A comparison of standard and high dose adenosine protocols in routine vasodilator stress cardiovascular magnetic resonance: dosage affects hyperaemic myocardial blood flow in patients with severe left ventricular systolic impairment

Table 3 Haemodynamics and response to adenosine

	CAD n = 20			HF LVEF ≥ 40% n = 16			HF LVEF < 40% n = 24			Comparison between groups (p)
	Standard dose	High dose	p	Standard dose	High dose	p	Standard dose	High dose	p	Standard dose	High dose
Rest HR (bpm)	62 ± 10	63 ± 9	0.534	65 ± 14	65 ± 13	1.000	75 ± 12	77 ± 14	0.547	0.002	0.001
Rest SBP (mmHg)	132 ± 17	131 ± 16	0.735	124 ± 16	124 ± 17	0.320	119 ± 16	119 ± 16	0.526	0.066	0.089
Stress HR (bpm)	75 ± 13^‡	78 ± 13^‡	0.027*	79 ± 20^‡	80 ± 17^‡	0.659	87 ± 16^‡	90 ± 18^‡	0.418	0.039	0.038
Stress SBP (mmHg)	124 ± 15	121 ± 12	0.219	124 ± 11	120 ± 13	0.005**	122 ± 18	124 ± 19	0.391	0.597	0.970
Change in HR (bpm)	12 ± 10	15 ± 8	0.112	14 ± 14	15 ± 9	0.637	12 ± 12	13 ± 19	0.751	0.875	0.889
Change in SBP	− 2 ± 10	− 6 ± 11	0.455	− 2 ± 13	− 2 ± 11	0.139	2 ± 8	3 ± 13	0.700	0.377	0.072
Non-responders (< 10 bpm) (%)	8 (40%)	4 (20%)	0.168	6 (38%)	3 (19%)	0.433	10 (42%)	11 (46%)	0.771	0.966	0.097
Failed splenic switch off (%)	2 (10%)	0	0.487	1 (6%)	0	1	2 (8%)	2 (8%)	1	1.0	0.334

Resting HR was significantly higher in the moderate-severe heart failure (HF) group, no difference was seen between groups in rate of non-responders or absolute measures of haemodynamic response to adenosine
Data given as mean ± standard deviation or n (%)
HR heart rate, SBP systolic blood pressure
^*Significant difference between adenosine doses, p < 0.05, **significant difference between adenosine doses, p < 0.01, ^‡significant difference from rest value, p < 0.01. Group 1—Patients with coronary artery disease and left ventricular ejection fraction (LVEF) > 40%. Group 2 – Mild to moderate heart failure, LVEF ≥ 40% and no evidence of coronary artery disease. Group 3—moderate to severe heart failure, LVEF < 40% and no evidence of coronary artery disease. Standard dose—140 µg/kg/min. High dose—210 µg/kg/min.

ISSN: 1532-429X