A processing apparatus for processing cardiac data of a living being, wherein the apparatus comprises - a first fractional flow reserve value providing unit configured to provide first fractional flow reserve values being indicative of the fractional flow reserve of different arteries of the living being, wherein said first fractional flow reserve values were calculated from non-invasive imaging data of arteries of the living being; - a second fractional flow reserve value providing unit configured to provide second fractional flow reserve values measured in the arteries of the living being by in-artery measurements; and - a correction unit configured to correct the provided first fractional flow reserve values based on the provided second fractional flow reserve values, wherein the correction unit is configured to correct a first fractional flow reserve value at a position for which a second fractional flow reserve value is not or not yet available by recalculating said first fractional flow reserve value using at least one second fractional flow reserve value of a different position in the coronary arteries of the living being, and wherein the correction unit is configured to correct the first fractional flow reserve values whenever a new second fractional flow reserve value is provided; - an arterial tree model providing unit configured to provide an arterial tree model from the non-invasive imaging data of the coronary arteries of the living being and in-artery imaging; and - a display unit configured to display the arterial tree and to display the first and second fractional flow reserve values at or near the locations in the arterial tree where they were determined or measured. - a first fractional flow reserve value providing unit configured to provide first fractional flow reserve values being indicative of the fractional flow reserve of different arteries of the living being, wherein said first fractional flow reserve values were calculated from non-invasive imaging data of arteries of the living being; - a second fractional flow reserve value providing unit configured to provide second fractional flow reserve values measured in the arteries of the living being by in-artery measurements; and - a correction unit configured to correct the provided first fractional flow reserve values based on the provided second fractional flow reserve values, wherein the correction unit is configured to correct a first fractional flow reserve value at a position for which a second fractional flow reserve value is not or not yet available by recalculating said first fractional flow reserve value using at least one second fractional flow reserve value of a different position in the coronary arteries of the living being, and wherein the correction unit is configured to correct the first fractional flow reserve values whenever a new second fractional flow reserve value is provided; - an arterial tree model providing unit configured to provide an arterial tree model from the non-invasive imaging data of the coronary arteries of the living being and in-artery imaging; and - a display unit configured to display the arterial tree and to display the first and second fractional flow reserve values at or near the locations in the arterial tree where they were determined or measured.