MI: SURVIVAL IMPROVED BY STOPPING SMOKING

About the Book <I>How to Practice and Teach EBM</i>

MI: SURVIVAL IMPROVED BY STOPPING SMOKING

Clinical Bottom Lines:

Yes. The effect on mortality can be seen as soon as 18 months [4,9] and even increases over time [1].

There is more effect on patients post-MI than post-coronary bypass randomization.

Smoking cessation is beneficial in women [6] and in the elderly [3] as well as men.

Appraiser: HN Lee October 19th 1992

The Evidence:

Study	Inception Cohort and Outcome measurement	Quitters	Cont. Smokers	Absolute Risk Reduction (ARR + CI)	NNQ (# needed to quit)
Daly [1]	13 yr mortality on 2yr CCU survivors	.37	.82	.45 (.36-.54)	2.2
	15 yr mort. on all CCU even assuming all 2 yr deaths were quitters only	.45	.82	.37 (.28-.46)	2.7
CASS [2]	10 yr mortality post CASS randomization	.20	.31	.11 (.01-.22)	8.7
CASS and elderly [3]	6 yr mortality age 65-69 years old age ³ 70 years old	.45 .53	.48 .73	.03(-.11-.17) .20(-.06-.46)	33 5
DART [4]	18 month mortality post MI (men only)	.04	.08	.03(.01-.07)	26
Johansson et al [6]	5 year mortality post MI (women only)	.17	.36	.19(.04-.33)	5

Comments:

The lack of biochemical verification in most of the studies would probably underestimate the true effect of smoking cessation; in other studies, the rate of cheating has been ³25%.

In CASS, there was a significant difference in morbidity between smokers and non-smokers. Outcomes that were stat. significant were: recurrent MI, hospitalization, catheterization, employability, recurrent angina and activity limitation. However, they did not discriminate quitters from non-smokers.

_____________________________________________________________________________________

REFERENCES:

[1] Daly LE, Mulcahy R, Graham IM. Long term effect on mortality of stoppin smoking after unstable angina and myocardial infarction. BMJ 1983;287:324-326.

[2] Cavender JB, Rogers WJ et al. Effects of Smoking on Survival and Morbidity in the Coronary Artery Bypass Study (CASS): 10 year follow-up. J Am Coll Cardiol 1992;20(2):287-94.

[3] Hermanson B, Omenn GS, Kronmal RA et al. Beneficial six-year outcome of smoking cessation in older men and women with coronary artery disease (CASS). NEJM 1988;319(21):1365-1369.

[4] Burr ML, Holliday RM et al. Hem. prognostic indices after MI (DART). Eur H J 1992;13:166-170.

[5] Salonen JT. Stopping smoking and long-term mortality after MI. Br H J 1980;43:463-9.

[6] Johansson S et al. Cessation of smoking after MI in women. Am J Epid 1985;121(6):823-831.

[7] Perkins J, Dick TBS. Smoking and MI: secondary prevention. Postgrad Med J 1985;61:295-300.

[8] Sparrow D, Dawber TR, Colton T. The Influence of Cigarette Smoking on Prognosis after a First M.I. A report from the Framingham Study. J Chron Dis 1978;31:425-432.

[9] Wilhelmsson C, Vedin JA, Elmfeldt D et al. Smoking and Myocardial Infarction. Lancet 1975(1):415-20

Click here to comment on this CAT