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.

Dobutamine echocardiography for assessment of viability in the current era.

PURPOSE OF REVIEW: Studies from the 1990s and early 2000s documented the utility of dobutamine echocardiography for the prediction of functional recovery and prognosis with revascularization. The results of The Surgical Treatment of Ischemic Heart Failure (STICH) trial called into question the value of viability assessment using dobutamine echocardiography. The purpose of this review is to re-examine the literature on dobutamine echocardiography, put into context the STICH results, and provide insight into the current role of dobutamine echocardiography viability testing. RECENT FINDINGS: In contrast to the results of previous nonrandomized trials, the STICH trial showed that patients with viability defined by nuclear perfusion imaging or dobutamine echocardiography did not have improved survival with CABG compared with optimal medical therapy. Viability by dobutamine echocardiography was defined as the presence of contractile reserve in at least five segments with baseline dysfunction. The results of dobutamine echocardiography studies published before and after initiation of the STICH trial suggest that the definition of viability utilized in that trial may be suboptimal for assessment of improvement in global function and prognosis in patients undergoing revascularization. Assessment of global contractile reserve using wall motion score (WMS) or ejection fraction may be superior to utilization of a binary definition of viability confined to assessment of contractile reserve in a fixed number of segments because these indices provide information on both the magnitude and extent of contractile reserve of the entire left ventricle (LV). SUMMARY: Assessment of WMS or ejection fraction with dobutamine echocardiography may be the optimal means of evaluating the impact of viability on prognosis.Video abstract http://links.lww.com/HCO/A56.

Current noninvasive imaging techniques for detection of coronary artery disease.

The development and widespread use of noninvasive imaging techniques have contributed to the improvement in evaluation of patients with known or suspected coronary artery disease. Stress echocardiography and single-photon computed tomography are well-established noninvasive techniques with a proven track record for the diagnosis of coronary atherosclerosis. These modalities are generally widely available and provide a relatively high sensitivity and specificity along with an incremental value over clinical risk factors for detection of coronary artery disease. PET has a high diagnostic performance but continues to have limited clinical use because of the high expense of the dedicated equipment and difficulties in obtaining adequate radionuclides. Cardiac MRI and multislice computed tomography constitute the most recent addition to the cardiac imaging armamentarium. Cardiac MRI offers a comprehensive cardiac evaluation, which includes wall-motion analysis, myocardial tissue morphology, rest and stress first-pass myocardial perfusion, as well as ventricular systolic function. Cardiac computed tomography allows coronary calcium scanning along with noninvasive anatomic assessment of the coronary tree. It can be combined with functional imaging to provide a complete evaluation of the presence and physiological significance of the atherosclerotic coronary disease. No single imaging modality has been proven to be superior overall. Available tests all have advantages and drawbacks, and none can be considered suitable for all patients. The choice of the imaging method should be tailored to each person based on the clinical judgment of the a priori risk of cardiac event, clinical history and local expertise.

Clinical assessment and rest and stress echocardiography for prediction of long-term prognosis in African Americans with known or suspected coronary artery disease.

BACKGROUND: There is limited information on noninvasive risk stratification of African Americans, a high-risk group for cardiovascular events. We investigated the value of clinical assessment and echocardiography for the prediction of a long-term prognosis in African Americans. METHODS: Dobutamine echocardiography was performed in 324 African Americans. Two-dimensional measurements were performed at rest, and rest and stress wall motion was assessed. A retrospective follow-up was conducted for cardiac events: myocardial infarction (MI) or cardiac death (CD). RESULTS: The mean age was 59 +/- 12 years, and 83% of patients had hypertension. The follow-up was obtained in 318 (98%) patients for a mean of 5.3 years. The events occurred in 107 (33%) subjects. The independent predictors of events were history of MI (P = 0.001, risk ratio [RR] 2.04), ischemia (P = 0.007, RR 1.97), fractional shortening (P = 0.033, RR 0.08), and left atrial (LA) dimension (P = 0.034, RR 1.39). An LA size of 3.6 cm and a fractional shortening of 0.30 were the best cutoff values for the prediction of events. Prior MI, ischemia, LA size >3.6 cm, and fractional shortening <0.30 were each considered independent risk predictors for events. The event rates were 13%, 21%, 38%, 59%, and 57% in patients with 0, 1, 2, 3, and 4 risk predictors, respectively. Event-free survival progressively worsened with an increasing number of predictors: 0 or 1 versus 2 predictors, P < 0.001; 2 versus 3 or 4 predictors, P = 0.003. CONCLUSION: The long-term prognosis of African Americans can be accurately predicted by clinical assessment combined with rest and stress echocardiography.

Positron emission tomography for assessment of viability.

PURPOSE OF REVIEW: The recent success of magnetic resonance imaging for viability assessment has raised questions about the future role of positron emission tomography and older imaging modalities in the assessment of viability. Recent information, however, indicates that positron emission tomography will remain a valuable tool. RECENT FINDINGS: The primary positron emission tomography tracer used for assessment of viability is 18F-fluorodeoxyglucose, a glucose analogue that exhibits enhanced uptake in ischemic tissue. The finding of enhanced 18F-fluorodeoxyglucose uptake and a relative reduction in perfusion is considered the positron emission tomography correlate of myocardial hibernation. The mismatch pattern has been shown to identify patients with improvement in systolic function, heart failure symptoms, and prognosis with revascularization. Mismatch identifies a subset of patients with vulnerable myocardium who have a higher likelihood of a cardiac event compared with those without significant mismatch. Delay in revascularization may pose extra risk for those with mismatch. Positron emission tomography and magnetic resonance imaging demonstrate a close correlation in the detection of viable myocardium. The development of combined positron emission tomography/computed tomography scanners can reduce imaging time and improve functional-anatomic correlations. SUMMARY: Positron emission tomography imaging utilizing 18F-fluorodeoxyglucose and perfusion tracers provides valuable diagnostic and prognostic information in patients with ischemic left ventricular dysfunction and has comparable accuracy to competing technologies for detection of viability.

Comparison of left ventriculography and coronary arteriography with positron emission tomography in assessment of myocardial viability.

BACKGROUND: Assessment of viability of myocardium after an ischemic insult is an important clinical question that affects decisions pertaining to potential revascularization. The results of contrast left ventriculograms and coronary angiography were compared to positron emission tomography (PET) in 64 patients with coronary artery disease and reduced left ventricular function. HYPOTHESIS: The study was undertaken to determine the relative utility of the invasive studies in the assessment of viability. METHODS: Right anterior oblique ventriculograms were assessed for hypokinesis, akinesis, or dyskinesis in six segments. The PET scans were assessed for viability by visual estimation of flourodeoxyglucose (FDG) uptake in six segments that corresponded to the segments analyzed on the ventriculograms. RESULTS: Of a total of 373 segments successfully analyzed by PET, 272 were judged to be viable (normal or hypokinetic) by contrast ventriculography. Of these, 253 (93%) were considered viable by PET. Of 177 segments deemed either normal or mild-to-moderately hypokinetic by ventriculography, 170 (94%) were viable by PET. Of 95 severely hypokinetic segments, 83 (84%) were viable by PET. Of 79 akinetic segments, 44 (56%) were considered viable by PET. For segments that were dyskinetic and thought to be nonviable by ventriculography, 19 of 22 (86%) were also considered nonviable by PET. For 294 segments for which a determination on viability was made based on the presence of wall motion on the ventriculogram (normal, hypokinetic, ordyskinetic; not akinetic), there was excellent agreement with PET (93%; p < 0.001). In 49 patients there was akinesis in no more than one segment in either the anterior or inferior territories, indicating the potential for assessment of viability by ventriculography in at least two of three segments in each territory. Coronary anatomy was analyzed to assess whether coronary patency could help in assessing viability. Segments supplied by patent arteries were more likely to be viable by PET than segments supplied by occluded arteries (p < 0.001). Akinetic segments were more likely to be supplied by occluded arteries (56 vs. 23, 72%). Dyskinetic segments were predominantly nonviable by PET (86%) and were usually supplied by occluded arteries (77%). CONCLUSION: In patients in whom the assessment of viability is clinically relevant, the presence of systolic inward motion on the contrast left ventriculogram correlates well with segment viability by PET, while outward or dyskinetic movement correlates well with nonviability. Thus, the use of PET to assess viability in many patients may be unnecessary.