Evaluation of paradoxic beneficial effects of smoking in patients receiving thrombolytic therapy for acute myocardial infarction: mechanism of the "smoker's paradox" from the GUSTO-I trial, with angiographic insights. Global Utilization of Streptokinase and Tissue-Plasminogen Activator for Occluded Coronary Arteries

The enigma of the 'smoker's paradox': Results from a single-center registry of patients with STEMI undergoing primary percutaneous coronary intervention

BACKGROUND

Smoker's paradox usually refers to the observation of a favorable outcome of smoking patients in acute myocardial infarction.

METHODS

From April 2006 to December 2018 a population of 2456 patients with ST segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (pPCI) were prospectively enrolled in the MATRIX registry. Ischemic time, clinical, demographics, angiographic data, and 1-year follow-up were collected.

RESULTS

Among 2546 patients admitted with STEMI, 1007 (41 %) were current smokers. Smokers were 10 years younger and had lower crude in-hospital and 1-year mortality (1.5 % vs 6 %, p < 0.0001 and 5 % vs 11 %, p < 0.0001), shorter ischemic time (203 [147-299] vs 220 [154-334] minutes, p = 0.002) and shorter decision time (60 [30-135] vs 70 [36-170] minutes, p = 0.0063). Smoking habit [OR:0.37(95 % CI:0.18-0.75)-p < 0.01], younger age [OR 1.06 (95%CI:1.04-1.09)-p < 0.001] and shorter ischemic time [OR:1.01(95%CI:1.01-1.02)-p < 0.05] were associated to lower in-hospital mortality. Only smoking habit [HR:0.65(95 % CI: 0.44-0.9)-p = 0.03] and younger age [HR:1.08 (95%CI:1.06-1.09)-p < 0.001] were also independently associated to lower all-cause death at 1-year follow-up. After propensity matching, age, cardiogenic shock and TIMI flow <3 were associated with in-hospital mortality, while smoking habit was still associated with reduced mortality. Smoking was also associated with reduced mortality at 1-year follow-up (HR 0.54, 95 % CI [0.37-0.78]; p < 0.001).

CONCLUSIONS

Smoking patients show better outcome after PCI for STEMI at 1-year follow-up. Although "Smoking paradox" could be explained by younger age of patients, other factors may have a role in the explanation of the phenomenon.

Smoking and cardiovascular outcomes after percutaneous coronary intervention: a Korean study

BACKGROUND AND AIMS

The authors investigated the impact of smoking and its cessation after percutaneous coronary intervention (PCI) on cardiovascular outcomes.

METHODS

Using a nationwide database from the Korean National Health Insurance System, 74 471 patients undergoing PCI between 2009 and 2016 were classified as non-, ex-, or current smokers, depending on smoking status at the first health check-up within 1 year after PCI. The primary outcome was major adverse cardiovascular and cerebrovascular event (MACCE), a composite of all-cause death, myocardial infarction, coronary revascularization, and stroke.

RESULTS

During 4.0 years of follow-up, current smokers had a 19.8% higher rate of MACCE than non-smokers [adjusted hazard ratio (aHR) 1.198; 95% confidence interval (CI) 1.137-1.263], and ex-smokers tended to have a comparable rate with that of non-smokers (aHR 1.036; 95% CI .992-1.081). For 31 887 patients with both pre- and post-PCI health check-up data, the effects of smoking cessation were analysed. Among quitters who stopped smoking after PCI, quitters with cumulative smoking exposure of <20 pack-years (PYs) tended to have a comparable rate of MACCE with that of persistent non-smokers. However, the rate in quitters with cumulative exposure of ≥20 PYs was comparable with that of persistent smokers [aHR (95% CI) for <10 PY, 1.182 (.971-1.438); 10-20 PYs 1.114 (.963-1.290); 20-30 PYs 1.206 (1.054-1.380); ≥ 30 PYs 1.227 (1.113-1.352); persistent smokers 1.223 (1.126-1.328), compared with persistent non-smokers, respectively, P for interaction <.001].

CONCLUSIONS

Smoking is associated with a higher risk of adverse outcomes in patients undergoing PCI. Quitters after PCI with <20 PYs were associated with a risk comparable with that of non-smokers.

Risk factors associated with contrast-associated acute kidney injury in ST-segment elevation myocardial infarction patients: a systematic review and meta-analysis

OBJECTIVE

The objective of this systematic review and meta-analysis was to evaluate the risk factors for contrast-associated acute kidney injury (CA-AKI) in ST-elevation myocardial infarction patients treated with primary percutaneous coronary intervention.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

We searched the databases of PubMed, Embase and Ovid, up to February 2022, for observational studies that investigated the association between risk factors and CA-AKI.

RESULTS

A total of 21 studies were included in the meta-analysis. Of the total 22 015 participants, 2728 developed CA-AKI. Pooled incidence was 11.91% (95% CI 9.69%, 14.14%). Patients with CA-AKI were more likely to be older, female, also had comorbidities (hypertension, diabetes, previous heart failure). Smoking (OR: 0.60; 95% CI 0.52, 0.69) and family history of CAD (coronary artery disease) (OR: 0.76; 95% CI 0.60, 0.95) were associated with lower risk of CA-AKI. Left anterior descending (LAD) artery occlusion (OR: 1.39; 95% CI 1.21, 1.59), left main disease (OR: 4.62; 95% CI 2.24, 9.53) and multivessel coronary disease (OR: 1.33; 95% CI 1.11, 1.60) were risk factors for CA-AKI. Contrast volume (weighted mean difference: 20.40; 95% CI 11.02, 29.79) was associated with increased risk in patients receiving iso-osmolar or low-osmolar non-ionic contrast.

CONCLUSIONS

In addition to the known risk factors, LAD artery infarction, left main disease and multivessel disease are risk factors for CA-AKI. The unexpected favourable association between smoking, as well as family history of CAD, and CA-AKI requires further investigation.

PROSPERO REGISTRATION NUMBER

CRD42021289868.

Sex difference after acute myocardial infarction patients with a history of current smoking and long-term clinical outcomes: Results of KAMIR Registry

BACKGROUND

The contribution of sex as an independent risk factor for cardiovascular disease still remains controversial. The present study investigated the impact of sex on long-term clinical outcomes in Korean acute myocardial infarction (AMI) patients with a history of current smoking on admission after drug-eluting stents (DESs).

METHODS

A total of 12,565 AMI patients (male: n = 11,767 vs. female: n = 798) were enrolled. Major adverse cardiac events (MACEs) comprising all-cause death, recurrent myocardial infarction (Re-MI), and any repeat revascularization were the primary outcomes that were compared between the two groups. Probable or definite stent thrombosis (ST) was the secondary outcome.

RESULTS

After adjustment, the early (30 days) cumulative incidences of MACEs (adjusted hazard ratio [aHR]: 1.457; 95% confidence interval [CI]: 1.021-2.216; p = 0.035) and all-cause death (aHR: 1.699; 95% CI: 1.074-2.687; p = 0.023) were significantly higher in the female group than in the male group. At 2 years, the cumulative incidences of all-cause death (aHR: 1.561; 95% CI: 1.103-2.210; p = 0.012) and Re-MI (aHR: 1.800; 95% CI: 1.089-2.974; p = 0.022) were significantly higher in the female group than in the male group. However, the cumulative incidences of ST were similar between the two groups (aHR: 1.207; 95% CI: 0.583-2.497; p = 0.613).

CONCLUSIONS

The female group showed worse short-term and long-term clinical outcomes compared with the male group comprised of Korean AMI patients with a history of current smoking after successful DES implantation. However, further studies are required to confirm these results.

Lipoprotein (a) and long-term outcome in patients with peripheral artery disease undergoing revascularization

BACKGROUND AND AIMS

Despite low LDL-C goals, the residual risk for further cardiovascular (CV) events in patients with peripheral artery disease (PAD) remains high. Lipoprotein (a) (Lp(a)) is a known risk factor for PAD incidence, but little is known regarding the outcome in patients with symptomatic PAD. Thus, this study investigates Lp(a) and CV mortality in PAD after endovascular repair.

METHODS

A total of 1222 patients with PAD in two cohorts according to Lp(a) assay in nmol/L (n = 964, Lip-LEAD-A) or mg/dl (n = 258, Lip-LEAD-B) were followed up for 4.3 (IQR 3.0-5.6) or 7.6 (IQR 3.2-8.1) years. Lp(a) was measured before endovascular repair for either intermittent claudication (IC) or critical limb ischemia (CLI). Outcome information was obtained from the federal death registry.

RESULTS

In Lip-LEAD-A, 141 CV-deaths occurred (annual calculated CV-death rate 3.4%), whereas 64 CV-deaths were registered in Lip-LEAD-B (annual calculated CV-death rate 3.3%). After adjustment for traditional CV risk factors Lp(a) was neither associated with outcome in Lip-LEAD-A (highest tertile HR 1.47, 95%CI [0.96-2.24]) nor in Lip-LEAD-B (highest tertile HR 1.34 [0.70-2.58]). Subanalyses for IC (HR 1.37 [0.74-2.55]; HR 1.10 [0.44-2.80], CLI (HR 1.55 [0.86-2.80], HR 3.01 [0.99-9.10]), or concomitant coronary artery disease (CAD; HR 1.34 [0.71-2.54]; HR 1.21 [0.46-3.17]) failed to show a significant association between Lp(a) and CV-mortality.

CONCLUSIONS

In this large-scale cohort of symptomatic PAD no association of elevated Lp(a) with CV mortality was found over a median observation period of 5 years. Thus, an even longer study including asymptomatic patients is warranted.

Association between baseline smoking status and clinical outcomes following myocardial infarction

Background

Whether the effect of smoking on clinical outcomes following an acute myocardial infarction (AMI) is beneficial or detrimental remains inconclusive. We invesetigated the effect of smoking on the clinical outcomes in patients following an AMI.

Methods

Among 13,104 patients between November 2011 and June 2015 from a nationwide Korean AMI registry, a total of 10,193 participants were extracted then classified into two groups according to their smoking habit: (1) smoking group (n = 6,261) and (2) non-smoking group (n = 3,932). The participants who smoked were further subclassified according to their smoking intensity quantified by pack years (PYs): (1) <20 PYs (n = 1,695); (2) 20–40 PYs (n = 3,018); and (3) ≥40 PYs (n = 2,048). Each group was compared to each other according to treatment outcomes. The primary outcome was the incidence of major adverse cardiac and cerebrovascular events (MACCEs), which is a composite of all-cause mortality, non-fatal MI (NFMI), any revascularization, cerebrovascular accident, rehospitalization, and stent thrombosis. Secondary outcomes included the individual components of MACCEs. The Cox proportional hazard regression method was used to evaluate associations between baseline smoking and clinical outcomes following an AMI. Two propensity score weighting methods were performed to adjust for confounders, including propensity score matching and inverse probability of treatment weighting.

Results

While the incidence of all clinical outcomes, except for stent thrombosis, was lower in the smoking group than in the non-smoking group in the unadjusted data, the covariates-adjusted data showed statistical attenuation of these differences but a higher all-cause mortality in the smoking group. For smokers, the incidence of MACCEs, all-cause mortality, cardiac and non-cardiac death, and rehospitalization was significantly different between the groups, with the highest rates of MACCE, all-cause mortality, non-cardiac death, and rehospitalization in the group with the highest smoking intensity. These differences were statistically attenuated in the covariates-adjusted data, except for MACCEs, all-cause mortality, and non-cardiac death, which had the highest incidence in the group with ≥40 PYs.

Conclusion

Smoking had no beneficial effect on the clinical outcomes following an AMI. Moreover, for those who smoked, clinical outcomes tended to deteriorate as smoking intensity increased.

No Paradoxical Effect of Smoking Status on Recurrent Cardiovascular Events in Patients Following Percutaneous Coronary Intervention: Thai PCI Registry

Background

"Smoker's paradox" is a controversial phenomenon that describes an unexpectedly favorable short-term outcome of smokers post-percutaneous coronary intervention (PCI). This study aimed to evaluate the effect of smoking status on recurrent major adverse cardiovascular events (MACEs) in patients who recently underwent PCI and to determine whether it was paradoxical.

Methods

This study utilized data from the nationwide Thai PCI registry, enrolling patients during 2018-2019. Our study factor was smoking status, classified as current smokers, ex-smokers, and nonsmokers. The outcome of interest was the time to occurrence of a composite of MACEs (i.e., all-cause death, myocardial infarction (MI), stroke, and unplanned revascularization) evaluated at about 1-year post-PCI. A propensity score (PS) model using inverse probability weighting with regression adjustment was used to estimate the effect of smoking on the occurrence of MACE.

Results

Current smokers, ex-smokers, and non-smokers accounted for 23, 32, and 45% of the 22,741 subjects, respectively. Smokers were younger, more frequently male, and had fewer traditional atherosclerotic risk factors. Current smokers presented more frequently with ST-elevation MIs (STEMIs) and cardiogenic shock (54 and 14.6%, respectively) than non-smokers. MACE rates were 1.9, 1.2, and 1.6 per 100 patients per month in the current smokers, ex-smokers, and non-smokers, respectively. After applying a PS, patients with a history of current smoking and ex-smoking developed the onset of recurrent MACEs significantly sooner than non-smokers, with a median time of 4.4 vs. 4.9 vs. 13.5 months (p < 0.001), respectively.

Conclusions

"Smoker's paradox" was not observed in our patient population. Current smokers and ex-smokers were prone to develop an earlier onset of a post-PCI MACEs than nonsmokers and need a smoke cessation program for further prevention.

Short and Long-Term Survival Rates Following Myocardial Infarction and Its Predictive Factors: A Study Using National Registry Data

Background: Coronary artery disease is the most common cause of death worldwide as well as in Iran. The present study was designed to predict short and long-term survival rates after the first episode of myocardial infarction (MI).

Methods: The current research is a retrospective cohort study. The data were collected from the Myocardial Infarction Registry of Iran in a 12-month period leading to March 20, 2014. The variables analyzed included smoking status, past medical history of chronic heart disease, hypertension, diabetes, hyperlipidemia, signs and symptoms during an attack, post-MI complications during hospitalization, the occurrence of arrhythmias, the location of MI, and the place of residence. Survival rates and predictive factors were estimated by the Kaplan–Meier method, the log-rank test, and the Cox model.

Results: Totally, 21 181 patients with the first MI were studied. There were 15 328 men (72.4%), and the mean age of the study population was 62.10±13.42 years. During a 1-year period following MI, 2479 patients (11.7%) died. Overall, the survival rates at 28 days, 6 months, and 1 year were estimated to be 0.95 (95% CI: 0.95 to 0.96), 0.90 (95% CI: 0.90 to 0.91), and 0.88 (95% CI: 0.88 to 0.89). After the confounding factors were controlled, history of chronic heart disease (p<0.001), hypertension (p<0.001), and diabetes (p<0.001) had a significant relationship with an increased risk of death and history of hyperlipidemia (p<0.001) and inferior wall MI (p<0.001) had a significant relationship with a decreased risk of death.

Conclusion: The results of this study provide evidence for health policy-makers and physicians on the link between MI and its predictive factors.

The Association of Smoking with Hospitalization and Mortality Differs According to Sex in Patients with Heart Failure Following Myocardial Infarction

Background: Smoking has been associated with higher morbidity and mortality following myocardial infarction (MI), but reports of the impact on morbidity and mortality for females and elderly patients experiencing MI complicated with left ventricular dysfunction or overt heart failure are limited. Materials and Methods: In an individual patient data meta-analysis of high-risk MI patients, the association of smoking with hospitalizations and death were investigated. Weighted Cox proportional hazard modeling were used to study the risks of smoking on adjudicated endpoints among different sex and age categories. Results: Twenty-eight thousand seven hundred thirty-five patients from the CAPRICORN, EPHESUS, OPTIMAAL, and VALIANT trials were assessed. After weighting, smokers (N = 18,148) were unfrequently women (29.2%) and a minority were above ≥80 years (9.8%). Smoking was significantly more associated with all-cause hospitalizations in women (hazard ratio [HR] 1.24; 95% confidence interval [95% CI] 1.16-1.32) than in men (HR = 1.10; 95% CI 1.05-1.16) resulting in a significant interaction between smoking and sex (p = 0.005). Smoking was predictive of all-cause mortality homogenously across age categories (p for interaction = 0.25) and sex (p for interaction = 0.58). Conclusions: The influence of smoking on morbidity differed according to sex following high-risk MI. The deleterious impact of smoking on hospitalization appeared particularly potent in women, which should further reinforce preventive strategies in females.

Effect of smoking on clinical outcomes in patients receiving rotational atherectomy in calcified coronary lesions: from the ROCK Registry, South Korea

BACKGROUND

Tobacco smoking and its harmful health effects also increase economic burdens globally. Surprisingly, despite the detrimental health consequences of smoking, some studies have shown better survival among smokers compared with non-smokers, a phenomenon called "smoker's paradox". However, the impact of smoking status on clinical outcomes in severe calcified coronary artery disease (CAD) patients has yet to be reported.

OBJECTIVES

Investigate the impact of smoking on clinical outcomes in calcified CAD receiving rotational atherectomy (RA).

DESIGN

Retrospective review of medical records.

SETTING

Multicenter registry in South Korea.

PATIENTS AND METHODS

This multicenter registry included consecutive patients with calcified CAD who underwent RA at nine tertiary centers in Korea between January 2010 and October 2019.

MAIN OUTCOME MEASURES

Target-vessel failure (TVF) which included the composite of cardiac death, target-vessel myocardial infarction (TVMI), and target-vessel revascularization (TVR).

SAMPLE SIZE

583 lesions in 540 patients followed for a median of 16.1 months.

RESULTS

Lesions were divided into two groups: non-smokers (n=472, 81.0%) and smokers (n=111, 19.0%). TVF in the smoker group was significantly more frequent than in non-smoker group (log rank P=.016). The inverse probability of treatment weighting analysis also showed that smoking was significantly associated with a higher incidence of the primary outcome (HR: 1.617; 95% CI: 1.127-2.320; P=.009), cardiac death (HR 1.912; 95% CI: 1.105-3.311; P=.021), myocardial infarction (HR: 3.914; 95% CI: 1.884-8.132; P<.001), TVMI (HR: 3.234; 95% CI: 1.130-9.258; P=.029), and TVR (HR: 1.661; 95% CI: 1.043-2.643; P=.032). However, any bleeding was significantly observed less in the smokers.

CONCLUSION

Smoking is significantly associated with adverse clinical outcomes in CAD patients requiring RA.

LIMITATIONS

Retrospective design.

CONFLICTS OF INTEREST

None.

Efficacy and safety of ticagrelor versus prasugrel in smokers and nonsmokers with acute coronary syndromes

BACKGROUND

The efficacy and safety of ticagrelor versus prasugrel according to smoking status in patients with acute coronary syndromes (ACS) are not known. We assessed the efficacy and safety of ticagrelor versus prasugrel according to smoking status in patients with ACS undergoing invasive management.

METHODS

This pre-specified analysis of the ISAR-REACT 5 trial included 1349 smokers and 2652 nonsmokers randomized to receive ticagrelor or prasugrel. The primary endpoint was the incidence of death, myocardial infarction, or stroke; the secondary endpoint was the incidence of Bleeding Academic Research Consortium (BARC) type 3 to 5 bleeding (both endpoints assessed at 12 months).

RESULTS

There was no significant treatment arm-by-smoking status interaction regarding the efficacy outcome. The primary endpoint occurred in 47 patients (7.0%) in the ticagrelor group and 41 patients (6.2%) in the prasugrel group in smokers (hazard ratio [HR] = 1.15; 95% confidence interval [CI] 0.76-1.75; P = 0.510) and in 133 patients (10.2%) in the ticagrelor group and 94 patients (7.2%) in the prasugrel group in nonsmokers (HR = 1.44 [1.10-1.87]; P = 0.007; P for interaction = 0.378). The secondary endpoint occurred in 27 patients (4.6%) in the ticagrelor group and 33 patients (5.6%) in the prasugrel group in smokers (HR = 0.81 [0.49-1.35]; P = 0.412) and in 66 patients (6.0%) in the ticagrelor group and 46 patients (4.4%) in the prasugrel group in nonsmokers (HR = 1.38 [0.94-2.01]; P = 0.097).

CONCLUSIONS

In patients with ACS undergoing an invasive management strategy, the smoking status did not significantly interact with the relative treatment effect of ticagrelor vs. prasugrel.

CLINICAL TRIAL REGISTRATION

NCT01944800.

The Impact of Smoking on Clinical Outcomes after Percutaneous Coronary Intervention in Women Compared to Men

Background

For decades, cardiovascular diseases (CVD) have been known as men's disease. However, recent research studies showed that they have become more common in women. Smoking is a strong risk factor for CVD especially that of coronary artery disease (CAD). Several studies reported that women are more susceptible to drastic sequels of smoking than men. There is limited data regarding the impact of smoking on post-revascularization clinical events stratified by gender. This study aimed to investigate if gender significantly changes the incidence of adverse clinical outcomes after percutaneous coronary intervention (PCI) among those with history of smoking.

Methods

Participants were selected from two hospitals from 2003 to 2019. Among patients who had PCI (index PCI), those with stable CAD who underwent elective PCI were included. Exclusion criteria were defined as primary PCI and those with multiple prior revascularizations. Participants were followed up seeking for major adverse cardiac events (MACE) including revascularization (PCI or coronary artery bypass grafting), myocardial infarction, and coronary death in three time intervals according to the time of index PCI (short term: up to 24 hours, mid-term: 24 hours to less than 6 months, and long term: more than 6 months).

Results

Of the 1799 patients, 61% were men and 47.08% had history of smoking (75% of the smokers were men). At the time of index PCI, smokers were significantly younger than nonsmokers. Also, MACE were significantly higher in smokers than nonsmokers, which was particularly pronounced at the long-term interval. In the nonsmokers group, there was no difference in MACE occurrence between men and women. However, of the smokers, women showed significantly higher MACE rate compared with men peers.

Conclusion

Smoking makes women more prone to MACE in comparison to men among patients with stable CAD after PCI with drug-eluting stent.

Clinical significance of high on-treatment platelet reactivity in patients with prolonged clopidogrel therapy

BACKGROUND/AIMS

Prolonged dual antiplatelet therapy (DAPT) with aspirin and clopidogrel beyond 1 year has been shown to reduce ischemic events at the expense of increased bleeding. However, limited data are available on the clinical significance of platelet reactivity (PR) at 1 year.

METHODS

We retrospectively identified 331 patients who underwent percutaneous coronary intervention (PCI) and assessed the on-clopidogrel PR using VerifyNow P2Y12 assay at 1 year in a single center. Two hundred eleven patients were on DAPT for > 1 year. The relationship between high on-treatment platelet reactivity (HPR) at 1 year and clinical outcomes beyond 1 year, as well as the longitudinal change in PR was analyzed.

RESULTS

At 1 year, 135 (64%) patients showed HPR and 76 (36%) did not. There was a significant increase in ischemic endpoint events, including cardiovascular death, non-fatal myocardial infarction, and stroke/transient ischemic attack in patients with compared to without HPR at 1 year (hazard ratio [HR], 2.68; 95% confidence interval [CI], 1.06 to 6.77; p = 0.036). However, the incidence of any Bleeding Academic Research Consortium bleeding was significantly lower in the HPR group (HR, 0.11; 95% CI, 0.02 to 0.65; p = 0.015). In the longitudinal analysis, PR significantly decreased from post-load to 1 year after index PCI in the non-HPR group. Conversely, the HPR group showed high PR from baseline through 1 year.

CONCLUSION

HPR at 1 year may be a useful surrogate for predicting ischemic and bleeding events in patients on prolonged DAPT. Patients with and without HPR at 1 year showed different patterns of longitudinal change in PR.

Risk Factors of New Cerebral Infarctions After Endovascular Treatment for Basilar Artery Stenosis Based on High-Resolution Magnetic Resonance Imaging

Objective: The current study aims to analyze the risk factors of new cerebral infarctions in the distribution of basilar artery (BA) detected by diffusion-weighted imaging (DWI) after endovascular treatment in patients with severe BA stenosis. Methods: Data was collected from the electronic medical records of patients with severely atherosclerotic basilar artery stenosis (≥70%) who underwent endovascular treatment. The plaque characteristics, including the plaque distribution, plaque burden, plaque enhancement index, remodeling ratio, and stenosis degree, were evaluated qualitatively and quantitatively using high-resolution magnetic resonance imaging (HR-MRI) and digital subtraction angiography (DSA). The characteristics of the procedure, such as the type of treatment, balloon diameter, balloon length, stent diameter, and stent length, were analyzed. Results: A total of 107 patients with severe basilar artery stenosis (≥70%) who underwent endovascular treatment were enrolled. The study participants included 77 men and 30 women, with an average age of 61.6 ± 8.1 years. The rate of postoperative new cerebral infarctions was 55.1% (59/107), of which 74.6% (44/59) were caused by artery-to-artery embolism, 6.8% (4/59) due to perforator occlusion, and 18.6% (11/59) were caused by a mixed mechanism. Twelve of 59 patients had ischemic events, with nine cases of stroke and three cases of transient ischemic attacks (TIA). The plaque burden in the DWI-positive group was significantly larger than that in the DWI-negative group (3.7% vs. -8.5%, p = 0.016). Positive remodeling was more common in the DWI-positive group than in the DWI-negative group (35.6% vs. 16.7%, p = 0.028). Smoking was inversely correlated with the rate of new cerebral infarctions (odds ratio, 0.394; 95% confidence interval, 0.167-0.926; p = 0.033). Conclusion: The plaque characteristics are not associated with new cerebral infarctions in the distribution of BA, although a large plaque burden and positive remodeling are more likely to appear in patients with new cerebral infarctions after BA stenting, which warrants further studies with a larger sample size. As for smoking, the inverse correlation with new cerebral infarctions in the BA territory needs large-scale prospective randomized controlled trials to verify.

Effects of Smoking on Long-Term Clinical Outcomes and Lung Cancer in Patients with Acute Myocardial Infarction

BACKGROUND AND OBJECTIVES

Smoking is well-established as a risk factor for coronary artery disease. However, recent studies demonstrated favorable results, including reduced mortality, among smokers, which are referred to as the "smoker's paradox". This study examined the impact of smoking on clinical outcomes in patients with acute myocardial infarction (AMI) undergoing percutaneous coronary intervention (PCI).

METHODS

Patients with AMI undergoing PCI between 2004 and 2014 were enrolled and classified according to smoking status. The primary endpoint was a composite of major adverse cardiovascular events (MACE) including cardiac death, myocardial infarction, stroke, and revascularization.

RESULTS

Among the 10,683 patients, 4,352 (40.7%) were current smokers. Smokers were 10.7 years younger and less likely to have comorbidities such as hypertension, diabetes mellitus, chronic kidney disease, stroke, and prior PCI. Smokers had less MACE (hazard ratio [HR], 0.644; 95% confidence interval [CI], 0.594-0.698; p<0.001) and cardiac death (HR, 0.494; 95% CI, 0.443-0.551; p<0.001) compared to nonsmokers during the 5 years in an unadjusted model. However, after propensity-score matching, smokers showed higher risk of MACE (HR, 1.125; 95% CI, 1.009-1.254; p=0.034) and cardiac death (HR, 1.190; 95% CI, 1.026-1.381; p=0.022). Smoking was a strong independent predictor of lung cancer (propensity-score matched HR, 2.749; 95% CI, 1.416-5.338; p=0.003).

CONCLUSIONS

In contrast to the unadjusted model, smoking is associated with worse cardiovascular outcome and higher incidence of lung cancer after adjustment of various confounding factors. This result can be explained by the characteristics of smokers, which were young and had fewer comorbidities.

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.

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.

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.

The association between smoking and unfavorable outcomes in acute ischemic stroke patients with mechanical thrombectomy

INTRODUCTION

Little is known about the relationship between smoking and clinical outcomes in acute ischemic stroke (AIS) patients undergoing mechanical thrombectomy (MT). The outcomes could depend on different stroke subtypes. The aim of this study was to investigate whether smoking affected differently the outcomes in patients with different stroke subtypes who received MT.

METHODS

AIS patients who underwent MT were prospectively enrolled from three hospitals between January 2014 and December 2018. Smokers were defined as current users of cigarettes. The stroke subtypes were classified according to TOAST criteria. Outcome measurements included treatment effects, intracerebral hemorrhage (ICH), and functional outcomes at 3 months. The effects of smoking on outcomes were assessed by logistic regression analysis.

RESULTS

A total of 128 AIS patients with MT were enrolled, including 64 smokers and 64 non-smokers. Logistic regression analysis indicated that smoking was related to higher risk of In-hospital ICH (OR=4.31; 95% CI: 1.10–16.96; p=0.036) in patients with cardioembolism subtype. Furthermore, smoking was also associated with lower rates of mild stroke at discharge (OR=0.07; 95% CI: 0.02–0.31; p<0.001) and functional independence (OR=0.13; 95% CI: 0.03–0.56; p=0.006) in patients with cardioembolism subtype.

CONCLUSIONS

In AIS patients undergoing MT, smoking could be related to a higher risk of In-hospital ICH and lower rates of mild stroke at discharge and functional independence if their stroke subtype is cardioembolism.

Association between hyperlipidemia and mortality after incident acute myocardial infarction or acute decompensated heart failure: a propensity score matched cohort study and a meta-analysis

OBJECTIVE

To examine the effect of HLP, defined as having a pre-existing or a new in-hospital diagnosis based on low density lipoprotein cholesterol (LDL-C) level ≥100 mg/dL during index hospitalisation or within the preceding 6 months, on all-cause mortality after hospitalisation for acute myocardial infarction (AMI) or acute decompensated heart failure (ADHF) and to determine whether HLP modifies mortality associations of other competing comorbidities. A systematic review and meta-analysis to place the current findings in the context of published literature.

DESIGN

Retrospective study, 1:1 propensity-score matching cohorts; a meta-analysis.

SETTING

Large academic centre, 1996-2015.

PARTICIPANTS

Hospitalised patients with AMI or ADHF.

MAIN OUTCOMES AND MEASURES

All-cause mortality and meta-analysis of relative risks (RR).

RESULTS

Unmatched cohorts: 13 680 patients with AMI (age (mean) 68.5 ± (SD) 13.7 years; 7894 (58%) with HLP) and 9717 patients with ADHF (age, 73.1±13.7 years; 3668 (38%) with HLP). In matched cohorts, the mortality was lower in AMI patients (n=4348 pairs) with HLP versus no HLP, 5.9 versus 8.6/100 person-years of follow-up, respectively (HR 0.76, 95% CI 0.72 to 0.80). A similar mortality reduction occurred in matched ADHF patients (n=2879 pairs) with or without HLP (12.4 vs 16.3 deaths/100 person-years; HR 0.80, 95% CI 0.75 to 0.86). HRs showed modest reductions when HLP occurred concurrently with other comorbidities. Meta-analyses of nine observational studies showed that HLP was associated with a lower mortality at ≥2 years after incident AMI or ADHF (AMI: RR 0.72, 95% CI 0.69 to 0.76; heart failure (HF): RR 0.67, 95% CI 0.55 to 0.81).

CONCLUSIONS

Among matched AMI and ADHF cohorts, concurrent HLP, compared with no HLP, was associated with a lower mortality and attenuation of mortality associations with other competing comorbidities. These findings were supported by a systematic review and meta-analysis.

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.

Peri-procedural stroke or death in stenting of symptomatic severe intracranial stenosis

BACKGROUND AND PURPOSE

There are limited data on predictors of 30-day stroke or death in patients with symptomatic intracranial atherosclerosis (sICAS) undergoing stenting. We aim to determine the factors associated with stroke or death at 30 days in the stenting arm of the SAMMPRIS trial.

METHODS

This is a post-hoc analysis of the SAMMPRIS trial including patients who underwent angioplasty/stenting. We compared patient-specific variables, lesion-specific variables, procedure-specific variables, and FDA-approved indications between patients with and without the primary outcome (stroke or death at 30 days). Logistic regression analyses were performed to evaluate associations with the primary outcome.

RESULTS

We identified 213 patients, 30 of whom (14.1%) met the primary outcome. Smoking status and lesion length were associated with the primary outcome: the odds of stroke or death for non-smokers versus smokers (adjusted OR 4.46, 95% CI 1.79 to 11.1, p=0.001) and for increasing lesion length in millimeters (adjusted OR 1.20, 95% CI 1.02 to 1.39, p=0.029). These had a modest predictive value: absence of smoking history (sensitivity 66.7%, specificity 65.4%) and lesion length (area under curve 0.606). Furthermore, event rates were not significantly different between patients with and without the FDA-approved indication for stenting (15.9% vs 12%, p=0.437).

CONCLUSION

In SAMMPRIS patients who underwent angioplasty/stenting, neither clinical and neuroimaging variables nor the FDA indication for stenting reliably predicted the primary outcome. Further work in identifying reliable biomarkers of stroke/death in patients with sICAS is needed before considering new clinical trials of stenting.

TRIAL REGISTRATION NUMBER

SAMMPRIS NCT00576693; Results.

The impact of smoking on mortality after acute ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention: a retrospective cohort outcome study at 3 years

The "smoker's paradox", where smokers have improved survival post-myocardial infarction, was predominantly observed in the thrombolytic era. However, evidence for the smoker's paradox in the current era of PCI therapy is both limited and inconsistent. We aimed to examine the effect of smoking status on survival in unselected ST-elevation myocardial infarction (STEMI) patients managed by primary percutaneous coronary intervention (PCI). Data were collected for all patients with acute STEMI undergoing primary PCI at The South Yorkshire Cardiothoracic Centre, UK over a 5-year period between 2009 and 2014. Differences in survival by smoking status were assessed before and after adjustment for differences in baseline variables using a Kaplan-Meier curve and a Cox regression analysis, respectively. A total of 3133 STEMI patients were included in the study. After adjustment for differences in baseline variables, smoking was associated with a significantly increased mortality (hazard ratio 1.35 (95% CI 1.04-1.74)) compared to never smokers after 3 years. The risk for ex-smokers (hazard ratio 0.99 (0.76-1.28)) was similar to never smokers. There were no significant differences in survival by smoking status at 30 days and 1 year. In this large registry of STEMI patients managed by primary PCI, smokers had a significantly higher 3-year mortality than non-smokers. This study is the first to not only dispel the existence of the smoker's paradox, but to highlight a high-risk subgroup who may warrant tailored secondary prevention treatment, including smoking cessation.

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 of the Smoker’s Paradox in Acute Ischemic Stroke Patients Receiving Intravenous Thrombolysis or Endovascular Treatment

Introduction

The existence of the smoker’s paradox is controversial and potential mechanisms have not been explained. We aimed to explore the association between cigarette smoking and functional outcome at 3 months in patients with acute ischemic stroke who were treated with intravenous thrombolysis (IVT) or endovascular treatment (EVT).

Methods

This meta-analysis was conducted in accordance with the PRISMA guidelines. Studies exploring the association between smoking and good functional outcome (modified Rankin Scale score ≤ 2) following IVT or EVT were searched via the databases of PubMed, Embase, and the Cochrane Library from inception to August 8, 2018. Information on the characteristics of included studies was independently extracted by two investigators. Data were pooled using a random-effects or fixed-effects meta-analysis according to the heterogeneity of included studies.

Results

Among 20 identified studies, 15 reported functional outcomes following IVT, and five reported functional outcomes following EVT. Unadjusted analyses showed that smoking increased the odds of good functional outcomes with a pooled odds ratio (OR) of 1.48 (95% confidence interval [CI]: 1.36–1.60) after IVT and 2.10 (95% CI: 1.47–3.20) after EVT. Of IVT studies, only eight reported outcomes adjusted for covariates and none of the EVT studies reported adjusted outcomes. After adjustment, the relation between smoking and good functional outcome following IVT lost statistical significance (OR 1.14 [95% CI: 0.81–1.59]).

Conclusion

Our meta-analysis suggested that smoking was not associated with good functional outcome (mRS ≤ 2) at 3 months in patients with acute ischemic stroke who were treated with intravenous thrombolysis.

Implications

The existence of the smoker’s paradox is controversial. A previous letter by Plas et al. published in 2013 reported a positive result for the association between smoking and good functional outcome at 3 months in acute ischemic stroke patients who received intravenous thrombolysis (IVT). However, a major limitation of their meta-analysis was that the process of data synthesis was based on unadjusted data. Therefore, we conducted this meta-analysis to investigate the association based on adjusted data and a larger sample size. Our meta-analysis suggested that smoking was not associated with good functional outcome after adjusting for covariates.

Association of Baseline Smoking Status with Long-Term Prognosis in Patients Who Underwent Percutaneous Coronary Intervention: Large Single-Center Data

OBJECTIVES

This study analyzed a large sample to explain the association of baseline smoking state with long-term prognosis of coronary artery disease (CAD) patients who underwent percutaneous coronary intervention (PCI).

BACKGROUND

Data is limited up to now regarding whether smoker's paradox exists in Chinese population.

METHODS

A total of 10724 consecutive cases were enrolled from January to December 2013. 2-year clinical outcomes were evaluated among current smokers and nonsmokers. Major adverse coronary event (MACCE) included all-cause death, revascularization, myocardial infarction (MI), and stroke.

RESULTS

Current smokers and nonsmokers accounted for 57.1% and 42.9%, respectively. Current smokers were presented with predominant male sex, lower age, and less comorbidities. The rates of 2-year all-cause death were not significantly different among two groups. But the rate of stroke and bleeding was significantly higher in nonsmokers than in current smokers (1.6% and 1.1%, P=0.031; 7.2% and 6.1%, P=0.019). The rate of revascularization was significantly higher in current smokers than in nonsmokers (9.1% and 8.0%, P=0.037). Multivariable Cox regression indicated that, compared with nonsmokers, current smokers were not independently associated with all endpoints (all P>0.05).

CONCLUSIONS

2-year all-cause death, MACCE, MI, revascularization, stroke, ST, and bleeding risk were similar between current smokers and nonsmokers in CAD patients undergoing PCI.

Impact of smoking on cardiac magnetic resonance infarct characteristics and clinical outcome in patients with non-ST-elevation myocardial infarction

Data derived from several studies suggest a better survival in smokers with acute myocardial infarction, a phenomenon referred to as the 'smoker's paradox'. We aimed to investigate the association of smoking with cardiac magnetic resonance (CMR) imaging determined infarct severity and major adverse cardiac events (MACE) defined as the occurrence of death, reinfarction, and congestive heart failure at 12 months in patients with non-ST-elevation myocardial infarction (NSTEMI) reperfused by early percutaneous coronary intervention (PCI). In this multicenter, registry study 311 NSTEMI patients underwent CMR imaging 3 (interquartile range [IQR] 2-4) days after PCI. Myocardial salvage index (MSI), infarct size (IS), and microvascular obstruction (MVO) as well as MACE rate were compared according to admission smoking status. Approximately one-third of patients were current smokers (n = 122, 39%). Smokers were significantly younger and less likely to have hypertension as compared to non-smokers (all p < 0.05). The extent of MSI (63.2, IQR 28.9-85.4 vs. 65.6, IQR 42.2-82.9, p = 0.30), and IS (7.2, IQR 2.3-15.7%LV vs. 7.0, IQR 2.2-12.4%LV, p = 0.27) did not differ significantly between smokers and non-smokers. Despite similar prevalence of MVO, MVO (%LV) was higher in smokers compared to non-smokers (2.0, IQR 0.9-4.7%LV vs. 1.2, IQR 0.7-2.2%LV, p = 0.03). MACE rates at 12 months were comparable in smokers and non-smokers (5.7% vs. 7.4%, p = 0.65). In NSTEMI patients, smoking is neither associated with increased myocardial salvage nor less severe myocardial damage. Clinical outcome at 12 months was similar in smokers and non-smokers.Trial registration NCT03516578.

Methods for the assessment of selection bias in drug safety during pregnancy studies using electronic medical data

Electronic health data are routinely used for population drug studies. Due to the ethical dilemma in carrying out experimental drug studies on pregnant women, the effects of medication usage during pregnancy on fetal and maternal outcomes are largely evaluated using this data collection medium. One major limitation in this type of study is the delayed inclusion of pregnancies in the cohort. For example, in the province of Quebec, Canada, a major pregnancy cohort only captured pregnancies after 20 weeks gestation. The purpose of this study was to demonstrate three methods that can be used to assess the extent of selection bias due to the delayed inclusion of pregnancies. We use causal directed acyclic graphs to explain the source of this selection bias. In an example involving a cohort of pregnant asthmatic women reconstructed from the linkage of administrative health databases from the province of Quebec, we use numerical derivations, a simulation study and a sensitivity analysis to investigate the potential for bias and loss of power due to the delayed inclusion. We find that this selection bias can be partially mitigated by controlling for variables related to (spontaneous or therapeutic) abortion and the outcome of interest. The three proposed methods allow for the pre and post hoc ascertainment of the bias. While delayed pregnancy inclusion selection bias (which includes "live birth bias") can produce substantial bias in pregnancy drug studies, all three methods are effective at producing estimates of the size of the bias.

Clinical and angiographic profiles and six months outcomes of smokers with acute ST segment elevation myocardial infarction undergoing primary percutaneous coronary angioplasty

Background

Outcomes of primary percutaneous coronary intervention (PCI) for acute STEMI (ST-segment elevation myocardial infarction) in smokers are expected to be better than non-smokers as for patients of acute STEMI with or without fibrinolytic therapy.

Objectives

This comparative study was designed to evaluate the outcomes of primary PCI in patients with acute STEMI in smokers and non-smokers. Clinical and angiographic profile of the two groups was also compared.

Methods

Over duration of two year, a total of 150 consecutive patients of acute STEMI eligible for primary PCI were enrolled and constituted the two groups [Smokers (n = 90), Non-smokers (n = 60)] of the study population. There was no difference in procedure in two groups.

Results

In the present study of acute STEMI, current smokers were about a decade younger than non-smokers (p value = 0.0002), majority were male (98.9% vs 56.6%) were male with a higher prevalence of hypertension and diabetes mellitus (61.67% vs 32.28% and 46.67% vs 14.44%, p = 0.001) respectively. Smokers tended to have higher thrombus burden (p = 0.06) but less multi vessel disease (p = 0.028). Thirty day and six month mortality was non-significantly higher in smokers 4.66% vs 1.33% (p = 0.261) and 5.33% vs 2.66% (p = NS) respectively. Rate of quitting smoking among smokers was 80.90% at 6 months.

Conclusion

The study documents that smokers with acute STEMI have similar outcomes as compared to non smokers with higher thrombus burden and lesser non culprit artery involvement. Smokers present at much younger age emphasizing the role of smoking cessation for prevention of myocardial infarction.

Cigarette smoking reduces platelet reactivity independently of clopidogrel treatment in patients with non-ST elevation acute coronary syndromes

Smokers receiving clopidogrel show a lower residual platelet reactivity than non-smokers, a phenomenon generally ascribed to smoking-induced increased production of clopidogrel active metabolite, but also associated with the high hemoglobin levels of smokers, which decreases platelet reactivity in tests that measure platelet function in whole blood. We evaluated the impact of cigarette smoking and of hemoglobin levels on platelet reactivity index (PRI) measured by the vasodilator-stimulated phosphoprotein phosphorylation (VASP-P) assay in whole blood samples from patients with non-ST elevation acute coronary syndrome (NSTE-ACS) undergoing percutaneous coronary interventions, both before and after clopidogrel administration. PRI was measured in 718 clopidogrel-naïve NSTE-ACS patients, both before and 1 month after treatment with clopidogrel (75 mg daily). Smokers (n = 347, 48%) had significantly lower mean PRI levels at both baseline (57.7 ± 24.1 vs. 64.8 ± 19.8, p < 0.001) and 1 month (43.4 ± 20.3% vs. 46.8 ± 18.0%, p = 0.017) than non-smokers. After adjusting for potential confounders (age, sex, diabetes, chronic kidney disease, Syntax score>15), the β coefficient of smoke on PRI was -8.51 [-11.90 to -5.11, p < 0.001] at baseline and -3.41 [-6.30 to -0.51, p = 0.02] after 1 month. Hemoglobin was higher in smokers (13.8 ± 1.5 g/dL) than non-smokers (13.1 ± 1.7 g/dL, p < 0.001), but was not significantly correlated with PRI both at baseline (Rho = 0.02, p = 0.60) and at 1 month (Rho = 0.01, p = 0.80). Our analysis confirms that clopidogrel-treated smokers have lower platelet reactivity, measured by the VASP-P assay, compared to clopidogrel-treated non-smokers. However, smokers had lower platelet reactivity already before receiving clopidogrel treatment, suggesting that smoke affects platelet reactivity independently of its potential effect on the pharmacokinetics of clopidogrel. Our data also indicate that such an effect is not mediated by increased hemoglobin levels.

Double-Dose Versus Standard-Dose Clopidogrel According to Smoking Status Among Patients With Acute Coronary Syndromes Undergoing Percutaneous Coronary Intervention

Background

Prior Studies have suggested better outcomes in smokers compared with nonsmokers receiving clopidogrel (“smoker's paradox”). The impact of a more intensive clopidogrel regimen on ischemic and bleeding risks in smokers with acute coronary syndromes requiring percutaneous coronary interventions remains unclear.

Methods and Results

We analyzed 17 263 acute coronary syndrome patients undergoing percutaneous coronary intervention from the CURRENT‐OASIS 7 (Clopidogrel and Aspirin Optimal Dose Usage to Reduce Recurrent Events—Seventh Organization to Assess Strategies in Ischemic Symptoms) trial, which compared double‐dose (600 mg day 1;150 mg days 2–7; then 75 mg daily) versus standard‐dose (300 mg day 1; then 75 mg daily) clopidogrel in acute coronary syndrome patients. The primary outcome was cardiovascular death, myocardial infarction, or stroke at 30 days. Interactions between treatment allocation and smoking status (current smokers versus nonsmokers) were evaluated. Overall, 6394 patients (37.0%) were current smokers. For the comparison of double‐ versus standard‐dose clopidogrel, there were significant interactions in smokers and nonsmokers for the primary outcome (P=0.031) and major bleeding (P=0.002). Double‐ versus standard‐dose clopidogrel reduced the primary outcome among smokers by 34% (hazard ratio [HR] 0.66, 95% confidence interval [CI], 0.50–0.87, P=0.003), whereas in nonsmokers, there was no apparent benefit (HR 0.96, 95% CI, 0.80–1.14, P=0.61). For major bleeding, there was no difference between the groups in smokers (HR 0.77, 95% CI, 0.48–1.24, P=0.28), whereas in nonsmokers, the double‐dose clopidogrel regimen increased bleeding (HR 1.89, 95% CI, 1.37–2.60, P<0.0001). Double‐dose clopidogrel reduced the incidence of definite stent thrombosis in smokers (HR 0.41, 95% CI, 0.24–0.71) and nonsmokers (HR 0.63, 95% CI, 0.42–0.93; P for interaction=0.19).

Conclusions

In smokers, a double‐dose clopidogrel regimen reduced major cardiovascular events and stent thrombosis after percutaneous coronary intervention, with no increase in major bleeding. This suggests that clopidogrel dosing in patients with acute coronary syndromes should be personalized, taking into consideration both ischemic and bleeding risk.

Clinical Trial Registration

URL: https://www.clinicaltrials.gov. Unique identifier: NCT00335452.

Association Between Health Insurance Status and In-Hospital Outcomes After ST-Segment Elevation Myocardial Infarction

Lack of health insurance is associated with adverse clinical outcomes; however, association between health insurance status and outcomes in patients presenting with ST-elevation myocardial infarction (STEMI) is unclear. Using the Nationwide Inpatient Sample data from 2003 to 2014, hospitalizations with STEMI in patients 18 years of age and older were extracted. Based on health insurance status, patients were categorized into insured and uninsured groups. The primary outcome measure was in-hospital mortality. Adjusted analysis using inverse probability weighting with multivariable regression was performed to identify independent predictors of in-hospital mortality. Of 2,710,375 patients included in the final analysis, 220,770 patients were uninsured. Unadjusted in-hospital mortality was lower in uninsured patients (5.1% vs 9.3%; p <0.001). Adjusted analysis showed that lack of health insurance was associated with the worst in-hospital mortality (odds ratio [OR] = 1.77, 95% confidence interval [CI] 1.72 to 1.82; p <0.001). Other independent predictors of in-hospital mortality were low household income (OR = 1.08, 95% CI 1.07 to 1.09; p <0.001), acute stroke (OR = 2.87, 95% CI 2.80 to 2.95; p <0.001), acute kidney injury (OR = 2.60, 95% CI 2.57 to 2.64; p <0.001), cardiac arrest (OR = 8.88, 95% CI 8.77 to 8.99; p <0.001), cardiogenic shock (OR = 5.81, 95% CI 5.74 to 5.88; p <0.001), requirement of pericardiocentesis (OR = 10.54, 95% CI 9.64 to 11.52; p <0.001), gastrointestinal bleeding (OR = 1.41, 95% CI 1.38 to 1.54; p <0.001), and pneumonia (OR = 1.43, 95% CI 1.41 to 1.45; p <0.001). The multivariate model demonstrated good statistical discrimination (c-statistic = 0.89). In conclusion, lack of health insurance is independently associated with increased in-hospital mortality in patients presenting with STEMI.

Functional, Cellular, and Molecular Remodeling of the Heart under Influence of Oxidative Cigarette Tobacco Smoke

Passive and active chronic cigarette smoking (CS) remains an international epidemic and a key risk factor for cardiovascular disease (CVD) development. CS-induced cardiac damage is divided into two major and interchangeable mechanisms: (1) direct adverse effects on the myocardium causing smoking cardiomyopathy and (2) indirect effects on the myocardium by fueling comorbidities such as atherosclerotic syndromes and hypertension that eventually damage and remodel the heart. To date, our understanding of cardiac remodeling following acute and chronic smoking exposure is not well elucidated. This manuscript presents for the first time the RIMD (oxidative stress (R), inflammation (I), metabolic impairment (M), and cell death (D)) detrimental cycle concept as a major player in CS-induced CVD risks and direct cardiac injury. Breakthroughs and latest findings in the field with respect to structural, functional, cellular, and molecular cardiac remodeling following chronic smoking exposure are summarized. This review also touches the genetics/epigenetics of smoking as well as the smoker's paradox and highlights the most currently prominent pharmacological venues to mitigate CS-induced adverse cardiac remodeling.

A retrospective cohort study of the association between smoking and mortality after acute ST-segment elevation myocardial infarction

BACKGROUND

Several studies have shown a 'smoker's paradox', where following an acute myocardial infarction, smokers have a paradoxically lower mortality than non-smokers. To date, no large study has investigated this paradox in unselected patients with acute ST-segment elevation myocardial infarction (STEMI) managed by primary percutaneous coronary intervention (PCI) alone.

OBJECTIVES

We aimed to examine the association of smoking status and 1-year mortality in patients who had STEMI managed by primary PCI.

METHODS

This retrospective study included all patients admitted with acute STEMI undergoing primary PCI in a single UK centre from January 2009 to April 2012. The survival status for all patients post-STEMI was obtained. Differences in survival by smoking status were assessed using a Kaplan-Meier curve, and after adjustment for age, gender and additional cardiovascular risk factors using a Cox regression analysis.

RESULTS

The 1-year mortality for patients with STEMI was 149/1796 (8.3%). There were 846/1796 (47.1%) current smokers, 476/1796 (26.5%) ex-smokers and 417/1796 (23.2%) never smokers. Current smokers were approximately 10 years younger than ex-smokers and never smokers (p=0.001). A multivariate Cox proportional hazards model found no evidence of an association between mortality and smoking status after adjustment; p=0.23. Compared with never smokers, the HR (95% CI) for 1-year mortality for current smokers was 1.47 (0.90 to 2.39) and 1.08 (0.66 to 1.77) for ex-smokers.

CONCLUSIONS

In this retrospective cohort study, we found no evidence of an association between mortality and smoking status in patients with acute STEMI treated with PCI, and thus no evidence of a 'smoker's paradox'.

Pooled Analysis Comparing the Efficacy of Intracoronary Versus Intravenous Abciximab in Smokers Versus Nonsmokers Undergoing Primary Percutaneous Coronary Revascularization for Acute ST-Elevation Myocardial Infarction

Cigarette smokers with ST-segment elevation myocardial infarction (STEMI) may present different response to potent antithrombotic therapy compared to nonsmokers. We assessed the impact of smoking status and intracoronary abciximab in patients with STEMI undergoing primary percutaneous coronary intervention (PCI). We pooled data from 5 randomized trials comparing intracoronary versus intravenous abciximab bolus in patients undergoing primary PCI. The primary end point was the composite of death or reinfarction at a mean follow-up of 292 ± 138 days. Of 3,158 participants, 1,369 (43.3%) were smokers, and they had a lower risk of the primary end point in crude, but not in adjusted analyses (hazard ratio [HR] 0.87, 95% confidence interval [CI] 0.63 to 1.21, p = 0.405). Intracoronary versus intravenous abciximab was associated with a significant reduction in the risk of primary end point among smokers (3.6% vs 8.0%; HR 0.43, 95% CI 0.26 to 0.72, p = 0.001), but not in nonsmokers (10.2% vs 9.9%; HR 0.99, 95% CI 0.72 to 1.36, p = 0.96), with a significant interaction (p = 0.009). Furthermore, intracoronary abciximab decreased the risk of reinfarction in smokers (HR 0.30, 95% CI 0.15 to 0.62, p = 0.001), with no difference in nonsmokers (HR 1.20, 95% CI 0.71 to 2.01, p = 0.50). Stent thrombosis was lowered by intracoronary abciximab in smokers (HR 0.28, 95% CI 0.06 to 0.66, p = 0.009), but was ineffective in nonsmokers (HR 1.04, 95% CI 0.54 to 2.00, p = 0.903). Interaction testing showed heterogeneity in treatment effect for reinfarction (p = 0.002) and stent thrombosis (p = 0.018) according to smoking status. In conclusion, among patients with STEMI undergoing primary PCI, smoking status did not affect the adjusted risk of clinical events. Intracoronary abciximab bolus improved clinical outcomes by reducing the risk of death or reinfarction.

The value of the Clinical SYNTAX Score in predicting long-term prognosis in patients with ST-segment elevation myocardial infarction who have undergone primary percutaneous coronary intervention

BACKGROUND

The Clinical SYNTAX Score (CSS) combines anatomical and clinical risk assessment.

OBJECTIVES

This study was designed to evaluate CSS as a predictor of prognosis in patients with ST-elevation myocardial infarction (STEMI) undergoing a primary percutaneous coronary intervention (p-PCI).

METHODS

We evaluated 433 patients who were diagnosed with STEMI and underwent p-PCI. CSS was calculated by multiplying the anatomically derived SYNTAX score (Sx) by the modified age, creatinine, and ejection fraction score. Patients were divided into tertiles according to the CSS: CSS(Low)≤14 (n=141), 14<CSS(Mid)≤26 (n=144), and CSS(High)>26 (n=148). The primary endpoints were defined as all-cause mortality, myocardial infarction, and cerebrovascular events over 15 months' follow-up.

RESULTS

Primary endpoints were achieved in 9.2% of patients with CSS≤14, 12.5% of those with 14<CSS≤26, and 28.4% of those with CSS>26 (P<0.001). Kaplan-Meier analysis showed that the CSS>26 group had a significantly higher incidence of primary endpoints [P (log-rank)<0.001]. CSS>26 was identified as an independent predictor for all-cause mortality, myocardial infarction, and cerebrovascular events (hazard ratio 3.58, 95% confidence interval 1.68-7.60, P=0.001). Receiver operating characteristic analysis found areas under the curve of 0.66, 0.59, and 0.64 for CSS, Sx score, and age, creatinine, and ejection fraction score (P<0.001, P=0.01, P<0.001, respectively).

CONCLUSION

CSS may be better than the Sx score for predicting long-term prognosis in patients with STEMI undergoing p-PCI.

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.