R. M. De Jong

Reduced regional myocardial perfusion reserve is associated with impaired contractile performance in idiopathic dilated cardiomyopathy

Background. In idiopathic dilated cardiomyopathy (IDC) an imbalance between myocardial oxygen consumption and supply has been postulated. Subclinical myocardial ischaemia may contribute to progressive deterioration of left ventricular function. The relation between regional myocardial perfusion reserve (MPR) and contractile performance was investigated.Methods. Patients with newly diagnosed IDC underwent positron emission tomography (PET) scanning using both 13N-ammonia as a perfusion tracer (baseline and dypiridamole stress), and 18F-fluorodeoxyglucose viability tracer and a dobutamine stress MRI. MPR (assessed by PET) as well as wall motion score (WMS, assessed by MRI) were evaluated in a 17-segment model.Results. Twenty-two patients were included (age 49±11 years; 15 males, LVEF 33±10%). With MRI, a total of 305 segments could be analysed. Wall motion abnormalities at rest were present in 127 (35.5%) segments and in 103 (29.9%) during dobutamine stress. Twenty-one segments deteriorated during stress and 43 improved. MPR was significantly higher in those segments that improved, compared with those that did not change or were impaired during stress (1.87±0.04 vs. 1.56± 0.07 p<0.01.)Conclusion. Signs of regional ischaemia were clearly present in IDC patients. Ischaemic regions displayed impaired contractility during stress. This suggests that impaired oxygen supply contributes to cardiac dysfunction in IDC. (Neth Heart J 2009;17:470–4.)

Measurement of myocardial β-adrenoceptor density in clinical studies: a role for positron emission tomography?

Abstract. The β-adrenoceptor (β-AR) plays an important role in the regulation of heart function and has been extensively studied in recent decades. In vitro studies have shown down-regulation of β-AR density in heart failure and cardiac conditions that may lead to heart failure. As in vitro measurements on cardiac tissue samples do not allow longitudinal and regional assessment of myocardial β-ARs in humans, new methods are being developed to measure β-ARs in vivo using positron emission tomography (PET). Studies using PET and the radioligand [11C]CGP 12177 have shown promising results that are in agreement with those of in vitro studies. However, the radiochemical synthesis of [11C]CGP 12177 is very demanding, preventing its widespread use. Hence, new radioligands are being developed using simpler methods of radiochemical synthesis. (S)-[11C]CGP 12388 has been presented as a promising new radioligand. So far, in vivo measurements of β-AR density using PET have mainly been performed to confirm in vitro studies. Using the full potential of PET, performance of regional measurements and longitudinal studies might add further knowledge on the pathophysiological role of the β-AR in cardiac disease and the effect of interventions. Furthermore, PET might gain a role in the clinical management of patients with abnormalities of cardiac contractile function.

Abnormal contractile responses during dobutamine stress echocardiography in patients with idiopathic dilated cardiomyopathy.

In chronic heart failure augmented wall stress leads to increased energy demand. Supply, however, may be reduced due to coronary vasoconstriction and endothelial dysfunction. This might lead to a mismatch between demand and supply. In the present study we further explored the effect of increased demand during dobutamine stress echocardiography.BACKGROUND In chronic heart failure augmented wall stress leads to increased energy demand. Supply, however, may be reduced due to coronary vasoconstriction and endothelial dysfunction. This might lead to a mismatch between demand and supply. In the present study we further explored the effect of increased demand during dobutamine stress echocardiography. METHODS AND RESULTS Sixteen patients with idiopathic dilated cardiomyopathy (mean age 44+/-13 years, New York Heart Association class II-III, mean left ventricular ejection fraction 0.27+/-0.10) underwent dobutamine stress echocardiography (5-40 microg/min per kg bodyweight+atropine if required). Wall motion and thickening was assessed in 16 segments using a four-point scale. Eleven patients (69%) showed regions with worsening of wall motion or a biphasic response during dobutamine infusion. Of the remaining five patients one patient did not show any wall motion changes and one patient showed a partial improvement while only in three patients wall motion improvement in the whole heart was found. CONCLUSION A majority of patients with idiopathic dilated cardiomyopathy showed decreased wall motion during increased demand, i.e. ischemia-like myocardial contractile responses during dobutamine stress echocardiography. These findings further support the concept that an energy mismatch between demand and supply might play a pathophysiological role in idiopathic dilated cardiomyopathy.

Health-related quality of life and anemia in hospitalized patients with heart failure

BACKGROUND Anemia is a serious and highly prevalent co-morbidity in chronic heart failure (HF) patients. Its influence on health-related quality of life (HR-QoL) has rarely been studied, and no data is available regarding the role it plays in hospitalized HF patients. METHODS Baseline data from the COACH study (Coordinating study evaluating Outcomes of Advising and Counselling in Heart Failure) were used. HR-QoL was assessed by means of generic and disease-specific questionnaires. Analyses were performed using ANOVA and ANCOVA, with covariates of age, gender, eGFR, diabetes, and NYHA class. RESULTS In total, 1013 hospitalized patients with a mean age of 71 (SD 11) years were included; 70% of these patients had no anemia (n=712), 14% had mild anemia (n=141), and 16% had moderate-to-severe anemia (n=160). Independent associations were found between anemia and physical functioning (p=0.019), anemia and role limitations due to physical functioning (p=0.002), anemia and general health (p=0.024), and anemia and global well-being (p=0.003). CONCLUSION In addition to the burden of HF itself, anemia is an important factor which influences HR-QoL in hospitalized HF patients, and one that is most pronounced in the domain related to physical functioning and general health.