Duke Cardiovascular Magnetic Resonance Center, Duke University Medical Center, Durham, NC 27710, USA.
J Am Coll Cardiol. 2012 Jul 31;60(5):408-20. doi: 10.1016/j.jacc.2012.02.070.
We tested whether an assessment of myocardial scarring by cardiac magnetic resonance imaging (MRI) would improve risk stratification in patients evaluated for implantable cardioverter-defibrillator (ICD) implantation.
Current sudden cardiac death risk stratification emphasizes left ventricular ejection fraction (LVEF); however, most patients suffering sudden cardiac death have a preserved LVEF, and many with poor LVEF do not benefit from ICD prophylaxis.
One hundred thirty-seven patients undergoing evaluation for possible ICD placement were prospectively enrolled and underwent cardiac MRI assessment of LVEF and scar. The pre-specified primary endpoint was death or appropriate ICD discharge for sustained ventricular tachyarrhythmia.
During a median follow-up of 24 months the primary endpoint occurred in 39 patients. Whereas the rate of adverse events steadily increased with decreasing LVEF, a sharp step-up was observed for scar size >5% of left ventricular mass (hazard ratio [HR]: 5.2; 95% confidence interval [CI]: 2.0 to 13.3). On multivariable Cox proportional hazards analysis, including LVEF and electrophysiological-study results, scar size (as a continuous variable or dichotomized at 5%) was an independent predictor of adverse outcome. Among patients with LVEF >30%, those with significant scarring (>5%) had higher risk than those with minimal or no (≤5%) scarring (HR: 6.3; 95% CI: 1.4 to 28.0). Those with LVEF >30% and significant scarring had risk similar to patients with LVEF ≤30% (p = 0.56). Among patients with LVEF ≤30%, those with significant scarring again had higher risk than those with minimal or no scarring (HR: 3.9; 95% CI: 1.2 to 13.1). Those with LVEF ≤30% and minimal scarring had risk similar to patients with LVEF >30% (p = 0.71).
Myocardial scarring detected by cardiac MRI is an independent predictor of adverse outcome in patients being considered for ICD placement. In patients with LVEF >30%, significant scarring (>5% LV) identifies a high-risk cohort similar in risk to those with LVEF ≤30%. Conversely, in patients with LVEF ≤30%, minimal or no scarring identifies a low-risk cohort similar to those with LVEF >30%.
我们通过心脏磁共振成像（CMR）评估心肌瘢痕来检验其是否能改善植入式心脏复律除颤器（ICD）植入患者的风险分层。
目前，猝死风险分层强调左心室射血分数（LVEF）；然而，大多数发生猝死的患者 LVEF 正常，而许多 LVEF 较差的患者不能从 ICD 预防中获益。
前瞻性纳入 137 名接受 ICD 植入评估的患者，行 LVEF 和瘢痕的 CMR 评估。主要终点是死亡或因持续性室性心动过速/心室颤动而进行适当的 ICD 放电。
中位随访 24 个月期间，39 例患者发生主要终点事件。虽然随着 LVEF 的降低，不良事件的发生率稳步增加，但瘢痕大小＞5%左心室质量（LV）时呈明显跳跃式上升（风险比[HR]：5.2；95%置信区间[CI]：2.0 至 13.3）。多变量 Cox 比例风险分析包括 LVEF 和电生理研究结果，瘢痕大小（作为连续变量或二分变量，即＞5%）是不良结局的独立预测因子。在 LVEF＞30%的患者中，瘢痕＞5%的患者比瘢痕最小或无（≤5%）的患者风险更高（HR：6.3；95%CI：1.4 至 28.0）。LVEF＞30%且有明显瘢痕的患者风险与 LVEF≤30%的患者相似（p=0.56）。在 LVEF≤30%的患者中，瘢痕较大的患者风险高于瘢痕较小或无的患者（HR：3.9；95%CI：1.2 至 13.1）。LVEF≤30%且瘢痕较小的患者风险与 LVEF＞30%的患者相似（p=0.71）。
心脏 MRI 检测到的心肌瘢痕是 ICD 植入患者不良结局的独立预测因子。在 LVEF＞30%的患者中，瘢痕＞5%LV 可识别出与 LVEF≤30%患者风险相似的高危患者。相反，在 LVEF≤30%的患者中，瘢痕最小或无瘢痕可识别出与 LVEF＞30%患者风险相似的低危患者。
