Table 2.

Reproducibility between validation studies

Category/Drug	Margin to EFTPC	AstraZeneca							Study 1							Study 2
		T	R	I	MAPD60	ProA	n	Score	T	R	Ia	MAPD60	ProA	n	Score	T	R	I	MAPD60	ProA	n	Score
1 dl sotalol	0.30		1R		MAPD60	EADs, TdP	3	111		R			EADs	6	101
1 Ibutilide	0.30	1T				EADs, TdP, VF	3	103	T	R	I	MAPD60	EADs	6	116
2 Cisapride	30			11	MAPD60	TdP	3	117			I	MAPD60	EADs VT	6	113
2 Terfenadine (1)	30	1T		11	MAPD60	EADs	6	115	I				EADs, VT	8	103	2T				VT	3	107
2 Terfenadine (2)	30	3T	1R	31			6	16										11			3	7
3 Flecainide	3	3T	7R		MAPD60	EADs	3	132				MAPD60		6	10
3 Erythromycin	30	1T	5R		MAPD60	EADs	6	116										11			3	6
3 Bepridil	300			11	MAPD60	TdP	3	117				MAPD60	VT, VF	2	110
3 Sertindole	300	2T	2R	21	MAPD60	EADs, TdP	6	121	T		I	MAPD60	EADs	2	125
4 Ziprasidone	300	2T		21	MAPD60	EADs, TdP, VF	6	120		R	I	MAPD60	EADs, VT	2	123
5 Diltiazem	30						3	0						6	0
5 Verapamil	30	1T	5R				6	6		R				6	5				-MAPD60		3	0

The table compares results from our study with independent validation studies commissioned by two pharmaceutical companies (Hondeghem and Hoffman, 2003; Hondeghem et al., 2003). Proarrhythmic scores have been calculated at single concentrations and thus may differ from those in Table 1. Nine drugs: dl-sotalol, ibutilide, terfenadine (1), cisapride, bepridil, sertindole, ziprasidone, diltiazem and verapamil, show very good reproducibility between studies. Three drugs, terfenadine (2), erythromycin and flecainide show discrepancies between the studies. Erythromycin and flecainide were shown to be proarrhythmic in our study and relatively benign in Study 2 and 1, respectively. See Table 1 legend for details of table symbols. Blank spaces indicate where no data are available.

^aThe number of TRIad elements at each concentration is unknown.