Life-years gained by smoking cessation after percutaneous coronary intervention

Smoking cessation for secondary prevention of cardiovascular disease

BACKGROUND

Smoking is a leading cause of cardiovascular disease (CVD), particularly coronary heart disease (CHD). However, quitting smoking may prevent secondary CVD events in people already diagnosed with CHD.  OBJECTIVES: To examine the impact of smoking cessation on death from CVD and major adverse cardiovascular events (MACE), in people with incident CHD.

SEARCH METHODS

We searched the Cochrane Tobacco Addiction Group's Specialised Register, CENTRAL, MEDLINE, Embase, Cumulative Index to Nursing and Allied Health Literature, and the trials registries clinicaltrials.gov and the International Clinical Trials Registry Platform. We ran all searches from database inception to 15 April 2021.  SELECTION CRITERIA: We included cohort studies, and both cluster- and individually randomised controlled trials of at least six months' duration. We treated all included studies as cohort studies and analysed them by smoking status at follow-up. Eligible studies had to recruit adults (> 18 years) with diagnosed CHD and who smoked tobacco at diagnosis, and assess whether they quit or continued smoking during the study. Studies had to measure at least one of our included outcomes with at least six months' follow-up. Our primary outcomes were death from CVD and MACE. Secondary outcomes included all-cause mortality, non-fatal myocardial infarction, non-fatal stroke, new-onset angina and change in quality of life.  DATA COLLECTION AND ANALYSIS: We followed standard Cochrane methods for screening and data extraction.  We assessed the risk of bias for the primary outcomes using the ROBINS-I tool. We compared the incidence of death from CVD and of MACE (primary outcomes) between participants who quit smoking versus those who continued to smoke for each included study that reported these outcomes. We also assessed differences in all-cause mortality, incidence of non-fatal myocardial infarction, incidence of non-fatal stroke and new onset angina. We calculated hazard ratios (HRs) and 95% confidence intervals (95% CI). For our outcome, change in quality of life, we calculated the pooled standardised mean difference (SMD) and 95% CI for the difference in change in quality of life from baseline to follow-up between those who had quit smoking and those who had continued to smoke. For all meta-analyses we used a generic inverse variance random-effects model and quantified statistical heterogeneity using the I²statistic. We assessed the certainty of evidence for our primary outcomes using the eight GRADE considerations relevant to non-randomised studies.

MAIN RESULTS

We included 68 studies, consisting of 80,702 participants. For both primary outcomes, smoking cessation was associated with a decreased risk compared with continuous smoking: CVD death (HR 0.61, 95% CI 0.49 to 0.75; I² = 62%; 18 studies, 17,982 participants; moderate-certainty evidence) and MACE (HR 0.57, 95% CI 0.45 to 0.71; I² = 84%; 15 studies, 20,290 participants; low-certainty evidence). These findings were robust to our planned sensitivity analyses. Through subgroup analysis, for example comparing adjusted versus non-adjusted estimates, we found no evidence of differences in the effect size. While there was substantial heterogeneity, this was primarily in magnitude rather than the direction of the effect estimates. Overall, we judged 11 (16%) studies to be at moderate risk of bias and 18 (26%) at serious risk, primarily due to possible confounding. There was also some evidence of funnel plot asymmetry for MACE outcomes. For these reasons, we rated our certainty in the estimates for CVD death as moderate and MACE as low.  For our secondary outcomes, smoking cessation was associated with a decreased risk in all-cause mortality (HR 0.60, 95% CI 0.55 to 0.66; I² = 58%; 48 studies, 59,354 participants), non-fatal myocardial infarction (HR 0.64, 95% CI 0.58 to 0.72; I² = 2%; 24 studies, 23,264 participants) and non-fatal stroke (HR 0.70, 95% CI 0.53 to 0.90; I² = 0%; 9 studies, 11,352 participants). As only one study reported new onset of angina, we did not conduct meta-analysis, but this study reported a lower risk in people who stopped smoking. Quitting smoking was not associated with a worsening of quality of life and suggested improvement in quality of life, with the lower bound of the CI also consistent with no difference (SMD 0.12, 95% CI 0.01 to 0.24; I² = 48%; 8 studies, 3182 participants).  AUTHORS' CONCLUSIONS: There is moderate-certainty evidence that smoking cessation is associated with a reduction of approximately one-third in the risk of recurrent cardiovascular disease in people who stop smoking at diagnosis. This association may be causal, based on the link between smoking cessation and restoration of endothelial and platelet function, where dysfunction of both can result in increased likelihood of CVD events.  Our results provide evidence that there is a decreased risk of secondary CVD events in those who quit smoking compared with those who continue, and that there is a suggested improvement in quality of life as a result of quitting smoking. Additional studies that account for confounding, such as use of secondary CVD prevention medication, would strengthen the evidence in this area.

Smoking behavior after coronary artery bypass surgery: Quit, relapse, continuing

Objective:

Tobacco smoking represents a major risk factor for coronary artery disease. Our study aimed to investigate whether Coronary Artery Bypass Graft (CABG) surgery could act as a motivating factor to enforce smoking cessation. Specifically, we observed the success rate in individuals who quitted smoking, along with the number and reasons of relapse(s) at least one year after the operation.

Methods:

The pre-operative characteristics, pre-operative tobacco exposure, socioeconomic factors and perioperative complications in patients who underwent isolated Coronary Artery Bypass Graft surgery in our Department from June 2012 to September 2016 were reviewed. Our survey was conducted via phone interview and using a standardized questionnaire. Only patients who were current smokers at the time of surgery were interviewed.

Results:

Our study group consisted of a total of 120 patients, 91 (75.8%) reported initially quitting tobacco smoking. Because of relapse(s), one year after the procedure the number of patients who were still non-smokers dropped to 69 (57.5%). Smoking cessation attempts were not supported by professional assistance.

Conclusions:

Our findings demonstrate that there is a desire from CABG patients to quit smoking, as indicated by the high percentage of initial attempts in early postoperative period. However, a year after the procedure, only 57.5% of CABG patients were able to achieve or maintain smoking cessation. Patients who were retired or who were unemployed at the time of the surgery, found it easier to stop smoking than patients who were active employees. Patients who lived alone at the time of surgery also found it harder to stop smoking. Finally, patients with COPD also found quitting smoking harder in the post-operative period.

The Role of Diabetes Mellitus as an Effect Modifier of the Association Between Smoking Cessation and Its Clinical Prognoses: An Observational Cohort Study

The smoker's paradox refers to an increased risk of adverse clinical outcomes after smoking cessation in patients with coronary artery disease. The mechanisms involved are controversial. The present study evaluated the effect of delay in smoking cessation on clinical outcomes among patients after percutaneous coronary intervention (PCI) stratified by diabetes mellitus (DM). Patients included in this study came from an established Fu Wai hospital PCI cohort. Smoking behavior was recorded; clinical end points included all-cause mortality and repeat revascularization. The analyses were based on 8489 smokers who underwent PCI. Patients with and without DM were examined separately. Multivariable model analysis suggested that smoking cessation was associated with significant lower all-cause mortality both for non-DM and DM patients. The smoking paradox was observed for revascularization. However, the increased risk of repeat revascularization correlated with quitting time among non-DM patients only, especially if they stopped smoking late (>90 days) after their index procedure (adjusted hazard ratio, 3.40; 95% CI: 2.45-4.72). In conclusion, smoking cessation is associated with a lower mortality rate for PCI patients. However, the relative benefit on repeated revascularization was only observed among non-DM patients if they quit smoking early.

Smoking cessation and risk of recurrent cardiovascular events and mortality after a first manifestation of arterial disease

AIMS

To quantify the relation between smoking cessation after a first cardiovascular (CV) event and risk of recurrent CV events and mortality.

METHODS

Data were available from 4,673 patients aged 61 ± 8.7 years, with a recent (≤1 year) first manifestation of arterial disease participating in the SMART-cohort. Cox models were used to quantify the relation between smoking status and risk of recurrent major atherosclerotic cardiovascular events (MACE including stroke, MI and vascular mortality) and mortality. In addition, survival according to smoking status was plotted, taking competing risk of non-vascular mortality into account.

RESULTS

A third of the smokers stopped after their first CV event. During a median of 7.4 (3.7-10.8) years of follow-up, 794 patients died and 692 MACE occurred. Compared to patients who continued to smoke, patients who quit had a lower risk of recurrent MACE (adjusted HR 0.66, 95% CI 0.49-0.88) and all-cause mortality (adjusted HR 0.63, 95% CI 0.48-0.82). Patients who reported smoking cessation on average lived 5 life years longer and recurrent MACE occurred 10 years later. In patients with a first CV event >70 years, cessation of smoking had improved survival which on average was comparable to former or never smokers.

CONCLUSIONS

Irrespective of age at first CV event, cessation of smoking after a first CV event is related to a substantial lower risk of recurrent vascular events and all-cause mortality. Since smoking cessation is more effective in reducing CV risk than any pharmaceutical treatment of major risk factors, it should be a key objective for patients with vascular disease.

Amputation-Free Survival in Patients With Diabetes Mellitus and Peripheral Arterial Disease With Heel Ulcer: Open Versus Endovascular Surgery

Background:

Heel ulcers in patients with diabetes mellitus (DM) and peripheral arterial disease (PAD) are hard to heal. The aim of the present study was to evaluate the difference in amputation-free survival (AFS) between open and endovascular revascularization in patients with DM, PAD, and heel ulcers.

Methods:

Retrospective comparative study of results of open versus endovascular surgery in patients with DM, PAD, and heel ulcer presented at the multidisciplinary diabetes foot clinic between 1983 and 2013.

Results:

Patients with heel ulcers were treated with endovascular intervention (n = 97) and open vascular surgery (n = 30). Kaplan-Meier analysis showed that the AFS was higher in patients undergoing open vascular surgery compared to the endovascular group ( P = .009). Multivariate analysis showed that open vascular surgery versus endovascular therapy (hazard ratio 2.1, 95% confidence interval 1.1-3.9; P = .025) was an independent factor associated with higher AFS. The proportion of patients undergoing endovascular therapy in the former (1983-2000) time period was 47% compared to 89% in the latter (2001-2013) time period ( P < .001).

Conclusion:

The AFS was higher after open than endovascular surgery among patients with DM and PAD with heel ulcer. These results suggest that open vascular surgery should be offered more often as opposed to current practice.

The long-term risk of smoking in diabetic patients with stable ischemic heart disease treated with intensive medical therapy and lifestyle modification

Introduction The long-term risk of smoking in diabetic patients with stable ischemic heart disease (SIHD) is unknown. We sought to analyze the impact of smoking on outcomes of diabetic patients with SIHD when other cardiovascular risk factors are being aggressively treated. Methods The Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial randomized 2368 diabetics with SIHD to intensive medical therapy (IMT) with prompt revascularization or IMT alone. Smoking status was obtained at baseline, 6 months, and 1, 2, 3, 4 and 5 years. The primary endpoint of interest was all-cause mortality. Results Of 2360 patients, 33.1% of patients never smoked, 54.4% were former smokers, and 12.5% were current smokers. The rate of all-cause mortality was greater for current (2.5 deaths/100 patient-years) and former smokers (3.1 deaths/100 patient-years) than never smokers (2.1 deaths/100 patient-years) (P = 0.007). Cardiac death, cardiovascular death, fatal or nonfatal myocardial infarction, and fatal or nonfatal stroke were not increased in current or former smokers compared with never smokers. Compared with never smokers, current smokers experienced a 49% increased hazard of death (Hazard Ratio (HR) 1.49, 95% Confidence Interval (CI): 0.97-2.29, P = 0.07) whereas former smokers had a 37% increased hazard of death (HR 1.37, 95% CI: 1.04-2.79, P = 0.02) when considering smoking status as a time-dependent variable and adjusting for factors that differed by smoking status. Conclusions Current and former smoking are associated with increased all-cause mortality in diabetics with SIHD but not with increased cardiovascular morbidity or mortality.

Cigarette Smoking, Reduction and Quit Attempts: Prevalence Among Veterans With Coronary Heart Disease

Introduction

Cigarette smoking increases the risk of illness and early death for people with coronary heart disease. In 2010, Brown estimated prevalence rates for smoking among veterans and nonveterans with or without coronary heart disease in the United States, based on the 2003 through 2007 data from the Behavioral Risk Factor Surveillance System (BRFSS). Recent changes in BRFSS methods promise more accurate estimates for veterans. To inform assessment of efforts to reduce smoking, we sought to provide prevalence rates for smoking behaviors among US veterans with coronary heart disease and to compare rates for veterans with those for civilians.

Methods

We conducted a cross-sectional analysis of participants who responded to BRFSS from 2009 to 2012. Accounting for complex BRFSS sampling, we estimated national prevalence rates by sex for smoking status, frequency, and quit attempts; for those with and those without coronary heart disease; for civilians; for veterans and active duty personnel combined; and, after adjusting for BRFSS mingling of active duty personnel and veterans, for veterans only. We examined differences between veterans and civilians by using age-standardized national estimates.

Results

Among men with coronary heart disease, more veterans than civilians smoked and more were daily smokers, but veterans were no more likely to attempt to quit. Among women with coronary heart disease, we found no differences between civilians and veterans.

Conclusion

Cigarette smoking is more prevalent among male veterans with coronary heart disease than among their civilian counterparts. Not distinguishing active duty personnel from veterans can materially affect prevalence estimates intended to apply solely to veterans.

Trends and predictors of smoking cessation after percutaneous coronary intervention (from Olmsted County, Minnesota, 1999 to 2010)

Smoke-free ordinance implementation and advances in smoking cessation (SC) treatment have occurred in the past decade; however, little is known about their impact on SC in patients with coronary artery disease. We conducted a retrospective cohort study of 2,306 consecutive patients from Olmsted County, Minnesota, who underwent their first percutaneous coronary intervention (PCI) from 1999 to 2009, and assessed the trends and predictors of SC after PCI. Smoking status was ascertained by structured telephone survey 6 and 12 months after PCI (ending in 2010). The prevalence of smoking in patients who underwent PCI increased nonsignificantly from 20% in 1999 to 2001 to 24% in 2007 to 2009 (p = 0.14), whereas SC at 6 months after PCI decreased nonsignificantly from 50% (1999 to 2001) to 49% (2007 to 2009), p = 0.82. The 12-month quit rate did not change significantly (48% in 1999 to 2001 vs 56% in 2007 to 2009, p = 0.38), even during the time periods after the enactment of smoke-free policies. The strongest predictor of SC at 6 months after PCI was participation in cardiac rehabilitation (odds ratio [OR] 3.17, 95% confidence interval [CI] 2.05 to 4.91, p <0.001), older age (OR 1.42 per decade, 95% CI 1.16 to 1.73, p <0.001), and concurrent myocardial infarction at the time of PCI (OR 1.77, 95% CI 1.18 to 2.65, p = 0.006). One-year mortality was lower in the group of smokers compared with never smokers (3% vs 7%, p <0.001). In conclusion, SC rates have not improved after PCI over the past decade in our cohort, despite the presence of smoke-free ordinances and improved treatment strategies. Improvements in delivery of systematic services aimed at promoting SC (such as cardiac rehabilitation) should be part of future efforts to improve SC rates after PCI.