How does smoking affect the heart, and how fast does quitting help?

Smoking damages endothelium, raises clotting, and accelerates plaque. Heart rate and blood pressure improve within hours; excess coronary risk drops roughly by half within a year of quitting and approaches that of non-smokers over 10–15 years.

No. Excess coronary risk falls roughly by half within a year of quitting and approaches non-smoker levels over 10-15 years, even after long-term smoking.

Combining nicotine replacement or prescribed medication with counselling roughly doubles success rates compared with willpower alone.