Abstract：
BACKGROUND: Cardiac resynchronization therapy (CRT) is effective for patients with heart failure with QRS duration (QRSd) ≥150 ms. However, its beneficial effect seems to be limited for those with \"mid-range\" QRSd (120-149 ms). Recent studies have demonstrated that modifying QRSd to left ventricular end-diastolic volume (LVEDV)-modified QRSd-improves the prediction of clinical outcomes of CRT.
OBJECTIVE: The purpose of this study was to investigate the clinical impact of the modified QRSd on the efficacy of CRT in patients with \"mid-range\" QRSd.
METHODS: We conducted a retrospective, multicenter, observational study, with heart failure hospitalization (HFH) after CRT as the primary endpoint. Modified QRSd is defined as QRSd divided by LVEDV, determined through the Teichholtz method of echocardiography.
RESULTS: Among the 506 consecutive patients considered, 119 (mean age 61 ± 15 years; 80% male, QRSd 135 ± 9 ms) with a \"mid-range\" QRSd who underwent de novo CRT device implantation were included for analysis. During median follow-up of 878 days [interquartile range 381-1663 days], HFH occurred in 45 patients (37%). Fine-Gray analysis revealed modified QRSd was an independent predictor of HFH (hazard ratio [HR] 0.97; 95% confidence interval [CI] 0.96-0.99; P <.01). Receiver operating characteristic curve analysis revealed a cutoff value of 0.65 ms/mL for the modified QRSd in predicting HFH. Patients above the threshold exhibited a significantly lower incidence of HFH than patients below the threshold (HR 0.46; 95% CI 0.25-0.86; P = .01).
CONCLUSIONS: Modified QRSd can effectively predict the efficacy of CRT in patients with a \"mid-range\" QRSd.
OBJECTIVE: The purpose of this study was to investigate the clinical impact of the modified QRSd on the efficacy of CRT in patients with \"mid-range\" QRSd.
METHODS: We conducted a retrospective, multicenter, observational study, with heart failure hospitalization (HFH) after CRT as the primary endpoint. Modified QRSd is defined as QRSd divided by LVEDV, determined through the Teichholtz method of echocardiography.
RESULTS: Among the 506 consecutive patients considered, 119 (mean age 61 ± 15 years; 80% male, QRSd 135 ± 9 ms) with a \"mid-range\" QRSd who underwent de novo CRT device implantation were included for analysis. During median follow-up of 878 days [interquartile range 381-1663 days], HFH occurred in 45 patients (37%). Fine-Gray analysis revealed modified QRSd was an independent predictor of HFH (hazard ratio [HR] 0.97; 95% confidence interval [CI] 0.96-0.99; P <.01). Receiver operating characteristic curve analysis revealed a cutoff value of 0.65 ms/mL for the modified QRSd in predicting HFH. Patients above the threshold exhibited a significantly lower incidence of HFH than patients below the threshold (HR 0.46; 95% CI 0.25-0.86; P = .01).
CONCLUSIONS: Modified QRSd can effectively predict the efficacy of CRT in patients with a \"mid-range\" QRSd.
摘要：
背景：心脏再同步治疗（CRT）对QRS持续时间（QRSd）>150毫秒（ms）的心力衰竭患者有效。然而,它的有益效果似乎是有限的那些“中档”QRSd（120-149ms）。最近的研究表明，将QRSd修改为左心室舒张末期容积（LVEDV），修改后的QRSd，提高了对CRT临床结局的预测。
目的：研究改良QRSd对“中程”QRSd患者CRT疗效的临床影响。
方法：我们进行了回顾性研究，多中心,观察性研究，以CRT后心力衰竭住院（HFH）为主要终点。修改后的QRSd定义为QRSd除以LVEDV，通过Teichholtz超声心动图方法测定。
结果：在考虑的506名连续患者中，119例患者（平均年龄：61±15岁，80%男性,QRSd：135±9ms）和“中档”QRSd，接受了从头CRT装置植入，用于分析。在878天的中位随访期间（四分位距：381-1663天），45例（37%）患者发生HFH。Fine-Gray分析显示改良QRSd是HFH的独立预测因子(风险比[HR]:0.97,95%置信区间[CI]:0.96-0.99,p<0.01)。接收器工作特征曲线分析显示，改良QRSd预测HFH的截止值为0.65ms/mL。与以下患者相比，上述患者的HFH发生率显着降低（HR：0.46，95％CI：0.25-0.86，p=0.01）。
结论：改良QRSd可有效预测“中程”QRSd患者的CRT疗效。
目的：研究改良QRSd对“中程”QRSd患者CRT疗效的临床影响。
方法：我们进行了回顾性研究，多中心,观察性研究，以CRT后心力衰竭住院（HFH）为主要终点。修改后的QRSd定义为QRSd除以LVEDV，通过Teichholtz超声心动图方法测定。
结果：在考虑的506名连续患者中，119例患者（平均年龄：61±15岁，80%男性,QRSd：135±9ms）和“中档”QRSd，接受了从头CRT装置植入，用于分析。在878天的中位随访期间（四分位距：381-1663天），45例（37%）患者发生HFH。Fine-Gray分析显示改良QRSd是HFH的独立预测因子(风险比[HR]:0.97,95%置信区间[CI]:0.96-0.99,p<0.01)。接收器工作特征曲线分析显示，改良QRSd预测HFH的截止值为0.65ms/mL。与以下患者相比，上述患者的HFH发生率显着降低（HR：0.46，95％CI：0.25-0.86，p=0.01）。
结论：改良QRSd可有效预测“中程”QRSd患者的CRT疗效。
