Hammersmith Hospital, Imperial College Healthcare NHS Trust, Du Cane Road, London W12 0HS, UK.
Rheumatology (Oxford). 2014 Jan;53(1):131-7. doi: 10.1093/rheumatology/ket338. Epub 2013 Oct 3.
RA associates with an increased rate of sudden cardiac death (SCD). A prolonged QTc interval has been associated with arrhythmogenic and SCD in patients with long QT syndrome. Despite the previously reported contemporary association of CRP with SCD, thus far no studies have examined the association of QTc with mortality in RA, a condition characterized by high inflammatory burden. The aim of this study was to examine the role of electrocardiography (QT corrected interval) in predicting all-cause mortality in patients with RA who have an increased rate of SCD and a high inflammatory burden.
Three hundred and fifty-seven RA patients with detailed baseline clinical characterization and 12-lead ECGs were followed up for a mean of 73.0 (S.D. 18.3) months. Linear and Cox regression analyses were used to identify variables that associate with QTc and examine its association with all-cause mortality.
The patients' mean age was 60.6 (S.D. 12.0) years, 267 (74.8%) were females and 54 (15.1%) died during the follow-up period. Age (β = 0.231, P < 0.001), gender (β = 0.137, P = 0.008) and CRP (β = 0.144, P = 0.006) associated independently with QTc in RA patients. The crude hazard ratio (HR) for total mortality per 50-ms increase in QTc was 2.17 (95% CI 1.21, 3.90). This association remained significant [HR = 2.18 (95% CI 1.09, 4.35)] after adjustment for identified confounders (cardiovascular and RA specific), but was lost [HR = 1.73 (95% CI 0.83, 3.62)] when CRP was included in the model.
A 50-ms increase in QTc interval associates with a doubling of the hazard for all-cause mortality in patients with RA. The observed contemporary association of QTc with CRP levels indicates a potentially hazardous interplay between inflammation and arrhythmogenesis. Future studies are needed to confirm the above findings and explore underlying mechanisms.
RA 与心源性猝死（SCD）发生率增加相关。QTc 间期延长与长 QT 综合征患者的心律失常和 SCD 相关。尽管之前有研究报道 CRP 与 SCD 有相关性，但目前尚无研究探讨 QTc 与 RA 死亡率之间的关系，RA 是一种炎症负担较高的疾病。本研究旨在探讨心电图（QTc 校正间期）在预测 SCD 发生率高且炎症负担高的 RA 患者全因死亡率中的作用。
对 357 例 RA 患者进行详细的基线临床特征描述和 12 导联心电图检查，平均随访 73.0（标准差 18.3）个月。采用线性和 Cox 回归分析确定与 QTc 相关的变量，并探讨其与全因死亡率的关系。
患者平均年龄为 60.6（标准差 12.0）岁，267 例（74.8%）为女性，54 例（15.1%）在随访期间死亡。年龄（β=0.231，P<0.001）、性别（β=0.137，P=0.008）和 CRP（β=0.144，P=0.006）与 RA 患者的 QTc 独立相关。QTc 每增加 50ms，全因死亡率的粗 hazard ratio（HR）为 2.17（95%CI 1.21，3.90）。调整已知混杂因素（心血管和 RA 特异性）后，这种相关性仍然显著[HR=2.18（95%CI 1.09，4.35）]，但当 CRP 纳入模型时，这种相关性丧失[HR=1.73（95%CI 0.83，3.62）]。
QTc 间期增加 50ms 与 RA 患者全因死亡率增加 2 倍相关。观察到的 QTc 与 CRP 水平的当代相关性表明炎症和心律失常之间可能存在潜在的相互作用。需要进一步研究来证实上述发现并探讨潜在机制。
