Abstract 16519: Impaired Cardiac Sympathetic Innervation is Associated With Microvascular Dysfunction in Non-Infarcted Remote Myocardium in Ischemic- and Dilated Cardiomyopathy
Background: Sympathetic denervation resulting from myocardial infarction is associated with sudden cardiac death. In addition, impaired sympathetic innervation in non-infarcted remote myocardium in ischemic and dilated cardiomyopathy (ICMP and DCMP) has been observed. Little is known about factors affecting sympathetic innervation in remote myocardium. The aim of this study was to assess the relation of positron emission tomography (PET) quantified sympathetic innervation and hyperemic myocardial blood flow (MBF) in non-infarcted remote myocardium in ICMP and DCMP patients.
Hypothesis: As sympathetic nerves are highly susceptible to ischemia, we hypothesized that subtle perfusion abnormalities due to microvascular dysfunction may be related with sympathetic nerve integrity in non-infarcted myocardium.
Methods: Seventy patients with ICMP or DCMP and left ventricular ejection fraction (LVEF) ≤35% were included (57 men, age 66 ± 9 years, LVEF 28 ± 7%, 52 ICMP). [15O]H2O- and [11C]Hydroxyephedrine (HED) - PET was performed to assess resting MBF, hyperemic MBF, and sympathetic innervation. Late gadolinium enhanced-cardiac magnetic resonance (LGE-CMR) imaging was performed to assess left ventricular end-systolic volume (LVESV), end-diastolic volume (LVEDV), and scar size. HED retention index (RI) and MBF were quantified in remote segments without scar, selected on LGE-CMR results.
Results: [11C]HED RI was significantly correlated with resting MBF (r=0.41, p<0.001) and hyperemic MBF (r=0.55, p<0.001) in remote myocardium in both ICMP and DCMP. LVEDV (r=-0.40, p<0.001), LVESV (r=-0.40, p<0.001), and LV mass (r=-0.32, p<0.01) correlated negatively with [11C]HED RI. Multivariable linear regression analysis revealed that hyperemic MBF (B=0.87, p<0.001) and LVEDV (B=-0.04, p=0.001) were independent predictors for [11C]HED RI in remote myocardium (R2=0.41).
Conclusion: Hyperemic MBF is independently associated with sympathetic innervation in non-infarcted remote myocardium in patients with both ICMP and DCMP. This suggests that microvascular dysfunction might be an important factor related to sympathetic nerve integrity. Whether impaired hyperemic MBF is the primary cause of this relation remains unclear.
Author Disclosures: M.T. Rijnierse: None. S. de Haan: None. H.J. Harms: None. M. Huisman: None. L. Wu: None. A.M. Beek: None. A.C. van Rossum: None. A.A. Lammertsma: None. C.P. Allaart: None. P. Knaapen: None.
- © 2014 by American Heart Association, Inc.