Background

Variability of parameter measurements in heart failure with reduced ejection fraction (HFrEF) may contribute to reducing the prediction accuracy of available prognostic models. We investigated whether the use of longitudinal versus cross-sectional measurements of established predictors of mortality in patients with HFrEF would increase the accuracy of prognostication.

Methods

We used longitudinal measurements of systolic blood pressure (SBP), heart rate, hemoglobin, creatinine and uric acid from HFrEF patients enrolled in the GISSI-HF trial. We performed linear mixed models to investigate the difference in first 6-month trajectories of these parameters between patients alive and dead at 4-year follow-up, and examined the change in prediction accuracy by comparing area under the curve (AUC) and net reclassification index (NRI) values obtained using a traditional cross-sectional survival model versus a longitudinal joint model using information up to 6-month follow-up.

Results

We included 5469 patients with 32,206 repeated visits and measurements. We demonstrated a significant difference in the first 6-month change of each one of the selected parameters between those alive and dead at the end of follow-up (p-value for time∗mortality interaction ≤0.01). The comparison of prediction accuracy of the two models revealed a significant increase of about 2% in the AUCs when using longitudinal values of each parameter of interest up to 6 months, with significant concomitant increase in NRI. The greatest increase in accuracy was noticed when using longitudinal SBP measurements in patients with baseline SBP ≤ 110 mmHg.

Conclusions

Our findings support the use of longitudinal data to improve prognostication in patients with HFrEF, and warrant validation in external cohorts and creation of new prognostic tools.

中文翻译：

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测试纵向数据以预测射血分数降低的动态性心力衰竭患者的预后。GISSI-HF数据库的原理证明。

背景

心力衰竭中射血分数（HFrEF）降低的参数测量结果的可变性可能有助于降低可用预后模型的预测准确性。我们调查了使用纵向或横断面测量的HFrEF患者死亡率的既定预测指标是否会提高预后的准确性。

方法

我们对参加GISSI-HF试验的HFrEF患者使用了收缩压（SBP），心率，血红蛋白，肌酐和尿酸的纵向测量值。我们进行了线性混合模型，以调查在4年随访中存活和死亡患者之间这些参数的前6个月轨迹的差异，并通过比较曲线下面积（AUC）和净重分类来检查预测准确性的变化使用传统的横断面生存模型与纵向关节模型（使用长达6个月的随访信息）获得的NRI指数（NRI）值。

结果

我们纳入了5469名患者，进行了3​​2,206次重复访问和测量。在随访结束时，我们证明了每个所选参数在生死之间的前6个月变化之间存在显着差异（时间*死亡交互作用的p值≤0.01）。两种模型的预测准确性的比较显示，使用长达6个月的每个关注参数的纵向值时，AUC显着增加了2％，同时NRI也显着增加。在基线SBP≤110 mmHg的患者中使用纵向SBP测量时，可以看到准确性的最大提高。

结论

我们的研究结果支持使用纵向数据来改善HFrEF患者的预后，并需要在外部队列中进行验证并创建新的预后工具。