Echocardiographic detection of coronary artery disease during dobutamine infusion

Discussion on the comparison of Raman spectroscopy and cardiovascular disease-related imaging techniques and the future applications of Raman technology: a systematic review

Cardiovascular disease (CVD) is a major cause of unnatural death worldwide, so timely diagnosis of CVD is crucial for improving patient outcomes. Although the traditional diagnostic tools can locate plaque and observe inner wall of blood vessel structure, they commonly have radioactivity and cannot detect the chemical composition of the plaque accurately. Recently emerging Raman techniques can detect the plaque composition precisely, and have the advantages of being fast, high-resolution and marker-free. This makes Raman have great potential for detecting blood samples, understanding disease conditions, and real-time monitoring. This review summarizes the origin and state-of-art of Raman techniques, including the following aspects: (a) the principle and technical classification of Raman techniques; (b) the applicability of Raman techniques and its comparison with traditional diagnostic tools at different diagnosis targets; (c) the applicability of Raman spectroscopy in advanced CVD. Lastly, we highlight the possible future applications of Raman techniques in CVD diagnosis.

Assessment of Vascular and Valvular Calcification Improves Screening for Coronary Artery Disease Before Liver Transplantation

Coronary artery disease (CAD) is common in patients with cirrhosis who underwent orthotopic liver transplantation (OLT) evaluation and stress echocardiogram (echo) has a low sensitivity in these patients. This study aimed to assess the impact of vascular and valvular calcification on the ability to identify CAD before OLT. We performed a case-control study of 88 patients with and 97 without obstructive CAD who underwent OLT evaluation. All patients had a preoperative stress echo, abdominal computed tomography, and cardiac catheterization. A series of nested logistic regression models of CAD were fit by adding independent variables of vascular (including coronary) calcification, aortic and mitral valve calcification, age, gender, and history of diabetes mellitus requiring insulin to a baseline model of abnormal stress echo. Compared with stress echo alone, identification of the presence or absence of vascular and valvular calcification on routine preoperative computed tomography and echo improved the diagnostic performance for the detection of CAD based on coronary angiogram when combined with stress echo in patients with cirrhosis who underwent OLT evaluation (area under the curve 0.58 vs 0.73, p <0.001), which is even further improved when age, gender, and history of diabetes mellitus requiring insulin are considered (area under the curve 0.58 vs 0.80, p <0.001). Achieving target heart rate (p = 0.92) or rate-pressure product >25,000 (p = 0.63) did not improve the ability of stress echo to identify CAD. In conclusion, the use of abdominal vascular, coronary artery, and valvular calcification, along with stress echo, improves the ability to identify and rule out obstructive CAD before OLT compared with stress echo alone.

Assessment of Postsystolic Shortening and Global Longitudinal Strain Improves the Sensitivity of Dobutamine Stress Echocardiography in End-Stage Liver Disease

BACKGROUND

Dobutamine stress echocardiography (DSE) remains a widely used method for detection of coronary artery disease (CAD) in patients with end-stage liver disease (ESLD) despite low sensitivity. Speckle-tracking assessment of strain may enhance the sensitivity of DSE in the general population, but the value of strain analysis in ESLD is unknown.

METHODS

Dobutamine stress echocardiography with two-dimensional speckle-tracking and quantitative coronary angiography were performed in 146 patients with ESLD. Thirty-six patients (25%) had CAD (≥50% diameter stenosis of a major vessel). Global longitudinal strain at rest (GLSr) and at peak stress (GLSp) and an index of postsystolic (PSSi) shortening ([maximal extent of shortening - extent of shortening in systole]/[extent of shortening in systole]) were determined. A PSSi of ≥ 0.25 was considered evidence for CAD. Receiver operating characteristic analysis was used to determine the optimal thresholds of GLSr and GLSp for CAD and to assess the diagnostic performance of visual assessment of wall motion (WMA) and strain parameters. The sensitivity and specificity of WMA, GLSr, GLSp, and PSSi were compared.

RESULTS

Thirty-six patients (25%) had significant CAD. The areas under the curve for WMA, GLSr, GLSp, and PSSi were 0.60, 0.72, 0.68, and 0.78, respectively. Visual assessment of wall motion had a sensitivity of 28%. The sensitivity of each of the strain parameters, GLSr (53%, P = .016), GLSp (69%, P = .004), and PSSi (78%, P < .001), exceeded the sensitivity for WMA. Visual assessment of wall motion specificity was 92%, which exceeded the specificity for each of the strain parameters (GLSr = 82%, P = .037; GLSp = 63%, P < .001; and PSSi =78%, P = .009). Of the strain parameters, PSSi had the best balance between sensitivity and specificity (both 78%).

CONCLUSION

Assessment of GLS and PSSi with DSE yields better sensitivity than WMA in ELSD patients. Index of postsystolic shortening had the best diagnostic performance of all parameters in this population with a low prevalence of CAD.

Prognostic value of left atrial size in hypertensive African Americans undergoing stress echocardiography

BACKGROUND

Left atrial (LA) enlargement is a marker of increased risk in the general population undergoing stress echocardiography. African American (AA) patients with hypertension are known to have less atrial remodeling than whites with hypertension. The prognostic impact of LA enlargement in AA with hypertension undergoing stress echocardiography is uncertain.

AIM

To investigate the prognostic value of LA size in hypertensive AA patients undergoing stress echocardiography.

METHODS

This retrospective outcomes study enrolled 583 consecutive hypertensive AA patients who underwent stress echocardiography over a 2.5-year period. Clinical characteristics including cardiovascular risk factors, stress and echocardiographic data were collected from the electronic health record of a large community hospital. Treadmill exercise and Dobutamine protocols were conducted based on standard practices. Patients were followed for all-cause mortality. The optimal cutoff value of antero-posterior LA diameter for mortality was assessed by receiver operating characteristic analysis. Cox regression was used to determine variables associated with outcome.

RESULTS

The mean age was 57 ± 12 years. LA dilatation was present in 9% (54) of patients (LA anteroposterior ≥ 2.4 cm/m²). There were 85 deaths (15%) during 4.5 ± 1.7 years of follow-up. LA diameter indexed for body surface area had an area under the curve of 0.72 ± 0.03 (optimal cut-point of 2.05 cm/m²). Variables independently associated with mortality included age [P = 0.004, hazard ratio (HR) 1.34 (1.10-1.64)], tobacco use [P = 0.001, HR 2.59 (1.51-4.44)], left ventricular hypertrophy [P = 0.001 , HR 2.14 (1.35-3.39)], Dobutamine stress [P = 0.003, HR 2.12 (1.29-3.47)], heart failure history [P = 0.031, HR 1.76 (1.05-2.94)], LA diameter ≥ 2.05 cm/m² [P = 0.027, HR 1.73 (1.06-2.82)], and an abnormal stress echocardiogram [P = 0.033, HR 1.67 (1.04-2.68)]. LA diameter as a continuous variable was also independently associated with mortality but LA size ≥ 2.40 cm/m² was not.

CONCLUSION

LA enlargement is infrequent in hypertensive AA patients when traditional reference values are used. LA enlargement is independently associated with mortality when a lower than “normal” threshold (≥ 2.05 cm/m²) is used.

Safety and feasibility of dopamine-atropine stress echocardiography

BACKGROUND

Dobutamine-atropine stress echocardiography (DSE) has lower sensitivity in patients with advanced liver disease (ALD) due to vasodilation.

HYPOTHESIS

Dopamine-atropine stress echocardiography (DopSE) may be an alternative to DSE in ALD patients by improving the blood pressure response to stress.

METHODS

The safety and tolerability of DSE and DopSE were compared in 10 volunteers. The safety, adverse effects, and efficacy of DopSE were then assessed in 105 patients, 98 of whom had ALD. Dopamine was infused in stepwise fashion from 5 µg/kg/min to a peak dose of 40 µg/kg/min. Atropine was given before and in early stages of dopamine infusion up to cumulative dose of 1.5 mg. The hemodynamic responses of 98 ALD patients were compared with 102 patients with ALD who underwent standard DSE.

RESULTS

In normal volunteers, systolic BP increased more with DopSE compared to DSE (61 ± 19 mm Hg vs 39 ± 15 mm Hg, P = .008). In 105 patients who underwent DopSE, none had adverse effects that required early stress termination. In the groups with ALD, the systolic BP increase (38 ± 28 mm Hg vs 12 ± 27 mm Hg, P < .001) and peak rate pressure product (RPP) (22 861 ± 5289 vs 17 211 ± 3848, P = <.001) were both higher in those undergoing DopSE versus DSE. The sensitivity and specificity of DopSE were 45% and 88%, respectively for coronary disease (≥70% stenosis) in 37 patients who had angiography.

CONCLUSIONS

Dopamine-atropine stress echocardiography appears to be a safe stress modality and provides greater increases in RPP in patients with ALD compared to DSE.

Detection of Functionally Significant Coronary Artery Disease: Role of Regional Post Systolic Shortening

Background:

The main goal of this manuscript was to evaluate the diagnostic value of the global and regional postsystolic shortening (PSS) parameters, assessed by two-dimensional (2D) speckle-tracking echocardiography, at rest and during dobutamine stress for the detection of functionally significant coronary artery stenoses in patients with moderate pretest probability of stable coronary artery disease (CAD).

Methods:

Dobutamine stress echocardiography (DSE) and adenosine stress myocardial perfusion imaging by cardiac magnetic resonance (CMR-MPI) were performed on 83 patients with moderate pretest probability of stable CAD and left ventricle ejection fraction ≥55%. CAD was defined as ≥50% diameter stenoses on invasive coronary artery angiography (CAA) validated as hemodynamically significant by CMR-MPI. According to invasive CAA and CMR-MPI results, patients were divided into two groups: Nonpathologic CAD (−) group: 38 (45.8%) and pathologic CAD (+) group: 45 (54.2%).

Results:

There were no significant differences in clinical characteristics, conventional 2D echocardiography between the two groups at rest and during low dobutamine dose. Regional postsystolic index (PSI) during recovery phase had the highest area under the receiver operating characteristic curve (AUC) (AUC 0.882, sensitivity 87%, specificity 92%) for the detection of functionally significant one-vessel disease. During high dobutamine dose, regional PSI had sensitivity 78% and specificity 81% (AUC 0.78) to detect significant CAD. Regional PSI remained the same tendency remains for the detection of multiple-vessel CAD. Other myocardial deformation parameters were less sensitive and specific during high dobutamine dose and recovery phase.

Conclusions:

PSS parameters showed to be sensitive and specific in detecting hemodynamically significant coronary artery stenosis in patients with stable CAD with moderate pretest probability. The study revealed that the assessment of regional PSI performed during recovery improves the diagnostic accuracy of DSE for the detection of functionally significant CAD.

Diagnostic Performance of Dobutamine Stress Echocardiography in End-Stage Liver Disease

OBJECTIVES

This study determined the test performance of dobutamine stress echocardiography (DSE) in end-stage liver disease (ESLD).

BACKGROUND

The reported sensitivity of DSE in ESLD has been variable.

METHODS

Data from 633 ESLD patients who had coronary angiography within 6 months after DSE was analyzed.

RESULTS

The prevalence of coronary arterial disease (CAD) (≥70% stenosis by quantitative angiography) was 12% (74 of 633 patients). DSE sensitivity was 24% (17 of 72 patients), and specificity was 90% (503 of 559 patients). The positive and negative predictive values were 23% (17 of 73 patients) and 90% (503 of 558 patients), respectively. Stratifying the cohort into low-, intermediate-, and high-risk CAD groups yielded sensitivities of 0%, 21%, and 32%, respectively. Independent predictors of an accurate ischemic DSE result included left ventricular internal dimension at end-diastole (LVIDd) >4.8 cm and assigning ischemia based on tardokinesis or lack of low-to-peak dose hyperkinesis (p < 0.05 for all). DSE sensitivity was 38% in LVIDd >4.8 cm versus 13% with LVIDd ≤4.8 cm (p = 0.013). The sensitivity was 67% when tardokinesis or lack of hyperkinesis was considered abnormal versus 15% (p < 0.001) for readings that did not consider tardokinesis or lack of hyperkinesis abnormal. There was a higher frequency of cardiac events in patients with significant CAD who had abnormal (45%) versus normal (18%) DSE (p = 0.01).

CONCLUSIONS

The sensitivity of DSE in ESLD was low. DSE sensitivity was higher for those with larger cavity dimension and when tardokinesis or lack of hyperkinesis was considered abnormal. An abnormal DSE in those with significant CAD was associated with worse outcome.

Speckle tracking imaging as a predictor of left ventricular remodeling 6 months after first anterior ST elevation myocardial infarction in patients managed by primary percutaneous coronary intervention

Acute myocardial infarction (AMI) remains a leading cause of morbidity and mortality worldwide. LV remodeling is an important factor in the pathophysiology of advancing heart failure (HF).

Aim of the work

To evaluate the value of speckle tracking imaging as a predictor of left ventricular remodeling 6 months after first anterior STEMI in patients managed by primary PCI.

Methodology

Eighty-five patients with first acute anterior STEMI underwent primary PCI. Patients were followed up for 6 months. Echocardiographywas done within 48 h [1] Standard transthoracic 2D echocardiographic examination: LV internal dimensions and volumes, Left Ventricular EF, and Wall Motion Score Index: [2] LV peak systolic global longitudinal strain and Torsion dynamics were assessed. Echocardiography was repeated at 6 months LV volumes and EF were calculated. LV remodeling was defined as an increase in LV EDV ≥ 20% 6 months after infarction as compared to baseline data. Patients were then classified into Group I: did not develop LV remodeling. Group II: developed LV remodeling. Both groups were studied to determine predictors of LV remodeling.

Results

At baseline echocardiographic evaluation there was no statistically significant difference between both groups regarding both LVEDD and LVEDV, while there was statistically significant increase in both LV ESD and LV ESV, with statistically significant lower Ejection Fraction, in LV remodeling group. There was also statistically significant higher LV peak systolic GLS values in LV remodeling group, the best cut-off value was >−12.5 (Sensitivity 87%, Specificity 85%) and LV torsion was also statistically significantly lower in the LV remodeling group, with the best cut-off value for LV torsion was <9.5°, [Sensitivity 91%, Specificity 85%].

Independent predictors of LV remodeling after AMI: baseline WMSI > 1.8, baseline LV EF < 40, GLS > −12.5%, LV torsion < 9.5°, CK-MB > 500 U/L, baseline Thrombus grade > 4 and total ischemic time.

Conclusion

Average peak systolic GLS and LV torsion at echocardiography done early after myocardial infarction are independent predictors of LV remodeling after anterior STEMI and can be used to predict occurrence of LV remodeling after 6 months.

Negative predictive value of dobutamine stress echocardiography for perioperative risk stratification in patients with cardiac risk factors and reduced exercise capacity undergoing non-cardiac surgery

BACKGROUND

Guidelines recommend functional testing for myocardial ischaemia in the perioperative setting in patients with greater than one recognised cardiac risk factor and self-reported reduced exercise capacity.

AIM

To determine the clinical utility of dobutamine stress echocardiography (DSE) for perioperative risk stratification in patients undergoing major non-cardiac surgery.

METHODS

Data on 79 consecutive patients undergoing DSE for perioperative risk stratification at a single centre were retrospectively reviewed to determine rates of major adverse cardiac events (MACE) during the index hospitalisation and 30 days post-discharge. Echocardiography and outcome data were obtained through a folder audit and echolab database.

RESULTS

Out of the 79 DSE performed for perioperative risk stratification, 11 (14%) were positive (DSE +ve) and 68 (86%) were negative (DSE -ve). Management in the DSE +ve group included medical optimisation without invasive intervention (n = 7(64%)), diagnostic coronary angiography (n = 3(27%)) and coronary artery bypass graft (n = 1(9%)). None of the patients underwent percutaneous coronary intervention preoperatively. Perioperative MACE in the DSE +ve group was 36% compared to 4% in the DSE-ve group (P = 0.006). DSE +ve was a powerful predictor of perioperative inpatient MACE (OR 12.4, 95% CI 2.3-67, P = 0.003). The positive predictive value of DSE +ve status was 36%, whereas the negative predictive value of DSE-ve status for perioperative MACE was 96%.

CONCLUSION

DSE for perioperative risk stratification had a high clinical utility in patients undergoing major non-cardiac surgery. In particular, a normal DSE had a high negative predictive value for perioperative MACE.

Left ventricular torsion assessed by two-dimensional echocardiography speckle tracking as a predictor of left ventricular remodeling and short-term outcome following primary percutaneous coronary intervention for acute myocardial infarction: A single-center experience

AIMS

Left ventricular (LV) torsion is a novel method to assess systolic LV function. This study aimed at exploring the utility of 2D speckle tracking-based assessment of left ventricular torsion in patients with acute myocardial infarction (AMI) undertaking primary percutaneous intervention (pPCI) in predicting left ventricular remodeling.

METHODS AND RESULTS

The study included 115 patients (mean±SD, age 52.2±9.67, males 84.3%) who underwent pPCI for AMI. Echocardiographic assessment of LV torsion by two-dimensional speckle tracking was performed early after the index pPCI. Patients underwent repeat echocardiography at 6 months to detect remodeling. LV torsion in the acute setting was significantly lower in those who demonstrated LV remodeling at follow-up compared to those without remodeling (7.56±1.95 vs 15.16±4.65; P<.005). Multivariate analysis identified peak CK & CK-MB elevation (β=-0.767 and -0.725; P<.001), SWMA index (β=-0.843; P<.001), and Simpson's derived LV ejection fraction (LVEF; β=0.802; P<.001) as independent predictors of baseline LV torsion. It also identified peak LV torsion (β: 0.27; 95% CI: 0.15-0.5, P=.001) and SWMA index (β: 1.07, 95% CI: 1.03-1.12, P=.005) as independent predictors of LV remodeling. Baseline Killip's grades II and higher (β: 48.6; 95% CI 5.5-428, P<.001) and diabetes mellitus (β: 29.7; 95% CI 1.1-763, P<.05) were independent predictors of mortality.

CONCLUSION

Left ventricular torsion in acute MI setting is impaired and predicts subsequent LV remodeling at 6-month follow-up.

A brief period of intensive cardiac rehabilitation improves global longitudinal strain and diastolic function after a first uncomplicated myocardial infarction

Objectives In patients with abnormal left ventricular ejection fraction (LVEF) after acute myocardial infarction (AMI), cardiac rehabilitation with physical training prevents cardiac remodelling. To define the role of rehabilitation in the recovery of ventricular function in less severe cases, we studied its effects on more refined indexes of left ventricular function in uncomplicated, low-risk patients. Methods and results Fifty-five patients underwent percutaneous coronary revascularization after uncomplicated first AMI. Thirty-four started cardiac rehabilitation with counselling and physical training; 21 patients did not train, followed a counselling program and were taken as controls. Echocardiography was performed at baseline, after rehabilitation or counselling program and at six months follow-up. We measured: global strain (GS%) with speckle tracking analysis, E/e' by tissue Doppler imaging (TDI), left ventricular elastance (K_LV) from the deceleration time (DT), LVEF, systolic and diastolic volumes, wall motion score index (WMSI). At baseline, groups had similar GS%, K_LV, LVEF, DT, E/e', systolic and diastolic volumes, WMSI. Rehabilitation increased peak VO₂ by 18% (P < 0.05) and improved GS%, K_LV, LVEF, E/e' and WMSI (P < 0.02) that were unchanged in controls. The improvement persisted at six months. Conclusions After a first uncomplicated AMI, abnormalities of left systolic and diastolic ventricular function may be present persisting over time despite a normal LVEF, which are fully reverted by cardiac rehabilitation.

The additional utility of two-dimensional strain in detection of coronary artery disease presence and localization in patients undergoing dobutamine stress echocardiogram

BACKGROUND

Dobutamine stress echocardiogram (DSE) is a feasible and safe exercise-independent stress modality for diagnoses of coronary artery disease (CAD), but it is subjective, and operator dependant. Two-dimensional strain at peak stress could overcome these limitations and thus increase the accuracy of DSE.

METHODS AND RESULTS

This was a prospective observational study in which 80 patients underwent DSE, two-dimensional strain at peak stress, and coronary angiography. Global longitudinal strains (GLS) cutoff point of -16.75 had 77.42% sensitivity and 83.33% specificity to detect significant CAD. Global circumferential strain (GCS) cutoff point of -20.75 had 93.55% sensitivity and 66.67% specificity to detect significant CAD (P=.003, areas under the curve [AUC]=0.73). The average territorial strain cutoff point for significant left anterior descending (LAD) lesion was -15.4 with 77.78% sensitivity and 82.86% specificity (P=.0001, AUC=0.78) and for non-LAD lesion was -16.9 with 82.93% sensitivity and 53.85% specificity (P=.0009, AUC=0.69). Two-dimensional strain at peak stress showed better agreement than DSE as regard number of vessels affected (K=0.579 vs 0.107), LAD lesion detection (K=0.783 vs 0.438), and non-LAD lesion detection (K=0.699 vs 0.233). Global longitudinal strain (GLS) at peak stress reduced DSE false positivity by 83%; the number of false-positive patients was reduced from 18 patients to only three patients.

CONCLUSION

Two-dimensional strain at peak stress had an incremental value over DSE visual assessment/ wall-motion score index (WMSI) in reducing false-positive results of DSE. Two-dimensional strain at peak stress had greater accuracy than DSE alone not only in detection of significant CAD but also in detection of number of vessels with significant lesion as well as CAD localization.

Evaluation of wall motion abnormality by comparing values of cardiac output obtained by M-mode and Doppler echocardiography: Parameter revealing wall motion abnormality in stress echocardiography

Dobutamine and dipyridamole stress echocardiographies are both well able to detect myocardial ischemia resulting from coronary diseases by recognizing the regional wall motion abnormality (WMA). Here we report a method for describing WMA in detail. In pharmacological stress echocardiography, because of difficulties in recognizing the two-dimensional pattern, accuracy sometimes depends upon the skill of the operator. Two stroke volumes obtained using the M-mode and Doppler methods were examined to detect abnormal regional cardiac function by the dipyridamole stress test. Stroke volume obtained by the M-modereflects regional cardiac function and that estimated from the outflow using the Doppler methodreflects total cardiac function. These two stroke volumes were compared in normal subjects and patients with coronary-diseases. The results indicated consistent discrepancies between these two stroke volume in the ischemic hearts as a results of coronary stenosis, whereas changes in stroke volumes in the normal subjects showed the same tendency. This method of combining information about the regional and total functions is thus useful in examining the WMA and regional cardiac function, although it can not be applied to subjects whose stroke volume does not increase under stress.

Coronary Interventions before Liver Transplantation Might Not Avert Postoperative Cardiovascular Events

Percutaneous coronary intervention and coronary artery bypass grafting may be performed before orthotopic liver transplantation (OLT) to try to improve the condition of patients who have severe ischemic heart disease. However, data supporting improved outcomes are lacking. We reviewed the medical records of 2,010 patients who underwent OLT at our hospital from 2000 through 2010. The 51 patients who underwent coronary artery angiography within 6 months of transplantation were included in this study: 28 had mild coronary artery disease, 10 had moderate disease, and 13 had severe disease. We compared all-cause and cardiac-cause mortality rates. We found a significant difference in cardiac deaths between the groups (P <0.001), but none in all-cause death (P=0.624). Of the 10 patients who had moderate coronary artery disease, one underwent pre-transplant coronary artery bypass grafting. Of 13 patients with severe disease, 3 underwent percutaneous coronary intervention, and 6 underwent coronary artery bypass grafting. Overall, 50% of patients who underwent either intervention died of cardiac-related causes, whereas no patient died of a cardiac-related cause after undergoing neither intervention (P <0.0001). We conclude that, despite coronary intervention, mortality rates remain high in OLT patients who have severe coronary artery disease.

Typical blood pressure response during dobutamine stress echocardiography of patients without known cardiovascular disease who have normal stress echocardiograms

AIMS

Blood pressure (BP) responses during dobutamine stress echocardiography (DSE) have not been systematically studied. Consequently, it is not known what constitutes a normal or an abnormal BP response to dobutamine stress. We sought to define the typical BP response during DSE of patients not known to have cardiovascular disease.

METHODS AND RESULTS

Of 24 134 patients who underwent DSE from November 2003 to December 2012 at Mayo Clinic, Rochester, MN, 2968 were selected for inclusion in this retrospective study. Excluded were patients with a history of hypertension, diabetes, or coronary artery disease, and those taking vasoactive medications. Patients who had baseline and/or stress-induced wall motion abnormalities were also excluded. The distribution of the study population's BP responses during DSE was Gaussian; we defined cut-point values for normative BP responses at 2 SD for each decade of age and for the whole study population. During DSE, systolic BP (SBP) increased from baseline to peak stress (Δ +2.9 ± 24 mmHg, P < 0.0001) and diastolic BP (DBP) decreased (Δ -7.4 ± 14 mmHg). BP changes were age and sex dependent; men and younger patients had greater ΔSBP and lesser ΔDBP, compared with women and older patients. Patients who received atropine had higher peak BP values than patients who did not receive atropine, due to greater ΔSBP (+7.4 ± 26 vs. -0.5 ± 22 mmHg, P < 0.0001) and lesser ΔDBP (-4 ± 14 vs. -9.7 ± 12 mmHg, P < 0.0001). This atropine effect was present in men and women, and was more pronounced in younger patients. The normative peak SBP values ranged from 82 to 182 mmHg.

CONCLUSION

BP responses during DSE vary and depend on patients' age, gender, and the use of atropine. We describe the typical BP responses seen during DSE and report normative reference values, which can be used for defining normal and abnormal BP responses to dobutamine stress.

Three-dimensional cardiac cine imaging using the kat ARC acceleration: Initial experience in clinical adult patients at 3T

OBJECTIVE

Three-dimensional cardiac cine imaging has demonstrated promising clinical 1.5-Tesla results; however, its application to 3T scanners has been limited because of the higher sensitivity to off-resonance artifacts. The aim of this study was to apply 3D cardiac cine imaging during a single breath hold in clinical patients on a 3T scanner using the kat ARC (k- and adaptive-t auto-calibrating reconstruction for Cartesian sampling) technique and to evaluate the interchangeability between 2D and 3D cine imaging for cardiac functional analysis and detection of abnormalities in regional wall motion.

METHODS

Following institutional review board approval, we obtained 2D cine images with an acceleration factor of two during multiple breath holds and 3D cine images with a net scan acceleration factor of 7.7 during a single breath hold in 20 patients using a 3T unit. Two readers independently evaluated the wall motion of the left ventricle (LV) using a 5-point scale, and the consistency in the detection of regional wall motion abnormality between 2D and 3D cine was analyzed by Cohen's kappa test. The LV volume was calculated at end-diastole and end-systole (LVEDV, LVESV); the ejection fraction (LVEF) and myocardial weight (LVmass) were also calculated. The relationship between functional parameters calculated for 2D and 3D cine images was analyzed using Pearson's correlation analysis. The bias and 95% limit of agreement (LA) were calculated using Bland-Altman plots. In addition, a qualitative evaluation of image quality was performed with regard to the myocardium-blood contrast, noise level and boundary definition.

RESULTS

Despite slight degradation in image quality for 3D cine, excellent agreement was obtained for the detection of wall motion abnormalities between 2D and 3D cine images (κ=0.84 and 0.94 for each reader). Excellent correlations between the two imaging methods were shown for the evaluation of functional parameters (r>0.97). Slight differences in LVEDV, LVESV, LVEF and LVmass were observed, with average values of 1.6±8.9mL, -0.6±5.9mL, 1.4±3.6%, and 1.3±8.7g, respectively.

CONCLUSIONS

Images obtained using the kat ARC 3D and conventional 2D cine techniques were equivalent in the detection of regional wall motion abnormalities and the evaluation of cardiac functional parameters.

Mechanism of decreased sensitivity of dobutamine associated left ventricular wall motion analyses for appreciating inducible ischemia in older adults

BACKGROUND

Dobutamine associated left ventricular (LV) wall motion analyses exhibit reduced sensitivity for detecting inducible ischemia in individuals with increased LV wall thickness. This study was performed to better understand the mechanism of this reduced sensitivity in the elderly who often manifest increased LV wall thickness and risk factors for coronary artery disease.

METHODS

During dobutamine cardiovascular magnetic resonance (DCMR) stress testing, we assessed rate pressure product (RPP), aortic pulse wave velocity (PWV), LV myocardial oxygen demand (pressure volume area, PVA, mass, volumes, concentricity, and the presence of wall motion abnormalities (WMA) and first pass gadolinium enhanced perfusion defects (PDs) indicative of ischemia in 278 consecutively recruited individuals aged 69 ± 8 years with pre-existing or known risk factors for coronary artery disease. Each variable was assessed independently by personnel blinded to participant identifiers and analyses of other DCMR or hemodynamic variables.

RESULTS

Participants were 80% white, 90% hypertensive, 43% diabetic and 55% men. With dobutamine, 60% of the participants who exhibited PDs had no inducible WMA. Among these participants, myocardial oxygen demand was lower than that observed in those who had both wall motion and perfusion abnormalities suggestive of ischemia (p = 0.03). Relative to those with PDs and inducible WMAs, myocardial oxygen demand remained different in these individuals with PDs without an inducible WMA after accounting for LV afterload and contractility (p = 0.02 and 0.03 respectively), but not after accounting for either LV stress related end diastolic volume index (LV preload) or resting concentricity (p = 0.31-0.71).

CONCLUSIONS

During dobutamine stress testing, elderly patients experience increased LV concentricity and declines in LV preload and myocardial oxygen demand, all of which are associated with an absence of inducible LV WMAs indicative of myocardial ischemia. These findings provide insight as to why dobutamine associated wall motion analyses exhibit reduced sensitivity for identifying inducible ischemia in elderly.

TRIAL REGISTRATION

This study was registered with Clinicaltrials.gov (NCT00542503).

Relationship of exercise capacity and left ventricular dimensions in patients with a normal ejection fraction. An exploratory study

OBJECTIVES

Extreme endurance exercise is known to be associated with an enlargement of the left ventricular (LV) chamber, whereas inactivity results in inverse changes. It is unknown if these dimensional relationships exist in patients.

METHODS

We analyzed the relationship of exercise capacity and LV dimension in a cohort of sequential patients with a normal ejection fraction undergoing stress echocardiography. In a total of 137 studies the following questions were addressed: (a) is there a difference in LV dimensions of patients with an excellent exercise capacity versus patients with a poor exercise capacity, (b) how is LV dimension and exercise capacity affected by LV wall thickness and (c) how do LV dimensions of patients who are unable to walk on a treadmill compare to the above groups.

RESULTS

Patients with a poor exercise capacity or who are unable to physically exercise have a 34 percent smaller LV cavity size when compared to patients with an excellent exercise capacity (p<0.001). This reduction in LV chamber size is associated with concentric LV hypertrophy and a reciprocal increase in resting heart rate. In addition, cardiac output reserve is further blunted by chronotropic incompetence and a tachycardia-induced LV volume reduction. In conclusion the relationship of exercise capacity and cardiac dimensions described in extreme athletes also applies to patients. Our exploratory analysis suggests that patients who cannot sufficiently exercise have small LV cavities.

Value of two-dimensional strain imaging in prediction of myocardial function recovery after percutaneous revascularization of infarct-related artery

BACKGROUND

Speckle tracking is integrated into echocardiographic systems for evaluation of left ventricular (LV) function by means of automated function imaging (AFI). This study aimed at evaluating role of AFI-based strain in predicting postpercutaneous coronary intervention (PCI) LV function recovery.

METHODS

Fifty patients with anterior wall myocardial infarction and impaired LV ejection fraction (LVEF) were prospectively enrolled. All patients showed positive viability results concerning left anterior descending (LAD) artery territory using low-dose dobutamine stress echocardiography (LDSE). All patients underwent strain imaging using AFI (before and after PCI).

RESULT

Mean age of the study population was 56.2 ± 5.4 years, 34 (68%) being males. 24 (48%) patients showed post-PCI LV function recovery after 4 months. They showed higher pre-PCI LVEF and AFI-based strain values. Logistic regression analysis presented baseline LVEF as an independent predictor of LV function recovery (Odds ratio = 0.7026, 95% CI: 0.54-0.93). A pre-PCI AFI strain value of -4.5% (sensitivity: 84% and specificity: 75%) for LAD territory and -9.5% (sensitivity and specificity of 50%) for global LV predicted LV function recovery.

CONCLUSION

Assessment of global and territorial LV strains using AFI; is of added value upon viability assessment using LDSE. Higher baseline LVEF and strain values are associated with post-PCI LV function recovery.

Atropine first is safer than conventional atropine administration in older people undergoing dobutamine stress echocardiography

OBJECTIVE

Early injection of atropine during dobutamine stress echocardiography (DSE) has been demonstrated in retrospective analyses to reduce the duration and dose of dobutamine infusion, while preserving a similar diagnostic accuracy with a lower incidence of adverse effects. This study explores the safety of using atropine as a start drug before dobutamine infusion (ADSE protocol) in comparison with the conventional protocol (DASE protocol) in older patients undergoing DSE for ischemia evaluation.

METHODS

One hundred consecutive older patients were prospectively enrolled. When eligible, they were randomly assigned to undergo either the DASE protocol (group A, 50 patients) or the ADSE protocol (group B, 50 patients) when atropine (1.0 mg) was first administered 3 min before dobutamine infusion followed by 0.5 mg increments (maximum 1.0 mg) thereafter. Patients were monitored for adverse drug effects. Test duration was calculated.

RESULTS

The mean age of the whole study cohort was 67.8±4.3 years and 58 (58%) were men. Patients in group A had longer test duration (21.8±1.3 versus 13.7±0.77 min, p<0.001) and higher mean dobutamine infusion rate (39±8.2 versus 28.2±9.5 μg/kg/min, p<0.001). The two groups received a similar total dose of atropine. Group A patients showed significantly higher incidence of extrasystoles, nonsustained ventricular tachycardia and severe hypotension (p<0.05).

CONCLUSION

In older patients undergoing DSE, using atropine as a start drug, that is, adopting the ADSE protocol, is associated with shorter test duration, lower mean dobutamine infusion rate and consequently fewer adverse effects.

Utility of dobutamine stress echocardiography as part of the pre-liver transplant evaluation: an evaluation of its efficacy

BACKGROUND

Dobutamine stress echocardiography (DSE) is commonly used to risk stratify patients in the cardiac evaluation prior to orthotopic liver transplantation (OLT). Data remain limited regarding the accuracy to predict obstructive coronary artery disease (CAD) using this approach.

HYPOTHESIS

We hypothesize that DSE may have limitations in the investigation of underlying CAD in patients with end-stage liver disease.

METHODS

A retrospective chart review of all patients who underwent OLT at Mayo Clinic in Florida between 1998 and 2010 was performed. Sixty-six underwent invasive coronary angiography (ICA) within 1 year of DSE and were included in our study. Based on DSE results, patients were stratified into 1 of 3 groups: nonischemic, ischemic, and indeterminate. The relationship between DSE, ICA, and death from all cause and cardiac-related cause with a minimum 3-year follow-up period were analyzed.

RESULTS

A total of 66 patients were included in our cohort. There was no difference in age, gender, severity of liver disease, and echocardiographic findings among the groups. Forty-three percent of patients (n = 12) with an abnormal result on DSE were found to have moderate or severe obstructive CAD on cardiac catheterization, whereas 49% of patients (n = 17) with a normal finding on DSE had moderate or severe CAD. Of 5 patients who died from a documented cardiac etiology, 3 had normal stress test results, 1 had abnormal findings, and 1 had an indeterminate DSE result. When compared with ICA, our study demonstrated that DSE has a sensitivity of 41.4% (95% confidence interval [CI]: 0.24-0.61), specificity of 47.1% (95% CI: 0.30-0.65), positive predictive value of 40.0% (95% CI: 0.23-0.59), and negative predictive value of 48.0% (95% CI: 0.31-0.66) in identification of underlying CAD.

CONCLUSIONS

Although widely used, DSE may not always accurately reflect the severity of obstructive CAD in patients undergoing OLT.

The Prognostic Significance of Resting Regional Left Ventricular Function in Patients With Varying Degrees of Myocardial Ischemia

Background

Our aim was to determine whether regional left ventricular (LV) function on a resting transthoracic echo (TTE) provides prognostic information in patients with varying degrees of ischemia on myocardial perfusion imaging.

Methods

Between 2004 - 2009, we identified 503 patients (mean age 69 (SD 11); 79% male) with reversible ischemia on a myocardial SPECT scan who had a TTE within 30 days. We evaluated the rate of subsequent revascularization and death for all patients.

Results

Following the SPECT scan and TTE, 246/503(49%) patients underwent revascularization, 64/503 (13%) patients died, 369 (73%) patients had a normal left ventricular ejection fraction (LVEF), 242 (48%) patients had a resting wall motion abnormality (WMA), 21/261 (8%) with no WMA died compared to 43/242 (18%) in patients with a WMA. In patients with a WMA (n = 242) there was no significant difference in mortality when comparing patients with small (< 6 segments) and large (> 6 segments) WMA (P = 0.44). In patients with moderate/severe ischemia, the presence of a resting WMA was associated with a higher mortality rate (18% v 7%; P = 0.005). In a multivariable model, LVEF (< 50%) was associated with a hazard ratio of 2.2 (P = 0.002, 95% CI 1.34 - 3.68) however, WMA and number of abnormal segments did not reach statistical significance.

Conclusion

A resting wall motion abnormality in patients with moderate/severe ischemia is associated with a higher mortality compared to patients with mild ischemia on myocardial perfusion imaging. Regional left ventricular dysfunction unlike LVEF was not an independent predictor of mortality.

Improving prediction of outcomes in African Americans with normal stress echocardiograms using a risk scoring system

Cardiovascular mortality is high in African Americans, and those with normal results on stress echocardiography remain at increased risk. The aim of this study was to develop a risk scoring system to improve the prediction of cardiovascular events in African Americans with normal results on stress echocardiography. Clinical data and rest echocardiographic measurements were obtained in 548 consecutive African Americans with normal results on rest and stress echocardiography and ejection fractions ≥50%. Patients were followed for myocardial infarction and death for 3 years. Predictors of cardiovascular events were determined with Cox regression, and hazard ratios were used to determine the number of points in the risk score attributed to each independent predictor. During follow-up of 3 years, 47 patients (8.6%) had events. Five variables-age (≥45 years in men, ≥55 years in women), history of coronary disease, history of smoking, left ventricular hypertrophy, and exercise intolerance (<7 METs in men, <5 METs in women, or need for dobutamine stress)-were independent predictors of events. A risk score was derived for each patient (ranging from 0 to 8 risk points). The area under the curve for the risk score was 0.82 with the optimum cut-off risk score of 6. Among patients with risk scores ≥6, 30% had events, compared with 3% with risk score <6 (p <0.001). In conclusion, African Americans with normal results on stress echocardiography remain at significant risk for cardiovascular events. A risk score can be derived from clinical and echocardiographic variables, which can accurately distinguish high- and low-risk patients.

Implications of acute left ventricular remodeling during squatting stress echocardiography

BACKGROUND

We previously demonstrated that squatting induces left ventricular (LV) wall motion abnormalities (WMA) in areas subtended by stenotic coronary arteries. In addition, it was observed that some subjects developed acute changes in LV shape (acute left ventricular remodeling [ALVRM]) during squatting.

OBJECTIVE

This study tested the hypothesis that patients with ALVRM during squatting echocardiography have higher incidences of severe coronary artery disease (CAD).

METHODS

Echocardiography was performed in all standard views during standing and squatting. End-systolic frames in the apical four-chamber view were analyzed.

RESULTS

The subjects were divided into three groups. Group 1 consisted of 12 subjects who developed squatting-induced ALVRM with apical and distal posterior septal akinesis, dilation of the apex and marked LV shape change at end-systole. Group 2 consisted of 20 subjects with distal posterior septal and apical akinesis without ALVRM, during squatting. Group 3 consisted of 64 subjects who developed WMA in areas other than the apex (n = 49), or normal wall motion (n = 15) during squatting. Coronary angiography in group 1 revealed that 6 subjects had left main coronary artery stenosis (LMCAS ≥ 50%), two had severe three vessel disease (≥ 90% stenosis), and one had 100% left anterior descending coronary artery occlusion. Severe CAD was defined for purpose of this study as the presence of LMCAS, or severe three vessel disease (≥ 90% stenosis). Six subjects in group 2 had LMCAS and none had severe three vessel disease (P < 0.05 vs. group 1 for LMCAS and/or three vessel disease). In group 3, eight had LMCAS and none had severe three vessel disease (P < 0.0001 vs. group 1).

CONCLUSION

Patients with ALVRM have severe CAD. Therefore, patients who develop ALVRM during squatting require urgent evaluation for revascularization therapy.

Imaging techniques in coronary atherosclerotic disease: dobutamine stress echocardiography--evidence and perspectives

Dobutamine stress echocardiography is the most widely disseminated noninvasive technique for the assessment of coronary artery disease. Its results are important for clinical decisions. It is a versatile technique with high sensitivity and specificity for detecting viable myocardium at jeopardy. More recently, strain rate imaging has been applied to stress echocardiography. This approach relies on tissue Doppler or two-dimensional strain imaging to quantify myocardial deformation. The application of contrast echocardiographic techniques to stress echocardiography enables left ventricular opacification for border enhancement and myocardial perfusion imaging. Thus, this application is not limited to stress echocardiography, but has utility whenever image quality adversely affects wall motion assessment. Recently, three-dimensional stress echocardiography imaging has been proposed as an alternative approach to assess myocardial ischemia.

Longitudinal Doppler strain measurement for assessment of damaged and/or hibernating myocardium by dobutamine stress echocardiography in patients with old myocardial infarction

BACKGROUND

The ratio of systolic lengthening to combined late and postsystolic shortening (L/TS ratio) on longitudinal Doppler strain imaging (Doppler SI) may be an index of myocardial viability. We hypothesized that measuring the postsystolic index (PSI) and the L/TS ratio during dobutamine stress echocardiography (DSE) could quantitatively identify viable myocardium with the potential for regional functional recovery.

METHODS

Thirty-eight patients with old myocardial infarction (OMI) underwent DSE with Doppler SI and coronary angiography (Group 1). To clarify the value of measuring the PSI and L/TS ratio by DSE with Doppler SI in patients with OMI, these Doppler parameters and visual analysis of wall motion abnormality (WMA) were compared on a segmental basis. To investigate the prediction of regional functional recovery, 10 patients with OMI (Group 2) and stenosis of the infarct-related coronary artery underwent DSE with Doppler SI before and after percutaneous coronary intervention.

RESULTS

In Group 1, 143 out of 556 segments showed a biphasic WMA pattern during DSE. There were no segments with evidence of necrosis. The PSI at peak stress was > or =0.25 in 114 out of 143 segments and the L/TS ratio at peak stress was >0 in 82 out of 114 segments. Regarding functional recovery, 42 of the 73 segments with WMA at rest showed improvement after reperfusion. The wall motion score (WMS) showed 86% sensitivity and 71% specificity for predicting regional recovery, while PSI and L/TS ratio showed 61% vs. 84% sensitivity and 60% vs. 79% specificity, respectively. The AUC for the ROC curve of the L/TS ratio as a predictor of regional recovery was significantly larger compared with that of WMS (0.894 vs. 0.783, p<0.05).

CONCLUSIONS

The peak stress L/TS ratio could be a specific and quantitative marker for identifying myocardial viability that has the potential for regional functional recovery.

Quantitative three-dimensional wall motion analysis predicts ischemic region size and location

Stress echocardiography is an important screening test for coronary artery disease. Currently, cardiologists rely on visual analysis of left ventricular (LV) wall motion abnormalities, which is subjective and qualitative. We previously used finite-element models of the regionally ischemic left ventricle to develop a wall motion measure, 3DFS, for predicting ischemic region size and location from real-time 3D echocardiography (RT3DE). The purpose of this study was to validate these methods against regional blood flow measurements during regional ischemia and to compare the accuracy of our methods to the current state of the art, visual scoring by trained cardiologists. We acquired RT3DE images during 20 brief (<2 min) coronary occlusions in dogs and determined ischemic region size and location by microsphere-based measurement of regional perfusion. We identified regions of abnormal wall motion using 3DFS and by blinded visual scoring. 3DFS predicted ischemic region size well (correlation r (2) = 0.64 against microspheres, p < 0.0001), reducing error by more than half compared to visual scoring (8 +/- 9% vs. 19 +/- 14%, p < 0.05), while localizing the ischemic region with equal accuracy. We conclude that 3DFS is an objective, quantitative measure of wall motion that localizes acutely ischemic regions as accurately as wall motion scoring while providing superior quantification of ischemic region size.

Effect of dobutamine and hyperoxia on free radicals production in relation to the ultrastructural alterations in the endothelial of myocardial capillary in rats, Rattus norvigicus

Hyperoxia has been widely used as model for oxidative stress. Free radicals (FR), suproxide anion (*O(-)(2)) and nitric oxide anion (*NO(-)), are highly toxic and have detrimental effects on nitroso-redox balance in the myocyte. Myocardium is rich with beta-adrenergic receptors and endothelial is the site of NO production. The authors hypothesized that graded doses of dobutamine result in hyperkinetic state, which shifts the nitroso-redox balance toward the buildup of reactive species in dose-dependent excess. The purpose of the present study was to investigate free radicals production and coronary endothelial cell pathological changes following increasing length of breathing oxygen (100% O(2)) and progressive doses of dobutamine. Thirty-five adult male rats, matched with age and body weight, were randomly assigned to 7 groups. The first group served as control (C) and the 2nd, 3rd, and 4th groups were exposed to hyperoxia (100% O(2) breathing) for 24,48, and 72 h, whereas the 5th, 6th, and 7th groups were injected dobutamine 10,20, and 30 microg kg(-1), respectively. Following the treatment condition for each group, animals were sacrificed and heart tissues were divided randomly into two parts. The first part was processed for the ultrastructure, using transmission electron microscope (TEM), and the second was homogenized for FR determination. TEM examination showed that O2 breathing for 24 h resulted in hypertrophy and proliferation of endothelial cells lining the coronary capillary, which was lodged by lymphoid cells. Distended and irregular contour of endothelium, enlarged nucleus, protrusion membrane, as well as pinocytotic vesicles were also observed. Free radicals (FR) production at all levels of hyperoxia exposures and dobutamine injections were significantly (p < .05) higher than control group. In addition, dobutamine induced higher relative FR production, as compared with hyperoxia, implying more severe myocyte injury. Based on the results of the present study, it can be concluded that O2 breathing for 24 h or higher resulted in variety of pathological changes of the endothelium of coronary capillary that were induced by the buildup of oxidants by-products. Because dobutamine caused relative higher in FR production levels, as compared with hyperoxia levels, throughout this implied it aggravated the myocyte capillaries' endothelium more heavily, which could have resulted in more intense ultrastructural deteriorations.

Incremental value of 2-dimensional speckle tracking strain imaging to wall motion analysis for detection of coronary artery disease in patients undergoing dobutamine stress echocardiography

BACKGROUND

Interpretation of dobutamine stress echocardiogram (DSE) is often subjective and requires expert training. The purposes of this study was to determine optimal cutoff values for longitudinal, circumferential, and radial strains at peak DSE for detection of significant stenoses on coronary angiography and to investigate incremental value of combining strain measurements to wall motion analysis.

METHODS

In this multicenter study, 102 patients underwent concomitant DSE and coronary angiography. Optimal cutoff values for mean global longitudinal (-20%), global circumferential (-26%), and mean radial (50%) strains at peak stress for detection of significant stenoses on coronary angiography were determined in a derivation group (n = 62) and tested in a prospectively recruited validation group (n = 40).

RESULTS

Respective sensitivities for longitudinal, circumferential, radial strains, and expert wall motion score index (WMSI) were 84.2%, 73.9%, 78.3%, and 76%; respective specificities were 87.5%, 78.6%, 57.1%, and 92.9%; and respective accuracies were 85.2%, 75.7%, 70.3%, and 82.1%. Longitudinal strain analysis had comparable accuracy to WMSI (P = .70). However, combination longitudinal strain and WMSI had the highest sensitivity, specificity, and accuracy (100%, 87.5%, and 96.3% respectively), and its diagnostic accuracy was incremental to either longitudinal strain (P = .034) or WMSI alone (P = .008).

CONCLUSION

Longitudinal strain analysis had higher diagnostic accuracy than circumferential and radial strains and was comparable to WMSI for detection of significant coronary artery disease. However, combination longitudinal strain and WMSI resulted in significant incremental increase in diagnostic accuracy.

Methodological Analysis of Diagnostic Dobutamine Stress Echocardiography Studies

BACKGROUND

Dobutamine stress echocardiography (DSE) is an accepted test for the diagnosis of coronary artery disease (CAD), despite its wide diagnostic accuracy.

AIM

Which factors cause test variability of DSE for the diagnosis of CAD.

METHODS

In a retrospective analysis of 46 studies in 5,353 patients, the potential causes of diagnostic variability were systematically analyzed, including patient selection, definition of CAD, chest pain characteristics, confounding factors for DSE (left ventricular hypertrophy, left bundle branch block, female gender), work-up bias (present when patient's chance to undergo coronary angiography is influenced by the result of DSE), review bias (present when DSE is interpreted in relation to CAG), DSE protocol and definition of a positive DSE.

RESULTS

Diagnostic variability was related to definition of a positive test, but not related to the definition of CAD or DSE protocol. However, only three of eight methodological standards for research design found general compliance. Differences in the selection of the study population (quality of echocardiographic window, angina pectoris), handling of confounding factors and analysis of disease in individual coronary arteries were observed. Lack of data on analysis of relevant chest pain syndromes and handling of nondiagnostic test results hampered further evaluation of these standards.

CONCLUSION

Methodological problems may explain the wide range in diagnostic variability of DSE. An improvement of clinical relevance of DSE testing is possible by stronger adherence to common and new methodological standards.

Factors affecting sensitivity and specificity of diagnostic testing: dobutamine stress echocardiography

BACKGROUND

Clinical characteristics of patients, angiographic referral bias, and several technical factors may all affect the reported diagnostic accuracy of tests. The aim of this study was to assess their influence on the diagnostic accuracy of dobutamine stress echocardiography (DSE).

METHODS

The medical literature from 1991 to 2006 was searched for diagnostic studies using DSE and meta-analysis was applied to the 62 studies thus retrieved, including 6881 patients. These studies were analyzed for patient characteristics, angiographic referral bias, and several technical factors.

RESULTS

The sensitivity of DSE was significantly related to the inclusion of patients with prior myocardial infarctions (0.834 vs 0.740, P < .01) and defining the results of DSE as already positive in case of resting wall motion abnormalities rather than obligatory myocardial ischemia (0.786 vs 0.864, P < .01). Specificity tended to be lower when patients with resting wall motion abnormalities were included in a study (0.812 vs 0.877, P < .10). The presence of referral bias adversely affected the specificity of DSE (0.771 vs 0.842, P < .01).

CONCLUSION

This analysis suggests that the reported sensitivity of DSE is likely higher and the specificity lower than expected in routine clinical practice because of the inappropriate inclusion of patients with prior myocardial infarctions, the definition of positive results on DSE, and the negative influence of referral bias. However, in the patient subset that will be sent to coronary angiography, the opposite results can be expected.

Impact of time to reperfusion after acute myocardial infarction on myocardial damage assessed by left ventricular longitudinal strain

The relation between cardiac troponin T (cTnT) and regional strain in patients with acute myocardial infarction (AMI) was investigated. Furthermore, the effect of symptoms-to-balloon time on impairment in regional strain after AMI was evaluated. A total of 157 consecutive patients with AMI who underwent primary percutaneous coronary intervention were included. Two-dimensional echocardiography soon after percutaneous coronary intervention was performed. Speckle-tracking analysis was applied to assess left ventricular global and regional longitudinal peak systolic strain (LPSS). Infarcted area was defined based on the culprit vessel. Mean left ventricular ejection fraction was 47 +/- 7%. Global LPSS was -14.4 +/- 3.2%. The infarcted area LPSS was significantly decreased compared with global LPSS (-11.3 +/- 4.5%, p <0.001). The major reflector of cTnT was infarcted area LPSS (beta 0.47, p <0.001). Mean symptoms-to-balloon time was 212 +/- 92 minutes. Based on this time, the study population was divided in tertiles. In the group with the shortest symptoms-to-balloon time, global LPSS and infarcted area LPSS were less impaired compared with groups with longer symptoms-to-balloon time (p <0.01 for the 2 comparisons). In conclusion, myocardial strain was related to peak levels of cTnT, thus reflecting damage after AMI. Early reperfusion resulted in decreased myocardial damage in the infarcted area as quantified with strain.

Comparison of pressure measurement, dobutamine contrast stress echocardiography and SPECT for the evaluation of intermediate coronary stenoses. The COMPRESS trial

BACKGROUND

DSE and SPECT are two well-established methods to non-invasively investigate the functional significance of coronary artery stenoses in patients with coronary artery disease. The measurement of Fractional Flow Reserve has emerged a new invasive reference standard for lesion specific quantification of coronary artery stenoses. The objective of our prospective study was to compare sensitivity and specificity of Dobutamine Stress Echocardiography (DSE) and Single Photon Emission Computer tomography (SPECT) with the pressure derived Fractional Flow Reserve (FFR) for the identification of hemodynamic relevant coronary lesions in patients with predominately coronary multivessel disease and angiographically intermediate stenoses.

METHODS

Inclusion criteria were a coronary lesion of 50-75% diameter stenosis by visual assessment in patients with known or suspected CAD. SPECT, DSE and FFR testing was performed within one week of coronary angiography.

RESULTS

The study comprised 48 consecutive symptomatic patients. In 41 cases, a coronary multivessel disease was present. Mean FFR was 0.80 +/- 0.13 (0.41-1.0). Overall sensitivity of DSE and SPECT was 67% and 69% whereas specificity reached 77% and 87%. However, sensitivity was significantly reduced if the target lesion was located distally. DSE showed poor results if the lesions were located in the circumflex artery or if a history of prior myocardial infarctions was present.

CONCLUSION

DSE and SPECT are both useful methods for the non-invasive assessment of coronary artery disease. DSE showed reasonable combination of sensitivity and specificity even in patients with multivessel disease. Although use of noninvasive stress tests is only limited in patients with prior myocardial infarctions and invasive stress testing should be preferred in these patients.

Dual-source CT coronary angiogram in heart transplant recipients in comparison with dobutamine stress echocardiography for detection of cardiac allograft vasculopathy

Conventional coronary angiography (CCA) is the gold standard in the diagnosis of cardiac allograft vasculopathy (CAV) in heart transplant recipients. Dobutamine stress echocardiography (DSE) is a useful technique for screening. Dual-source computed tomography (DSCT) is the last generation of computed tomography scanners, which could be useful to noninvasively assess CAV. Thirty cardiac transplant recipients underwent DSE and DSCT coronary angiogram. Exclusion criteria were as follows: renal insufficiency, iodinated contrast media allergy, less than 12 months since transplant, and unstable clinical conditions. DSE showed ischemia in two patients. At DSCT scan 13 patients had a normal angiogram, 13 ones wall thickening and four significant diseases. DSCT showed a sensitivity of 100% with a specificity of 92%. DSCT allowed detection of more patients with CAV than DSE. Four patients showed significant CAV at DSCT compared with two at DSE. Thirteen patients showed initial signs of disease at DSCT despite a normal DSE.