Smoking After Cardiac Transplantation
Although smoking cessation is a prerequisite prior to listing for cardiac transplantation, some patients return to smoking after recovery. We have covertly assessed the smoking habits of our cardiac transplant recipients (with ethical approval) since 1993 by measuring urinary cotinine: a level of >500 ng/mL signifying continued tobacco use. We retrospectively analyzed survival, causes of death and the development of graft coronary artery disease (GCAD) with respect to the number of positive and negative cotinine levels. One hundred four of 380 (27.4%) patients tested positive for active smoking at some point posttransplant, and 57 (15.0%) tested positive repeatedly. Smokers suffered significantly more deaths due to GCAD (21.2% vs. 12.3%, p < 0.05), and due to malignancy (16.3% vs. 5.8%, p < 0.001). In univariate analysis, smoking after heart transplantation shortened median survival from 16.28 years to 11.89 years. After correcting for the effects of pretransplant smoking in time-dependent multivariate analysis, posttransplant smoking remained the most significant determinant of overall mortality (p < 0.00001). We conclude that tobacco smoking after cardiac transplantation significantly impacts survival by accelerating the development of graft vasculopathy and malignancy. We hope that this information will deter cardiac transplant recipients from relapsing, and intensify efforts in improving cessation rates.

Cigarette smoking is the single greatest modifiable risk factor for death from ischemic heart disease (IHD) and malignancy in the developed world. Through free radical-mediated endothelial damage, smoking accelerates coronary vascular atherothrombosis by inducing endothelial dysfunction, leukocyte and platelet activation, lipid peroxidation, smooth muscle proliferation and a prothrombotic hematological milieu. In those who survive the acute effects of atherosclerotic plaque rupture and myocardial ischemia, the end result of chronic limitation of myocardial blood flow is ischemic cardiomyopathy. In patients with idiopathic dilated cardiomyopathy, a history of prior smoking is also not uncommon. Heart transplantation remains the treatment option of choice for both these patient groups when end-stage cardiac failure ensues, and offers significantly superior survival over maximal medical therapy. Although the survival benefit from smoking cessation after a diagnosis of cardiac failure or coronary vascular disease is well documented, compliance rates with cessation measures remain poor. Only intensive counseling and appropriate medical treatment of nicotine withdrawal have been shown to improve compliance rates. Even after surviving heart failure of a severity requiring cardiac transplantation, tobacco relapse is common. Previous reports of the risks of smoking after transplantation have been limited by self-reported assessment of smoking and the quantification of risks based on a point prevalence of smoking in the population. We have covertly assessed smoking habits in cardiac transplant recipients at our center over a period of 13 years. We aimed to correlate this assessment with survival data and development of graft vasculopathy and malignancy in an attempt to provide outcome data to encourage smoking cessation or continued abstinence in cardiac transplant recipients.