Background

Heart rate score (HRSc), the percentage of atrial sensed and paced beats in the largest 10 beat/min bin of a device histogram and mean intrinsic heart rate (MIHR), predicted survival in nonrandomized studies of implantable defibrillator (ICD) patients. We evaluated whether HRSc and MIHR independently predicted mortality and heart failure (HF) hospitalization in the prospective, randomized, controlled INTRINSIC RV trial.

Methods and results

The INTRINSIC RV trial enrolled 1530 patients receiving dual-chamber ICDs. This analysis involves patients (n = 1471) for whom MIHR and HRSc data were available. Mean follow-up was 10.4 months. The relationship between pre-randomization MIHR and HRSc on the primary endpoint of all-cause mortality and HF hospitalization was assessed using multivariate regression and Cox modeling. As categorical variables, MIHR > 70 bpm and HRSc > 70% were considered high.

Results

The median baseline MIHR and HRSc were 74 (IQR = 16) and 50% (IQR = 20) respectively. As a continuous variable, for every 1% increase in HRSc, death/HF hospitalization increased by 1% (95%CI: 1.002–1.017; p = 0.01). Regression analysis showed baseline MIHR was associated with HRSc (p = 0.01); for every 1 beat/min increase in MIHR, HRSc increased by 1.8%. A MIHR > 70 bpm and HRSc ≥ 70% predicted, but were independently associated with, the primary endpoint (HR: 1.39; 95%CI: 1.10–1.76, p = 0.005 for MIHR and HR: 1.654; 95%CI: 1.11–2.46, p = 0.01 for HRSc). Male gender (HR: 0.75), history of HF (HR: 1.29), and atrial fibrillation (HR: 1.37) also predicted death/hospitalization in the Cox model.

Conclusions

In this large, prospectively studied ICD population, HRSc was a robust and independent predictor of death/HF hospitalization. High MIHR and high HRSc were associated but each predicted outcomes independently.

中文翻译：

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ICD 患者的心率评分和结果：来自前瞻性随机 INTRINSIC RV 试验的见解

背景

心率评分 (HRSc)、设备直方图最大 10 次/分钟区间中心房感测和起搏的百分比和平均内在心率 (MIHR)，可预测植入式除颤器 (ICD) 患者的非随机研究的生存率。我们在前瞻性、随机、对照的 INTRINSIC RV 试验中评估了 HRSc 和 MIHR 是否独立预测死亡率和心力衰竭 (HF) 住院。

方法和结果

INTRINSIC RV 试验招募了 1530 名接受双腔 ICD 的患者。该分析涉及 可获得 MIHR 和 HRSc 数据的患者 ( n = 1471)。平均随访时间为 10.4 个月。使用多变量回归和 Cox 模型评估随机化前 MIHR 和 HRSc 在全因死亡率和 HF 住院的主要终点之间的关系。作为分类变量，MIHR > 70 bpm 和 HRSc > 70% 被认为是高的。

结果

中位基线 MIHR 和 HRSc 分别为 74 (IQR = 16) 和 50% (IQR = 20)。作为连续变量，HRSc 每增加 1%，死亡/心衰住院率增加 1%（95%CI：1.002–1.017；p  = 0.01）。回归分析显示基线 MIHR 与 HRSc 相关（p  = 0.01）；MIHR 每增加 1 次/分钟，HRSc 增加 1.8%。MIHR > 70 bpm 和 HRSc ≥ 70% 预测，但与主要终点独立相关（HR：1.39；95%CI：1.10–1.76， MIHR 和 HR：1.654；95%CI：1.11– 的p = 0.005 2.46， 对于 HRSc ，p = 0.01）。在 Cox 模型中，男性（HR：0.75）、HF 病史（HR：1.29）和心房颤动（HR：1.37）也预测了死亡/住院。

结论

在这一大型、前瞻性研究的 ICD 人群中，HRSc 是死亡/心衰住院的可靠且独立的预测因素。高 MIHR 和高 HRSc 相关，但各自独立预测结果。