Table 1.

Study characteristics and patient demographics.

Paper details	Imaging and stress modality	Patient cohort	Cohort size	Contractile reserve criteria	DCM criteria used	Outcomes/endpoints assessed	Follow-up period
Stipac et al. (20)	High-dose dobutamine stress echocardiography – 5–40 µg/kg/min	38 consecutive patients with DCM (31 men, mean age 50 +/− 10, LV EF 18.1% +/− 7, NYHA I–III)	38	Change in WMSI >0.19, EF increase of >2%	LVEDV >60 mm, LV EF <35%, (ETOH, IHD, arrhythmia, toxins, myocarditis, valvular heart disease, AF excluded)	Cardiac mortality	60 months
Pratali et al. (10)	High-dose dobutamine stress echo (up to 40 µg/kg/min)	186 patients with DCM (131 men, mean age 56 +/− 12 years, LV EF 25% +/− 7, NYHA I–IV)	186	Change in WMSI >0.44	LV EF <35%, no coronary disease at angiogram	Cardiac mortality	15 +/− 3 months
Pratali et al. (21)	Dipyridamole and dobutamine stress echocardiography. High-dose DSE 5-40 µg/kg/min	87 patients with DCM (63 males, mean age 54 +/− 12, LV EF 23.7% +/− 8.2, NYHA 2.34 +/− 0.6)	87	Change in WMSI ≥ 0.25	LV EF <35%, no coronary disease at angio within 5 years	All-cause mortality	52 months (range 6–72)
Pinamonti et al. (22)	Dobutamine stress echo, 5–30 µg/kg/min	51 patients with DCM, (33 males, 67%; mean age 45 +/−13, LV EF 24% +/− 6, NYHA 2.06 +/− 0.81)	51	Change in LV EF >10% and peak LVEF 40%	LV EF <40%, coronary angiogram and biopsy to exclude IHD/myocarditis	Transplant-free survival. Cardiac mortality or transplantation primary endpoints. Secondary endpoints include NYHA class and LVEF	34 +/− 16 months
Pratali et al. (23)	Dipyridamole stress echo	116 patients with DCM, (99 males, mean age 58 +/−12, LV EF 27.4% +/− 6.8, NYHA 2.5 +/− 0.6)	116	Change in WMSI ≥ 0.15	Global LVSD, EF <35%, no IHD at angio within 5 years	Cardiac death free survival	60 months
Parthenakis et al. (24)	Low dose dobutamine stress echo (5, 10, 15 µg/kg/min)	43 consecutive patients with DCM (33 males, mean age 60.8 +/− 9.6, LV EF 31.9% +/− 7.2, NYHA II–III)	43	Change in WMSI >25%	Non-ischaemic DCM, not clearly defined	Cardiac mortality and re-hospitalisation for HF decompensation	45 +/− 22 months
Ramahi et al. (25)	Low dose dobutamine equilibrium radionuclide ventriculography at 10 µg/kg/min	62 patients with HFREF, non-ischaemic, (42 males, mean age 48 +/− 11, LV EF 20% +/− 6, NYHA 2.6 +/− 0.6)	62	Change in LVEF ≥ 8%	Severe LVSD, EF <30%, coronary disease excluded by angiography	All-cause mortality before cardiac transplantation	25 +/− 15 months
Nagaoka et al. (26)	Exercise stress radionuclide angiography	71 patients (52 men, 19 women) mean age 54. NYHA 1–II, LV EF 20– 50%	71	Change in LVEF ≥5%	Ischaemic CM excluded at angiography, AF, specific heart muscle disease, toxins and inherited conditions excluded	Cardiac mortality	60 months
Rigo et al. (27)	Dipyridamole stress echo (0.84 mg/kg in 10 mins)	132 patients with DCM, 90 males, age 62+/− 11. LVEF <40% (mean 32% +/− 7), angiographically normal coronaries & NYHA <or = III	132	Change in WMSI >0.25	LV EF <40%, no history of coronary heart disease and angiographically normal coronary arteries at angiography before enrolment	All-cause mortality, cardiac mortality & development or progression of HF	40 months

DCM, dilated cardiomyopathy; LV EF, left ventricular ejection fraction; LVSD, LV systolic dysfunction; NYHA, New York Heart Association; WMSI, wall motion score index.