Theoretically,it should be correct.I mean your hearth was designed for your starting height.It might be struggling for your +10 cm taller body-legs(I actually heard this from a doctor too,it really makes sense).But you know this whole thing is insane afterall..
The heart supposedly is similar sized to that of your fist and stops growing at a similar time to when growth stops. Heart size isn't completely consistent and there is variation between people of the same size and height though it does fall within a proportional range - as far as I am aware some ethnic groups have larger hearts than others and exercise/hormonal change can directly affect the size of the heart.
Would a person with a large body and proportionally shorter legs have organs that would be the same size as somebody who simply had longer legs and the same size body? What about somebody with extremely long limbs and a short body - would there heart by proportional to their body size and have to work harder for their proportionally longer limbs? I think growth is general rather than entirely specific and the heart is very good at its specific task and working at the rate that is needed.
Shedding a few pounds would likely have the same impact as increasing bone and soft tissue mass as a fat/muscular person will require much more work from their heart than if they had minimal muscle/fat. I believe this factor will have a far larger impact than a slight increase in an increase of bone and soft tissue which will be negligible in comparison.