Table 3.

Studies of QRS-T angle for risk prediction in dialysis patients.

Study	Participants	Age (years)	IHD	Calculation	Follow up	Outcome
de Bie et al., 2013b	277 (prevalent) Male 62.1% HD 62.8% Peritoneal dialysis 37.2%	56.3 ± 17.0	24.5%	Inverse Dower matrix from standard 12 lead snapshot ECG. Measured as angle between mean QRS and T vectors.	60 months	QRS-T angle independent predictor of all-cause mortality (N = 91) and SCD (N = 18).
Tereshchenko et al., 2016	358 (incident HD) Male 59% Black 73%	55 ± 13	37%	Calculated from continuous unfiltered averaged xyz ECG signal. Measured as angle between spatial mean QRS vector and spatial peak T vector.	864.6 person-years of follow-up	QRS-T angle associated with all-cause mortality (N = 77) cardiovascular mortality (N = 35) and SCD (N = 15).
Skampardoni et al., 2018a	178 (prevalent HD) Male 72% Caucasian 80% South Asian 17% Black 3%	67 ± 14	23.5%	Singular value decomposition to standard snapshot 12 lead ECG. Measured as total cosine R to T.	36 ± 19 months	TCRT independent predictor of cardiac deaths (N = 17) and major cardiac events (N = 54).
Poulikakos et al., 2018	72 (prevalent HD) Males 58% Caucasian 44% Black 31% South Asians 25%	61 ± 15	21%	Singular value decomposition to overlapping 10 s segment 12 lead ECGs during continuous monitoring repeated 5 times every 2 weeks. Measured as total cosine R to T.	54.8 months	TRCT independent predictor of all-cause mortality (N = 16) and major cardiac events (N = 9).
Lin et al., 2007	325 (incident) HD Male 44% Taiwanese population	64 ± 13	19%	Singular value decomposition to standard snapshot 12 lead ECG. Measured as total cosine R to T	25 ± 22 months	TRCT not associated with all-cause mortality (N = 154) cardiovascular mortality (N = 79) or arrhythmia related deaths (N = 59). T wave residuum independent predictor for all outcomes.

ECG, electrocardiogram; F/up, follow up; HD, hemodialysis; IHD, Ischemic heart disease; SCD, sudden cardiac death; TCRT, Total Cosine R to T.