Fig. 2

Agreement and correlation analyses between invasively derived peak aortic valve pressure gradient assessment and three other methods. Agreement and correlation analyses between invasively derived peak aortic valve pressure gradients (AVPG) and A) transthoracic echocardiography (TTE); B) 4D flow CMR (manual method); C) 4D flow CMR (semi-automated pipeline method). Left panel relates to agreement analyses (Bland–Altman statistics), where bias refers to the mean difference between the two methods of peak AVPG assessment (measured in mmHg) and is deemed statistically significant if the corresponding p-valve (denoted p) is < 0.05 (i.e., high risk of systematic bias). For negative bias values, this indicates that the non-invasive method (either TTE or 4D flow CMR) for peak AVPG assessment is systematically lower than the values derived from the invasive method. The right panel relates to correlation analyses between the reference invasive method of peak AVPG assessment and TTE, 4D flow CMR (manual method) and 4D flow CMR (semi-automated pipeline method) derived values. The Pearson correlation coefficient is denoted r, with accompanying p-values (denoted p). The line of best fit (black) and r = 1 (red) is presented