Search

Aims Sympathetic denervation typically occurs in the infarcted myocardium and is associated with sudden cardiac death. Impaired innervation was also demonstrated in non-infarcted myocardium in ischaemic and dilated cardiomyopathy (ICMP and DCMP). Factors affecting sympathetic nerve integrity in remote myocardium are unknown. Perfusion abnormalities, even in the absence of epicardial coronary artery disease, may relate to sympathetic dysfunction. This study was aimed to assess the interrelations of myocardial blood flow (MBF), contractile function, and sympathetic innervation in non-infarcted remote myocardium. Methods and results Seventy patients with ICMP or DCMP and LVEF ≤35% were included. [15O]H2O- and [11C]hydroxyephedrine (HED) PET was performed to quantify resting MBF, hyperaemic MBF, and sympathetic innervation. Cardiovascular magnetic resonance (CM R) imaging was performed to assess left ventricular function, mass, wall thickening, and scar size. Wall thickening, [11C]HED retention index (RI),and MBF were assessed in remote segments without scar, selected on CMR. [11 C]HED RI was correlated with resting MBF (r = 0.41, P < 0.001) and hyperaemic MBF (r = 0.55, P < 0.001) in remote myocardium in both ICMP and DCMP. In addition, LV volumes (r = 20.40, P = 0.001), LV mass (r = 2 0.31, P = 0.008), and wall thickening (r = 0.45, P < 0.001) correlated with remote [11 C]H ED RI. Multivariable analysis revealed that hyperaemic MBF (B = 0.79, P < 0.001), wall thickening (B = 0.01, P = 0.03), and LVEDV (B = 20.03, P = 0.02) were independent predictors for remote [11C]HED RI. Conclusion Hyperaemic MBF is independently associated with sympathetic innervation in non-infarcted remote myocardium in patients with ICMP and DCMP. This suggests that microvascular dysfunction might be an important factor related to sympathetic nerve integrity. Whether impaired hyperaemic MBF is the primary cause of this relation remains unclear. [ABSTRACT FROM AUTHOR]

Aims There is growing evidence that coronary artery disease (CAD) affects not only the conduit epicardial coronary arteries, but also the microvascular coronary bed. Moreover, coronary microvascular dysfunction (CMVD) often precedes the stage of clinically overt epicardial CAD. Coronary artery calcium (CAC) and carotid intima-media thickness (C-IMT) measured with computed tomography (CT) and ultrasound, respectively, are among the available techniques to non-invasively assess atherosclerotic burden. An increased CAC score and C-IMT have also been associated with CMVD. It is therefore of interest to explore and compare the potential of CAC against C-IMT to predict minimal coronary vascular resistance (CVR). Methods and results We evaluated 120 patients (mean age 56 ± 9 years, 58 men) without a documented history of CAD in whom obstructive CAD was excluded. All patients underwent C-IMT measurements, CAC scoring, and vasodilator stress 15O-water positron emission tomography (PET)/CT, during which the coronary flow reserve (CFR) and minimal CVR were analysed. Minimal CVR increased significantly with increasing tertiles of C-IMT (22 ± 6, 27 ± 11, and 28 ± 9 mmHg mL−1min−1 g−1, P < 0.01), whereas the CFR was comparable across all C-IMT groups (P = 0.50). Minimal CVR increased significantly with an increase in CAC score (23 ± 9, 27 ± 8, 32 ± 10, and 32 ± 7 mmHg mL−1 min−1 g−1, P < 0.01), whereas the CFR did not show a significant decrease with higher CAC scores (P = 0.18). Multivariable regression analysis revealed that C-IMT (P = 0.03), but not CAC, was independently associated with minimal CVR. Conclusion C-IMT, but not CAC score, independently predicts minimal CVR in patients with multiple cardiovascular risk factors and suspected of CAD. [ABSTRACT FROM AUTHOR]

The introduction of the implantable cardioverter defibrillator (ICD) has had a major impact on survival and treatment of patients with ischaemic cardiomyopathy. However, only a third of patients receive appropriate ICD discharges during the first 3 years of follow-up, hence creating opportunities for improvement in patient care as well as for health care costs containment. Therefore, refinement of ICD implantation criteria is needed. Evaluation of pathophysiological substrates related to electrical instability with imaging modalities such as nuclear imaging, cardiac magnetic resonance imaging, and echocardiography might yield important prognostic information. This review discusses the currently available literature regarding the value of these imaging modalities for prediction of ventricular arrhythmias in patients with ischaemic cardiomyopathy. [ABSTRACT FROM PUBLISHER]