Smoking cessation after first STEMI enhances infarct healing: a cardiac MRI study

AIMS: Smoking cessation represents an important step in primary and secondary prevention of myocardial infarction. While there are few data on the extent of initial myocardial damage in current smokers, there are hardly any data on the evolution of the infarct in active smokers and in patients giving up smoking. This prospective study investigated infarct dynamics in patients quitting smoking after ST-elevation myocardial infarction (STEMI). METHODS AND RESULTS: Overall, 672 revascularized first-time STEMI patients were included. Smoking behaviour was documented at baseline and after 4 months. Cardiac magnetic resonance imaging (CMR) was performed at baseline and after 4 and 12 months, including infarct characteristics evaluation. Major adverse cardiac events (MACE) comprised all-cause death and reinfarction within a median observation period of 3.4 years. Initially, 382 patients (57%) were active smokers, of whom 183 (48%) quit smoking after the infarction. There were no differences in initial infarct size; however, at follow-up CMR examinations, infarct size reduced more in the cessation group compared to continuing smokers (after 12 months: 62% vs. 47%, P < 0.001). Additionally, MACE occurred less often in quitters (4%vs. 12%, P = 0.005). In multivariable logistic regression, continuing smoking was predictive of reduced infarct healing; in multivariable Cox-regression, it was a marker for MACE, independent of traditional cardiovascular risk markers. CONCLUSION: Smoking cessation after the first STEMI appears to be an important factor positively influencing infarct healing. Within the observation period, fewer patients died in the cessation group. In sum, these data provide another valuable argument for quitting smoking, even after an infarction had already occurred.