Smoking cessation even a year prior to coronary artery bypass grafting (CABG) surgery does not fully normalize the changes smoking has made to the saphenous (leg) veins used for the surgery and may lead to later graft failure, according to a study published in the January 2013 issue of The Annals of Thoracic Surgery.
Sun Yongxin, MD and colleagues from Zhongshan Hospital at Fudan University in Shanghai, China, analyzed heart surgery outcomes in 208 patients undergoing elective CABG surgery. After dividing the patients into six groups based on the current quantity smoked and previous smoking status, the researchers found that heavy smoking noticeably increased matrix metalloproteinase enzyme levels in the saphenous vein. These enzymes have been linked to vein graft failure.
The researchers also found that while dysregulation of enzymes may gradually normalize after smoking cessation, a noticeable vein recovery needs at least 6 months, and vein enzymes do not completely return to normal levels even after 1 year.
"Although recovery after smoking cessation appears somewhat disappointing, it illustrates exactly the importance of prompt smoking cessation for patients who will receive CABG," the researchers wrote.
The ultimate goal of CABG is to achieve complete revascularization with conduits that will remain open for the duration of the patient's lifetime.
About 1.1 billion people— one in every three adults—are smokers, according to the World Health Organization. China is the world's largest producer and consumer of cigarettes with more than 350 million residents reporting being current or former smokers.