Table 1.

Studies demonstrating associations between rheumatoid arthritis and QT parameters, inflammation and mortality

Ref.	Design	RA patients	Controls	Impact of RA and QT dispersion (QTd) and QTc	Association between QT parameter, and disease activity/duration (1), arrhythmia (2), autonomic dysfunction (3), mortality (4)
[54]	Cross-sectional	42	42	↑ QTd variables (QTd, QTcD, JTD, JTcD) vs controls No difference in QTc vs controls	(1) ESR, CRP (2) Complex premature ventricular beats
[55]	Cross-sectional	40	48	↑ QTd variables (QTd, QTcD) vs controls	(1) Disease duration
[56]	Cross-sectional	40	40	↑ QTd vs controls	(1) Extra-articular manifestations, erosive disease
[57]	Cross-sectional	58	29	↑ QT vs controls	(1) Secondary Sjörgen’s syndrome
[58]	Cross-sectional	100	100	↑ QTd vs controls	(1) Disease duration, DAS28, ESR, number of joints involved
[59]	Cross-sectional	25	21 controls 76 with spondylarthopathy	↑ QTc vs controls and those with spondyloarthopathies Infliximab therapy duration inversely correlated to QTc (P < 0.01)	(1) CRP (3) ↑ QTC associated with ↑ HR, autonomic dysfunction, particularly sympathetic dysfunction as assessed by spectral parameters of heart rate variability
[60]	Prospective cohort	357	_	↑ QTc 10% males (QTc ≥ 450 ms) and 5.6% of females (QTc ≥ 460 ms)	(1) CRP (4) Doubled risk of all-cause mortality per 50 ms increase in QTc, (lost after adjustment for CRP) HR = 2.17 (95%CI: 1.21-3.90)
[61]	Retrospective cohort	417	422	↑ % of RA patients with QTc prolongation (> 450 ms males, > 460 ms females) vs controls 20 yr after disease onset (48% vs 38%, P = 0.004)	(1) ESR (4) Any cause QTc prolongation was associated with ↑ all-cause mortality HR = 2.99 (95%CI: 1.93-4.65)
[62]	Prospective cohort	17	_	↑ QTc (> 440 ms) in 76% of patients Toclizumab associated with 47% ↓ in No. patients with QTc prolongation (P = 0.006)	(1) CRP and TNF-α
[70]	Cross-sectional	117	-		(1) CRP, TNF-α, IL-1β and IL 10 ( QTc BAZ) (1) IL-1β and IL 10, trend towards TNF-α (QTc FHS)

RA: Rheumatoid arthritis; QTd: QT interval dispersion; QTc: Heart-rate corrected QT interval; QTcD: Heart-rate corrected QT interval dispersion; JTD: JT interval dispersion; JTcD: Heart-rate corrected JT interval dispersion; DAS28: Disease activity score in 28 joints; ESR: Erythrocyte sedimentation rate; CRP: C-reactive protein; ms: Milliseconds; QTc BAZ: QTc calculated using Bazett formula; QTc FHS: QTc calculated using Framingham formula.