Prognosis of patients with ischaemic cardiomyopathy after coronary revascularisation: relation to viability and improvement in left ventricular ejection fraction

Radionuclide imaging in stage B heart failure

This article discusses currently available radionuclide techniques in the diagnostic and prognostic evaluation of patients with chronic heart failure, with a focus on stage B/asymptomatic left ventricular dysfunction. Radionuclide imaging is promising for such patients because it can simultaneously determine left ventricular function, evaluate for the presence of obstructive coronary disease, determine the extent of viable myocardium, and evaluate dyssynchronous left ventricular contraction. Radionuclide imaging can thus provide important noninvasive insights into the pathophysiology, prognosis, and management of patients with asymptomatic left ventricular dysfunction as well as more advanced heat failure.

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.

Use of coronary anatomy and late enhancement information both derived from contrast-enhanced whole-heart coronary MRA at 3 T for the assessment of ischemic left ventricular dysfunction

Recognizing the etiology of patients with left ventricular dysfunction (LVD) is essential for the risk stratification and treatment selection. We report the case of a 59-year-old man suspected of ischemic LVD with non acute symptoms studied with whole-heart cardiac magnetic resonance imaging including noninvasive coronary angiography and in whom we obtained comprehensive information of both coronary artery stenosis and myocardial tissue damage.

Clinical relevance of hibernating myocardium in ischemic left ventricular dysfunction

Patients with chronic ischemic left ventricular dysfunction may have a substantial amount of viable, hibernating myocardium, which is a state of chronic contractile dysfunction with reduced blood flow at rest. Coronary revascularization in these patients may result in improvement of left ventricular function; in the absence of viability, left ventricular function will not improve postrevascularization. Various noninvasive imaging techniques are available for detection of viable myocardium, including magnetic resonance imaging, dobutamine stress echocardiography, and nuclear imaging with single photon emission computed tomography or positron emission tomography. Because these techniques probe different characteristics of viable myocardium, the sensitivities and specificities of the techniques are not precisely identical; in general, dobutamine stress echocardiography has the highest specificity, whereas the nuclear techniques have the highest sensitivity. The presence of myocardial viability also is related to prognosis: patients with viable myocardium who undergo revascularization have a good prognosis, whereas patients with viable myocardium who are treated medically have poor outcome. Accordingly, assessment of viability is important in the therapeutic decision-making process of patients with chronic ischemic left ventricular dysfunction.