1.9] versus 8.0 [2.3] minutes for patients negative on MS).

CONCLUSIONS

Echocardiography can be successfully used to document myocardial ischemia induced by MS. MS-induced ischemia was associated with an increase in hemodynamic parameters during MS and worse function of the left ventricle. MS may shorten the duration of subsequent exercise stress testing and can potentiate exercise-induced ischemia in susceptible patients with coronary artery disease.

Diagnostic performance of noninvasive myocardial perfusion imaging using single-photon emission computed tomography, cardiac magnetic resonance, and positron emission tomography imaging for the detection of obstructive coronary artery disease: a meta-analysis

OBJECTIVES

This study aimed to determine the diagnostic accuracy of the 3 most commonly used noninvasive myocardial perfusion imaging modalities, single-photon emission computed tomography (SPECT), cardiac magnetic resonance (CMR), and positron emission tomography (PET) perfusion imaging for the diagnosis of obstructive coronary artery disease (CAD). Additionally, the effect of test and study characteristics was explored.

BACKGROUND

Accurate detection of obstructive CAD is important for effective therapy. Noninvasive myocardial perfusion imaging is increasingly being applied to gauge the severity of CAD.

METHODS

Studies published between 1990 and 2010 identified by PubMed search and citation tracking were examined. A study was included if a perfusion imaging modality was used as a diagnostic test for the detection of obstructive CAD and coronary angiography as the reference standard (≥50% diameter stenosis).

RESULTS

Of the 3,635 citations, 166 articles (n = 17,901) met the inclusion criteria: 114 SPECT, 37 CMR, and 15 PET articles. There were not enough publications on other perfusion techniques such as perfusion echocardiography and computed tomography to include these modalities into the study. The patient-based analysis per imaging modality demonstrated a pooled sensitivity of 88% (95% confidence interval [CI]: 88% to 89%), 89% (95% CI: 88% to 91%), and 84% (95% CI: 81% to 87%) for SPECT, CMR, and PET, respectively; with a pooled specificity of 61% (95% CI: 59% to 62%), 76% (95% CI: 73% to 78%), and 81% (95% CI: 74% to 87%). This resulted in a pooled diagnostic odds ratio (DOR) of 15.31 (95% CI: 12.66 to 18.52; I(2) 63.6%), 26.42 (95% CI: 17.69 to 39.47; I(2) 58.3%), and 36.47 (95% CI: 21.48 to 61.92; I(2) 0%). Most of the evaluated test and study characteristics did not affect the ranking of diagnostic performances.

CONCLUSIONS

SPECT, CMR, and PET all yielded a high sensitivity, while a broad range of specificity was observed. SPECT is widely available and most extensively validated; PET achieved the highest diagnostic performance; CMR may provide an alternative without ionizing radiation and a similar diagnostic accuracy as PET. We suggest that referring physicians consider these findings in the context of local expertise and infrastructure.

Wait, treat and see: echocardiographic monitoring of brain-dead potential donors with stunned heart

BACKGROUND

Heart transplantation is limited by a severe donor organ shortage. Potential donors with brain death (BD) and left ventricular dysfunction due to neurogenic stunning are currently excluded from donation--although such abnormalities can be reversible with aggressive treatment including Hormonal Treatment (HT) and deferred organ retrieval.

AIM

To assess the recovery of left ventricular dysfunction in potential brain-dead donors with hemodynamic instability treated by aggressive treatment and HT.

METHODS

In a single-center, observational study design, we evaluated 15 consecutive brain-dead potential donors (DBD) (8 males, age = 48 ± 15 years) with hemodynamic instability. All underwent standard hemodynamic monitoring and transthoracic 2-dimensional echo (2-DE) with assessment of Ejection Fraction (EF). Measurements were obtained before BD and after BD within 6 h, at 24 h and within 48 h. HT (with insulin, methylprednisolone, vasopressin and T3) was started as soon as possible to treat hemodynamic instability and avoid administration of norepinephrine (NE). Eligible potential heart donors underwent coronary angiography.

RESULTS

After HT, we observed a normalization of hemodynamic conditions with improvement of mean arterial pressure (pre = 68 ± 8 mmHg vs post = 83 ± 13 mmHg, p < .01), cardiac index (pre = 2.4 ± 0.6 L/min/m2 vs post 3.7 ± 1.2 L/min/m2, p < .05), EF (pre = 48 ± 15 vs post = 59 ± 3%, p < .01) without administration of norepinephrine (NE) in 67% of cases. Five potential donors were excluded from donation (opposition, n = 3, tubercolosis n = 1, malignancy n = 1). At pre-harvesting angiography, coronary artery stenosis was present in 2 of the 10 consented donors. Eight hearts were uneventfully transplanted. No early graft failure occurred and all eight recipients were alive at 6-month follow-up.

CONCLUSION

In BD donors, intensive treatment including HT is associated with improvement of regional and global LV function and reverse remodeling detectable by transthoracic 2DE. Donor hearts with recovered LV function may be eligible for uneventful heart transplant. The wait (in brain death), treat (with HT) and see (with 2D echo) strategy can help rescue organs suitable for heart donation.

Exercise Stress Echocardiography with Tissue Doppler Imaging (TDI) Detects Early Systolic Dysfunction in Beta-Thalassemia Major Patients without Cardiac Iron Overload

OBJECTIVES

To evaluate left and right myocardial performance at rest and after maximal exercise by conventional and Tissue Doppler Imaging (TDI) echocardiography.

BACKGROUND

Iron Overload Cardiomyopathy (IOC) is the main cause of death in thalassemia major (TM) patients but conventional Echocardiography fails to predict early cardiac dysfunction. As TDI is able to demonstrate regional myocardial dysfunction and stress test may reveal abnormalities which are not evident at rest, we wondered if echocardiographic parameters may reveal abnormalities when applied first at rest and then after a physical effort.

METHODS

We enrolled 46 consecutive beta-TM patients and 39 control subjects without evidence of cardiac disease; two echocardiograms, at baseline and at the end of maximal exercise on supine bicycle ergometer, were done. All TM patients had a liver iron assessment by SQUID (Superconducting Quantum Interference Device) and a cardiac iron one by MRI (T2*) evaluation.

RESULTS

38 TM patients had no evidence of cardiac iron overload. Whereas TM patients did not shown diastolic dysfunction and all of them presented a good global response to exercise, TDI detected a reduced increase of the S' waves of left ventricle basal segment during exercise. This finding seems to have some weak but interesting relations with iron overload markers. Pulmonary artery systolic pressure (PAPs) values were greater than in control subjects both at rest and after exercise

CONCLUSIONS

in our study, exercise stress TDI-echocardiography was able to demonstrate subtle systolic abnormalities that were missed by Conventional Echocardiography. Further studies are required to determine the meaning and the clinical impact of these results.

Right ventricle myocardial perfusion scintigraphy: feasibility and expected values in children

Stress myocardial perfusion scintigraphy imaging (SMPSI) has important applications for evaluating coronary disease and ventricular function. Studies consistently focus on the left ventricle (LV), with no normal right ventricle (RV) data available. This study sought to evaluate the feasibility of RV perfusion with technetium (Tc-99m) sestamibi using a low radiotracer dose for children free of coronary artery (CA) anomalies and to determine its normal pattern. Patients with a history of Kawasaki disease who showed no coronary complications on selective angiography or no LV perfusion defects on SMPSI were studied at rest and during an exercise challenge. The RV uptake counts were compared with those for different segments of the LV, and multiple ratios of the uptakes between RV and LV segments were calculated. The study subjects were 23 children (age, 11.1 ± 3.3 years) imaged with 0.12 ± 0.03 mCi/kg at rest and 0.31 ± 0.06 mCi/kg during stress. The RV to LV uptake proportion was approximately 6%. Exercise-related uptake increased threefold in both the RV and the LV. The findings showed RV myocardial scintigraphy to be feasible with reproducible ratios. Potential clinical applications include acquired and congenital CA anomalies such as Kawasaki disease, right CA ostium stenosis after a switch operation, and anomalous origin of the right CA.

Long Term Outcomes in Stress Echocardiography: Ten Year Follow up of a Cohort in a Single Centre

Backgroud

The high service burden for acute admissions and referrals via rapid access chest pain clinics for evaluation of possible coronary artery disease means that many patients are now undergoing an investigation such as stress echocardiography as part of their evaluation. We aimed to see if the reassurance provided by negative stress echocardiography correlates with long-term event free survival.

Methods

A cohort of all patients who were referred at a single centre for stress echocardiography for diagnosis of coronary artery disease between January 1st 1999 and December 31st 2000 were followed up at least 10 years following theirs stress echocardiogram for further major cardiovascular events and mortality.

Results

A total of 64 patients were identified where records could be obtained for analysis. There were 16 positive scans, 37 negative scans and 11 inconclusive scans. The indeterminacy rate of scans was 17%, the sensitivity rate for detecting significant disease as indexed to invasive angiography was 88 % and the specificity rate compared with angiography was 75%. There were no myocardial infarctions or new diagnoses of heart failure in the negative echocardiogram group. There were seven deaths in the total population and only one death from cardiovascular causes in the negative echocardiogram group.

Conclusion

Stress echocardiography even in this small group predicts long-term outcomes as well as invasive coronary angiography.

Non-invasive imaging in acute chest pain syndromes

This review has the purpose of informing the reader about the current use of imaging techniques in patients presenting with acute chest pain to the emergency department. We will focus on three aspects of managing the patient with acute chest pain: Imaging to increase the number of correct diagnoses in the acute situation; Imaging to rule out other than coronary causes of chest pain; Use of imaging for risk stratification once myocardial infarction has been ruled out in the CPU. Special emphasis is given to how these management aspects are discussed in current guidelines on the management of patients with acute chest pain or acute coronary syndrome.

Favorable short-term outcome of transplanted hearts selected from marginal donors by pharmacological stress echocardiography

BACKGROUND

Because of the shortage of donor hearts, the criteria for acceptance have been considerably expanded. Abnormal results on pharmacologic stress echocardiography are associated with significant coronary artery disease and/or occult cardiomyopathy on verification by cardiac autopsy. The aim of this study was to establish the feasibility of an approach based on pharmacologic stress echocardiography as a gatekeeper for extended heart donor criteria.

METHODS

From April 2005 to April 2010, 39 "marginal" candidate donors (mean age, 56 ± 6 years; 21 men) were initially enrolled. After legal declaration of brain death, marginal donors underwent rest echocardiography, and if the results were normal, dipyridamole (0.84 mg/kg over 6 min, n = 25) or dobutamine (up to 40 μg/kg/min, n = 3) stress echocardiography.

RESULTS

A total of 19 eligible hearts were found with normal findings. Of these, three were not transplanted because of the lack of a matching recipient, and verification by cardiac autopsy showed absence of significant coronary artery disease or cardiomyopathy abnormalities. The remaining 16 eligible hearts were uneventfully transplanted in marginal emergency recipients. All showed normal (n = 14) or nearly normal (minor single-vessel disease in two) angiographic, intravascular ultrasound, hemodynamic and ventriculographic findings at 1 month. At follow-up (median, 14 months; interquartile range, 4-31 months), 14 patients survived and two had died, one at 2 months from general sepsis and one at 32 months from allograft vasculopathy in recurrent multiple myeloma.

CONCLUSIONS

Pharmacologic stress echocardiography can safely be performed in candidate heart donors with brain death and shows potential for extending donor criteria in heart transplantation.

How should we measure global and regional left ventricular systolic function?

The assessment of left ventricular (LV) systolic function is frequently the most important task during the echocardiography examination. LV ejection fraction (EF) is the most commonly used measure to assess LV systolic function. EF is well established, with strong prognostic and therapeutic implications, but, nevertheless, it may not always be satisfactory in all patients. Other measures of myocardial contractility can provide valuable additive information in some patients. This is particularly true in patients with suspected heart failure but normal EF. The measurement of longitudinal function using M-mode and/or deformation analysis from tissue Doppler data or speckle tracking algorithms can be useful in this respect. Regional LV dysfunction can be difficult to detect using visual semi-quantitative assessment of regional wall motion. Contrast echocardiography can be most helpful in delineating the LV endocardial border and, thus, increasing sensitivity for detecting wall motion abnormalities. Deformation analysis can also be helpful for detecting subtle wall motion abnormalities, but these methods should be used with caution due to measurement variability and image quality dependence.

Coronary vasoreactivity is not altered in young people with type 1 diabetes

BACKGROUND AND AIM

Abnormal coronary microvascular circulation has been demonstrated in diabetes and is associated with increased rate of cardiovascular events. Our objective was to evaluate coronary vasoreactivity in young people with type 1 diabetes with and without microvascular complications.

METHODS AND RESULTS

Twenty-five type 1 diabetic patients without microvascular complications (DC-), 23 with microvascular complications (DC+), and 18 control subjects (C) were studied. Coronary vasoreactivity was assessed by means of coronary flow reserve (CFR). Blood flow velocity in the left anterior descending coronary artery was measured at rest and after high-dose dipyridamole using transthoracic color-guided pulsed Doppler echocardiography. CFR was defined as the ratio of hyperaemic to resting diastolic peak flow velocities. The three groups had similar cardiac function parameters, and also systolic and diastolic blood pressure at rest, which remained unchanged during dipyridamole infusion. Resting coronary flow velocity was comparable in C, DC-, and DC+ (p=ns). Dipyridamole infusion produced a threefold increase in coronary diastolic peak velocity, which reached similar values in C (0.69±0.16 m/s), DC- (0.69±0.18 m/s), and DC+ (0.66±0.11 m/s). Mean CFR ratio was similar in C (3.33±0.66), DC- (3.30±0.51), and DC+ (3.24±0.60). At multiple linear regression analysis, no association was found between CFR and age, sex, HbA(1c), duration of diabetes, and complications.

CONCLUSION

Coronary vasodilatory function is preserved in young D patients, even those with early microvascular complications, suggesting that coronary vasoreactivity deteriorates at more advanced stages of microvascular complications and/or in the presence of other cardiovascular risk factors.

Stress Doppler echocardiography in valvular heart diseases: utility and assessment

This article is a review on the role of stress echocardiography in valvular heart diseases, describing what the validated indications are, how to perform the test and the utility of performing this examination. Most valve diseases are characteristically dynamic and this dynamic component is best appreciated by exercise Doppler echocardiography. Dobutamine stress echocardiography is also useful in patients with severe aortic stenosis and left ventricular dysfunction. The main advantage of stress echocardiography is to concomitantly allow the evaluation of symptoms, exercise capacity and the hemodynamic consequences of valve diseases, especially in patients with severe valve diseases who deny symptoms or present equivocal symptoms. It also provides important prognostic information and may help to optimize surgical timing in difficult cases. Whether these data should be integrated in the management of patients needs further validation.

Exercise echocardiography

Exercise echocardiography has been used for 30 years. It is now considered a consolidated technique for the diagnosis and risk stratification of patients with known or suspected coronary artery disease (CAD). Of the stress echocardiography techniques, it represents the first choice for patients who are able to exercise. Given that the cost-effectiveness and safety of stress echocardiography are higher than those of other imaging techniques, its use is likely to be expanded further. Recent research has also proposed this technique for the evaluation of cardiac pathology beyond CAD. Although the role of new technology is promising, the assessment of cardiac function relies on good quality black and white harmonic images.

[Screening of silent myocardial ischaemia by dobutamine stress echocardiography among type 2 diabetics at high cardiovascular risk in Senegal]

INTRODUCTION

Diabetes is a major risk factor for coronary artery disease witch may develop insidiously. Several non-invasive methods are used to detect silent myocardial ischaemia, especially in diabetic patients at high cardiovascular risk. We project to screen, by dobutamine stress echocardiography, silent myocardial ischaemia in type 2 diabetics in Senegal.

METHODOLOGY

We randomly recruited in hospital in Senegal type 2 diabetics aged at least 40 years and a dobutamine stress echocardiography was performed in those selected according to the French Society of Cardiology and the French Language Association for the Study of Diabetes and Metabolic Diseases.

RESULTS

Dobutamine stress echocardiography was performed in 79 diabetics at high cardiovascular risk, including 56 women. The average age was 58.8±11.8 years. The exam was positive in 67.1% of cases (53/79), with a predominance of motion abnormalities in anterior territory (83%). Cardiovascular risk factors associated with positivity of test were microalbuminuria (p=0.0001), inactivity (p=0.0001), dyslipidemia (p=0.0002), arterial hypertension (p=0.001), smoking (0.003) and male sex (p=0.004).

CONCLUSION

In Africa, dobutamine stress echocardiography has the advantage of its accessibility and its feasibility. Early detection of silent myocardial ischaemia in diabetics at high risk could optimize their care.

Association between coronary flow reserve, left ventricular systolic function, and myocardial viability in acute myocardial infarction

AIMS

To investigate the relationships between coronary flow reserve (CFR), left ventricular (LV) systolic function, and myocardial viability in patients with acute myocardial infarction (AMI).

METHODS AND RESULTS

In 149 patients with a first AMI, we estimated CFR non-invasively and assessed LV systolic function with low-dose dobutamine Doppler echocardiography (LDDE), which also identified viability. Resting echocardiographic variables did not differ between patients with preserved (54.4%) and low CFR (45.6%). During LDDE, longitudinal LV function was decreased [9.5 cm/s (8;11.3) vs. 10.6 cm/s (8.5;12.5), P = 0.04] and end-systolic volume increased [49.5 mL (38;66) vs. 42 (31;61), P = 0.04] in patients with low compared with preserved CFR. Among 87 (58%) patients with resting wall motion abnormalities, 28 met the criteria for viability. One of 53 (2%) met the criteria for viability in patients with CFR < or =2 compared with 27 of 34 (79%) with CFR > 2, P < 0.0001.

CONCLUSION

Resting echocardiographic parameters were similar in patient groups. During LDDE, patients with reduced CFR had increased LV size and compromised longitudinal function of LV and were less likely to have evidence of myocardial viability.

Cardiovascular problems in noncardiac surgery

PURPOSE OF REVIEW

Perioperative cardiac complications remain a major area of concern as our surgical population increases in volume, age and frequency of comorbidity. A variety of strategies can be used to optimize patients and potentially reduce the incidence of these serious complications.

RECENT FINDINGS

Recent literature suggests a trend towards less invasive testing for detection and quantification of coronary artery disease and greater interest in pharmacologic 'cardioprotection' using beta-blockers, statins and other agents targeting heart rate control and other mechanisms (e.g. reducing inflammatory responses). The recent Perioperative Ischemic Evaluation study has substantially altered this approach at least towards widespread application to lower/intermediate risk cohorts. Considerable attention has been focused on ensuring optimal standardized perioperative management of patients with a recent percutaneous coronary intervention, particularly those with an intracoronary stent. Widespread surveillance of postoperative troponin release and increasing recognition of the prognostic potential of elevated preoperative brain natriuretic peptides point towards changing strategies for long-term risk stratification.

SUMMARY

The complexity of a particular patient's physiologic responses to a wide variety of surgical procedures, which are undergoing constant technological refinement generally associated with lesser degrees of invasivity and stress make calculation of patients' perioperative risk very challenging. At the present time, adequate information is available for the clinician to screen patients with high-risk preoperative predictors, delay elective surgery for patients with recent intracoronary stents and continue chronic beta-blockade in appropriate patients. New large-scale database and subanalyses of major trials (e.g. Perioperative Ischemic Evaluation and Coronary Artery Revascularization Prophylaxis) should provide additional information to minimize perioperative cardiac risk.

Characterization of the rdar morphotype, a multicellular behaviour in Enterobacteriaceae

The rdar morphotype, a multicellular behaviour of Salmonella enterica and Escherichia coli is characterized by the expression of the adhesive extracellular matrix components cellulose and curli fimbriae. The response regulator CsgD, which transcriptionally activates the biosynthesis of the exopolysaccharide cellulose and curli, also transforms cell physiology to the multicellular state. However, the only role of CsgD in cellulose biosynthesis is the activation of AdrA, a GGDEF domain protein that mediates production of the allosteric activator cyclic-di-(3'-5')guanylic acid (c-di-GMP). In S. enterica serovar Typhimurium a regulatory network consisting of 19 GGDEF/EAL domain-containing proteins tightly controls the concentration of c-di-GMP. c-di-GMP not only regulates the expression of cellulose, but also stimulates expression of adhesive curli and represses various modes of motility. Functions of characterized GGDEF and EAL domain proteins, as well as database searches, point to a global role for c-di-GMP as a novel secondary messenger that regulates a variety of cellular functions in response to diverse environmental stimuli already in the deepest roots of the prokaryotes.