4-13 EFFECT OF SMOKING STATUS ON THE LONG-TERM OUTCOME AFTER SUCCESSFUL PERCUTANEOUS CORONARY REVASCULARIZATION
This study examined the effect of smoking status on outcome after successful percutaneous coronary revascularization (PCR). Does cessation after the intervention affect survival?
Conclusion: Patients who continue to smoke after PCR are at higher risk of myocardial infarction and death.

STUDY

1. Retrospectively analyzed all patients who had undergone successful PCR over a 16-year period.
2. Non-smokers (n = 2009); former smokers (those who had quit before the procedure— n = 2259); quitters (those who stopped after the procedure— n = 435); and persistent smokers (smoked before and after the procedure—n = 734).

RESULTS

1. After adjustment for confounding factors, persistent smokers, compared with non-smokers, had a greater relative risk of death (RR = 1.8) and Q wave infarction (RR = 2.1).
2. Persistent smokers compared with quitters were also at greater risk for Q-wave infarction and death.

DISCUSSION

1. A substantial proportion of patients undergoing PCR smoke cigarettes—in this study, 22% at the time of the intervention. Of these about 2/3 continue to smoke.
2. The long term risk of death from any cause was 44% greater in patients who continued to smoke than in quitters. The estimated survival curves for these 2 groups diverged early after the index PCR and continued to diverge throughout follow-up.
3. At the time of the procedure, smokers were about 10 years younger than non-smokers. The earlier onset of coronary atherosclerosis in smokers may be attributed to smoking. Smokers had fewer existing conditions predisposing to atherosclerosis such as diabetes and hypertension than non-smokers.

CONCLUSION
Patients who continued to smoke after successful percutaneous coronary revascularization were at greater risk for Q wave infarction and death than non-smokers. Cessation before and after PCR was beneficial.
NEJM March 13, 1997; 336: 755-61 Original study from Mayo Clinic, Rochester, Minn.

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