Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota 55905, USA.
J Nucl Med. 2012 Jan;53(1):47-54. doi: 10.2967/jnumed.111.095448. Epub 2011 Dec 12.
Refining the criteria for patient selection for cardiac resynchronization therapy (CRT) may improve its outcomes. The study objective was to determine the effect of scar location, scar burden, and left ventricular (LV) lead position on CRT outcomes.
The study included 213 consecutive CRT recipients with radionuclide myocardial perfusion imaging before CRT between January 2002 and December 2008. Scar localization and myocardial viability were analyzed using a 17-segment model and a 5-point semiquantitative scale. New York Heart Association (NYHA) class and echocardiography were assessed before and after CRT. The anatomic LV lead location in the 17-segment model was assessed by review of fluoroscopic cinegrams in right and left anterior oblique views. As in published studies, clinical response was defined as an absolute improvement in LV ejection fraction of ≥5 percentage points after CRT.
A total of 651 scar segments was identified in 213 patients. Eighty-three percent of scar segments were located in the LV anterior, posterior, septal, and apical regions, whereas 84% of LV leads were in the lateral wall. Only 11% of LV leads were positioned in scar segments. The extent of scarring was significantly higher in nonresponders than in responders (18.0% vs. 6%, P = 0.001). Compared with patients with scarring >22%, patients ≤70 y with scarring ≤22% of the left ventricle had a greater increase in LV ejection fraction (10.1% ± 10.5% vs. 0.8% ± 6.1%; P < 0.001) and improvement in NYHA class (-0.9 ± 0.7 vs. -0.5 ± 0.8; P = 0.02).
LV leads were often located in viable myocardial regions. Less scar burden was associated with a greater improvement in heart failure but only in relatively younger CRT recipients.
确定瘢痕位置、瘢痕负荷和左心室（LV）导线位置对心脏再同步治疗（CRT）结果的影响。
本研究纳入了 2002 年 1 月至 2008 年 12 月期间 213 例 CRT 前接受放射性核素心肌灌注成像的连续 CRT 受者。采用 17 节段模型和 5 分半定量评分分析瘢痕定位和心肌活力。在 CRT 前后评估纽约心脏协会（NYHA）心功能分级和超声心动图。通过回顾右前斜位和左前斜位的透视电影片评估 17 节段模型中 LV 导线的解剖位置。与已发表的研究一样，临床反应定义为 CRT 后 LV 射血分数绝对值增加≥5%。
共识别出 213 例患者的 651 个瘢痕节段。83%的瘢痕节段位于 LV 前壁、后壁、间隔和心尖区，而 84%的 LV 导线位于侧壁。只有 11%的 LV 导线位于瘢痕节段。无反应者的瘢痕程度明显高于有反应者（18.0%比 6%，P=0.001）。与瘢痕>22%的患者相比，≤70 岁且瘢痕≤22%的患者的 LV 射血分数增加更大（10.1%±10.5%比 0.8%±6.1%；P<0.001），NYHA 心功能分级改善更大（-0.9±0.7比-0.5±0.8；P=0.02）。
LV 导线通常位于存活心肌区域。瘢痕负荷较小与心力衰竭改善更大相关，但仅见于相对较年轻的 CRT 受者。
