Smoking and myocardial infarction case-fatality: hospital and population approach

Smoking and 10-year risk of cardiovascular and non-cardiovascular events after contemporary coronary stenting

The impact of smoking cessation on long-term clinical outcomes after contemporary percutaneous coronary intervention (PCI) is not well known. We estimated the association of smoking and smoking cessation on the 10-year risk of cardiovascular and non-cardiovascular events in patients after contemporary PCI in a multicenter retrospective cohort of all patients having PCI with second generation drug-eluting stents in the VA Healthcare System between 2008 and 2016. Smoking status, comorbidities and clinical outcomes were extracted from the medical record and the National Death Index. Hazard ratios and 95 % confidence intervals (HR, 95 %CI) were derived from Cox Proportional Hazards Models. Estimates of events prevented from smoking cessation were derived from the differences in absolute risks between subjects who smoked and had stopped smoking. Among 29,001 patients, 10,598 (36.5 %) were current smoking patients, 13,093 (45.1 %) were former smoking patients, and 5,310 (18.3 %) never smoked. Over 10 years, 7,806 (26.9 %) subjects died with non-cardiovascular deaths exceeding cardiovascular deaths. In multivariable models, current smoking was significantly associated with increased long-term risks of all-cause death (HR = 1.27, 95 %CI = 1.19, 1.36), myocardial infarction (HR = 1.32, 95 %CI = 1.21-1.43), cancer death (HR = 2.55, 95 % CI = 2.10, 3.08), and pulmonary death (HR = 4.07, 95 % CI = 2.85, 5.83). Smoking cessation may prevent 18.5 % (95 %CI = 16.0 %, 20.9 %) all-cause deaths, 14.8 % (95 %CI = 9.8 %, 19.6 %) cardiovascular deaths, 42.6 % (95 %CI = 37.7 %, 47.2 %) cancer deaths, and 48.3 % (95 %CI = 41.8 %, 54.2 %) pulmonary deaths among smokers. Stopping smoking will likely have major impacts on non-cardiovascular events as well as cardiovascular events in patients after PCI with second generation drug-eluting stents.

The Smoker's Paradox Revisited: A Patient-Level Pooled Analysis of 18 Randomized Controlled Trials

OBJECTIVES

This study examined the smoker's paradox using patient-level data from 18 prospective, randomized trials of patients undergoing percutaneous coronary intervention (PCI) with stent implantation.

BACKGROUND

Studies on the effects of smoking and outcomes among patients undergoing PCI have reported conflicting results.

METHODS

Data from the RAVEL, E-SIRIUS, SIRIUS, C-SIRIUS, TAXUS IV and V, ENDEAVOR II to IV, SPIRIT II to IV, HORIZONS-AMI, COMPARE I and II, PLATINUM, and TWENTE I and II randomized trials were pooled. Patients were stratified by smoking status at time of enrollment. The 1- and 5-year ischemic outcomes were compared.

RESULTS

Among 24,354 patients with available data on smoking status, 6,722 (27.6%) were current smokers. Smokers were younger and less likely to have diabetes mellitus; hypertension; hyperlipidemia; or prior myocardial infarction (MI), PCI, or coronary artery bypass grafting. Angiographically, smokers had longer lesions, more complex lesions, and more occlusions, but were less likely to have moderate or severe calcification or tortuosity. At 5 years, smokers had significantly higher rates of MI (7.8% vs. 5.6%; p < 0.0001) and definite or probable stent thrombosis (3.5% vs. 1.8%; p < 0.0001); however, there were no differences in the rates of death, cardiac death, target lesion revascularization, or composite endpoints (cardiac death, target vessel MI, or ischemic target lesion revascularization). After multivariable adjustment for potential confounders, smoking was a strong independent predictor of death (hazard ratio [HR]: 1.86; 95% confidence interval [CI]: 1.63 to 2.12; p < 0.0001), cardiac death (HR: 1.68; 95% CI: 1.38 to 2.05; p < 0.0001), MI (HR: 1.38; 95% CI: 1.20 to 1.58; p < 0.0001), stent thrombosis (HR: 1.60; 95% CI: 1.28 to 1.99; p < 0.0001), and target lesion failure (HR: 1.17; 95% CI: 1.05 to 1.30; p = 0.005).

CONCLUSIONS

The present large, patient-level, pooled analysis with 5-year follow-up clearly demonstrates smoking to be an important predictor of adverse outcomes after PCI.

Association between smoking and in-hospital mortality in patients with acute myocardial infarction: results from a prospective, multicentre, observational study in China

INTRODUCTION

Smoking is a well-established risk factor for cardiovascular disease. However, the effect of smoking on in-hospital mortality in patients with acute myocardial infarction (AMI) who are managed by contemporary treatment is still unclear.

METHODS

A cohort study was conducted using data from the China AMI registry between 2013 and 2016. Eligible patients were diagnosed with AMI in accordance with the third universal definition of MI. Propensity score (PS) matching and multivariable logistic regression were used to control for confounders. Subgroup analysis was performed to examine whether the association between smoking and in-hospital mortality varies according to baseline characteristics.

RESULTS

A total of 37 614 patients were included. Smokers were younger and more frequently men with fewer comorbidities than non-smokers. After PS matching and multivariable log regression analysis were performed, the difference in in-hospital mortality between current smokers versus non-smokers was reduced, but it was still significant (5.1% vs 6.1%, p=0.0045; adjusted OR 0.78, 95% CI 0.69 to 0.88, p<0.001). Among all subgroups, there was a trend towards lower in-hospital mortality in current or ex-smokers compared with non-smokers.

CONCLUSIONS

Smoking is associated with lower in-hospital mortality in patients with AMI, even after multiple analyses to control for potential confounders. This 'smoker's paradox' cannot be fully explained by confounding alone.

TRIAL REGISTRATION NUMBER

NCT01874691.

The impact of cigarette smoking on infarct location and in-hospital outcome following acute ST-elevation myocardial infarction

Introduction: Smoking, which is a major modifiable risk factor for coronary artery diseases, affects cardiovascular system with different mechanisms. We designed this study to investigate the association of smoking with location of ST-segment elevation myocardial infarction (STEMI), and short-term outcomes during hospitalization. Methods: In 1017 consecutive patients with anterior/inferior STEMI, comprehensive demographic, biochemical data, as well as clinical complications and mortality rate, were recorded. Patients were allocated into two groups based on smoking status and compared regarding the location of myocardial infarction, the emergence of clinical complications and in-hospital mortality in univariate and multivariate logistic regression analysis. Results: Among 1017 patients, 300 patients (29.5%) were smoker and 717 patients (70.5 %) were non-smoker. Smokers were significantly younger and had lower prevalence of diabetes, hyperlipidemia and hypertension. Inferior myocardial infarction was considerably more common in smokers than in non-smokers (45.7% vs. 36%, P = 0.001). Heart failure was developed more commonly in non-smokers (33.9% vs. 20%, P = 0.001). In-hospital mortality was significantly lower in smokers (6.7% vs. 17.3%, P = 0.001). After adjustment for confounding variables, smoking was independently associated with inferior myocardial infarction and lower heart failure [odds ratio: 1.44 (1.06-1.96), P = 0.01 and odds ratio: 0.61 (0.40-0.92), P = 0.02, respectively]. However, in-hospital mortality was not associated with smoking after adjustment for other factors [odds ratio: 0.69 (0.36-1.31), P = 0.2]. Conclusion: Smoking is independently associated with inferior myocardial infarction. Although smokers had lower incidence of heart failure, in-hospital mortality was not different after adjustment for other factors.

Meta-Analysis Comparing Outcomes of Smokers Versus Nonsmokers With Acute Coronary Syndrome Underwent Percutaneous Coronary Intervention

Several studies have found improved mortality in smokers after acute coronary syndrome (ACS) especially in the thrombolytic era. We aimed to assess the association of smoking status with mortality and cardiovascular outcomes in patients with ACS treated with percutaneous coronary intervention (PCI). We searched PubMed, EMBASE, CINAHL, and Cochrane CENTRAL for randomized controlled trials since inception through February 15, 2018 and used random effects model for analysis. The outcomes analyzed were all-cause mortality, major adverse cardiac events (MACE), myocardial infarction, and target vessel revascularization at 1 month and 1 year. We included 17 randomized and nonrandomized studies with a total of 55,491 patients with 21,989 smokers' and 33,502 nonsmokers. In ACS patients treated with PCI, smokers were found to have lower mortality than nonsmokers at 30-day ([2.3% vs 3.3%; Odds ratio; 0.54; 95% confidence interval: 0.39 to 0.76; p <0.001, I² = 74%] and 1-year [2.3% vs 3.6%; Odds ratio 0.54 (0.3 to 0.7); p <0.001, I² = 77%]. Meta-regression showed lower mortality in smokers was associated with younger age, man gender, and lower prevalence of diabetes mellitus. No significant differences were observed in myocardial infarction, MACE, and target-vessel revascularization between smokers and nonsmokers. In conclusion, smoking is associated with lower mortality but not MACE in ACS patients treated with PCI at 1-month and 1-year. This association with mortality was strongly associated with younger age, man gender, prevalence of diabetes mellitus, and extent of coronary artery disease.

Change in left ventricular systolic function in patients with ST elevation myocardial infarction: Evidence for smoker's paradox or pseudo-paradox?

Background

The ‘smoker's paradox’ refers to the observation of favorable prognosis in current smokers following an acute ST elevation myocardial infarction (STEMI) in the era of fibrinolysis, however, several STEMI studies have demonstrated conflicting results in patients undergoing primary percutaneous coronary intervention (p-PCI).

Objective

Aim of the current study was to evaluate the impact of cigarette smoking on left ventricular function in STEMI patients undergoing p-PCI.

Methods

Our population is represented by 74 first-time anterior STEMI patients undergoing p-PCI, 37 of whom were smokers. We assessed left ventricular function by left ventricular ejection fraction (LVEF) on the second day after admission and at 3-month follow-up. Early predictors of adverse left ventricular remodelling after STEMI treated by p-PCI were examined.

Results

Basal demographics and comorbidities were similar between groups. Although the LVEF during the early phase was higher in smokers compared to non-smokers (44.95 ± 7.93% vs. 40.32 ± 7.28%; p = 0.011); it worsened in smokers at follow-up (mean decrease in LVEF: −2.70 ± 5.95%), whereas it improved in non-smokers (mean recovery of LVEF: +2.97 ± 8.45%). In univariate analysis, diabetes mellitus, peak troponin I, current smoking, and lower TIMI flow grade after p-PCI, pain-to-door time and door-to-balloon times were predictors of adverse left ventricular remodelling. After multivariate logistic regression analysis, smoking at admission, lower TIMI flow grade after p-PCI, the pain-to-door time and door-to-balloon times remained independent predictors of deterioration in LVEF.

Conclusion

True or persistent ‘smoker's paradox’ does not appear to be relevant among STEMI patients undergoing p-PCI. The ‘smoker's paradox’ is in fact a pseudo-paradox. Further studies with larger numbers may be warranted.

Prevalence and outcome of cigarette and waterpipe smoking among patients with acute coronary syndrome in six Middle-Eastern countries

OBJECTIVE

We evaluated the prevalence and effect of cigarette smoking (CS) and waterpipe (WP) smoking on patients with acute coronary syndrome (ACS) in six Middle-Eastern countries.

METHODS

Analysis of the Gulf Registry of Acute Coronary Events (Gulf RACE) survey, which included 6704 consecutive patients hospitalized with ACS, was made and patients were divided into four groups depending on whether they were smokers - cigarette-CS, waterpipe-WS, combined cigarette and waterpipe (CW) - or non-smokers (NS).

RESULTS

Overall 38% of patients were smokers; 4.4% of patients were waterpipe smokers (1.4% WS and 3% CW). When compared to the three smokers' groups, non-smokers were older. Overall, smokers had fewer cardiovascular risk factors when compared to NS. ST-segment elevation myocardial infarction was more common among nicotine smokers (CS 54.4%, WS 57.3%, 47.3% CW vs 30% NS, p = 0.001) while NS were more likely to have non-ST elevation ACS. Cigarette (and not waterpipe) smokers were more likely to present early and with typical symptoms when compared to NS and WS. Admission heart rate and blood pressures were higher in the non-smoker group and WS. Non-smokers and WS were also more likely to present with Killip class >1. After adjustment for baseline variables, smoking was not an independent predictor of adverse cardiac events.

CONCLUSION

Cigarette smoking is prevalent among Middle-Eastern patients presenting with acute coronary syndrome. Waterpipe smoking use is low; however it is relatively more frequent in women when compared to cigarette smoking. The current study underscores the need for further studies into the effects of different forms of nicotine smoking.

The "smoker's paradox" in patients with acute coronary syndrome: a systematic review

BACKGROUND

Smokers have been shown to have lower mortality after acute coronary syndrome than non-smokers. This has been attributed to the younger age, lower co-morbidity, more aggressive treatment and lower risk profile of the smoker. Some studies, however, have used multivariate analyses to show a residual survival benefit for smokers; that is, the "smoker's paradox". The aim of this study was, therefore, to perform a systematic review of the literature and evidence surrounding the existence of the "smoker's paradox".

METHODS

Relevant studies published by September 2010 were identified through literature searches using EMBASE (from 1980), MEDLINE (from 1963) and the Cochrane Central Register of Controlled Trials, with a combination of text words and subject headings used. English-language original articles were included if they presented data on hospitalised patients with defined acute coronary syndrome, reported at least in-hospital mortality, had a clear definition of smoking status (including ex-smokers), presented crude and adjusted mortality data with effect estimates, and had a study sample of > 100 smokers and > 100 non-smokers. Two investigators independently reviewed all titles and abstracts in order to identify potentially relevant articles, with any discrepancies resolved by repeated review and discussion.

RESULTS

A total of 978 citations were identified, with 18 citations from 17 studies included thereafter. Six studies (one observational study, three registries and two randomised controlled trials on thrombolytic treatment) observed a "smoker's paradox". Between the 1980s and 1990s these studies enrolled patients with acute myocardial infarction (AMI) according to criteria similar to the World Health Organisation criteria from 1979. Among the remaining 11 studies not supporting the existence of the paradox, five studies represented patients undergoing contemporary management.

CONCLUSION

The "smoker's paradox" was observed in some studies of AMI patients in the pre-thrombolytic and thrombolytic era, whereas no studies of a contemporary population with acute coronary syndrome have found evidence for such a paradox.

[Body mass index in the prognosis of first myocardial infarction]

BACKGROUND AND OBJECTIVES

The value of body mass index in the prognosis of patients with ischemic heart disease is not well defined. The objective of our study was to determine the association of body mass index with classic and emergent cardiovascular risk factors and with intra-hospital and 6-months mortality.

PATIENTS AND METHODS

We conducted a prospective, multicenter study with a 6-months follow-up. We included 1063 patients between the ages of 25-75 years old who were consecutively admitted to the hospital within the first 24 hours of the onset of symptoms between years 2001 and 2003. We determined demographic and anthropometric variables, as well as classic and emergent factors of risk, clinical variables and the treatment administered. We carried out a univariate and multivariate analysis.

RESULTS

The percentage of patients with overweight or obesity in this population was 73.56%. Overweight and obesity were associated with classical risk factors, except for smoking, and emergent risk factors. Body mass index was not associated with short-or mid-term prognosis.

CONCLUSIONS

Body mass index is not a useful anthropometric measure to determine the prognosis of patients after a first myocardial infarction.

Percutaneous coronary intervention, comorbidities, and mortality among emergency department-admitted ST-elevation myocardial infarction patients in Florida

BACKGROUND

Risk of mortality following an ST-elevation myocardial infarction (STEMI) can be significantly reduced by prompt percutaneous coronary intervention (PCI). National guidelines specify primary PCI as the preferred recommended treatment for STEMI. In this study, we examined same-day PCI as an independent predictor of in-hospital mortality, after adjustment for comorbidities, other patient factors, and hospital PCI-volume using unselected surveillance data from Florida.

METHODS

We analyzed hospital discharge data for adults, 18+ years old, with a primary diagnosis of STEMI who were admitted to PCI-capable hospitals through the emergency department during 2001-2005 (n = 43,849). Hierarchical (multilevel) logistic regression models were used for analysis.

RESULTS

Overall, 4,143 STEMI patients (9.4%) did not survive to hospital discharge. In late 2005, the in-hospital mortality rates were 1.9% for those who received same-day PCI versus 13.0% for those who did not. After adjustment for multiple patient factors, same-day PCI was a significant predictor of in-hospital survival with a strong protective effect (adjusted OR = 0.35, 95% CI 0.31-0.38 P < 0.0001). Restriction of the analysis to those patients who survived the first day of admission did not appreciably change this result (adjust OR = 0.37, 95% CI 0.33-0.42, P < 0.0001). Hospital PCI-volume did not significantly impact mortality risk.

CONCLUSIONS

Same-day PCI markedly reduced the risk of in-hospital mortality among STEMI patients after multivariate adjustment. Serious comorbidities and complications, older age, and female gender continued to predict elevated risk of mortality after control for treatment status. Our results provide additional evidence in support of national clinical recommendations and aggressive treatment of STEMI.