NICOTINE PATCH THERAPY IN SMOKING CESSATION REDUCES THE EXTENT OF EXERCISE-INDUCED MYOCARDIAL-ISCHEMIA

Objectives. We sought to determine the effects of nicotine patch thera py, when used to promote smoking cessation, on myocardial ischemia in patients,vith coronary artery disease. Background. Nicotine patches su bstantially increase quit rates among cigarette smokers, but their saf ety in patients with myocardial ischemia who are attempting to quit sm oking is unknown. Methods. This is a prospective study using exercise thallium-201 single-photon emission computed tomography (SPECT) to ass ess serial changes in the total and ischemic myocardial perfusion defe ct size at baseline while patients were smoking and during treatment w ith 14- and 21-mg nicotine patches. Entry criteria required that patie nts If smoked greater than or equal to 1 pack of cigarettes per day; 2 ) had known coronary artery disease; and 3) had myocardial ischemia (i .e., greater than or equal to 5% reversible perfusion defect) on SPECT . All patients performed symptom-limited treadmill exercise, and the b aseline SPECT study served as its own control. We interpreted and comp uter quantified the SPECT images with no knowledge of the testing sequ ence. Results. Thirty-six of the 40 enrolled patients had exercise SPE CT at baseline and during treatment with at least 14-mg nicotine patch es. These patients had an initial perfusion defect size of 17.5 +/- 10 .6% while smoking an average of 31 +/- 11 cigarettes per day for 40 +/ - 12 years. A significant reduction in the total perfusion defect size (p < 0.001) was observed from baseline (17.5 +/- 10.6%) to treatment with 14-mg (12.6 +/- 10.1%) and 21-mg (11.8 +/- 9.9%) nicotine patches . This reduction occurred despite an increase in treadmill exercise du ration (p < 0.05) and higher serum nicotine levels (p < 0.001). There was a significant correlation between the reduction in defect size and exhaled carbon monoxide levels (p < 0.001) because patients reduced t heir smoking by similar to 74% during the trial. Conclusions. Nicotine patches, when used to promote smoking cessation, significantly reduce the extent of exercise-induced myocardial ischemia as assessed by exe rcise thallium-201 SPECT. (C) 1997 by the American College of Cardiolo gy.