Welcome to the forum
@Richard9
Sorry to hear about your heart attack, but good that it has prompted you to aim to get a bit fitter and healthier.
The blood check you have had is canned an HbA1c, and it measures how much glucose has ‘stuck’ to your red blood cells over the past 3-4 months. The more glucose you have in your blood stream, the more red blood cells will be affected, so it’s a sort of proxy measure that is used to assess circulating glucose levels in the previous months.
Once you get to 42mmol/mol you are said to be ‘at increased risk of diabetes’ (sometimes called prediabetes), because it’s an indication that your body and metabolism are beginning to struggle with your intake of carbohydrates (starches and sugars).
Losing weight, especially from the belly/abdomen can really help, as can reducing the portions of carbs in your meals, including rice, pasta, potatoes, bread, pastry, grains, cereals, fruit juice, and many fruits - as well as the more obvious sweet and sugary things like cakes, biscuits, chocolate, sweets and sugary drinks.
It’s not that you have to avoid all carbs entirely, often just a few tweaks, swaps, and portion reductions can go a long way.