Impact of smoking status on outcomes of primary coronary intervention for acute myocardial infarction--the smoker's paradox revisited

Investigation of smoking on the antiplatelet response to clopidogrel: Unravelling the smoker's paradox

The intricate relationship between smoking and the effects of the antiplatelet drug clopidogrel has been termed the "smoker's paradox". This paradox details the enhanced efficacy of clopidogrel in smokers compared to non-smokers. This review begins with an exploration of the proposed mechanisms of the smoker's paradox, particularly drawing attention to the induction of cytochrome P450 (CYP) isoenzymes via tobacco smoke, specifically the enzymes CYP1A2 and CYP2C19. Moreover, an investigation of the effects of genetic variability on the smoker's paradox was undertaken from both clinical and molecular perspectives, delving into the effects of ethnicity and genetic polymorphisms. The intriguing role of CYP1A2 genotypes and the response to clopidogrel in smoking and non-smoking populations was examined conferring insight into the individuality rather than universality of the smoker's paradox. CYP1A2 induction is hypothesised to elucidate the potency of smoking in exerting a counteracting effect in those taking clopidogrel who possess CYP2C19 loss of function polymorphisms. Furthermore, we assess the comparative efficacies of clopidogrel and other antiplatelet agents, namely prasugrel and ticagrelor. Studies indicated that prasugrel and ticagrelor provided a more consistent effect and further reduced platelet reactivity compared to clopidogrel within both smoking and non-smoking populations. Personalised dosing was another focus of the review considering patient comorbidities, genetic makeup, and smoking status with the objective of improving the antiplatelet response of those taking clopidogrel. In summation, this review provides insight into multiple areas of research concerning clopidogrel and the smoker's paradox taking into account proposed mechanisms, genetics, other antiplatelet agents, and personalised dosing.

Preinterventional pan-immune-inflammation value as a tool to predict postcontrast acute kidney injury among acute coronary syndrome patients implanted drug-eluting stents: a retrospective observational study

We evaluated the value of pan-immune-inflammation value (PIV) in predicting the risk for postcontrast acute kidney injury (PCAKI), an important complication following percutaneous coronary intervention (PCI) in acute coronary syndrome (ACS) patients. Medical records of 839 ACS patients underwent PCI between June 2019 and December 2022 were retrospectively analyzed. Patients were divided into two groups: PCAKI (-) and PCAKI (+). PCAKI was defined as a ≥ 0.5 mg/dL and/or a ≥ 25% increase in serum creatinine within 72 h after PCI. The PIV was computed as [neutrophils × platelets × monocytes]÷lymphocytes. The mean age was 60.7 ± 12.9 years. PCAKI was detected in 105 (12.51%) patients. PIV was higher in the PCAKI (+) group compared to PCAKI (-) group (median 1150, interquartile range [IQR] 663-2021 vs median 366, IQR 238-527, p < 0.001). Receiver operating characteristic curve analysis showed that the best cutoff of PIV for predicting PCAKI was 576 with 81% sensitivity and 80% specificity. PIV was superior to neutrophil-lymphocyte ratio and platelet-lymphocyte ratio for the prediction of PCAKI (area under curve:0.894, 0.849 and 0.817, respectively, p < 0.001 for all). A high PIV was independently correlated with PCAKI (≤576 vs. >576, odds ratio [OR] 12.484, 95%confidence interval [CI] 4.853-32.118, p < 0.001) together with older age (OR 1.058, p = 0.009), female gender (OR 4.374, p = 0.005), active smoking (OR 0.193, p = 0.012), left ventricular ejection fraction (OR 0.954, p = 0.021), creatinine (OR 10.120, p < 0.001), hemoglobin (OR 0.759, p = 0.019) and c-reactive protein (OR 1.121, p = 0.002). In conclusion, a high PIV seems to be an easily assessable tool that can be used in clinical practice for predicting the risk of PCAKI in ACS patients implanted drug-eluting stents.

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.

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.

Clopidogrel Resistance in Patients With Stroke Recurrence Under Single or Dual Antiplatelet Treatment

Background: The factors associated with clopidogrel resistance in patients with stroke recurrence receiving single or dual antiplatelet treatment (SAPT or DAPT) may differ. This study compared the high on-treatment platelet reactivities (HPRs) and the factors associated with clopidogrel resistance in recurrent ischemic stroke patients receiving clopidogrel or aspirin and clopidogrel.

Methods: We enrolled and allocated 275 recurrent ischemic stroke patients to the clopidogrel and DAPT groups and compared their demographics, conventional risk factors, and P2Y12 reaction units (PRUs). Clopidogrel resistance was categorized as PRU higher than 275. We performed a multivariate logistic regression analysis to determine the factors underlying clopidogrel resistance during SAPT and DAPT.

Results: In total, 145 (52.7%) and 130 (47.3%) patients received clopidogrel and DAPT, respectively at recurrence. The risk factors of the two groups were not significantly different, except that coronary artery disease was more frequent in the DAPT group. The PRU was higher (255 ± 91 vs. 221 ± 84; p = 0.002) and clopidogrel resistance was more frequent (45.5 vs. 31.5%; p = 0.018) in the SAPT than in the DAPT group. Hyperlipidemia was associated with clopidogrel resistance during SAPT, and smoking (Odds ratio = 0.426, 95% confidence interval 0.210–0.861; p = 0.018) had a protective effect against clopidogrel resistance. For those receiving DAPT, old age, female, low hemoglobin A1c level, and high ARU were associated with clopidogrel resistance.

Conclusions: HPR and clopidogrel resistance were more frequent in recurrent ischemic stroke patients receiving clopidogrel than in those receiving DAPT. Smoking was independently associated with less clopidogrel resistance among those receiving clopidogrel SAPT but not in those receiving DAPT.

Effects of smoking on delayed neuropsychiatric sequelae in acute carbon monoxide poisoning: A prospective observational study

Smoking is a well-known risk factor for cardio-cerebrovascular disease. However, several studies have reported the "smoker's paradox" whereby smokers have a better prognosis for cardio-cerebrovascular diseases. Similar to cardio-cerebrovascular diseases, hypoxia is one of the major mechanisms of injury in carbon monoxide (CO) poisoning. This study investigated the association between smoking and delayed neuropsychiatric sequelae (DNS) in acute CO poisoning.This study involved patients with CO poisoning treated at a university hospital in Bucheon, Korea between September 2017 and March 2020. The exclusion criteria were age <18 years, discharge against medical advice, loss to follow-up, persistent neurological symptoms at discharge, transfer from another hospital 24 hours after exposure, and transfer from another hospital after hyperbaric oxygen therapy. Logistic regression analysis was performed to find factors associated with DNS.Two hundred sixty three patients visited the hospital due to CO poisoning and of these, 54 were excluded. DNS was evaluated up to 3 months after discharge, and until this time, DNS occurred in 35 (16.8%) patients. And the incidence rate of DNS was lower in smokers than non-smokers (15, 12% vs 20, 23.8%, P = .040). Multivariable logistic regression analysis revealed that CO exposure time (odds ratio [OR] 1.003; confidence interval [CI] 1.001-1.005; P = .003), the Glasgow coma scale (GCS) (OR 0.862; CI 0.778-0.956; P = .005), and pack-years (OR 0.947; CI 0.903-0.993; P = .023) were statistically significant for DNS development.These results indicate that more pack-years smoked were associated with reduced risk of the development of DNS in acute CO poisoning, and that CO exposure time and GCS is a predictive factor for DNS occurrence.

Association between smoking and in-hospital mortality in patients with left ventricular dysfunction undergoing coronary artery bypass surgery: a propensity-matched study

Background

Data on the effect of smoking on In-hospital outcome in patients with left ventricular dysfunction undergoing coronary artery bypass graft (CABG) surgery are limited. We sought to determine the influence of smoking on CABG patients with left ventricular dysfunction.

Methods

A retrospective study was conducted using data from the China Heart Failure Surgery Registry database. Eligible patients with left ventricular ejection fraction less than 50% underwent isolated CABGS were included. In addition to the use of multivariate regression models, a 1–1 propensity scores matched analysis was performed. Our study (n = 6531) consisted of 3635 smokers and 2896 non-smokers. Smokers were further divided into ex-smokers (n = 2373) and current smokers (n = 1262).

Results

The overall in-hospital morality was 3.9%. Interestingly, current smokers have lower in-hospital mortality than non-smokers [2.3% vs 4.9%; adjusted odds ratio (OR) 0.612 (95% CI 0.395–0.947) ]. No difference was detected in mortality between ex-smokers and non-smokers [3.6% vs 4.9%; adjusted OR 0.974 (0.715–1.327)]. No significant differences in other clinical end points were observed. Results of propensity-matched analyses were broadly consistent.

Conclusions

It is paradoxically that current smokers had lower in-hospital mortality than non-smokers. Future studies should be performed to further understand the biological mechanisms that may explain this ‘smoker’s paradox’ phenomenon.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02056-9.

A brief history of carbon monoxide and its therapeutic origins

It is estimated that 10% of carbon throughout the cosmos is in the form of carbon monoxide (CO). Earth's earliest prebiotic atmosphere included the trinity of gasotransmitters CO, nitric oxide (NO), and hydrogen sulfide (H₂S), for which all of life has co-evolved with. The history of CO can be loosely traced to mythological and prehistoric origins with rudimentary understanding emerging in the middle ages. Ancient literature is focused on CO's deadly toxicity which is understandable in the context of our primitive relationship with coal and fire. Scientific inquiry into CO appears to have emerged throughout the 1700s followed by chemical and toxicological profiling throughout the 1800s. Despite CO's ghastly reputation, several of the 18th and 19th century scientists suggested a therapeutic application of CO. Since 2000, the fundamental understanding of CO as a deadly nuisance has undergone a paradigm shift such that CO is now recognized as a neurotransmitter and viable pharmaceutical candidate. This review is intended to provide a brief history on the trace origins pertaining to endogenous formation and therapeutic application of CO.

Comparing the Timeliness of Treatment in Younger vs. Older Patients with ST-Segment Elevation Myocardial Infarction: A Multi-Center Cohort Study

BACKGROUND

ST-segment elevation myocardial infarction (STEMI) predominantly affects older adults. Lower incidence among younger patients may challenge diagnosis.

OBJECTIVES

We hypothesize that among patients ≤ 50 years old, emergent percutaneous coronary intervention (PCI) for STEMI is delayed when compared with patients aged > 50 years.

METHODS

This 3-year, 10-center retrospective cohort study included emergency department (ED) STEMI patients ≥ 18 years of age treated with emergent PCI. We excluded patients with an electrocardiogram (ECG) completed prior to ED arrival or a nondiagnostic initial ECG. Our primary outcome was door-to-balloon (D2B) time. We compared characteristics and outcomes among younger vs. older STEMI patients, and among age subgroups.

RESULTS

There were 576 ED STEMI PCI patients, of whom 100 were ≤ 50 years old and 476 were > 50 years old. Median age was 44 years in the younger cohort (interquartile range [IQR] 41-47) vs. 62 years (IQR 57-70) among older patients. Median D2B time for the younger cohort was 76.5 min (IQR 67.5-102.5) vs. 81.0 min (IQR 65.0-105.5) in the older cohort (p = 0.91). This outcome did not change when ages 40 or 45 years were used to demarcate younger vs. older. The younger cohort had a higher prevalence of nonwhite races (38% vs. 21%; p < 0.001) and those currently smoking (36% vs. 23%; p = 0.005). The very young (≤30 years; 6/576) and very old (>80 years; 45/576) had 5.51 and 2.2 greater odds of delays.

CONCLUSION

We found no statistically significant difference in D2B times between patients ≤ 50 years old and those > 50 years old. Nonwhite patients and those who smoke were disproportionately represented within the younger population. The very young and very old had higher odds of D2B times > 90 min.

Role of Carbon Monoxide in Host-Gut Microbiome Communication

Nature is full of examples of symbiotic relationships. The critical symbiotic relation between host and mutualistic bacteria is attracting increasing attention to the degree that the gut microbiome is proposed by some as a new organ system. The microbiome exerts its systemic effect through a diverse range of metabolites, which include gaseous molecules such as H₂, CO₂, NH₃, CH₄, NO, H₂S, and CO. In turn, the human host can influence the microbiome through these gaseous molecules as well in a reciprocal manner. Among these gaseous molecules, NO, H₂S, and CO occupy a special place because of their widely known physiological functions in the host and their overlap and similarity in both targets and functions. The roles that NO and H₂S play have been extensively examined by others. Herein, the roles of CO in host-gut microbiome communication are examined through a discussion of (1) host production and function of CO, (2) available CO donors as research tools, (3) CO production from diet and bacterial sources, (4) effect of CO on bacteria including CO sensing, and (5) gut microbiome production of CO. There is a large amount of literature suggesting the "messenger" role of CO in host-gut microbiome communication. However, much more work is needed to begin achieving a systematic understanding of this issue.

Impacts of smoking status on the clinical outcomes of coronary non-target lesions in patients with coronary heart disease: a single-center angiographic study

Background

Coronary atherosclerotic plaque could go through rapid progression and induce adverse cardiac events. This study aimed to evaluate the impacts of smoking status on clinical outcomes of coronary non-target lesions.

Methods

Consecutive patients with coronary heart disease who underwent two serial coronary angiographies were included. All coronary non-target lesions were recorded at first coronary angiography and analyzed using quantitative coronary angiography at both procedures. Patients were grouped into non-smokers, quitters, and smokers according to their smoking status. Clinical outcomes including rapid lesion progression, lesion re-vascularization, and myocardial infarction were recorded at second coronary angiography. Multivariable Cox regression analysis was used to investigate the association between smoking status and clinical outcomes.

Results

A total of 1255 patients and 1670 lesions were included. Smokers were younger and more likely to be male compared with non-smokers. Increase in percent diameter stenosis was significantly lower (2.7 [0.6, 7.1] % vs. 3.5 [0.9, 8.9]%) and 3.4 [1.1, 7.7]%, P = 0.020) in quitters than those in smokers and non-smokers. Quitters tended to have a decreased incidence of rapid lesions progression (15.8% [76/482] vs. 21.6% [74/342] and 20.6% [89/431], P = 0.062), lesion re-vascularization (13.1% [63/482] vs. 15.5% [53/432] and 15.5% [67/431], P = 0.448), lesion-related myocardial infarction (0.8% [4/482] vs. 2.6% [9/342] and 1.4% [6/431], P = 0.110) and all-cause myocardial infarction (1.9% [9/482] vs. 4.1% [14/342] and 2.3% [10/431], P = 0.128) compared with smokers and non-smokers. In multivariable analysis, smoking status was not an independent predictor for rapid lesion progression, lesion re-vascularization, and lesion-related myocardial infarction except that a higher risk of all-cause myocardial infarction was observed in smokers than non-smokers (hazards ratio: 3.00, 95% confidence interval: 1.04–8.62, P = 0.042).

Conclusion

Smoking cessation mitigates the increase in percent diameter stenosis of coronary non-target lesions, meanwhile, smokers are associated with increased risk for all-cause myocardial infarction compared with non-smokers.

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.

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.

Association of Smoking Cessation and Survival Among Young Adults With Myocardial Infarction in the Partners YOUNG-MI Registry

IMPORTANCE

Despite significant progress in primary prevention, the rate of myocardial infarction (MI) continues to increase in young adults.

OBJECTIVES

To identify the prevalence of tobacco use and to examine the association of both smoking and smoking cessation with survival in a cohort of adults who experienced an initial MI at a young age.

DESIGN, SETTING, AND PARTICIPANTS

The Partners YOUNG-MI registry is a retrospective cohort study from 2 large academic centers in Boston, Massachusetts, that includes patients who experienced an initial MI at 50 years or younger. Smoking status at the time of presentation and at 1 year after MI was determined from electronic medical records. Participants were 2072 individuals who experienced an MI at 50 years or younger between January 2000 and April 2016. The dates of analysis were October to December 2019.

MAIN OUTCOMES AND MEASURES

Deaths were ascertained from the Social Security Administration Death Master File, the Massachusetts Department of Vital Statistics, and the National Death Index. Cause of death was adjudicated independently by 2 cardiologists. Propensity score-adjusted Cox proportional hazards modeling was used to evaluate the association between smoking cessation and both all-cause and cardiovascular mortality.

RESULTS

Among the 2072 individuals (median age, 45 years [interquartile range, 42-48 years]; 1669 [80.6%] men), 1088 (52.5%) were smokers at the time of their index hospitalization. Of these, 910 patients were further classified into either the cessation group (343 [37.7%]) or the persistent smoking group (567 [62.3%]) at 1 year after MI. Over a median follow-up of 11.2 years (interquartile range, 7.3-14.2 years), individuals who quit smoking had a statistically significantly lower rate of all-cause mortality (hazard ratio [HR], 0.35; 95% CI, 0.19-0.63; P < .001) and cardiovascular mortality (HR, 0.29; 95% CI, 0.11-0.79; P = .02). These values remained statistically significant after propensity score adjustment (HR, 0.30 [95% CI, 0.16-0.56; P < .001] for all-cause mortality and 0.19 [95% CI, 0.06-0.56; P = .003] for cardiovascular mortality).

CONCLUSIONS AND RELEVANCE

In this cohort study, approximately half of individuals who experienced an MI at 50 years or younger were active smokers. Among them, smoking cessation within 1 year after MI was associated with more than 50% lower all-cause and cardiovascular mortality.

Smoking Cessation After Surgery and Midterm Outcomes of Surgical Revascularization

BACKGROUND

Although multiple studies have reported the devastating effect of cigarette smoking (CS) on short-term outcomes of patients who underwent coronary artery bypass grafting surgery (CABG), its effect on long-term outcomes is still questionable. We aimed to evaluate the long-term outcomes of CS cessation after CABG surgery.

METHODS

This retrospective cohort study included all patients who underwent isolated CABG at our center between 2007 and 2016 and were cigarette smokers either just before or at the time of surgery. Patients were stratified into those who continued CS and those who were persistently CS abstinent after CABG. The endpoints of the study were 5-year mortality and 5-year major adverse cardiovascular and cerebrovascular events.

RESULTS

Of 28,945 patients who underwent isolated CABG, 9173 current cigarette smokers (93.5% men; mean age, 58.6 years) met our selection criteria and were included in the final analysis. Of these 3302 patients (40.0%) continued CS after surgery and 5688 patients were persistently abstinent. Multivariable survival analysis demonstrated that CS cessation after CABG, adjusted for major coronary risk factors, could reduce the 5-year mortality by 35% (hazard ratio, 0.65; 95% confidence interval, 0.54-0.77; P < .001) and 5-year major adverse cardiovascular and cerebrovascular events by 18% (hazard ratio, 0.82; 95% confidence interval, 0.74-0.92; P = .001).

CONCLUSIONS

Our study shows that CS abstinence after CABG significantly reduces long-term mortality and number of major adverse events. As a result, patients who smoke should be encouraged to participate in CS cessation programs after CABG surgery.

Impact of Smoking on Platelet Reactivity and Clinical Outcomes After Percutaneous Coronary Intervention

Background:

Smoking is a potent risk factor for coronary artery disease; however, prior studies describe increased platelet inhibition with clopidogrel among smokers, and some studies report improved outcomes among smokers, a finding described as the smoker’s paradox. This study assessed the relationship between platelet reactivity and clinical outcomes after percutaneous coronary interventions among current smokers and nonsmokers.

Methods:

ADAPT-DES (Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents) was a prospective, multicenter registry of patients treated with coronary drug-eluting stents. Platelet reactivity was assessed by the VerifyNow point-of-care assay; high on-treatment platelet reactivity (HPR) was defined as P2Y12 reaction units >208. A propensity-adjusted multivariable analysis was performed to determine the relationship between current smoking, platelet reactivity, and subsequent adverse events.

Results:

Among 8582 patients, 22.6% were active smokers at the time of their percutaneous coronary intervention procedure. Current smokers were younger and had fewer comorbidities compared with nonsmokers. Current smokers had lower mean P2Y12 reaction units and lower rates of HPR compared with nonsmokers. Current smokers had similar rates of adverse events compared with nonsmokers. HPR was associated with higher rates of adverse events for both smokers and nonsmokers; however, there was evidence of interaction between smoking status and the effect of HPR. Smokers with HPR had significantly higher rates of stent thrombosis. Adverse event rates were highest among current smokers with HPR.

Conclusions:

Current smoking was associated with lower P2Y12 reaction units and lower rates of HPR on average; however, the combination of current smoking and HPR was associated with high rates of stent thrombosis.

Clinical Trial Registration:

URL: https://www.clinicaltrials.gov . Unique identifier: NCT00638794.

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

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

TRIAL REGISTRATION NUMBER

NCT01874691.

Clinical, Angiographic Characteristics and In-Hospital Outcomes of Smoker and Nonsmoker Patients After Primary Percutaneous Coronary Intervention

BACKGROUND

Smoking is a well-established cardiac risk factor there is dearth of Local data regarding clinical and angiographic characteristics of smoker patients.

OBJECTIVES

This study was planned to assess the differences in the clinical characteristics, angiographic characteristics, and in-hospital outcomes of smokers and nonsmokers after primary percutaneous coronary intervention at a tertiary care hospital in Karachi, Pakistan.

METHODS

We included patients between 40 and 80 years of age diagnosed with ST-segment elevation myocardial infarction who underwent primary percutaneous coronary intervention from July 1, 2017, to March 31, 2018. Clinical and angiographic characteristics and in-hospital outcomes were obtained from the cases submitted to the National Cardiovascular Data Registry's CathPCI (Catheterization-Percutaneous Coronary Intervention) Registry from our site.

RESULTS

A total of 3,255 patients were included in this study. Smokers consist of 25.1% (817) of the total sample. A high majority of smokers were male, 98.8% (807), and smokers were relatively younger as compared to nonsmokers with a mean age of 52.89 ± 10.59 versus 55.98 ± 11.24 years; p < 0.001. Smokers had higher post-procedure TIMI (Thrombolysis In Myocardial Infarction) flow grade III: 97.8% (794) versus 95.53% (2,329); p = 0.037, and they had a relatively low mortality rate: 2.69% (22) versus 3.16% (77); p = 0.502.

CONCLUSIONS

Smokers were predominantly male and around 3 years younger than nonsmokers. Diabetes mellitus and hypertension were less common among smokers and single-vessel disease was the more common angiographic finding for smokers as compared to 3-vessel disease for nonsmokers. No statistically significant differences in in-hospital outcomes were observed. ST-segment elevation myocardial infarction in smokers despite younger age and the low atherosclerotic risk profile, in our region, emphasize the need for nicotine addiction management and smoking cessation campaigns at large and for pre-discharge counseling.

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.

Risk stratification model for in-hospital death in patients undergoing percutaneous coronary intervention: a nationwide retrospective cohort study in Japan

OBJECTIVES

To provide an accurate adjustment for mortality in a benchmark, developing a risk prediction model from its own dataset is mandatory. We aimed to develop and validate a risk model predicting in-hospital mortality in a broad spectrum of Japanese patients after percutaneous coronary intervention (PCI).

DESIGN

A retrospective cohort study was conducted.

SETTING

The Japanese-PCI (J-PCI) registry includes a nationally representative retrospective sample of patients who underwent PCI and covers approximately 88% of all PCIs in Japan.

PARTICIPANTS

Overall, 669 181 patients who underwent PCI between January 2014 and December 2016 in 1018 institutes.

MAIN OUTCOME MEASURES

In-hospital death.

RESULTS

The study population (n=669 181; mean (SD) age, 70.1(11.0) years; women, 24.0%) was divided into two groups: 50% of the sample was used for model derivation (n=334 591), while the remaining 50% was used for model validation (n=334 590). Using the derivation cohort, both 'full' and 'preprocedure' risk models were developed using logistic regression analysis. Using the validation cohort, the developed risk models were internally validated. The in-hospital mortality rate was 0.7%. The preprocedure model included age, sex, clinical presentation, previous PCI, previous coronary artery bypass grafting, hypertension, dyslipidaemia, smoking, renal dysfunction, dialysis, peripheral vascular disease, previous heart failure and cardiogenic shock. Angiographic information, such as the number of diseased vessel and location of the target lesion, was also included in the full model. Both models performed well in the entire validation cohort (C-indexes: 0.929 and 0.926 for full and preprocedure models, respectively) and among prespecified subgroups with good calibration, although both models underestimated the risk of mortality in high-risk patients with the elective procedure.

CONCLUSIONS

These simple models from a nationwide J-PCI registry, which is easily applicable in clinical practice and readily available directly at the patients' presentation, are valid tools for preprocedural risk stratification of patients undergoing PCI in contemporary Japanese practice.

Predictors of Outcomes and Complications After Microsurgical and Endovascular Treatment of 1300 Intracranial Aneurysms

BACKGROUND

We performed a rigorous statistical analysis of the complications and outcomes of patients with ruptured or unruptured intracranial aneurysms. Our emphasis was on the potential predictive factors when both surgical and endovascular management are offered by a team with balanced microsurgical and endovascular expertise.

METHODS

From January 2005 to December 2011, 1297 consecutive patients presenting with ruptured (n=829) or unruptured (n=468) aneurysms were prospectively enrolled in our vascular database. The treatment modality was determined by consensus of the endovascular and microsurgical teams. The patients' medical and neurological conditions and aneurysm characteristics were compared against the postintervention complication rates and outcomes using multivariate analyses.

RESULTS

The patients mostly underwent clipping for ruptured (63.7%) or unruptured (56.6%) aneurysms. For ruptured aneurysms, higher Hunt and Hess and Fisher grades on admission were key predictors of increased neurological (P < 0.001 and P < 0.001, respectively) and medical (P < 0.001 and P=0.041, respectively) complication rates. No significant differences in the outcomes were observed between the coiling or clipping groups during the follow-up period. For the unruptured group, a family history of intracranial aneurysms was the most relevant predictor for reducing neurological complication rates and increasing survival at 6 months. Hypertension was, however, the strongest factor associated with complications negatively affecting the outcomes.

CONCLUSIONS

For the ruptured and unruptured groups both, the outcomes were generally good, although neurological and medical complications were reasonably more frequent for the ruptured aneurysms. Coiling provided a sustained benefit in lowering the complication rates only in the short term for the unruptured aneurysms. Smoking was associated, paradoxically, with improved outcomes.

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.

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

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

The effects of cigarette smoking and smoking cessation on high-density lipoprotein functions: implications for coronary artery disease

BACKGROUND

Smoking cessation was associated with improved prognosis of coronary artery disease. This study was designed to investigate the effect of smoking cessation on high-density lipoprotein functionality in coronary artery disease patients.

METHODS

In this prospective, randomized and parallel controlled study, coronary artery disease smokers ( n = 28) and healthy smokers ( n = 30) were divided into smoking cessation group and continuous smoking group, respectively. Blood samples were collected before and after three-month smoking cessation. Plasma high-density lipoprotein was isolated by density gradient centrifugation. The ability of high-density lipoprotein against copper-induced oxidation of lipoprotein was determined to evaluate the antioxidative property of high-density lipoprotein, and the macrophage migration inhibited by high-density lipoprotein was tested to identify the antichemotactic property of high-density lipoprotein. High-density lipoprotein-induced macrophage cholesterol efflux was measured by fluorescence spectrometry using NBD cholesterol analogue. Healthy non-smoking volunteers were enrolled as the baseline control.

RESULTS

The baseline antioxidative, antichemotactic ability of high-density lipoprotein and high-density lipoprotein-induced cellular cholesterol efflux in coronary artery disease smokers and healthy smokers were significantly attenuated when compared with those in healthy non-smokers. After three-month smoking cessation, both the antioxidative ability and antichemotactic ability of high-density lipoprotein were improved significantly in coronary artery disease smokers. However, high-density lipoprotein-induced cellular cholesterol efflux was not increased by smoking cessation. In in vitro experiments, carbon monoxide reduced the antioxidative ability and nicotine enhanced the antichemotactic ability of high-density lipoprotein.

CONCLUSIONS

Smoking cessation is an effective measure to improve high-density lipoprotein functions in coronary artery disease smokers. Our study re-emphasizes the importance of smoking cessation in the secondary prevention of coronary artery disease.

Current Smoking and Prognosis After Acute ST-Segment Elevation Myocardial Infarction: New Pathophysiological Insights

Objectives

The aim of this study was to mechanistically investigate associations among cigarette smoking, microvascular pathology, and longer term health outcomes in patients with acute ST-segment elevation myocardial infarction (MI).

Background

The pathophysiology of myocardial reperfusion injury and prognosis in smokers with acute ST-segment elevation MI is incompletely understood.

Methods

Patients were prospectively enrolled during emergency percutaneous coronary intervention. Microvascular function in the culprit artery was measured invasively. Contrast-enhanced magnetic resonance imaging (1.5-T) was performed 2 days and 6 months post-MI. Infarct size and microvascular obstruction were assessed using late gadolinium enhancement imaging. Myocardial hemorrhage was assessed with T2* mapping. Pre-specified endpoints included: 1) all-cause death or first heart failure hospitalization; and 2) cardiac death, nonfatal MI, or urgent coronary revascularization (major adverse cardiovascular events). Binary logistic regression (odds ratio [OR] with 95% confidence interval [CI]) with smoking status was used.

Results

In total, 324 patients with ST-segment elevation MI were enrolled (mean age 59 years, 73% men, 60% current smokers). Current smokers were younger (age 55 ± 11 years vs. 65 ± 10 years, p < 0.001), with fewer patients with hypertension (52 ± 27% vs. 53 ± 41%, p = 0.007). Smokers had better TIMI (Thrombolysis In Myocardial Infarction) flow grade (≥2 vs. ≤1, p = 0.024) and ST-segment resolution (none vs. partial vs. complete, p = 0.010) post–percutaneous coronary intervention. On day 1, smokers had higher circulating C-reactive protein, neutrophil, and monocyte levels. Two days post-MI, smoking independently predicted infarct zone hemorrhage (OR: 2.76; 95% CI: 1.42 to 5.37; p = 0.003). After a median follow-up period of 4 years, smoking independently predicted all-cause death or heart failure events (OR: 2.20; 95% CI: 1.07 to 4.54) and major adverse cardiovascular events (OR: 2.79; 95% CI: 2.30 to 5.99).

Conclusions

Smoking is associated with enhanced inflammation acutely, infarct-zone hemorrhage subsequently, and longer term adverse cardiac outcomes. Inflammation and irreversible myocardial hemorrhage post-MI represent mechanistic drivers for adverse long-term prognosis in smokers. (Detection and Significance of Heart Injury in ST Elevation Myocardial Infarction. [BHF MR-MI]; NCT02072850)

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.

Stabilisation of atherosclerotic plaques

Plaque rupture and subsequent thrombotic occlusion of the coronary artery account for as many as three quarters of myocardial infarctions. The concept of plaque stabilisation emerged about 20 years ago to explain the discrepancy between the reduction of cardiovascular events in patients receiving lipid lowering therapy and the small decrease seen in angiographic evaluation of atherosclerosis. Since then, the concept of a vulnerable plaque has received a lot of attention in basic and clinical research leading to a better understanding of the pathophysiology of the vulnerable plaque and acute coronary syndromes. From pathological and clinical observations, plaques that have recently ruptured have thin fibrous caps, large lipid cores, exhibit outward remodelling and invasion by vasa vasorum. Ruptured plaques are also focally inflamed and this may be a common denominator of the other pathological features. Plaques with similar characteristics, but which have not yet ruptured, are believed to be vulnerable to rupture. Experimental studies strongly support the validity of anti-inflammatory approaches to promote plaque stability. Unfortunately, reliable non-invasive methods for imaging and detection of such plaques are not yet readily available. There is a strong biological basis and supportive clinical evidence that low-density lipoprotein lowering with statins is useful for the stabilisation of vulnerable plaques. There is also some clinical evidence for the usefulness of antiplatelet agents, beta blockers and renin-angiotensin-aldosterone system inhibitors for plaque stabilisation. Determining the causes of plaque rupture and designing diagnostics and interventions to prevent them are urgent priorities for current basic and clinical research in cardiovascular area.

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.

The prognostic significance of smoking cessation after acute coronary syndromes: an observational, multicentre study from the Melbourne interventional group registry

OBJECTIVE

We aim to ascertain the prognostic significance of persistent smoking and smoking cessation after an acute coronary syndrome (ACS) in the era of percutaneous coronary intervention (PCI) and optimal secondary prevention pharmacotherapy.

METHODS

Consecutive patients from the Melbourne Interventional Group registry (2005-2013) who were alive at 30 days post-ACS presentation were included in our observational cohort study. Patients were divided into four categories based on their smoking status: non-smoker; ex-smoker (quit >1 month before ACS); recent quitter (smoker at presentation but quit by 30 days) and persistent smoker (smoker at presentation and at 30 days). The primary endpoint was survival ascertained through the Australian National Death Index linkage. A Cox-proportional hazards model was used to estimate the adjusted HR and 95% CI for survival.

RESULTS

Of the 9375 patients included, 2728 (29.1%) never smoked, 3712 (39.6%) were ex-smokers, 1612 (17.2%) were recent quitters and 1323 (14.1%) were persistent smokers. Cox-proportional hazard modelling revealed, compared with those who had never smoked, that persistent smoking (HR 1.78, 95% CI 1.36 to 2.32, p<0.001) was an independent predictor of increased hazard (mean follow-up 3.9±2.2 years) while being a recent quitter (HR 1.27, 95% CI 0.96 to 1.68, p=0.10) or an ex-smoker (HR 1.03, 95% CI 0.87 to 1.22, p=0.72) were not.

CONCLUSIONS

In a contemporary cohort of patients with ACS, those who continued to smoke had an 80% risk of lower survival while those who quit had comparable survival to lifelong non-smokers. This underscores the importance of smoking cessation in secondary prevention despite the improvement in management of ACS with PCI and pharmacotherapy.

Clinical characteristics and prognosis of acute myocardial infarction in young smokers and non-smokers (≤ 45 years): a systematic review and meta-analysis

The effect of smoking on the prognosis of young patients with acute myocardial infarction (AMI) is inconclusive. We enrolled 2188 young AMI patients (≤ 45 years) from the cardiac center of the Chinese PLA General Hospital and Anzhen Hospital and analyzed their clinical characteristics and prognosis. We also searched the PubMed, EMBASE, and Cochrane Central Register of Controlled Trials electronic databases for January 2001 to March 2017 and considered for inclusion in a meta-analysis those clinical trials that compared prognoses of young smokers and non-smokers with AMI. The proportion of males and alcohol users was higher in young AMI smokers than in non-smokers; the proportion of hypertension was slightly lower. There was no difference in medical treatment between smokers and non-smokers. No differences were evident between smokers and non-smokers regarding in-hospital cardiac events and major adverse cardiovascular events on follow-up, including incidence of stroke. For young AMI patients, smoking did not lead to poorer prognosisin comparison with not smoking. This “smoker's paradox” needs to be confirmed by more randomized controlled multicenter prospective clinical trials.

Are women with type 2 diabetes mellitus more susceptible to cardiovascular complications following coronary angioplasty?: a meta-analysis

Background

Scientific reports have shown Type 2 Diabetes Mellitus (T2DM) to be independently associated with adverse outcomes following Percutaneous Coronary Intervention (PCI). However, gender difference has also often been a controversial issue following PCI. Till date, very few meta-analyses have systematically compared the adverse cardiovascular outcomes in male versus female patients with T2DM following PCI. Therefore, we aimed to carry out this analysis in order to find out an answer to this interesting question.

Methods

Electronic databases were searched for English language publications reporting adverse cardiovascular outcomes in male versus female patients with diabetes mellitus respectively following coronary angioplasty. The RevMan 5.3 software was used to analyze selected adverse cardiovascular events whereby Odds Ratios (OR) and 95% Confidence Intervals (CI) were the statistical parameters.

Results

A total number of 19,304 patients with T2DM (12,986 male patients versus 6318 female patients) were included in this analysis. At baseline, female patients were older (68.7 versus 62.9 years), with a higher percentage of hypertension (75.6% versus 66.5%) and dyslipidemia (53.3% versus 50.0%) whereas majority of the male patients were smokers (46.3% versus 14.9%). Results of this analysis showed short and long-term mortality to be significantly higher in female patients with T2DM (OR: 1.71, 95% CI: 1.46–2.00; P = 0.00001), and (OR: 1.20, 95% CI: 1.07–1.35; P = 0.002) respectively. In addition, women were also more at risk for short and long-term major adverse cardiac events (MACEs) with OR: 1.49, 95% CI: 1.07–2.07; P = 0.02 and OR: 1.15, 95% CI: 1.04–1.28; P = 0.009 respectively. Subgroup analysis showed this significant result to have mainly been observed in patients with acute myocardial infarction compared to those with stable coronary artery disease.

Conclusions

Following PCI, women with T2DM were indeed more susceptible to short and long-term cardiovascular complications compared to male patients with the same chronic disease. Even though this result was more applicable to patients with acute myocardial infarction, the fact that women were older with higher co-morbidities at baseline compared to men, should also not be ignored.

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'.

Impact of smoking on health-related quality of Life after percutaneous coronary intervention treated with drug-eluting stents: a longitudinal observational study

Background

Smoking has been shown to reduce health-related quality of life (HRQOL) in patients with coronary artery disease (CAD) undergoing percutanous coronary intervention (PCI) either by means of balloon angioplasty or with the use of bare-metal stents (BMS). Drug-eluting stents (DES) have now been widely used and are related to substantial reduction of restenosis and significantly improved HRQOL compared with BMS. This study aimed to evaluate the effects of smoking on HRQOL in patients after PCI in DES era.

Methods

A cohort of 649 patients admitted for CAD and treated with drug-eluting stents were included in this prospective, observational study. Patients were classified as non-smokers (n = 351, 54.1%), quitters (n = 126, 19,4%), or persistent smokers (n = 172, 26.5%) according to their smoking status at the time they first admitted to hospital and during the first year of follow-up. Each patient was prospectively interviewed at baseline, 6 months and 1 year following PCI. HRQOL was assessed with the use of Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36).

Results

For the overall population, HRQOL scores at 1-year follow-up were significantly higher than baseline for all 8 domains. At 1-year follow-up, the HRQOL scores in persistent smokers were still lower than that in non-smokers in 6 domains except for bodily pain and mental health, and than that in quitters in 5 domains except for bodily pain, role emotional and mental health. There were no significant differences with regard to the scores between non-smokers and quitters except role emotional for which non-smokers had higher scores. After adjustment, persistent smokers demonstrated significantly less improvements in HRQOL than non-smokers in 6 domains except for bodily pain and social functioning and significantly less improvement than quitters for general health. Improvements of quitters were comparable to that of non-smokers in all domains. Multivariate linear regression analyses showed persistent smoking was an independent risk factor for PCS and MCS improvements.

Conclusions

Persistent smoking substantially diminishes the potential quality-of-life benefits of DES. Efforts should be made to promote smoking cessation after DES implantation which could greatly improve the health quality outcomes.

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.

Prognostic Factors in Patients With Stemi Undergoing Primary PCI in the Clopidogrel Era: Role of Dual Antiplatelet Therapy at Admission and the Smoking Paradox on Long-Term Outcome

BACKGROUND

Several clinical and laboratory variables have an impact on the prognosis of STEMI patients undergoing PPCI; however, little is known about the role of ongoing DAPT at the time of the event and the smoking status as prognostic factors affecting the outcome of these patients.

METHODS AND RESULTS

Seven-hundred and thirteen consecutive STEMI patients undergoing PPCI, admitted to the S. Anna and S. Sebastiano Hospital (Caserta, Italy) and to the OLV Clinic (Aalst, Belgium), between March 2009 and December 2011, were retrospectively enrolled. Rescue PCI was the only exclusion criterion. Primary end-point was the combination of death for all causes, re-infarction, stroke, and target lesion revascularization (TLR). Patients already on DAPT at admission (26.4%) showed a significant increase in the event rate at univariate analysis (HR 2.34, CI 1.62-3.75, P < 0.05), while current smokers (56.5%) had a lower event rate, as compared to non-smokers (HR 0.67, CI 0.46-0.96, P < 0.05). In smoking patients already on DAPT at admission, a lower event rate was observed than in non-smoking patients on DAPT. Although, patients already on DAPT had a higher-risk profile (renal impairment, ongoing statin treatment, ST resolution <50%, and Killip class >1 were more frequently present than in patients not on DAPT), Cox regression analysis confirmed that both DAPT (HR 1.74, 95%CI 1.20-2.53, P < 0.01) and smoking status (HR 0.69, 95%CI 0.48-1.00, P < 0.05) retained their statistical significance, as they and were significantly associated with a worse and a better outcome, respectively, underlying their role as independent prognostic factors.

CONCLUSIONS

Not being a current smoker and ongoing DAPT at admission, in patients with STEMI undergoing PPCI, represent independent negative prognostic value.

Comparison of Various Strategies for the Prognosis and Outcomes of Ischaemic Dilated Cardiomyopathy in Smokers: Complete Revascularisation and Smoking Cessation Produces a Superior Outcome

BACKGROUND

Various therapies have been used to improve the symptoms and prognosis of patients with coronary artery disease. However, comparative studies showing more suitable choices for patients with ischaemic dilated cardiomyopathy (IDCM) and who smoke cigarettes are lacking.

METHODS

A total of 338 patients were divided into four groups according to whether they received complete revascularisation (CR), and/or underwent smoking cessation (SC). They were followed prospectively for 12 months. The major adverse cardiac and cerebrovascular events (MACCEs: all-cause mortality, non-fatal MI, non-fatal stroke, repeat revascularisation, and AHF) were the primary endpoint, and decompensation necessitating hospitalisation and the combined endpoint thereof were secondary endpoints.

RESULTS

During a mean follow-up of 12 months, the prevalence of MACCEs was significantly lower in patients receiving CR plus SC (CRSC) than in patients receiving CR only (CR), SC only (SC), and neither R nor SC (NoRSC) (CRSC 4.4% vs. CR 11.9, p<0.05; vs. SC 26.5%, p<0.001; vs. NoRSC 34.5%, p<0.001, respectively). At 12 months, CR plus SC induced the greatest clinical benefits of the secondary outcomes in the CRSC group (49.1% relative increase in LVEF; 89.8% decrease in NT-proBNP level; 30.9% decrease in LVEDD; 38.3% decrease in LVESD; 51.4% decrease in LVEDVi; 51.2% decrease in LVESVi; 96.4% decrease in hs-cTnT level; 93.5% decrease in CK-MB level; 91.1% decrease in hs-CRP level; 94.0% decrease in IL-6 level; 1.9-fold increase in eNOS level; 1.8-fold increase in NO level; 1.3-fold increase in NOS level, all p<0.001). Absence of revascularisation brought about fewer benefits, and those who continued smoking had worse outcomes.

CONCLUSIONS

The combination of CR and SC could be an optimal therapeutic regimen for patients with IDCM who smoke because it improves myocardial blood perfusion and endothelial function.

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.

"Smoker's paradox" in patients with cardiogenic shock complicating myocardial infarction - A substudy of the IABP-SHOCK II-trial and registry

BACKGROUND

Several studies in patients with acute myocardial infarction (AMI) without cardiogenic shock (CS) indicate a better survival in smokers, the so called "smoker's paradox". For CS, this relationship has not been investigated so far in the primary percutaneous coronary intervention (PCI) era.

METHODS

In a predefined substudy of the Intraaortic Balloon Pump in Cardiogenic Shock II (IABP-SHOCK II) trial and its accompanying registry including patients with CS complicating AMI we investigated differences in outcome of smokers compared to non-smokers. All-cause-mortality at 1year was used as primary endpoint.

RESULTS

Of 772 patients with available smoking status 263 patients were smokers (34%). Smokers were more often male (79% vs. 65%; p<0.001), of younger age (61 [interquartile range IQR 52-70] vs. 73 [IQR 64-79] years; p<0.001), had less comorbidity including arterial hypertension (62% vs. 71%; p=0.007) and diabetes mellitus (26% vs. 38%; p<0.001) and had lower levels of serum creatinine (13% vs. 25%; p<0.001). There was no significant difference between the 2 groups regarding left ventricular ejection fraction, initial revascularization strategy or use of IABP. Smokers had lower rates of mortality at 12months in univariable analysis (43% vs. 59%; p<0.001) but not after adjustment for important confounders using Cox-regression analysis (hazard ratio 0.77, 95% confidence interval 0.59-1.03; p=0.08).

CONCLUSION

Smoking is not predictive of outcome in patients with CS complicating AMI. The observed survival benefit in univariable analysis seems to be explained by the younger age and lower risk profile of smokers.