Long term prognostic value of myocardial viability and ischaemia during dobutamine stress echocardiography in patients with ischaemic cardiomyopathy undergoing coronary revascularisation

Establishment and validation of a prediction model for nonrecovery of left ventricular ejection fraction in acute myocardial infarction patients combined with decreased left ventricular ejection fraction

BACKGROUND

This study aimed to investigate the risk factors for nonrecovery of left ventricular ejection fraction (LVEF) during follow-up in patients with acute myocardial infarction (AMI) who underwent percutaneous coronary intervention (PCI) combined with reduced LVEF, and establish and verify a risk prediction model based on these factors.

METHODS

In this study, patients with AMI who underwent PCI in a high-volume PCI center between December 2018 and December 2021 were consecutively enrolled, screened, and randomly assigned to the model establishment and validation cohorts. A predictive model method based on least absolute shrinkage and selection operator regression was used for establishment and validation.

RESULTS

Cardiac troponin I, myoglobin, left ventricular end-diastolic dimension, multivessel disease, and no-reflow were identified as potential predictors of LVEF recovery failure. The areas under the curve were 0.703 and 0.665 in the model establishment and validation cohorts, respectively, proving that the prediction model had some predictive ability. The calibration curves of the two cohorts showed good agreement with those of the nomogram model. In addition, the decision curve analysis showed that the model had a net clinical benefit.

CONCLUSION

This prediction model can assess the risk of nonrecovery of LVEF in patients with AMI undergoing PCI combined with LVEF reduction during follow-up, and conveniently screen high-risk patients with nonrecoverable LVEF early.

Predictors and Prognostic Impact of Left Ventricular Ejection Fraction Recovery after Impella-Supported Percutaneous Coronary Interventions in Acute Myocardial Infarction

Aim: The aim of our study is to assess the predictors and the prognostic role of left ventricle ejection fraction (LVEF) recovery after Impella-supported percutaneous coronary intervention (PCI) in patients presenting with acute myocardial infarction (AMI). Methods: This retrospective, observational study included patients admitted for AMI who underwent Impella-supported PCI in two Italian high-volume cardiac catheterization laboratories. Only patients who underwent an echocardiographic assessment of left ventricle ejection fraction (LVEF) before the procedure (acute LVEF) and during follow-up (follow-up LVEF) were included in the present analysis. Patients with a baseline LVEF ≥40% were excluded from the present analysis. LVEF recovery was calculated as the difference between follow-up LVEF and acute LVEF. A delta ≥5% was considered significant and was used to define the responder group. Results: From April 2007 to December 2020, 64 consecutive patients were included in our study. A total of 55 patients (86%) received hemodynamic support with Impella 2.5, and 9 patients (14%) with Impella CP. Median LVEF at follow-up was significantly higher compared to baseline (36% (30−42) vs. 30% (24−33), p < 0.001). Based on LVEF recovery, 37 patients (57.8%) were deemed responders. According to multivariate analysis, complete functional revascularization was an independent predictor of a significant EF recovery (OR: 0.159; 95% CI: 0.038−0.668; p = 0.012). At three-year follow-up, lack of LVEF recovery was the only predictor of mortality (HR: 5.315; 95% CI: 1.100−25.676; p = 0.038). Conclusions: Functional complete revascularization is an independent predictor of the recovery of LVEF in patients presenting with AMI who underwent Impella-supported PCI. The recovery of LV function is associated with improved prognosis and could be used to stratify the risk of future events at long-term follow-up.

Undiagnosed Chronic Obstructive Pulmonary Disease is Highly Prevalent in Patients Referred for Dobutamine Stress Echocardiography with Shortness of Breath

PURPOSE

Shortness of breath (SOB) is a common symptom referral for dobutamine stress echocardiography (DSE). Patients with SOB and a normal DSE have worse long-term outcome than the general population. This suggests multiple aetiologies are involved. The purpose of this study was to assess the prevalence and clinical significance of undiagnosed COPD amongst patients referred for a DSE with SOB.

METHODS

We prospectively studied 114 patients referred for DSE with SOB without prior evidence of lung disease (mean age 64.9 ± 18.5 years, 60 male). Respiratory function testing using spirometry was performed on all patients on the day of their DSE. The study end-points were cardiac events and total mortality.

RESULTS

Respiratory function testing and DSE was performed in all patients and COPD was highly prevalent (n = 93). Multivariate Cox regression analysis was used to estimate the effect of dyspnoea on non-fatal cardiac events (NFCE) and all-cause mortality. Over a mean follow-up of 4.5 ± 2.6 years, the composite end-point of NFCE and all-cause mortality occurred in 62.7% and 16.7% patients, respectively. COPD (HR 1.27; 95% CI 1.17-1.93), previous myocardial infarction (HR 1.84; 95% CI 1.06-3.2), myocardial ischaemia (HR 2.56; 95% CI 1.48-4.43), peak wall motion score index (HR 4.66; 95% CI 2.26-9.6), and mitral E/E' (HR 1.21; 95% CI 1.1-1.33) were significantly associated with a NFCE. Myocardial ischaemia (HR 4.43; 95% CI 1.24-15.81) was the only independent predictor of all-cause mortality.

CONCLUSION

Undiagnosed COPD is highly prevalent and independently associated with worse outcome amongst patients with SOB referred for DSE. Symptom presentation is therefore an important consideration when interpreting DSE results.

Myocardial viability testing: all STICHed up, or about to be REVIVED?

Patients with ischaemic left ventricular dysfunction frequently undergo myocardial viability testing. The historical model presumes that those who have extensive areas of dysfunctional-yet-viable myocardium derive particular benefit from revascularization, whilst those without extensive viability do not. These suppositions rely on the theory of hibernation and are based on data of low quality: taking a dogmatic approach may therefore lead to patients being refused appropriate, prognostically important treatment. Recent data from a sub-study of the randomized STICH trial challenges these historical concepts, as the volume of viable myocardium failed to predict the effectiveness of coronary artery bypass grafting. Should the Heart Team now abandon viability testing, or are new paradigms needed in the way we interpret viability? This state-of-the-art review critically examines the evidence base for viability testing, focusing in particular on the presumed interactions between viability, functional recovery, revascularization and prognosis which underly the traditional model. We consider whether viability should relate solely to dysfunctional myocardium or be considered more broadly and explore wider uses of viability testingoutside of revascularization decision-making. Finally, we look forward to ongoing and future randomized trials, which will shape evidence-based clinical practice in the future.

Cardiac Strains As a Tool for Optimization of Cardiac Resynchronization Therapy in Non-responders: a Pilot Study

Background

Approximately 30% of patients do not respond to implantation of Cardiac Resynchronization Therapy – Defibrillators (CRT-D). The aim of this study was to investigate the potential for cardiac strain speckle tracking to optimize the performance of CRT-D in non-responding patients.

Methods

30 patients not responding to Cardiac Resynchronization Therapy-Defibrillators after 3 months were randomly divided into control and intervention groups. Atrioventricular interval was adjusted so that E and A waves did not overlap, the interventricular interval was subsequently optimized to yield maximum improvement of the sum of longitudinal+radial+circumferential strains. The left ventricular ejection fraction (LVEF) and NYHA improvement 3 months after optimization were evaluated and use of other strain combinations assessed.

Results

A significant correlation between the (combined) strain change and LVEF improvement was detected (p<0.01). 75% of patients with non-ischemic etiology of heart failure who did not respond to the original CRT-D reacted favorably with significant LVEF and NYHA improvement. The area strain was the best predictor of LVEF/NYHA improvement in those patients. No significant improvement was recorded in patients with ischemic etiology.

Conclusions

AV and VV optimization based on speckle tracking is a very promising method potentially leading to a significant improvement of the outcome of CRT-D, especially in patients with non-ischemic etiology of heart failure.

[The Clinical use of Stress Echocardiography in Ischemic Heart Disease Cardiovascular Ultrasound (2017)15:7. Translation authors: Arystan A.Zh., Fettser D.V.]

Stress echocardiography is an established technique for the assessment of extent and severity of coronary artery disease. The combination of echocardiography with a physical, pharmacological or electrical stress allows detecting myocardial ischemia with an excellent accuracy. A transient worsening of regional function during stress is the hallmark of inducible ischemia. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging or magnetic resonance, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. The evidence on its clinical impact has been collected over 35 years, based on solid experimental, pathophysiological, technological and clinical foundations. There is the need to implement the combination of wall motion and coronary flow reserve, assessed in the left anterior descending artery, into a single test. The improvement of technology and in imaging quality will make this approach more and more feasible. The future issues in stress echo will be the possibility of obtaining quantitative information translating the current qualitative assessment of regional wall motion into a number. The next challenge for stress echocardiography is to overcome its main weaknesses: dependence on operator expertise, the lack of outcome data (a widespread problem in clinical imaging) to document the improvement of patient outcomes. This paper summarizes the main indications for the clinical applications of stress echocardiography to ischemic heart disease.

Baseline mitral regurgitation predicts outcome in patients referred for dobutamine stress echocardiography

A number of parameters recorded during dobutamine stress echocardiography (DSE) are associated with worse outcome. However, the relative importance of baseline mitral regurgitation (MR) is unknown. The aim of this study was to assess the prevalence and associated implications of functional MR with long-term mortality in a large cohort of patients referred for DSE. 6745 patients (mean age 64.9 ± 12.2 years) were studied. Demographic, baseline and peak DSE data were collected. All-cause mortality was retrospectively analyzed. DSE was successfully completed in all patients with no adverse outcomes. MR was present in 1019 (15.1%) patients. During a mean follow up of 5.1 ± 1.8 years, 1642 (24.3%) patients died and MR was significantly associated with increased all-cause mortality (p < 0.001). With Kaplan-Meier analysis, survival was significantly worse for patients with moderate and severe MR (p < 0.001). With multivariate Cox regression analysis, moderate and severe MR (HR 2.78; 95% CI 2.17-3.57 and HR 3.62; 95% CI 2.89-4.53, respectively) were independently associated with all-cause mortality. The addition of MR to C statistic models significantly improved discrimination. MR is associated with all-cause mortality and adds incremental prognostic information among patients referred for DSE. The presence of MR should be taken into account when evaluating the prognostic significance of DSE results.

The clinical use of stress echocardiography in ischemic heart disease

Stress echocardiography is an established technique for the assessment of extent and severity of coronary artery disease. The combination of echocardiography with a physical, pharmacological or electrical stress allows to detect myocardial ischemia with an excellent accuracy. A transient worsening of regional function during stress is the hallmark of inducible ischemia. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging or magnetic resonance, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician.

The evidence on its clinical impact has been collected over 35 years, based on solid experimental, pathophysiological, technological and clinical foundations. There is the need to implement the combination of wall motion and coronary flow reserve, assessed in the left anterior descending artery, into a single test. The improvement of technology and in imaging quality will make this approach more and more feasible. The future issues in stress echo will be the possibility of obtaining quantitative information translating the current qualitative assessment of regional wall motion into a number. The next challenge for stress echocardiography is to overcome its main weaknesses: dependance on operator expertise, the lack of outcome data (a widesperad problem in clinical imaging) to document the improvement of patient outcomes. This paper summarizes the main indications for the clinical applications of stress echocardiography to ischemic heart disease.

Myocardial inotropic reserve: An old twist that constitutes a reliable index in the modern era of heart failure

Current national and international guidelines, including those of the European Society of Cardiology, recognize that the assessment of prognosis should be a part of the standard management for patients with chronic heart failure (CHF). However, these same guidelines recognize the inherent difficulty of this process. A variety of factors contribute to this difficulty, including the varying etiology, frequent co-morbidity and, perhaps most importantly, huge inter-individual variability in the disease progression and outcome. Although CHF is chronic, it is also a condition in which significant proportions of patients experience apparently 'sudden' death, which almost certainly contributes to our difficulty in assessing individual patient prognosis. A useful tool for the risk stratification of heart failure patients is dobutamine stress echocardiography (DSE), which determines the myocardial viability in ischemic cardiomyopathy and myocardial contractile reserve in idiopathic cardiomyopathy.

Introduction to Cardiovascular Magnetic Resonance: Technical Principles and Clinical Applications

Cardiovascular magnetic resonance (CMR) is a set of magnetic resonance imaging (MRI) techniques designed to assess cardiovascular morphology, ventricular function, myocardial perfusion, tissue characterization, flow quantification and coronary artery disease. Since MRI is a non-invasive tool and free of radiation, it is suitable for longitudinal monitoring of treatment effect and follow-up of disease progress. Compared to MRI of other body parts, CMR faces specific challenges from cardiac and respiratory motion. Therefore, CMR requires synchronous cardiac and respiratory gating or breath-holding techniques to overcome motion artifacts. This article will review the basic principles of MRI and introduce the CMR techniques that can be optimized for enhanced clinical assessment.

KEY WORDS

Cardiovascular MR • Coronary arteries • Flow quantification • Myocardial fibrosis • Myocardial perfusion • Myocardial scarring • Regional wall motion • Ventricular function.

The prognostic value of dobutamine stress echocardiography amongst British Indian Asian and Afro-Caribbean patients: a comparison with European white patients

Background

The incidence of cardiovascular disease is considerably disparate among different racial and ethnic populations. While dobutamine stress echocardiography (DSE) has been shown to be useful in Caucasian patients, its role among ethnic minority groups remains unclear. This study aimed to investigate the prognostic importance of DSE in three ethnic groups in the UK.

Methods

DSE was performed on 6231 consecutive patients. After exclusions, 5329 patients formed the study (2676 [50.2 %] Indian Asian, 2219 [41.6 %] European white and 434 [8.1 %] Afro-Caribbean). Study outcome measures were non-fatal cardiac events (NFCE) and all-cause mortality.

Results

There were 849 (15.9 %) NFCE and 1365 (25.6 %) deaths over a median follow-up period of 4.6 years. In total 1174 (22 %) patients had inducible myocardial ischaemia during DSE, 859 (16.1 %) had fixed wall motion abnormalities and 3645 (68.4 %) patients had a normal study. Ethnicity did not predict events. Among the three ethnic groups, ischaemia on DSE was associated with 2 to 2.5 times the risk of non-fatal cardiac events and 1.2 to 1.4 times the risk of all-cause mortality. Peak wall motion score index was the strongest independent predictor of non-fatal cardiac events and all-cause mortality in all groups. The C statistic for the prediction of NFCE and all-cause mortality were significantly higher when DSE parameters were added to the standard risk factors for all ethnic groups.

Conclusions

DSE is a strong predictor of NFCE and all-cause mortality and provides predictive information beyond that provided by standard risk factors in three major racial and ethnic groups. No major differences among racial and ethnic groups in the predictive value of DSE was detected.

Electronic supplementary material

The online version of this article (doi:10.1186/s12947-015-0028-1) contains supplementary material, which is available to authorized users.

Prognostic value of myocardial ischemia and necrosis in depressed left ventricular function: a multicenter stress cardiac magnetic resonance registry

INTRODUCTION AND OBJECTIVES

The incremental prognostic value of inducible myocardial ischemia over necrosis derived by stress cardiac magnetic resonance in depressed left ventricular function is unknown. We determined the prognostic value of necrosis and ischemia in patients with depressed left ventricular function referred for dipyridamole stress perfusion magnetic resonance.

METHODS

In a multicenter registry using stress magnetic resonance, the presence (≥ 2 segments) of late enhancement and perfusion defects and their association with major events (cardiac death and nonfatal infarction) was determined.

RESULTS

In 391 patients, perfusion defect or late enhancement were present in 224 (57%) and 237 (61%). During follow-up (median, 96 weeks), 47 major events (12%) occurred: 25 cardiac deaths and 22 myocardial infarctions. Patients with major events displayed a larger extent of perfusion defects (6 segments vs 3 segments; P <.001) but not late enhancement (5 segments vs 3 segments; P =.1). Major event rate was significantly higher in the presence of perfusion defects (17% vs 5%; P =.0005) but not of late enhancement (14% vs 9%; P =.1). Patients were categorized into 4 groups: absence of perfusion defect and absence of late enhancement (n = 124), presence of late enhancement and absence of perfusion defect (n = 43), presence of perfusion defect and presence of late enhancement (n = 195), absence of late enhancement and presence of perfusion defect (n = 29). Event rate was 5%, 7%, 16%, and 24%, respectively (P for trend = .003). In a multivariate regression model, only perfusion defect (hazard ratio = 2.86; 95% confidence interval, 1.37-5.95]; P = .002) but not late enhancement (hazard ratio = 1.70; 95% confidence interval, 0.90-3.22; P =.105) predicted events.

CONCLUSIONS

In depressed left ventricular function, the presence of inducible ischemia is the strongest predictor of major events.

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).

Assessment of left ventricular ejection fraction using the wall motion score index in cardiac magnetic resonance imaging

BACKGROUND

Left ventricular ejection fraction (LVEF) is an important indicator of left ventricular function and of the severity and prognosis of ischaemic heart disease. Assessment of regional function using the wall motion score index (WMSI) is an alternative means of evaluating left ventricular function.

AIM

We attempted to evaluate LVEF by a method using the WMSI with cardiac magnetic resonance imaging (MRI).

METHODS

One hundred and twenty-two patients referred for evaluation of heart disease had rest WMSI evaluation by cardiac MRI. The WMSI was evaluated using the 16-segment model and score proposed by the American Society of Echocardiography. In our first group of 80 patients, a correlation between WMSI and cardiac MRI LVEF was established and a regression equation was derived. This regression equation was then used in 42 consecutive patients to compare WMSI LVEF with the gold standard MRI LVEF.

RESULTS

In the first 80 patients, MRI LVEF and WMSI correlated very well (r=0.93). Similarly, in the second group of 42 patients, WMSI LVEF derived from the regression equation correlated very well with MRI LVEF (r=0.94).

CONCLUSION

An objective evaluation of LVEF can be easily made using the WMSI with cardiac MRI, which correlates very well with standard MRI planimetric methods.

Effect of improvement in left ventricular ejection fraction on long-term survival in revascularized patients with ischaemic left ventricular systolic dysfunction

AIMS

The importance of improvement in the ejection fraction to the prognosis of revascularized patients with ischaemic left ventricular (LV) dysfunction is uncertain.

METHODS AND RESULTS

Eighty-seven patients with ischaemic LV dysfunction (mean ejection fraction 29 ± 8% by biplane Simpson's) had dobutamine echocardiography before revascularization (coronary bypass graft surgery-81, percutaneous intervention-6). Follow-up echocardiograms were performed a mean of 4.8 ± 6.2 months after revascularization. An 8% increase in the ejection fraction was considered significant (two times the inter-observer difference of 3.7%). Patients were followed for cardiac death. During a mean follow-up of 5.2 ± 3.9 years, there were 20 (23%) cardiac deaths. Class 3/4 heart failure, increasing low-dose wall motion score, increasing % non-viable myocardium, and digoxin use in follow-up were univariate predictors of death. Beta-blocker use, ejection fraction improvement, angina, aspirin use, and increasing fractional shortening were univariate predictors of survival. Ejection fraction improvement [P= 0.02, hazard ratio (HR) = 0.26], digoxin use in follow-up (P= 0.006, HR = 5.85), and low-dose wall motion score (P= 0.017, HR = 4.78) were independent predictors of outcome. In step-wise analysis, low-dose wall motion score added incremental prognostic value to ejection fraction improvement (P= 0.003), and digoxin use in follow-up (P= 0.003) added incremental value to a low-dose score and ejection fraction improvement.

CONCLUSION

Ejection fraction improvement is an independent predictor of long-term outcome in revascularized patients but viability (low-dose wall motion score) and digoxin use in follow-up are also independent predictors and add incremental prognostic value to ejection fraction improvement.

Myocardial perfusion imaging with first-pass computed tomographic imaging: Measurement of coronary flow reserve in an animal model of regional hyperemia

BACKGROUND

The accurate assessment of myocardial blood flow (MBF) is a potential adjunct to the anatomy of CT coronary angiography.

PURPOSE

To compare semi-quantitative parameters from first-pass CT (FP CT) imaging with absolute measures of MBF in an animal model of altered MBF.

METHODS

A pig model of intracoronary adenosine (n = 8) was used during FP CT. This produces a zone with hyperemic MBF and a control zone within a slice. A subset of these animals also underwent LAD occlusion with imaging. Fluorescent microspheres (Mcsp) were injected into the left atrium to determine absolute MBF concurrent with CT imaging. Pigs were placed in a 64-slice (Philips) CT with acquisition performed during IC adenosine and occlusion. A 40% dilution of Iopamidol 370 (1 mL/kg) was injected IV at 5 mL/second. CT acquisition was ECG gated over 40 cardiac phases with the following parameters: 180 degrees axial mode (pitch = 0), field of view = 250 mmsq, 512 x 512 matrix, slice thickness = 2.5 mm x 10 slices, temporal resolution = 330 ms, 120 kV, 495 ma. Mcsp were injected immediately following CT imaging. The heart was sectioned into 2.5 mm slices to match the CT images and segmented. Time attenuation curves (TAC) were generated from CT in intervention and control zones based on Mcsp values. Mcsp coronary flow reserve (CFR) = hyperemic/control MBF, and CT CFR was derived from intervention/control area under curve from baseline corrected TIC.

RESULTS

MBF control = .65 +/- .28, MBF adenosine = 2.6 +/- .7 mL/min/g (P < .0001). CFR = 4.1 +/- 1.1, CT CFR = 4.3 +/- 1.4 (P = NS). There was a significant (r = .94, P < .0001) correlation between CFR and CT CFR.

CONCLUSIONS

CT first-pass myocardial perfusion imaging is feasible using a simple semi-quantitative analysis which provides reasonable estimates of MBF.

Prognostic value of dobutamine stress echocardiography in diabetic patients

CAD is the main cause of morbidity and mortality in diabetic patients; we need reliable clinical parameters to stratify cardiovascular risk in these patients. We thus assessed prognostic value of clinical parameters, rest and stress echocardiographic data in diabetic patients, with known or suspected CAD. We studied 322 type 2 diabetic patients, who underwent dobutamine stress echocardiography (DSE) for known or suspected CAD; for prognostic assessment, end-points were all-cause mortality and hard cardiac events (cardiac death and non fatal myocardial infarction). During DSE, viability and inducible ischemia developed in 65 (20%) and 192 (60%) subjects, respectively; a severe ischemia (an asynergic area including more than 40% of all segments combined with a rate pressure product < 17,000) appeared in 88 (27%). Presence of a diabetic treatment or microvascular diabetic complications didn't influence prognosis, while a longer diabetes duration was associated with a higher all-cause mortality at univariate analysis. At multivariate analysis, an advanced age (RR = 1.108, CI: 1.039-1.182, P = 0.002), a lower left ventricular ejection fraction (RR = 0.956, CI: 0.919-0.994, P = 0.025) and, tendentially, peripheral vascular disease (RR = 2.942, CI: 0.985-8.785, P = 0.053) independently determined an increased all-cause mortality. New hard cardiac events occurred more frequently in presence of peripheral vascular disease (RR = 2.975, CI: 1.339-6.608, P = 0.007), viability (RR = 3.427, CI: 1.400-8.390, P = 0.007) and severe ischemia (RR = 3.245, CI: 1.503-7.005, P = 0.003). In diabetic patients with known or suspected CAD, presence of viability and severe ischemia during DSE are independently associated with higher occurrence of hard cardiac events.

Negative contractile reserve with low-dose dobutamine in patients with ischemic cardiomyopathy investigated by gated myocardial perfusion SPECT

INTRODUCTION AND OBJECTIVES

To investigate negative contractile responses in the left ventricle during low-dose dobutamine (LDD) gated single-photon emission computed tomography (SPECT) in patients with ischemic cardiomyopathy.

METHODS

Sixty-eight consecutive patients (mean age, 60 + or - 11 years; 7 male) with ischemic cardiomyopathy (i.e., left ventricular ejection fraction [LVEF] < or = 40%) were evaluated using gated-SPECT at rest and during LDD infusion. Associations between a negative contractile reserve (i.e., a > or = 1-grade improvement in wall thickening score with LDD infusion) and scintigraphic viability criteria and coronary angiography findings were analyzed.

RESULTS

Some 42.6% (29/68) of patients had a negative contractile reserve in one or more segments. In 14.7% (n=10), the LVEF decreased by > or = 4% with LDD. These patients had more segments with a negative contractile reserve (2.8 + or - 2.5 vs. 0.87 + or - 0.40; P=.042), and the cut-off value on receiver operating characteristic curve analysis was > or =2 segments with a negative contractile reserve (sensitivity 70%, specificity 74%, positive likelihood ratio 2.71, negative likelihood ratio 0.40). Some 94% (74/79) of segments with a negative contractile reserve were in viable myocardium (i.e. normal or viable on scintigraphy). Twelve of 17 segments with akinesia or severe hypokinesia and a negative contractile reserve satisfied scintigraphic viability criteria, with the majority (10/12) lying in territories supplied by a patent coronary artery.

CONCLUSIONS

A negative contractile reserve was not uncommon in patients with ischemic cardiomyopathy and was associated with a general decrease in left ventricular systolic function. It was observed mainly in myocardial segments that appeared viable on scintigraphy and were supplied by a patent coronary artery.

Ischemic cardiomyopathy: a clinical nuclear cardiology perspective

Ischemic cardiomyopathy results from severe extensive coronary artery disease, which is associated with left ventricular dysfunction and also, in many cases, with significant left ventricular dilatation. Mortality is high, especially in patients who satisfy myocardial viability criteria but who have not undergone revascularization. Although age, exercise capacity and comorbidity influence survival, the most important prognostic factors are the extent of the ischemia, myocardial viability and left ventricular remodeling, all of which can be successfully evaluated by gated myocardial perfusion single-photon emission computed tomography (SPECT).

Stress echocardiography expert consensus statement: European Association of Echocardiography (EAE) (a registered branch of the ESC)

Stress echocardiography is the combination of 2D echocardiography with a physical, pharmacological or electrical stress. The diagnostic end point for the detection of myocardial ischemia is the induction of a transient worsening in regional function during stress. Stress echocardiography provides similar diagnostic and prognostic accuracy as radionuclide stress perfusion imaging, but at a substantially lower cost, without environmental impact, and with no biohazards for the patient and the physician. Among different stresses of comparable diagnostic and prognostic accuracy, semisupine exercise is the most used, dobutamine the best test for viability, and dipyridamole the safest and simplest pharmacological stress and the most suitable for combined wall motion coronary flow reserve assessment. The additional clinical benefit of myocardial perfusion contrast echocardiography and myocardial velocity imaging has been inconsistent to date, whereas the potential of adding - coronary flow reserve evaluation of left anterior descending coronary artery by transthoracic Doppler echocardiography adds another potentially important dimension to stress echocardiography. New emerging fields of application taking advantage from the versatility of the technique are Doppler stress echo in valvular heart disease and in dilated cardiomyopathy. In spite of its dependence upon operator's training, stress echocardiography is today the best (most cost-effective and risk-effective) possible imaging choice to achieve the still elusive target of sustainable cardiac imaging in the field of noninvasive diagnosis of coronary artery disease.

Non-invasive diagnosis of ischaemic heart failure using 64-slice computed tomography

AIMS

We evaluated the accuracy of 64-slice computed tomography (CT) to identify ischaemic aetiology of heart failure (IHF).

METHODS AND RESULTS

Ninety-three consecutive patients in sinus rhythm with dilated cardiomyopathy but without suspicion of coronary artery disease (CAD) were enrolled when admitted for angiography. Accuracy of CT to detect significant stenosis (>50% lumen narrowing) was compared with quantitative coronary angiography. IHF was defined as a significant stenosis on left main or proximal left anterior descending artery or two or more vessels. Forty-three out of 1395 segments (3%) were heavily calcified and excluded. CT correctly assessed 103 of 142 (73%) significant stenosis and identified 46 of 50 (92%) patients without and 42 of 43 (98%) patients with CAD, 60 of 62 (97%) patients without and 28 of 31 (90%) patients with IHF. Overall, accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CT for identifying CAD by segment was 96, 73, 99, 92, and 97%, respectively; by patient was 95, 98, 92, 91, and 98%, respectively; and for identifying IHF was 95, 90, 97, 93, and 95%, respectively.

CONCLUSION

Non-invasive 64-slice CT assessment of the extent of CAD may offer a valid alternative to angiography for the diagnosis of IHF.

F-18-fluorodeoxyglucose positron emission tomography imaging-assisted management of patients with severe left ventricular dysfunction and suspected coronary disease: a randomized, controlled trial (PARR-2)

OBJECTIVES

We conducted a randomized trial to assess the effectiveness of F-18-fluorodeoxyglucose (FDG) positron emission tomography (PET)-assisted management in patients with severe ventricular dysfunction and suspected coronary disease.

BACKGROUND

Such patients may benefit from revascularization, but have significant perioperative morbidity and mortality. F-18-fluorodeoxyglucose PET can detect viable myocardium that might recover after revascularization.

METHODS

Included were patients with severe left ventricular (LV) dysfunction and suspected coronary disease being considered for revascularization, heart failure, or transplantation work-ups or in whom PET was considered potentially useful. Patients were stratified according to recent angiography or not, then randomized to management assisted by FDG PET (n = 218) or standard care (n = 212). The primary outcome was the composite of cardiac death, myocardial infarction, or recurrent hospital stay for cardiac cause, within 1 year.

RESULTS

At 1 year, the cumulative proportion of patients who had experienced the composite event was 30% (PET arm) versus 36% (standard arm) (relative risk 0.82, 95% confidence interval [CI] 0.59 to 1.14; p = 0.16). The hazard ratio (HR) for the composite outcome, PET versus standard care, was 0.78 (95% CI 0.58 to 1.1; p = 0.15); for patients that adhered to PET recommendations for revascularization, revascularization work-up, or neither, HR = 0.62 (95% CI 0.42 to 0.93; p = 0.019); in those without recent angiography, for cardiac death, HR = 0.4 (95% CI 0.17 to 0.96; p = 0.035).

CONCLUSIONS

This study did not demonstrate a significant reduction in cardiac events in patients with LV dysfunction and suspected coronary disease for FDG PET-assisted management versus standard care. In those who adhered to PET recommendations and in patients without recent angiography, significant benefits were observed. The utility of FDG PET is best realized in this subpopulation and when adherence to recommendations can be achieved.

Hibernating myocardium: diagnosis and patient outcomes

Approximately 50% of the patients with chronic obstructive coronary artery disease resulting in chronic contractile dysfunction have hibernating myocardium and may benefit from revascularization. This pooled analysis describes the relative merits of dobutamine echocardiography, thallium-201 and technetium-99m scintigraphy, positron emission tomography, and magnetic resonance imaging, for the diagnosis of hibernating myocardium and prediction of patient outcomes.

The long prognostic value of wall motion abnormalities during the recovery phase of dobutamine stress echocardiography after receiving acute beta-blockade

OBJECTIVE

To assess the prognostic value of wall motion abnormalities during the recovery phase of dobutamine stress echocardiography in addition to wall motion abnormalities at peak stress.

METHODS

Wall motion abnormalities were assessed at peak and during recovery phase of dobutamine stress echocardiography in 187 consecutive patients, who were followed for occurrence of cardiac events.

RESULTS

During follow-up (mean 36+/-28 months), 19 patients (10%) died from cardiac causes, 34 (18%) patients suffered nonfatal myocardial infarction, and 77 (41%) patients underwent late revascularization. Univariable predictors of cardiac events by Cox regression analysis were age (hazard ratio: 1.01; confidence interval: 1.00-1.03), dyslipidemia (hazard ratio: 1.41; confidence interval: 1.02-1.95), rest wall motion abnormalities (hazard ratio: 1.37; confidence interval: 1.14-1.64), new wall motion abnormalities (hazard ratio: 1.18; confidence interval: 0.95-1.45) at peak and new wall motion abnormalities (hazard ratio: 1.33; confidence interval: 1.11-1.59) at recovery phase of dobutamine stress echocardiography. The best multivariable model to predict cardiac events included new wall motion abnormality (hazard ratio: 5.34; confidence interval: 1.71-16.59) at recovery phase of dobutamine stress echocardiography, after controlling for clinical and peak dobutamine stress echocardiography data.

CONCLUSIONS

Myocardial ischemia at recovery phase of dobutamine stress echocardiography is an independent predictor of cardiac events and has an incremental value when added to ischemia at peak.

Myocardial viability estimation during the recovery phase of stress echocardiography after acute beta-blocker administration

BACKGROUND

Myocardial viability assessment in severely dysfunctional segments by dobutamine stress echocardiography (DSE) is less sensitive than nuclear scanning.

AIM

To assess the additional value of using the recovery phase of DSE after acute beta-blocker administration for identifying viable myocardium.

METHODS

The study included 49 consecutive patients with ejection fraction (LVEF)<or=35%. All patients underwent DSE evaluation at low-high dose and during recovery phase, and dual-isotope single photon emission tomography (DISA-SPECT) evaluation for viability of severely dysfunctional segments. Patients with >or=4 viable segments were considered viable. Coronary revascularization followed within 3 months in all patients. Radionuclide evaluation of LVEF was performed before and 12 months after revascularization.

RESULTS

Viability with DISA-SPECT was detected in 463 (59%) segments, while 154 (19.7%) segments presented as scar. The number of viable segments increased from 415 (53%) at DSE to 463 (59%) at DSE and recovery, and the number of viable patients increased from 43 to 49 respectively. LVEF improved by >or=5% in 27 patients. Multivariate regression analysis showed that, DSE with recovery phase was the only independent predictor of >or=5% LVEF improvement after revascularization (OR 14.6, CI 1.4-133.7).

CONCLUSION

In this study, we demonstrate that the recovery phase of DSE has an increased sensitivity for viability estimation compared to low-high dose DSE.

Prognostic role of dobutamine stress echocardiography in myocardial viability

PURPOSE OF REVIEW

The aim of this review is to provide a perspective on the role of dobutamine stress echocardiography to evaluate myocardial viability and assess prognosis in patients with ischemic left ventricular dysfunction.

RECENT FINDINGS

Pooled analysis of currently available data demonstrates that dobutamine stress echocardiography provides useful information on recovery of dysfunctional but viable myocardium and prognosis. In fact, improvement of long-term prognosis may be the ultimate clinical challenge in the management of patients with ischemic left ventricular dysfunction. Dobutamine stress echocardiography can be used to assess residual ischemia and contractile reserve, which are significant determinants of prognosis. Additionally, other echocardiographic variables, such as end-diastolic wall thickness, end-systolic volume, and extent of viability, affect outcome after revascularization in patients with ischemic cardiomyopathy.

SUMMARY

Dobutamine stress echocardiography provides information on myocardial ischemia, contractile reserve, and other prognostically relevant parameters in patients with ischemic left ventricular dysfunction. This information can be used to select the optimal treatment strategy for these patients and to estimate and improve clinical outcome.

Diagnostic and imaging considerations: role of viability

Left ventricular systolic dysfunction is a recognised feature of heart failure. In developed nations, the leading cause of left ventricular systolic dysfunction is coronary artery disease. Revascularisation is a treatment strategy for patients with predominant symptoms of heart failure and significant left ventricular dysfunction. Presence or absence of myocardial viability has been shown to affect outcome after revascularisation. There are various techniques to assess myocardial viability. However, limitations of current literature, lack of completed randomised trials and high peri-procedural trials create significant uncertainty about the optimal strategy. This review focuses on the role of non-invasive testing for myocardial viability in patients with left ventricular systolic dysfunction and heart failure and also outlines the pros and cons of each technique.