The smoker's paradox: insights from the angiographic substudies of the TIMI trials

Preoperative smoking status and long-term survival after coronary artery bypass grafting: a competing risk analysis

OBJECTIVES

Patients with severe coronary artery disease who undergo coronary artery bypass grafting consistently demonstrate that continued smoking after surgery increases late mortality rates. Smoking may exert its harmful effects through the ongoing chronic process of atherosclerotic progression both in the grafts and the native system. However, it is not clear whether cardiac mortality is primary and solely responsible for the inferior late survival of current smokers.

METHODS

In this retrospective analysis, we included all consecutive patients undergoing primary isolated coronary artery bypass surgery from 1 January 2000 to 30 September 2015 in an Academic Hospital in Northern Portugal. The predictive or independent variable was the patients' smoking history status, a categorical variable with 3 levels: non-smoker (the comparator), ex-smoker for >1 year (exposure 1) and current smoker (exposure 2). The primary end point was long-term all-cause mortality. Secondary outcomes were long-term cause-specific mortality (cardiovascular and noncardiovascular). We fitted overall and Fine and Gray subdistribution hazard models.

RESULTS

We identified 5242 eligible patients. Follow-up was 99.7% complete (with 17 patients lost to follow-up). The median follow-up time was 12.79 years (interquartile range, 9.51-16.60). Throughout the study, there were 2049 deaths (39.1%): 877 from cardiovascular causes (16.7%), 727 from noncardiovascular causes (13.9%) and 445 from unknown causes (8.5%). Ex-smokers had an identical long-term survival than non-smokers [hazard ratio (HR) 0.99; 95% confidence interval (CI) 0.88, 1.12; P = 0.899]. Conversely, current smokers had a 24% increase in late mortality risk (HR 1.24; 95% CI 1.07, 1.44; P = 0.004) as compared to non-smokers. While the current smoker status increased the relative incidence of noncardiac death by 61% (HR 1.61; 95% CI 1.27, 2.05, P < 0.001), it did confer a 25% reduction in the relative incidence of cardiac death (HR 0.75; 95% CI 0.59, 0.97; P = 0.025).

CONCLUSIONS

Whereas ex-smokers have an identical long-term survival to non-smokers, current smokers exhibit an increase in late all-cause mortality risk at the expense of an increased relative incidence of noncardiac death. By subtracting the inciting risk factor, smoking cessation reduces the relative incidence of cardiac death.

Risk factors, clinical features, and outcomes of premature acute myocardial infarction

AIMS

To investigate the risk factors, clinical features, and prognostic factors of patients with premature acute myocardial infarction (AMI).

MATERIALS AND METHODS

A retrospective cohort study of patients with AMI included in data from the West China Hospital of Sichuan University from 2011 to 2019 was divided into premature AMI (aged < 55 years in men and < 65 years in women) and non-premature AMI. Patients' demographics, laboratory tests, Electrocardiography (ECG), cardiac ultrasound, and coronary angiography reports were collected. All-cause death after incident premature MI was enumerated as the primary endpoint.

RESULTS

Among all 8,942 AMI cases, 2,513 were premature AMI (79.8% men). Compared to the non-premature AMI group, risk factors such as smoking, dyslipidemia, overweight, obesity, and a family history of coronary heart disease (CHD) were more prevalent in the premature AMI group. The cumulative survival rate of patients in the premature AMI group was significantly better than the non-premature AMI group during a mean follow-up of 4.6 years (HR = 0.27, 95% CI 0.22-0.32, p < 0.001). Low left ventricular ejection fraction (LVEF) (Adjusted HR 3.00, 95% CI 1.85-4.88, P < 0.001), peak N-terminal pro-B-type natriuretic peptide (NT-proBNP) level (Adjusted HR 1.34, 95% CI 1.18-1.52, P < 0.001) and the occurrence of in-hospital major adverse cardiovascular and cerebrovascular events (MACCEs) (Adjusted HR 2.36, 95% CI 1.45-3.85, P = 0.001) were predictors of poor prognosis in premature AMI patients.

CONCLUSION

AMI in young patients is associated with unhealthy lifestyles such as smoking, dyslipidemia, and obesity. Low LVEF, elevated NT-proBNP peak level, and the occurrence of in-hospital MACCEs were predictors of poor prognosis in premature AMI patients.

CIGARETTE SMOKING IS ASSOCIATED WITH DECREASED MORTALITY IN CRITICALLY ILL TRAUMA PATIENTS

ABSTRACT

Background: Smoking may offer pathophysiologic adaptations that increase survivability in certain patients with cardiovascular disease. We sought to identify if smoking increases survivability in trauma patients, hypothesizing that critically ill trauma patients who smoke have a decreased risk of mortality compared with non-smokers. Methods: The Trauma Quality Improvement Program (2010-2016) database was queried for trauma patients with intensive care unit admissions. A multivariable logistic regression model was performed. Results: From the 630,278 critically ill trauma patients identified, 116,068 (18.4%) were current cigarette smokers. Critically ill trauma smokers, compared with non-smokers, had a higher rate of pneumonia (7.8% vs. 6.9%, P< 0.001) and lower mortality rate (4.0% vs. 8.0%, P< 0.001). After controlling for covariates, smokers had a decreased associated risk of mortality compared with non-smokers (OR = 0.55, CI = 0.51-0.60, P< 0.001), and no difference in the risk of major complications (OR = 0.98, CI = 0.931.03, P = 0.44). The same analysis was performed using age as a continuous variable with associated decreased risk of mortality (OR 0.57 (CI 0.53-0.62), P< 0.001). Conclusion: Critically ill trauma smokers had a decreased associated mortality risk compared with non-smokers possibly due to biologic adaptations such as increased oxygen delivery developed from smoking. Future basic science and translational studies are needed to pursue potential novel therapeutic benefits without the deleterious long-term side effects of smoking.

Correlation Between Smoking Paradox and Heart Rhythm Outcomes in Patients With Coronary Artery Disease Receiving Percutaneous Coronary Intervention

BACKGROUND

The effect of smoking on short-term outcomes among patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) is controversial. However, little is known about the impact of smoking on long-term outcomes in patients with stable coronary artery disease (CAD) who receive PCI.

METHODS

A total of 2,044 patients with stable CAD undergoing PCI were evaluated. They were divided into two groups according to smoking status (current smokers vs. non-smokers). Baseline characteristics, exposed risk factors, angiographic findings, and interventional strategies were assessed to compare the long-term clinical outcomes between groups. Predictors for myocardial infarction (MI), all-cause death, cardiovascular (CV) death, and repeated PCI procedures were also analyzed.

RESULTS

Compared with non-smokers, current smokers were younger and mostly male (both P < 0.01). They also had a lower prevalence of chronic kidney disease (CKD) and diabetes (both P < 0.01). Drugs including a P2Y12 receptor inhibitor of platelets (P2Y12 inhibitor), beta-blockers (BB), and statins were used more frequently in current smokers (P < 0.01, P < 0.01, P = 0.04, respectively). Freedom from all-cause death and CV death was lower in the non-smoker group (P < 0.001, P = 0.003, respectively). After adjustment, logistic regression revealed smoking was a major predictor for all-cause death and repeated PCI procedure [hazard ratio(HR): 1.71 and 1.46, respectively].

CONCLUSIONS

Smoker's paradox extends to long-term outcome in patients with stable CAD undergoing PCI, which is partially explained by differences in baseline characteristics. However, smoking strongly predicted all-cause mortality and repeated PCI procedures in patients with stable CAD undergoing PCI.

Effect of Smoking on Outcomes of Primary PCI in Patients With STEMI

BACKGROUND

Smoking is a well-established risk factor for ST-segment elevation myocardial infarction (STEMI); however, once STEMI occurs, smoking has been associated with favorable short-term outcomes, an observation termed the "smoker's paradox." It has been postulated that smoking might exert protective effects that could reduce infarct size, a strong independent predictor of worse outcomes after STEMI.

OBJECTIVES

The purpose of this study was to determine the relationship among smoking, infarct size, microvascular obstruction (MVO), and adverse outcomes after STEMI.

METHODS

Individual patient-data were pooled from 10 randomized trials of patients with STEMI undergoing primary percutaneous coronary intervention. Infarct size was assessed at median 4 days by either cardiac magnetic resonance imaging or technetium-99m sestamibi single-photon emission computed tomography. Multivariable analysis was used to assess the relationship between smoking, infarct size, and the 1-year rates of death or heart failure (HF) hospitalization and reinfarction.

RESULTS

Among 2,564 patients with STEMI, 1,093 (42.6%) were recent smokers. Smokers were 10 years younger and had fewer comorbidities. Infarct size was similar in smokers and nonsmokers (adjusted difference: 0.0%; 95% confidence interval [CI]: -3.3% to 3.3%; p = 0.99). Nor was the extent of MVO different between smokers and nonsmokers. Smokers had lower crude 1-year rates of all-cause death (1.0% vs. 2.9%; p < 0.001) and death or HF hospitalization (3.3% vs. 5.1%; p = 0.009) with similar rates of reinfarction. After adjustment for age and other risk factors, smokers had a similar 1-year risk of death (adjusted hazard ratio [adjHR]: 0.92; 95% CI: 0.46 to 1.84) and higher risks of death or HF hospitalization (adjHR: 1.49; 95% CI: 1.09 to 2.02) as well as reinfarction (adjHR: 1.97; 95% CI: 1.17 to 3.33).

CONCLUSIONS

In the present large-scale individual patient-data pooled analysis, recent smoking was unrelated to infarct size or MVO, but was associated with a worse prognosis after primary PCI in STEMI. The smoker's paradox may be explained by the younger age and fewer cardiovascular risk factors in smokers compared with nonsmokers.

Impact of smoking on all-cause mortality and cardiovascular events in patients after coronary revascularization with a percutaneous coronary intervention or coronary artery bypass graft: a systematic review and meta-analysis

Although cigarette smoking is an independent risk factor for cardiovascular disease, inconsistent results have been published in the literature on its impacts on the cardiovascular health of patients after coronary revascularization with a percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG). We performed a comprehensive electronic database search through July 2018. Studies reporting the risk estimates of all-cause mortality and cardiovascular outcomes in patients after coronary revascularization with PCI or CABG on the basis of smoking status were selected. Multivariate-adjusted relative risks (RRs) and 95% confidence intervals (CIs) were pooled using random-effects models with inverse variance weighting. Data from 37 records including 126 901 participants were finally collected. Overall, the pooled RR (95% CI) associated with cigarette smoking was 1.26 (95% CI: 1.09-1.47) for all-cause mortality, 1.08 (95% CI: 0.92-1.28) for major adverse cardiovascular events, 0.96 (95% CI: 0.69-1.35) for cardiovascular mortality and 1.15 (95% CI: 0.81-1.64) for myocardial infarction. The increased risk of all-cause mortality was also observed in former smokers compared with those who had never smoked (RR: 1.19; 95% CI: 1.03-1.38). Furthermore, the negative effects of cigarette smoking on all-cause mortality were also observed in most subgroups. Cigarette smoking has been shown to increase the likelihood of all-cause mortality in patients after coronary revascularization with PCI or CABG. Smoking cessation is essential for PCI or CABG patients to manage their coronary artery disease.

Outcomes After Left Main Coronary Artery Revascularization by Percutaneous Coronary Intervention or Coronary Artery Bypass Grafting According to Smoking Status

Cigarette smoking is a well-known risk factor for coronary artery disease (CAD). However, the impact of smoking on outcomes after coronary revascularization, especially in patients with left main CAD (LMCAD) is less well understood. The EXCEL trial randomized 1,905 patients with LMCAD and visually assessed low or intermediate anatomical complexity (SYNTAX score ≤32) to PCI with everolimus-eluting stents or CABG. Patients were categorized according to smoking status (current, former, or never), and their outcomes at 5 years were compared by logistic regression with follow-up time included as a log-transformed offset variable. The primary endpoint was a composite of death, myocardial infarction, or stroke. Among 1893 patients with known smoking status at baseline, 416 (22%) were current smokers and 774 (41%) were former smokers. The crude rates of the primary endpoint were 19.5% for never smokers, 20.5% for former smokers (p = 0.61 vs never smokers), and 23.1% for smokers (p = 0.15 vs never smokers). Compared with never smokers, the adjusted risk of the primary endpoint was higher for current smokers (adjOR 1.82, 95% confidence interval [CI] 1.126 to 2.63; p = 0.001), but not for former smokers (adjOR 1.00, 95% CI 0.75 to 1.33, p = 0.10). The relative efficacy of PCI versus CABG for the 5-year primary endpoint was similar irrespective of smoking status (P_interaction = 0.22). In conclusion, current smokers in the EXCEL trial had a higher adjusted 5-year risk of the primary composite endpoint of death, myocardial infarction, or stroke than never smokers, whereas former smokers were not at increased risk. Active smoking was a risk factor after LMCAD revascularization irrespective of revascularization method.

Smoking is associated with an improved short-term outcome in patients with rib fractures

BACKGROUND

Smokers with cardiovascular disease have been reported to have decreased mortality compared to non-smokers. Rib fractures are associated with significant underlying injuries such as lung contusions, lacerations, and/or pneumothoraces. We hypothesized that blunt trauma patients with rib fractures who are smokers have decreased ventilator days and risk of in-hospital mortality compared to non-smokers.

STUDY DESIGN

The Trauma Quality Improvement Program (2010-2016) was queried for patients presenting with a blunt rib fracture. Patients that died within 24 h of admission were excluded. A multivariable logistic regression model was performed.

RESULTS

From 282,986 patients with rib fractures, 57,619 (20.4%) were smokers. Compared to non-smokers with rib fractures, smokers had a higher median injury severity score (17 vs. 16, p < 0.001). Smokers had a higher rate of pneumonia (7.5% vs. 6.6%, p < 0.001), however, less ventilator days (5 vs. 6, p = 0.04), and lower in-hospital mortality rate (2.3% vs. 4.6%, p < 0.001), compared to non-smokers. After controlling for covariates, smokers with rib fractures were associated with a decreased risk for in-hospital mortality compared to non-smokers with rib fractures (OR 0.64, 0.56-0.73, p < 0.001).

CONCLUSION

Despite having more severe injuries and increased rates of pneumonia, smokers with rib fractures were associated with nearly a 40% decreased risk of in-hospital mortality and one less ventilator day compared to non-smokers. The long-term detrimental effects of smoking have been widely established. However, the biologic and pathophysiologic adaptations that smokers have may confer a survival benefit when recovering in the hospital from chest wall trauma. This study was limited by the database missing the number of pack-years smoked. Future prospective studies are needed to confirm this association and elucidate the physiologic mechanisms that may explain these findings.

Lung function impairment is not associated with the severity of acute coronary syndrome but is associated with a shorter stay in the coronary care unit

Background

Previous population-based studies have suggested that lung function impairment (LFI) could be associated with an increase in the mortality of cardiovascular events.

Methods

We evaluated the association between LFI and the severity and short-term prognosis of acute coronary syndrome (ACS). LFI was established through presence of a forced expiratory volume in one second (FEV1) and/or a forced vital capacity (FVC) less than 80% of predicted.

Results

Seventy-one LFI subjects (61.45±10.70 years, 83.10% males) and 247 non-LFI subjects (58.98±11.18 years, 80.57% males) with ACS were included. Subjects with LFI exhibited a higher prevalence of systemic hypertension (57.75% vs. 40.89%, P=0.02) and tobacco exposure (28.50±26.67 vs. 18.21±19.83 pack-years, P=0.007). No significant differences between groups were found regarding the severity of ACS (ejection fraction, Killip class, number of affected vessels, and peak plasma troponin). However, in comparison to non-LFI subjects, a significantly shorter length of stay in the coronary care unit (CCU) was observed in the LFI group (1.83±1.10 vs. 2.24±1.21 days, P=0.01) and this was even shorter in subjects with obstructive LFI (1.62±1.17 days, P=0.009). When considering obstructive sleep apnea (OSA), an interaction with length of stay was found, revealing that OSA subjects with obstructive LFI had the shortest length of stay in the CCU (0.60±0.89 days, P=0.05) also in comparison to non-LFI.

Conclusions

This study indicates a possible association between LFI and a shorter length of stay in the CCU but does not show a significant association with ACS severity.

Alpha-2-antiplasmin Arg407Lys polymorphism and cryptogenic ischemic cerebrovascular events: Association with neurological deficit

OBJECTIVE

Genetic background of cryptogenic ischemic stroke (IS) and transient ischemic attack (TIA) remains uncertain. Alpha-2-antiplasmin (α2AP) Arg407Lys polymorphism has been shown to be less common in patients with abdominal aortic aneurysm (AAA) compared with healthy controls. We investigated associations of α2AP Arg407Lys polymorphism with cryptogenic IS and TIA.

METHODS

We studied 165 consecutive Caucasian patients who experienced cryptogenic IS (n=123) or TIA (n=42). Neurological outcomes were assessed using the modified Rankin Scale (mRS) in the acute phase of cerebral ischemia and 8 (6-12) months after the index episode. Patients were genotyped for α2AP Arg407Lys polymorphism (rs1057335) using real time PCR technique.

RESULTS

The allele frequency of Arg407Lys polymorphism was: 0.82/0.18. The 407Lys allele was more frequent in TIA patients compared to the IS group (0.29 vs. 0.14, p=0.003). In the whole group, as well as in IS and TIA patients analyzed separately, possession of the 407Lys allele was associated with excellent outcome (mRS 0-1) during follow-up (p<0.05) but not in the acute phase of ischemic events both in thrombolyzed and nonthrombolyzed IS patients. The multivariate logistic regression model showed that the excellent outcome (mRS 0-1) assessed after 8 (6-12) months since the index cerebral ischemia was predicted by the occurrence of Lys407 allele (OR 6.18, 95% CI, 2.01-18.98, p=0.001).

CONCLUSION

The presence of 407Lys allele is associated with better prognosis in cryptogenic cerebrovascular events. Our findings suggest that the α2AP Arg407Lys polymorphism could be involved in the pathogenesis of cerebral ischemia and its outcomes.

White Blood Cell Count and Major Adverse Cardiovascular Events After Percutaneous Coronary Intervention in the Contemporary Era

Background—

Elevated white blood cell (WBC) count is associated with increased major adverse cardiovascular events (MACE) in the setting of acute coronary syndrome. The aim of this study was to evaluate whether similar associations persist in an all-comers population of patients undergoing percutaneous coronary intervention in the contemporary era.

Methods and Results—

In the multicenter, prospective, observational PARIS study (Patterns of Non-Adherence to Anti-Platelet Regimens in Stented Patients Registry), 4222 patients who underwent percutaneous coronary intervention in the United States and Europe between July 1, 2009, and December 2, 2010, were evaluated. The associations between baseline WBC and MACE (composite of cardiac death, stent thrombosis, spontaneous myocardial infarction, or target lesion revascularization) at 24-month follow-up were analyzed using multivariable Cox regression. Patients with higher WBC were more often younger, smokers, and with less comorbid risk factors compared with those with lower WBC. After adjustment for baseline and procedural characteristics, WBC remained independently associated with MACE (hazard ratio [HR] per 10 3 cells/μL increase, 1.05 [95% confidence intervals (CI), 1.02–1.09]; P =0.001), cardiac death (HR, 1.10 [95% CI, 1.05–1.17]; P <0.001), and clinically indicated target revascularization (HR, 1.04 [95% CI, 1.00–1.09]; P =0.03) but not stent thrombosis (HR, 1.07 [95% CI, 0.99–1.16]; P =0.10) or spontaneous myocardial infarction (HR, 1.03 [95% CI, 0.97–1.09]; P =0.29). The association between WBC and MACE was consistent in acute coronary syndrome and non–acute coronary syndrome presentations (interaction P =0.15).

Conclusions—

Increased WBC is an independent predictor of MACE after percutaneous coronary intervention in a contemporary all-comers cohort. Further studies to delineate the underlying pathophysiologic role of elevated WBC across a spectrum of coronary artery disease presentations are warranted.

Clinical Trial Registration—

URL: http://www.clinicaltrials.gov . Unique identifier: NCT00998127.

Effect of Smoking on Infarct Size and Major Adverse Cardiac Events in Patients With Large Anterior ST-Elevation Myocardial Infarction (from the INFUSE-AMI Trial)

We sought to investigate the effect of smoking on infarct size (IS) and major adverse cardiac events (MACE) in patients with large anterior ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention. Participants from the Intracoronary Abciximab and Aspiration Thrombectomy in Patients with Large Anterior Myocardial Infarction study were categorized according to smoking status (current or previous smoking vs no history of smoking). The primary imaging outcome was cardiac magnetic resonance imaging-assessed IS of left ventricular mass (%) at 30 days. The primary clinical outcome was the rate of MACE at 30 days and 1 year, defined as the composite of death, reinfarction, new-onset heart failure, or rehospitalization. Of 447 patients enrolled in Intracoronary Abciximab and Aspiration Thrombectomy in Patients with Large Anterior Myocardial Infarction, 271 (60.6%) were current or past smokers. Compared with nonsmokers, smokers were almost 10 years younger and had a lower prevalence of clinical co-morbidities. Smokers had better procedural success and angiographic reperfusion compared with nonsmokers. At 30 days, there were no differences between smokers and nonsmokers in median IS (16.8% vs 17.4%, p = 0.67) or metrics of left ventricular function. By multivariable linear regression analysis, smoking was not significantly associated with IS at 30 days (beta coefficient: 0.83, p = 0.42). At 1 year, smokers had lower crude rates of MACE (7.6% vs 15%, p = 0.01). After multivariable adjustment, there were no significant differences in 1-year MACE between smokers and nonsmokers (adjusted hazard ratio 0.73, 95% CI 0.40 to 1.33, p = 0.30). In conclusion, smoking history had no significant effect on IS at 30 days. Although current or previous smokers had lower rates of 1-year MACE than those with no history of smoking, adjustment for baseline characteristics rendered this association nonsignificant. These findings support the hypothesis that the smoker's paradox is largely attributable to differences in demographic and clinical baseline risk, rather than differences in IS after primary percutaneous coronary intervention.

Epidemiology and pathogenesis of diffuse obstructive coronary artery disease: the role of arterial stiffness, shear stress, monocyte subsets and circulating microparticles

Despite falling age-adjusted mortality rates coronary artery disease (CAD) remains the leading cause of death worldwide. Advanced diffuse CAD is becoming an important entity of modern cardiology as more patients with historical revascularisation no longer have suitable anatomy for additional procedures. Advances in the treatment of diffuse obstructive CAD are hampered by a poor understanding of its development. Although the likelihood of developing clinically significant (obstructive) CAD is linked to traditional risk factors, the morphology of obstructive CAD among individuals is highly variable - some patients have diffuse stenotic disease, while others have a focal stenosis. This is challenging to explain in mechanistic terms as vascular endothelium is equally exposed to injury stimulants. Patients with diffuse disease are at high risk of adverse outcomes, particularly if unsuitable for revascularisation. We searched multiple electronic databases (MEDLINE, EMBASE and the Cochrane Database) and reviewed the epidemiology, pathogenesis and prognosis relating to advanced diffuse CAD with particular focus on the role of endothelial shear stress, large artery stiffness, monocyte subsets and circulating microparticles. Key messages Although traditional CAD risk factors correlate strongly with disease severity, significant individual variation in disease morphology exists. Advanced, diffuse CAD is difficult to treat effectively and can significantly impair quality of life and increases mortality. The pathophysiology associated with the progression of CAD is the result of complex maladaptive interaction between the endothelium, cells of the immune system and patterns of blood flow.

Effect of Smoking Status on Clinical Outcome and Efficacy of Clopidogrel in Acute Coronary Syndrome

BACKGROUND

The "smoker's paradox" is an otherwise unexplained phenomenon in which the mortality of smokers after acute myocardial infarction is reduced, contrary to expectations. It has been suggested that an association with antiplatelet agents exists, but the true mechanism remains largely unidentified.

METHODS AND RESULTS

The analysis included 6,195 consecutive patients who underwent percutaneous coronary intervention (PCI) for acute coronary syndrome, registered in the Japanese multicenter PCI registry. Smokers were significantly younger and had less comorbidity than non-smokers. Unadjusted in-hospital mortality rate, general complication rate, and bleeding complication rate were lower in smokers than in non-smokers. After adjustment, the trend persisted and smoking was not associated with overall mortality (odds ratio [OR], 0.90; 95% confidence interval [CI]: 0.61-1.34; P=0.62), and was associated with lower overall (P=0.032) and bleeding complication events (P=0.040). Clopidogrel effectively reduced the occurrence of in-hospital complications and major adverse cardiac events in smokers compared with non-smokers (OR, 0.55; 95% CI: 0.53-0.98 vs. OR, 1.20; 95% CI: 0.87-1.67; and OR, 0.37; 95% CI: 0.20-0.70 vs. OR, 1.48; 95% CI: 0.90-2.43, respectively).

CONCLUSIONS

The smoker's paradox was largely explained by confounding factors related to the lower risk profile of smokers, and they benefited from a positive modification of the efficacy of clopidogrel. (Circ J 2016; 80: 1590-1599).

"Smoker's Paradox" in Patients Treated for Severe Injuries: Lower Risk of Mortality After Trauma Observed in Current Smokers

BACKGROUND

Studies evaluating the effect of smoking status on mortality outcomes in trauma patients have been limited, despite the fact that survival benefits of smoking have been reported in other critical care settings. The phenomenon "smoker's paradox" refers to the observation that following acute cardiovascular events, such as acute myocardial infarction and cardiac arrest, smokers often experience decreased mortality in the hospital setting. The objective of our study was to determine whether smoking imparts a survival benefit in patients with traumatic injuries.

METHODS

We performed a retrospective cohort study that analyzed cases included in the National Trauma Data Bank research dataset. Hierarchical logistic regression analyses were used to determine whether smoking alters the risk of mortality and complications in patients who smoke.

RESULTS

The percentage of patients experiencing mortality differed significantly between smokers (n = 38,564) and nonsmokers (n = 319,249) (1.8% vs. 4.3%, P < .001); however, the percentage experiencing a major complication did not (9.7% vs. 9.6%, P = .763). Regression analyses indicated that smokers were significantly less likely to die during the hospital stay compared to nonsmokers after adjusting for individual and hospital factors (OR = 0.15; CI = 0.10, 0.22). Additionally, smokers were also less likely to develop a major complication than nonsmokers (OR = 0.73, CI = 0.59-0.91).

CONCLUSIONS

Patients who smoke appear to have a much lower risk of in-hospital mortality than nonsmokers. Further investigation into biological mechanisms responsible for this effect should be carried out in order to potentially develop therapeutic applications.

Plasma Fibrinolysis Parameters in Smokers and Non-smokers of the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study

Cardiovascular diseases (CVD) are an important cause of morbidity and mortality worldwide. Parameters of coagulation and fibrinolysis are risk factors of CVD and might be affected by cigarette smoking. Aim of our study was to analyze the effect of cigarette smoking on parameters of fibrinolysis in active smokers (AS) and life-time non-smokers (NS) of the Ludwigshafen Risk and Cardiovascular Health (LURIC) Study as well as the use of these parameters for risk prediction. We determined plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator antigen (t-PA), protein C activity, and D-dimers in 3,316 LURIC patients. Smoking status was assessed by a questionnaire and measurement of plasma cotinine concentration. Cox regression was used to assess the effect of parameters on mortality. We found that of the 3,316 LURIC patients 777 were AS and 1,178 NS. Within the observation period of 10 years (median) 221 AS and 302 NS died. In male AS vs. NS, PAI-1 (19.0 (10.0-35.0) vs. 15.0 (9.0-29.0) U/ml; p=0.026) and t-PA antigen (12.7 (9.6-16.3) vs. 11.6 (8.9-14.6) μg/l; p=0.020) were slightly increased, while t-PA activity was slightly decreased (0.63 (0.30-1.05) vs. 0.68 (0.42-1.10) U/l; p=0.005). In female AS vs. NS, t-PA antigen (10.5 (8.3-13.9) vs. 11.5 (8.8-15.0) μg/l; p=0.025) and protein C (108.0±24.1% vs. 118.0±25.7%; p=0.004) were decreased. All parameters except for protein C were predictive for mortality in AS. Fully adjusted hazard ratios (95% CI) were 1.14 (1.04-1.25), 1.19 (1.06-1.34), and 1.29 (1.11-1.49) per 1SD increase for D-dimer, t-PA, and PAI-1, respectively. Including fibrinolysis parameters in risk prediction models for mortality improved the area-under-the-curve (AUC) significantly compared with the conventional risk factors. In conclusion, we found alterations in the fibrinolytic system in smokers, which were more pronounced in male AS. PAI-1, t-PA and D-dimers were significant predictors of mortality in AS in LURIC and should be included into the assessment of cardiovascular risk particularly in patients at risk.

Impact of cigarette smoking on extent of coronary artery disease and prognosis of patients with non-ST-segment elevation acute coronary syndromes: an analysis from the ACUITY Trial (Acute Catheterization and Urgent Intervention Triage Strategy)

OBJECTIVES

This study sought to evaluate the short- and long-term outcomes for smokers with non-ST-segment elevation acute coronary syndromes (NSTE-ACS).

BACKGROUND

Smoking has been associated with the "paradox" of reduced mortality after acute myocardial infarction (MI). This is thought to be due to favorable baseline characteristics and less diffuse coronary artery disease (CAD) among smokers.

METHODS

In the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial, 13,819 patients (29.1% smokers) with moderate- to high-risk NSTE-ACS underwent angiography and, if indicated, revascularization.

RESULTS

Smokers were significantly younger and had fewer comorbidities than nonsmokers. Incidence of death and MI were comparable at 30 days, although smokers had significantly reduced risks of 30-day major bleeding (hazard ratio [HR]: 0.80, 95% confidence interval [CI]: 0.67 to 0.96; p = 0.016) and 1-year mortality (HR: 0.797, 95% CI: 0.65 to 0.97; p = 0.027). After correction for baseline and clinical differences, smoking was no longer predictive of major bleeding (odds ratio: 1.06, 95% CI: 0.86 to 1.32; p = 0.56) and was associated with higher 1-year mortality (HR: 1.37, 95% CI: 1.07 to 1.7; p = 0.013). This pattern of reversed risk after multivariable correction held true for those smokers requiring percutaneous coronary intervention. Core laboratory angiographic analysis showed that smokers and nonsmokers were comparable in terms of the extent of CAD, Thrombolysis In Myocardial Infarction flow, myocardial blush, and the presence of thrombi.

CONCLUSIONS

In contrast to the paradox previously described in ST-segment elevation MI, our analysis finds smoking to be an independent predictor of higher 1-year mortality in patients presenting with NSTE-ACS, and our angiographic study demonstrates CAD in smokers that is comparable to that in nonsmokers but evident ∼1 decade earlier. (Acute Catheterization and Urgent Intervention Triage Strategy [ACUITY]; NCT00093158).

Absence of a 'smoker's paradox' in field triaged ST-elevation myocardial infarction patients undergoing percutaneous coronary intervention

PURPOSE

The 'smoker's paradox' refers to the observation of favorable prognosis in current smokers following an acute myocardial infarction (AMI). Initial positive findings were in the era of fibrinolysis, with more contemporary studies finding conflicting results. We sought to determine the presence of a 'smoker's paradox' in a cohort of ST Elevation Myocardial Infarction (STEMI) patients identified via field triage, treated with primary percutaneous coronary intervention (pPCI).

METHODS

This was a single center retrospective cohort study identifying consecutive STEMI patients presenting for pPCI via field triage. The primary end points were all cause mortality, major adverse cardiac events (MACE), major bleeding, in-hospital cardiac arrest and length of stay (LOS).

RESULTS

A total of 382 patients were included in the study. Current smokers were more likely to be younger (p<0.00001), male (p<0.001) and have fewer comorbidities, including renal impairment (p<0.01) and a history of AMI (p<0.05). Current smokers also had a shorter ischemic time (p<0.05), were less likely to have collateral circulation (p<0.05), and more likely to have signs of pulmonary edema at presentation (p<0.05). There was no difference between smoking groups and all cause mortality (p=0.67), MACE (p=0.49), major bleeding (p=0.49) or in-hospital cardiac arrest (p=0.43). Current smokers had a shorter LOS (p<0.05). In multivariate analysis smoking status did not correlate with primary outcomes.

CONCLUSION

The 'smoker's paradox' does not appear to be relevant among STEMI patients undergoing pPCI, identified via field triage. The previously documented 'smoker's paradox' may have been an indication of patient characteristics and the historical treatment of STEMI with thrombolysis. Further studies with larger numbers may be warranted.

Mechanisms of Coronary Thrombosis in Cigarette Smoke Exposure

Acute rupture or erosion of a coronary atheromatous plaque and subsequent coronary artery thrombosis cause the majority of sudden cardiac deaths and myocardial infarctions. Cigarette smoking is a major risk factor for acute coronary thrombosis. Indeed, a majority of sudden cardiac deaths attributable to acute thrombosis are in cigarette smokers. Both active and passive cigarette smoke exposure seem to increase the risk of coronary thrombosis and myocardial infarctions. Cigarette smoke exposure seems to alter the hemostatic process via multiple mechanisms, which include alteration of the function of endothelial cells, platelets, fibrinogen, and coagulation factors. This creates an imbalance of antithrombotic/prothrombotic factors and profibrinolytic/antifibrinolytic factors that support the initiation and propagation of thrombosis.

Impact of smoking on antiplatelet effect of clopidogrel and prasugrel after loading dose and on maintenance therapy

BACKGROUND

Pharmacodynamic studies reported an amplified on-clopidogrel platelet inhibition in smokers potentially caused by an increased metabolic drug activation via induction of cytochrome P450 1A2. The aims of this analysis were to evaluate the impact of smoking on the antiplatelet effect of clopidogrel and prasugrel and to test the potential interaction of smoking with the treatment effect of these drugs.

METHODS

A variety of platelet function results was analyzed from 2 large cohorts of patients undergoing coronary intervention after loading with clopidogrel 600 mg (n = 2,533 and n = 1,996), a cohort of patients undergoing dose adaptation from 75 to 150 mg according to response to clopidogrel (n = 117) and a crossover trial comparing clopidogrel 150 mg with prasugrel 10 mg (n = 87). Linear regression analyses were used to test the impact of smoking on platelet function and to identify independent predictors of on-treatment platelet reactivity. The potential interaction of smoking with the clinical effect of clopidogrel versus prasugrel was analyzed in the TRITON-TIMI 38 cohort (n = 13,608).

RESULTS

No significant association of smoking with platelet reactivity on clopidogrel was seen in unadjusted and adjusted analyses. The variables most consistently associated with on-clopidogrel platelet function were age, sex, diabetes, and body mass index. There was no significant interaction of smoking status at presentation with the clinical efficacy of prasugrel versus clopidogrel (P for interaction = .39).

CONCLUSIONS

Smoking does not impact on platelet reactivity in patients after loading or on different maintenance doses of clopidogrel. The clinical treatment effect of clopidogrel versus prasugrel is not affected by smoking status at presentation.

Acute cigarette smoke exposure reduces clot lysis--association between altered fibrin architecture and the response to t-PA

BACKGROUND

Enhanced thrombolysis is a proposed mechanism for reduced mortality in cigarette smokers with STEMI ("smoker's paradox"). The mechanisms remain unclear but studies suggest fibrin architecture (FA) may affect thrombolysis. Our group has previously shown that acute cigarette smoke exposure (CSE) alters FA. This study was done to evaluate the association between FA, thrombolysis and CSE.

METHODS AND RESULTS

Otherwise healthy smokers (n=22) were studied before and after smoking two cigarettes. Non-smokers (n=22) served as controls. Two ex-vivo models were used to evaluate clot lysis of venous blood and these data were compared to FA as determined by SEM. In the first model, clot lysis in a glass tube at 60minutes after addition of t-PA was measured. The second model quantified lysis utilizing thromboelastography. With the latter, after a clot reached maximum strength, t-PA was added and clot lysis at 60min was noted. SEM studies were performed on platelet poor plasma mixed with thrombin and FA was examined at 20K. Clot lysis was similar in both groups except that post-smoking, TEG showed a significantly lower lysis compared to pre- and non-smoking clots. SEM analysis showed significantly thinner fibers and denser clots post-smoking.

CONCLUSIONS

Venous clots from smokers failed to show an enhanced lysis when exposed to t-PA. In fact, acute CSE was associated with changes in FA and increased resistance to thrombolysis. These findings in part may explain enhanced thrombogenicity but suggest that mechanisms other than enhanced fibrinolysis are likely to be responsible for "smoker's paradox."

Comparison of traditional risk factors, angiographic findings, and in-hospital mortality between smoking and nonsmoking Turkish men and women with acute myocardial infarction

BACKGROUND

The prevalence of smoking is high in Turkey. However, there are no data available evaluating the differences between smokers and nonsmokers according to their sex in patients with acute myocardial infarction (AMI) in Turkey.

HYPOTHESIS

The aim of the study was to determine the prevalence of smoking and its relationship to age, localization, and extension of coronary heart disease (CHD), and other risk factors in Turkish men and women with first AMI.

METHODS

This study included, 1502 patients with first AMI from 3 different cities in Turkey. The baseline characteristics and traditional risk factors for CHD, Coronary angiographic results, and in-hospital outcome were recorded.

RESULTS

The proportion of male smokers was significantly higher than that of women (68% vs 18%, P < 0.001). Smokers were younger by almost a decade than nonsmokers (P < 0.001). Male nonsmokers were younger than females; however, the mean age of first AMI was similar in male and female smokers. In both genders, prevalence of hypertension and diabetes mellitus was significantly lower in smokers than in nonsmokers (P < 0.001). Smokers had less multivessel disease and less comorbidity as compared to nonsmokers. Although the in-hospital mortality rate was lower in smokers, smoking status was not an independent predictor of mortality.

CONCLUSIONS

Smoking, by decreasing the age of first AMI in women, offsets the age difference in first AMI between men and women. The mean age of first AMI is lower in Turkey than most European countries due to a high percentage of smoking.

The etiology of 'smoker's paradox' in acute myocardial infarction with special emphasis on the association with inflammation

Despite increased risk for coronary artery disease and acute myocardial infarction (AMI), prior studies have found that smokers with AMI have lower mortality rates than nonsmokers, a phenomenon often termed 'smoker's paradox'. The present study was designed to examine the etiology of 'smoker's paradox', especially with respect to the association with inflammation. The subjects included 528 consecutive AMI patients who were admitted within 24 hours of onset and underwent successful coronary intervention. Of the 528 subjects, 232 (44%) were smokers. The cardiac mortality rates over a 6 month period was significantly lower in the smoking group than the nonsmoking group (3% versus 9%, P = 0.01). There were significantly more male patients in the smoking group, and the smoking group was significantly younger than the nonsmoking group (P < 0.0001). The value of high sensitivity C-reactive protein (hs-CRP) on admission and 24 hours after onset, and serum amyloid A protein (SAA) were significantly higher, and acute phase BNP was significantly lower (hs-CRP on admission 1.36 +/- 1.03 mg/dL versus 0.75 +/- 0.82 mg/dL, P = 0.02, hs-CRP at 24 hours 3.86 +/- 4.32 mg/dL versus 2.90 +/- 3.46 mg/dL, P = 0.008, SAA; 288 +/- 392 microg/dL versus 176 +/- 206 microg/dL, P < 0.05, BNP; 248 +/- 342 pg/mL versus 444 +/- 496 pg/mL, P = 0.0002) in the smoking group than in the nonsmoking group. The early ST-segment resolution rate was higher in the smoking group compared with the nonsmoking group (80% versus 66%, P = 0.003). The reason why smokers with AMI have lower mortality rates than nonsmokers, the so-called 'smoker's paradox', is believed to be because smoking induces inflammation and smokers may have less damage to microvascular function after primary percutaneous coronary intervention.

Association of platelet counts on presentation and clinical outcomes in ST-elevation myocardial infarction (from the TIMI Trials)

Platelet activation and aggregation play pivotal roles in the thrombotic process of acute coronary syndromes. However, data regarding platelet count and its association with clinical outcomes in the setting of ST-elevation myocardial infarction (STEMI) are limited. We hypothesized that higher platelet counts on presentation would be associated with poorer clinical outcomes. Data from 10,793 patients with STEMI in the Thrombolysis In Myocardial Infarction (TIMI) trials database were analyzed. Mean platelet count on presentation was 254.8 x 10(3)/microl. Higher platelet counts were associated with higher rates of adverse clinical outcomes at 30 days. In a multivariable analysis that adjusted for confounders of platelet counts (age, gender, weight, diabetes, and smoking), higher platelet counts remained associated with an increased risk of the combined end point of death, reinfarction, and congestive heart failure. With a reference group of platelet counts <200 x 10(3)/microl, the multivariable odds ratios were 1.22 (95% confidence interval 1.05 to 1.42, p = 0.009) for platelet counts of 201 to 300 x 10(3)/microl, 1.37 (95% confidence interval 1.11 to 1.68, p = 0.002) for counts of 301 to 400 x 10(3)/microl, and 1.71 (95% confidence interval 1.16 to 2.51, p = 0.005) for counts >400 x 10(3)/microl. Further, a greater decrease in follow-up platelet counts (compared with baseline values) was independently associated with an increased risk of reinfarction at 30 days (odds ratio 1.44 for every decrease of 100 x 10(3)/microl unit of platelets, 95% confidence interval 1.13 to 1.82, p = 0.03). In conclusion, in STEMI, a higher platelet count on presentation was independently associated with adverse clinical outcomes, whereas a greater subsequent platelet count decrease was associated with an increased risk of reinfarction.

Predictors of type and site of first acute myocardial infarction in men and women

BACKGROUND

The importance of pathophysiological mechanisms involved in onset of acute myocardial infarction (AMI) differs with age, gender, and risk profiles. Diversity in the triggering of cardiovascular events has been observed, particularly between men and women. Therefore, we investigated the relationship between age, gender, and risk factors and location of AMI and the presence of Q waves in ECG.

PATIENTS AND METHODS

Data was obtained from a chart review of 2958 patients with first AMI: 770 (26%) patients with non-Q-wave AMI and 2188 (74%) patients with Q-wave AMI. Four clinical groups were formed by predetermined criteria (anterior Q-wave, anterior non-Q-wave, inferior Q-wave, inferior non-Q-wave). A logistic regression was performed to assess independent predictors of AMI type and site.

RESULTS

Key findings were: 1) inferior non-Q-wave AMI was more frequent in young women (P<0.001); 2) inferior Q-wave AMI was more common in young men (P<0.001); 3) anterior non-Q-wave AMI was more common in older men (P<0.001). Multivariate analysis revealed that independent predictors of anterior non-Q-wave AMI were age over 65 (P=0.002), male gender (P=0.04) and hypercholesterolemia (P=0.0003), and that predictors of inferior Q-wave AMI were male gender (P<0.0001), smoking (P=0.04) and diabetes (P=0.049). In the gender-subgroup analyses, age <45 years (P=0.04), hypecholesterolemia (P=0.02) and smoking (P=0.01) were independent predictors of inferior Q-wave AMI whereas age >65 years (P<0.0001) and smoking (P=0.0003) were predictors of anterior non-Q-wave AMI in men. In women, age <45 years (P<0.0001) and smoking (P=0.02) were independent predictors of non-Q-wave AMI and hypercholesterolemia (P=0.02) was a predictor of inferior Q-wave AMI.

CONCLUSION

The link between particular types and the site of AMI and age, gender and risk factors suggest that the importance of pathophysiological mechanisms for onset of AMI differs according to sex and age subgroup.

Determinants of lumbar artery occlusion among patients with sciatica: a three-year follow-up with magnetic resonance angiography

We showed previously that chronic Chlamydia pneumoniae infection increases the risk of lumbar artery occlusion. We did not evaluate, however, the effect of other risk factors for cardiovascular diseases in combination with this chronic infection. The purpose of this study was to investigate the combined effect of chronic C. pneumoniae infection and other known determinants of artery occlusion in a population of sciatica patients. Two-dimensional time-of-flight magnetic resonance angiography (MRA) was used to evaluate lumbar arteries at baseline and three years. The arteries on both sides (L1-L4) were evaluated visually and scored as normal, narrowed or occluded. Logistic regression analysis was performed separately for baseline total arterial stenosis and each L1-L4 segmental artery pair, and for incident new stenosis during the follow-up period. The determinants analyzed included age, body mass index (BMI, kg/m(2)), education, gender, and smoking, in addition to presence of chronic C. pneumoniae infection. MRA was obtained at baseline for 147 patients and at 3 years for 134 patients. Sixty-four (47.8%) of 134 patients had new arterial stenosis. Total incidence of new arterial stenosis was distributed quite evenly between the individual segmental levels, varying from 12.7 to 18.6%. BMI was the only predictor of new arterial stenosis (odds ratio (OR) 1.13). A reasonable logistic model could be established only for baseline L4 and total arterial scores. At L4, education was a protective factor (OR 0.07), whereas age (OR for the oldest age group 6.7) and BMI (OR 1.17) were associated with increased risk of occlusion. For total arterial score, chronic C. pneumoniae infection was an independent determinant of arterial occlusion, increasing the risk to almost eightfold. Additionally, BMI (OR 1.16), and age (for the oldest age group OR 11.4) were significant determinants for stenosis. Smoking was not statistically significant. As chronic C. pneumoniae infection was an independent determinant of lumbar artery occlusion, treatments of this chronic infection may have an impact on lumbar diseases. The importance of BMI for new arterial stenosis suggests that weight reduction may also have a beneficial effect in lumbar artery disease.

Comparison of mortality rates after acute myocardial infarction in smokers versus nonsmokers

Patients who smoke paradoxically have favorable outcomes after acute myocardial infarctions compared with nonsmokers. However, after adjustment for age only, the decrease in all-cause mortality in the smoker population is explained by the smokers' generally younger age, with better prognoses due to their age.

Differential distribution of risk factors and outcome of acute coronary syndrome in Kuwait: three years' experience

OBJECTIVE

To compare the distribution of risk factors and clinical outcome of acute coronary syndrome (ACS) between Kuwaiti and other Arab men living in Kuwait.

SUBJECTS AND METHODS

The data for this study was collected from the computerized database at the Mubarak Al-Kabeer Hospital, Kuwait and the 1997-2000 census data for the State of Kuwait. 1,329 Arab men (666 Kuwaitis and 663 other Arabs) older than 25 years who were admitted between September 1997 and August 2000 with a diagnosis of ACS were included in the study.

RESULTS

The rate of admission for the entire patient population was twofold higher for Kuwaiti (1.68/1,000) than other Arab men (0.72/1,000), (p < 0.001); the mean age of the Kuwaiti men was 56.7 +/- 11.9 years and other Arab men 53.0 +/- 10.5 years (p < 0.001). The prevalence of hypertension, diabetes, smoking and hypercholesterolemia for Kuwaiti men was 35.9, 56.9, 51.7 and 36.2%, respectively; the corresponding prevalence for other Arab men was 28.8, 42.7, 68.2 and 32.0%, the difference in the prevalence except for hypercholesterolemia was significant (p < 0.001). In Kuwaiti men younger than 55 years of age, the prevalence of hypertension, diabetes mellitus, smoking and hypercholesterolemia was 26.6, 49.5, 68.6 and 43.3%, respectively; the corresponding values for other Arab men was 22.3, 36.2, 77.7 and 43.3%; the difference in prevalence except for hypertension was significant (p < 0.001). The in-hospital mortality for the whole study was 6.2% (Kuwaiti) and 2.3% (other Arab men; p < 0.001); while that for men younger than 55 years was 2.7% (Kuwaiti) and 0.8% (other Arab men; p < 0.05).

CONCLUSION

The rate of admission for the entire patient population with a diagnosis of ACS was twofold higher for Kuwaiti than other Arab men. Among all patients and also those less than 55 years, the prevalence of diabetes mellitus was consistently higher among Kuwaiti than other Arab men thereby probably leading to the higher admission rate and in-hospital mortality.

Influence of smoking on predictors of vascular disease

Beyond the already well-established strong causative relationship with cancer, smoking increases the risk for vascular disease. Smoking may act directly or adversely influence risk factors contributing to the development of vascular disease. Smoking causes endothelial dysfunction, dyslipidemia (decreased high-density lipoprotein cholesterol levels, hypertriglyceridemia and increased oxidation of low-density lipoprotein cholesterol) and platelet activation leading to a prothrombotic state. Smoking increases emerging risk factors (eg, fibrinogen, homocysteine, and high-sensitivity C-reactive protein) and increases insulin resistance and the risk of developing type 2 diabetes mellitus. The beneficial effects of statins and antioxidants (eg, vitamins C and E, beta-carotene) are counteracted by smoking. Smoking-induced alterations in growth factors, adhesion molecules, and even in genes can accelerate the progression of atherosclerosis. The aim of this review is to consider the adverse consequences of smoking on the factors predisposing to vascular disease and to emphasize the beneficial effects of smoking cessation.