Quitting smoking after undergoing a balloon angioplasty procedure to improve blood flow to the heart could add an average of two years to a person’s life, a new study concludes.

Researchers in the Netherlands compared people undergoing balloon angioplasty who quit smoking within a year after the procedure, to those who continued smoking. Those who quit smoking lived another 18.5 years, compared with 16.4 years for those who continued to smoke, Reuters reports.

The study included 806 patients who underwent balloon angioplasty, in which a balloon-tipped catheter is threaded through blood vessels. The doctor inflates the balloon to clear narrowed blood vessels.

Thirty years after the survey, 29 percent of smokers who had quit were still alive, compared with 14 percent of those who had continued smoking. The study appears in The American Journal of Cardiology.