Short answer: If you are sensitive to stimulants or caffeine, or manage high blood pressure or a heart condition, please take this into account and speak with your doctor.
Why this caution is specifically tied to Guarana
Glucovex contains Guarana, which naturally contains caffeine — the specific, named source behind this particular blood-pressure-and-heart caution.
Why this is a genuinely separate caution from the blood-sugar-lowering one
Berberine, Cinnamon and Gymnema's blood-sugar caution and Guarana's caffeine caution address two distinct physiological concerns, worth discussing separately with a doctor.
⚠️ Worth knowing: those sensitive to stimulants or caffeine, or managing high blood pressure or a heart condition, should take note of Guarana's natural caffeine content specifically.