Capitanio Selene, Nanni Cristina, Marini Cecilia, Bonfiglioli Rachele, Martignani Cristian, Dib Bassam, Fuccio Chiara, Boriani Giuseppe, Picori Lorena, Boschi Stefano, Morbelli Silvia, Fanti Stefano, Sambuceti Gianmario
Nuclear Medicine, IRCCS AOU San Martino-IST, Department of Health Sciences, University of Genoa, Genoa, Italy.
Nuclear Medicine, Hematology-Oncology and Laboratory Medicine Department, Azienda Ospedaliero-Universitaria di Bologna Policlinico Sant' Orsola-Malpighi, University of Bologna, Italy.
Nucl Med Biol. 2015 Nov;42(11):858-63. doi: 10.1016/j.nucmedbio.2015.07.002. Epub 2015 Jul 8.
Cardiac resynchronization therapy (CRT) is an accepted treatment in patients with end-stage heart failure. PET permits the absolute quantification of global and regional homogeneity in cardiac sympathetic innervation. We evaluated the variation of cardiac adrenergic activity in patients with idiopathic heart failure (IHF) disease (NYHA III-IV) after CRT using (11)C-hydroxyephedrine (HED) PET/CT.
Ten IHF patients (mean age = 68; range = 55-81; average left ventricular ejection fraction 26 ± 4%) implanted with a resynchronization device underwent three HED PET/CT studies: PET 1 one week after inactive device implantation; PET 2, one week after PET 1 under stimulated rhythm; PET 3, at 3 months under active CRT. A dedicated software (PMOD 3.4 version) was used to estimate global and regional cardiac uptake of HED through 17 segment polar maps.
At baseline, HED uptake was heterogeneously distributed throughout the left ventricle with a variation coefficient of 18 ± 5%. This variable markedly decreased after three months CRT (12 ± 5%, p < 0.01). Interestingly, subdividing the 170 myocardial segments (17 segments of each patient multiplied by the number of patients) into two groups, according to the median value of tracer uptake expressed as % of maximal myocardial uptake (76%), we observed a different behaviour depending on baseline innervation: HED uptake significantly increased only in segments with "impaired innervation" (SUV 2.61 ± 0.92 at PET1 and 3.05 ± 1.67 at three months, p < 0.01).
As shown by HED PET/CT uptake and distribution, improvement in homogeneity of myocardial neuronal function reflected a selective improvement of tracer uptake in regions with more severe neuronal damage.
These finding supported the presence of a myocardial regional variability in response of cardiac sympathetic system to CRT and a systemic response involving remote tissues with rich adrenergic innervation.
This work might contribute to identify imaging parameters that could predict the response to CRT therapy.
心脏再同步治疗（CRT）是终末期心力衰竭患者公认的治疗方法。正电子发射断层扫描（PET）可对心脏交感神经支配的整体和区域均匀性进行绝对定量。我们使用（11）C-羟基麻黄碱（HED）PET/CT评估了特发性心力衰竭（IHF）疾病（纽约心脏协会III-IV级）患者在CRT治疗后心脏肾上腺素能活性的变化。
10例植入再同步装置的IHF患者（平均年龄=68岁；范围=55-81岁；平均左心室射血分数26±4%）接受了三次HED PET/CT检查：PET 1在植入非激活装置一周后进行；PET 2在PET 1后一周，处于刺激节律下进行；PET 3在积极CRT治疗3个月时进行。使用专用软件（PMOD 3.4版本）通过17节段极坐标图估计HED在心脏的整体和区域摄取情况。
基线时，HED摄取在整个左心室呈不均匀分布，变异系数为18±5%。CRT治疗三个月后，该变量显著降低（12±5%，p<0.01）。有趣的是，将170个心肌节段（每位患者17个节段乘以患者数量）根据示踪剂摄取中位数（表示为最大心肌摄取的百分比，76%）分为两组，我们观察到根据基线神经支配情况有不同的表现：仅在“神经支配受损”节段中HED摄取显著增加（PET1时标准化摄取值为2.61±0.92，三个月时为3.05±1.67，p<0.01）。
如HED PET/CT摄取和分布所示，心肌神经元功能均匀性的改善反映了在神经元损伤更严重区域示踪剂摄取的选择性改善。
这些发现支持心脏交感神经系统对CRT反应中存在心肌区域变异性以及涉及富含肾上腺素能神经支配的远程组织的全身反应。
这项工作可能有助于确定可预测对CRT治疗反应的成像参数。
