Riedlbauchová Lucie, Brunken Richard, Jaber Wael A, Popová Lucie, Patel Dimpi, Lánská Vera, Civello Kenneth, Cummings Jennifer, Burkhardt J David, Saliba Walid, Martin David, Schweikert Robert, Wilkoff Bruce L, Grimm Richard, Natale Andrea
Department of Cardiovascular Medicine, Cleveland Clinic, Cleveland, Ohio, USA.
J Cardiovasc Electrophysiol. 2009 Jan;20(1):50-7. doi: 10.1111/j.1540-8167.2008.01294.x. Epub 2008 Sep 17.
Around 30% of patients do not respond to cardiac resynchronization therapy (CRT). Nonischemic cardiomyopathy has been identified as an independent predictor of response to CRT, probably due to the absence of compact scar.
The relationship between cardiac scar, ischemia, and hibernation (both at the left-ventricular pacing site and as a total burden) and response to CRT was studied in patients with ischemic cardiomyopathy using the perfusion-viability positron emission tomography (PET) test. Sixty-six patients with ischemic cardiomyopathy and traditional criteria for CRT were included. All patients underwent PET scan prior to CRT. Using PET, the amount and location of scarred, ischemic, and hibernating myocardium were characterized. No revascularization was indicated. Responders were defined by an improvement of left-ventricular ejection fraction (LVEF) >or= 5% and/or New York Heart Association (NYHA) class >or= 1 degree. During a mean follow-up of 26.2 +/- 22.2 months, there was a significant improvement in NYHA class and reverse remodeling in patients with the LV lead inserted remotely from the scar. However, reverse remodeling of a similar degree was present also in patients with extensive scarring including the lateral wall. The presence of ischemia, hibernation, or nontransmural scar at the pacing-site did not significantly modify the outcome of CRT as compared with viable myocardium. There were only 38% of CRT-nonresponders. Neither the extent of scar, ischemia, hibernation, or viability predicted outcome or mortality. Twenty patients died during the follow-up, one patient underwent heart transplant.
At follow-up, response to CRT is observed regardless of the presence of extensive scarring. Left ventricular (LV) pacing at sites with ischemia, hibernation, or nontransmural scar does not appear to modify the effect of CRT as compared to viable tissue.
约30%的患者对心脏再同步治疗（CRT）无反应。非缺血性心肌病已被确定为CRT反应的独立预测因素，可能是由于不存在致密瘢痕。
使用灌注-存活正电子发射断层扫描（PET）试验，研究了缺血性心肌病患者心脏瘢痕、缺血和冬眠（在左心室起搏部位以及作为总体负担）与CRT反应之间的关系。纳入了66例符合CRT传统标准的缺血性心肌病患者。所有患者在CRT前均接受PET扫描。使用PET对瘢痕、缺血和冬眠心肌的数量和位置进行了表征。未进行血运重建。反应者定义为左心室射血分数（LVEF）提高≥5%和/或纽约心脏协会（NYHA）心功能分级改善≥1级。在平均26.2±22.2个月的随访期间，左心室导线远离瘢痕植入的患者NYHA心功能分级有显著改善且出现逆向重构。然而，包括侧壁在内有广泛瘢痕的患者也出现了类似程度的逆向重构。与存活心肌相比，起搏部位存在缺血、冬眠或非透壁瘢痕并未显著改变CRT的结果。CRT无反应者仅占38%。瘢痕、缺血、冬眠或存活的程度均不能预测结果或死亡率。随访期间有20例患者死亡，1例患者接受了心脏移植。
随访时，无论是否存在广泛瘢痕，均可观察到对CRT的反应。与存活组织相比，在存在缺血、冬眠或非透壁瘢痕的部位进行左心室起搏似乎不会改变CRT的效果。
