Table 3 Summary of MCE perfusion parameters arranged into three groups of stenosis severity

	Stenosis severity, diameter reduction
	<50%		50–74%		⩾75%
	Mean	SD	Mean	SD	Mean	SD
Stenosis
Number	93		24		27
Severity (%)	10	16*†	61	8*‡	85	9†‡
rBV (ml.ml⁻¹)
Baseline	0.123	0.031	0.119	0.035	0.118	0.031
Hyperaemia	0.145	0.032¶	0.145	0.042¶	0.144	0.034¶
β (min⁻¹)
Baseline	9.034	3.814	11.088	5.468	10.834	4.271
Hyperaemia	21.181	7.761¶	15.138	7.054¶**	13.466	5.703**
MBF (ml.min⁻¹.g⁻¹)
Baseline	1.020	0.414	1.186	0.307	1.156	0.372
Hyperaemia	2.859	1.090¶	1.937	0.690¶**	1.784	0.681¶**
β-reserve (1)	2.572	0.960	1.538	0.799**	1.293	0.383**
MBFR (1)	3.020	0.911	1.774	0.640**	1.569	0.398**

*p<0.05 vs ⩾75% stenosis severity; †p<0.05 vs 50–74% stenosis severity; ‡p<0.05 vs <50 stenosis severity; ¶p<0.05 vs baseline; **p<0.05 vs <50% stenosis severity (Bonferroni-corrected).
Values are mean (SD).
Statistical test: Kruskal-Wallis tests have been used for comparison between groups and if significant followed by Wilcoxon rank-sum test.
β, blood volume exchange frequency; MBF, myocardial blood flow; MBFR, myocardial blood flow reserve. MCE, myocardial contrast echocardiography; rBV, relative blood volume.