Five-year mortality in patients with acute chest pain in relation to smoking habits

Smoking status on outcomes after percutaneous coronary intervention

BACKGROUND

The effect of smoking on prognosis among patients undergoing percutaneous coronary intervention (PCI) is controversial, and data on the importance of smoking cessation or reductions were lacking.

HYPOTHESIS

Smoking cessation or reductions could reduce the risk of adverse outcomes in patient after PCI.

METHODS

There were 19 506 consecutive patients who had undergone successful PCI between April 2004 and January 2010 followed. Extensive data, including self-reported smoking habits, were obtained at baseline and during follow-up.

RESULTS

Compared with post-PCI quitters and persistent smokers, the nonsmokers and pre-PCI quitters were older and had a higher prevalence of comorbid factors such as hypertension and impaired left ventricle function. The adjusted hazard ratios for mortality were 2.52 (95% confidence interval [CI]: 1.92-3.30) for nonsmokers, 0.52 (95% CI: 0.32-0.84) for pre-PCI quitters, and 0.11 (95% CI: 0.06-0.22) for post-PCI quitters, compared to persistent smokers. With respect to additional revascularizations, a higher risk was observed among the quitters (1.70 [95% CI: 1.40-2.08] for pre-PCI quitters and 1.59 [95% CI: 1.36-1.85] for post-PCI quitters) as well as the nonsmokers (1.40 [95% CI: 1.20-1.64]). Among persistent smokers, each reduction of 5 cigarettes/day was associated with a 72% decline in mortality risk (P < 0.001) but did not reach statistical significant for repeated revascularizations (0.80 [95% CI: 0.46-1.37], P = 0.4132).

CONCLUSIONS

Despite a higher risk of revascularization, the cessation of smoking either before or after PCI is beneficial in all-cause mortality. The apparent smoker's paradox may be explained by the differences in baseline risk or the reduced sensitivity to adverse outcomes as well as the reluctance to seek medical help among smokers.

WITHDRAWN: Smoking cessation for the secondary prevention of coronary heart disease

BACKGROUND

Although the importance of smoking as a risk factor for coronary heart disease is beyond doubt, the speed and magnitude of risk reduction when a smoker with coronary heart disease quits are still subjects of debate.

OBJECTIVES

To estimate the magnitude of risk reduction when a patient with CHD stops smoking.

SEARCH METHODS

We searched the Cochrane Register of Controlled Trials (CENTRAL) , MEDLINE, EMBASE, Science Citation Index, CINAHL, PsychLit, Dissertation Abstracts, BIDS ISI Index to Scientific and Technical Proceedings, UK National Research Register from the start of each database. Sixty-one large international cohort studies of cardiovascular disease were identified, and contact made with authors to search for any unpublished results. The search was supplemented by cross-checking references and contact with various experts. Date of last search was April 2003.

SELECTION CRITERIA

Any prospective cohort studies of patients with a diagnosis of CHD, which include all-cause mortality as an outcome measure. Smoking status must be measured on at least two occasions to ascertain which smokers have quit, and followed-up for at least two years.

DATA COLLECTION AND ANALYSIS

Eligibility and trial quality were assessed independently by two reviewers.

MAIN RESULTS

Twenty studies were included. There was a 36% reduction in crude relative risk (RR) of mortality for those who quit smoking compared with those who continued to smoke (RR 0.64, 95% confidence interval (CI) 0.58 to 0.71). There was also a reduction in non-fatal myocardial infarctions (crude RR 0.68, 95% CI 0.57 to 0.82). Many studies did not adequately address quality issues, such as control of confounding, and misclassification of smoking status. However, there was little difference in the results for the six 'higher quality' studies, and little heterogeneity between these studies. This review was not able to assess how quickly the risk of mortality was reduced.

AUTHORS' CONCLUSIONS

Quitting smoking is associated with a substantial reduction in risk of all-cause mortality among patients with CHD. The pooled crude RR was 0.64 (95% CI 0.58 to 0.71). This 36% risk reduction appears substantial compared with other secondary preventive therapies such as cholesterol lowering which have received greater attention in recent years. The risk reduction associated with quitting smoking seems consistent regardless of differences between the studies in terms of index cardiac events, age, sex, country, and time period. However, relatively few studies have included large numbers of older people, women, or people of non-European descent, and most were carried out in Western countries.

Factors associated with development of stroke long-term after myocardial infarction: experiences from the LoWASA trial

OBJECTIVE

To describe factors associated with the development of stroke during long-term follow-up after acute myocardial infarction (AMI) in the LoWASA trial.

PATIENTS

Patients who had been hospitalized for AMI were randomized within 42 days to receive either warfarin 1.25 mg plus aspirin 75 mg daily or aspirin 75 mg alone.

DESIGN

The study was performed according to the probe design, that is open treatment and blinded end-point evaluation.

SETTING

The study was performed in 31 hospitals in Sweden. The mean follow-up time was 5.0 years with a range of 1.7-6.7 years.

RESULTS

In all, 3300 patients were randomized in the trial, of which 194 (5.9%) developed stroke (4.2% nonhaemorrhagic, 0.5% haemorrhagic and 1.3% uncertain. The following factors appeared as independent predictors for an increased risk of stroke: age, hazard ratio and 95% confidence interval (1.07; 1.05-1.08), a history of diabetes mellitus (2.4; 1.8-3.4), a history of stroke (2.3; 1.5-3.5), a history of hypertension (2.0; 1.5-2.7) and a history of smoking (1.5;1.1-2.0). Most of these factors were also predictors of a nonhaemorrhagic stroke whereas no predictor of haemorrhagic stroke was found.

CONCLUSION

Risk indicators for stroke long-term after AMI were increasing age, a history of either diabetes mellitus, stroke, hypertension or smoking.

Smoking cessation for the secondary prevention of coronary heart disease

BACKGROUND

Although the importance of smoking as a risk factor for coronary heart disease is beyond doubt, the speed and magnitude of risk reduction when a smoker with coronary heart disease quits are still subjects of debate.

OBJECTIVES

To estimate the magnitude of risk reduction when a patient with CHD stops smoking.

SEARCH STRATEGY

We searched the Cochrane Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Science Citation Index, CINAHL, PsychLit, Dissertation Abstracts, BIDS ISI Index to Scientific and Technical Proceedings, UK National Research Register from the start of each database. Sixty-one large international cohort studies of cardiovascular disease were identified, and contact made with authors to search for any unpublished results. The search was supplemented by cross-checking references and contact with various experts. Date of last search was April 2003.

SELECTION CRITERIA

Any prospective cohort studies of patients with a diagnosis of CHD, which include all-cause mortality as an outcome measure. Smoking status must be measured on at least two occasions to ascertain which smokers have quit, and followed-up for at least two years.

DATA COLLECTION AND ANALYSIS

Eligibility and trial quality were assessed independently by two reviewers.

MAIN RESULTS

Twenty studies were included. There was a 36% reduction in crude relative risk (RR) of mortality for those who quit smoking compared with those who continued to smoke (RR 0.64, 95% confidence interval 0.58 to 0.71). There was also a reduction in non-fatal myocardial infarctions (crude RR 0.68, 95% confidence interval 0.57 to 0.82). Many studies did not adequately address quality issues, such as control of confounding, and misclassification of smoking status. However, there was little difference in the results for the six 'higher quality' studies, and little heterogeneity between these studies. This review was not able to assess how quickly the risk of mortality was reduced.

REVIEWER'S CONCLUSIONS

Quitting smoking is associated with a substantial reduction in risk of all-cause mortality among patients with CHD. The pooled crude RR was 0.64 (95% CI 0.58 to 0.71). This 36% risk reduction appears substantial compared with other secondary preventive therapies such as cholesterol lowering which have received greater attention in recent years. The risk reduction associated with quitting smoking seems consistent regardless of differences between the studies in terms of index cardiac events, age, sex, country, and time period. However, relatively few studies have included large numbers of older people, women, or people of non-European descent, and most were carried out in Western countries.

Hospital- and clinic-based smoking cessation interventions for smokers with cardiovascular disease

Cigarette smoking is the leading preventable cause of death in the United States and a major risk factor for cardiovascular disease (CVD). Large observational epidemiologic studies conducted in diverse populations have demonstrated a strong association between smoking and CVD morbidity and mortality. Observational epidemiologic studies have also demonstrated a substantial benefit of smoking cessation on cardiovascular morbidity and mortality. Smoking cessation after myocardial infarction reduces subsequent cardiovascular mortality by nearly 50%. Therefore, the use of effective strategies to reduce the prevalence of tobacco use is a high priority for both the primary and secondary prevention of CVD. Effective smoking cessation interventions have been identified in randomized controlled trials in the general population of smokers. These methods, which include behavioral counseling and pharmacotherapy, are incorporated into clinical practice guidelines for physicians in the United States and Great Britain. A smaller but still substantial body of evidence demonstrates the efficacy of these interventions in hospital- and clinic-based settings for smokers with CVD. This evidence is sufficient to support the routine implementation of these smoking cessation methods in inpatient and outpatient settings for smokers with CVD.

Smoking cessation for the secondary prevention of coronary heart disease

BACKGROUND

Although the importance of smoking as a risk factor for coronary heart disease is beyond doubt, the speed and magnitude of risk reduction when a smoker with coronary heart disease quits are still subjects of debate.

OBJECTIVES

To estimate the magnitude of risk reduction when a patient with CHD stops smoking.

SEARCH STRATEGY

We searched the Cochrane Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Science Citation Index, CINAHL, PsychLit, Dissertation Abstracts, BIDS ISI Index to Scientific and Technical Proceedings, UK National Research Register from the start of each database. Sixty-one large international cohort studies of cardiovascular disease were identified, and contact made with authors to search for any unpublished results. The search was supplemented by cross-checking references and contact with various experts. Date of last search was April 2003.

SELECTION CRITERIA

Any prospective cohort studies of patients with a diagnosis of CHD, which include all-cause mortality as an outcome measure. Smoking status must be measured on at least two occasions to ascertain which smokers have quit, and followed-up for at least two years.

DATA COLLECTION AND ANALYSIS

Eligibility and trial quality were assessed independently by two reviewers.

MAIN RESULTS

Twenty studies were included. There was a 36% reduction in crude relative risk (RR) of mortality for those who quit smoking compared with those who continued to smoke (RR 0.64, 95% confidence interval 0.58 to 0.71). There was also a reduction in non-fatal myocardial infarctions (crude RR 0.68, 95% confidence interval 0.57 to 0.82). Many studies did not adequately address quality issues, such as control of confounding, and misclassification of smoking status. However, there was little difference in the results for the six 'higher quality' studies, and little heterogeneity between these studies. This review was not able to assess how quickly the risk of mortality was reduced.

REVIEWER'S CONCLUSIONS

Quitting smoking is associated with a substantial reduction in risk of all-cause mortality among patients with CHD. The pooled crude RR was 0.64 (95% CI 0.58 to 0.71). This 36% risk reduction appears substantial compared with other secondary preventive therapies such as cholesterol lowering which have received greater attention in recent years. The risk reduction associated with quitting smoking seems consistent regardless of differences between the studies in terms of index cardiac events, age, sex, country, and time period. However, relatively few studies have included large numbers of older people, women, or people of non-European descent, and most were carried out in Western countries.