As a fellow heart failure sufferer, I empathise with you. One thing I learnt from my recent bypass op is that the damage shown in the angiogram started decades ago, and my recent heart attacks were more due to that buildup than anthing I have done recently in the way of low carb high(ish) fat diet. The Consultant has advised me to keep it up since it is controlling my bgl levels, my BP, my TC and general blood panel results, and I have recovered from the op quite well now. It was only 3 weeks ago, and I am mowing the lawn already.
Yes LCHF is totally turning dietary advice on its head, but I have been using it for 4 years now, and it certainly worked for me. My HbA1c dropped from over 100 down to 41 within a few months, and even after 3 months on hospital food, and no diabetes meds due to contraindictions with heart meds, then my HbA1c was only raised to 51. So my LC diet has put me in a good position to survive all that I did, and now I am out, my bgl levels have started to recover back to the 4's and 5's that I became used to. So IMHO it would be worthy of consideration for your future lifestyle. Try it and see how your bgl levels react to it.
As regarding washing fingers before testing, then yes it is essential. The bgl meter is measuring conductivity of the blood sample, and uses enzymes in the strip to convert glucose into lower resistance. However, our fingers have sweat glands, and sweat contains salt, so we naturally exude something that lowers conductivity, and will affect a reading. Also our fingers exude natural oils that can increase resistivity, again affecting the result, so a quick wash with slightly soapy solution, followed by a good dry off is recommended.
Edit: Sorry, derailment over, I do not use any of these products, and my instinct is why use them as there are other things I can use that are healthier. Even the manager in H&B agreed that they are not diabetic friendly, even the protein bars he sells. But I guess they are ok for those needing snacks on the go. There are worse ones on the shelves after all.