Clinical implications of cigarette smoking in acute myocardial infarction: acute angiographic findings and long-term prognosis

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.

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.

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.

No correlation between body mass index and 30-day prognostic outcome in Asians with acute ST-elevation myocardial infarction undergoing primary coronary intervention

BACKGROUND

This study investigated whether body mass index (BMI) was a risk factor predictive of 30-day prognostic outcome in Asians with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI).

MATERIAL AND METHODS

Data regarding the impact of BMI on the prognostic outcome in Asian populations after acute STEMI is scarce. A number of 925 STEMI patients were divided into three groups according to the BMI: normal weight (<25 kg/m²), overweight (≥25.0 to <30.0 kg/m²) and obese (≥30.0 kg/m²).

RESULTS

The obese group was significantly younger with significantly higher incidences of smoking and diabetes mellitus. The incidences of multi-vessel disease, final thrombolysis in myocardial infarction (TIMI)-3 flow, advanced Killip score, advance congestive heart failure, 30-day mortality and combined 30-day major adverse clinical outcome (MACO) did not differ among the three groups. Multiple regression analysis showed the age, unsuccessful reperfusion and lower left ventricular ejection fraction were most significant and independent predictor of 30-day mortality.

CONCLUSION

BMI is not a predictor of 30-day prognostic outcome in Asians with STEMI undergoing primary PCI.

One-year Mortality after an Acute Coronary Event and its Clinical Predictors: The ERICO Study

Background

Information about post-acute coronary syndrome (ACS) survival have been mostly short-term findings or based on specialized, cardiology referral centers.

Objectives

To describe one-year case-fatality rates in the Strategy of Registry of Acute Coronary Syndrome (ERICO) cohort, and to study baseline characteristics as predictors.

Methods

We analyzed data from 964 ERICO participants enrolled from February 2009 to December 2012. We assessed vital status by telephone contact and official death certificate searches. The cause of death was determined according to the official death certificates. We used log-rank tests to compare the probabilities of survival across subgroups. We built crude and adjusted (for age, sex and ACS subtype) Cox regression models to study if the ACS subtype or baseline characteristics were independent predictors of all-cause or cardiovascular mortality.

Results

We identified 110 deaths in the cohort (case-fatality rate, 12.0%). Age [Hazard ratio (HR) = 2.04 per 10 year increase; 95% confidence interval (95%CI) = 1.75–2.38], non-ST elevation myocardial infarction (HR = 3.82 ; 95%CI = 2.21–6.60) or ST elevation myocardial infarction (HR = 2.59; 95%CI = 1.38–4.89) diagnoses, and diabetes (HR = 1.78; 95%CI = 1.20‑2.63) were significant risk factors for all-cause mortality in the adjusted models. We found similar results for cardiovascular mortality. A previous coronary artery disease diagnosis was also an independent predictor of all-cause mortality (HR = 1.61; 95%CI = 1.04–2.50), but not for cardiovascular mortality.

Conclusion

We found an overall one-year mortality rate of 12.0% in a sample of post-ACS patients in a community, non-specialized hospital in São Paulo, Brazil. Age, ACS subtype, and diabetes were independent predictors of poor one‑year survival for overall and cardiovascular-related causes.

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

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Plasma concentrations of soluble CD40 ligand in smokers with acute myocardial infarction: a pilot study

Coronary artery disease (CAD) is believed to be the single leading cause of death in both men and women in the world. Smoking is the most important risk factor for CAD. Smoking increases platelet aggregation and thrombus formation. CD40 ligand (CD40L) is a transmembrane glycoprotein derived from activated platelets. It participates in thrombus formation during the acute phase of acute myocardial infarction (MI). Elevation of CD40L identifies the patients who are at highest risk for cardiac events and who are likely to benefit from treatment with the glycoprotein IIb/IIIa (GPIIb/IIIa) receptor antagonists. The purpose of this study was to evaluate levels of CD40L in smokers with acute MI. Fifty-seven patients with acute MI were enrolled in this study. Thirty-one smokers were compared with 26 non-smokers. Soluble CD40L level in the plasma was determined by a standard enzyme-linked immunosorbent assay. Circulating levels of CD40L were higher in the smokers' group. Smokers with acute MI may have increased risk for thrombotic complications during acute MI, and optimal antiaggregant therapy should be administered.

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

BACKGROUND

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

HYPOTHESIS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

["Smoker's paradox" and reperfusion's strategy in acute myocardial infarction]

Previous studies have shown that smokers with acute myocardial infarction (AMI) treated by thrombolysis have lower mortality rates than nonsmokers, a phenomenon often termed "smoker's paradox". This "smoker's paradox" has been rarely studied in case of primary angioplasty.

AIM OF THE STUDY

To evaluate the impact of smoking status on the early mortality of patients admitted with AMI with regard to the strategy of reperfusion (intravenous thrombolysis versus primary angioplasty).

PATIENTS AND METHODS

Study undertaken from the Monsatir registry of ST elevation MI including 688 patients having had either a hospital or a prehospital thrombolysis (n=397) or a primary angioplasty (n=291). Among those patients, 482 (70.1%) were active smokers.

RESULTS

In the thrombolysis group, the prevalence of hypertension, diabetes and anterior location of MI was significantly less among smokers. In the group primary angioplasty, only diabetes and hypertension were less frequent. The immediate mortality was significantly less among smokers in case of thrombolysis comparatively to non-smokers (5.3 vs 13%; p=0.008). By multivariate analysis, cardiogenic shock (p<0.0001), anterior MI (p=0.03) and active smoking (p=0.03) were independent predictive factors of mortality in case of thrombolysis. A trend toward a lower mortality among smokers was observed in the primary angioplasty group (10 vs 17.6%; p=0.07).

CONCLUSION

"The smoker's paradox" seems to be observed mainly among patients having had thrombolysis.

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

BACKGROUND

Smoking is a risk factor for coronary heart disease, but it has been associated with better short-term prognosis in hospitalized patients with acute myocardial infarction. The aims of this study were to determine the association between smoking and myocardial infarction 28-day case-fatality in hospitalized patients and at the population level; and, whether smokers presenting with fatal myocardial infarction are more likely to die before reaching a hospital.

DESIGN AND METHODS

Population-based myocardial infarction registry, carried out in 1997-1998 in seven regions of Spain, used standardized methods to find and analyze suspected myocardial infarction patients (10 654 patients; 7796 hospitalized). Four categories of smoking status were defined: never-smokers, former smokers for more than 1 year, former smokers for less than 1 year, and current smokers.

RESULTS

The main end-point was 28-day case-fatality, found to be 20.1, 17.1, 15.6, and 8.9%, in the four smoking status categories, respectively, for hospitalized patients; and 37.4, 33.0, 24.5, and 23.2%, respectively, at population level. Hospitalized current smokers had lower age, sex, and comorbidity-adjusted 28-day case-fatality than never-smokers (odds ratio=0.71; 95% confidence interval: 0.56-0.90). This association held at population level (odds ratio=0.68; 95% confidence interval: 0.60-0.76), in which former smoking was also associated with lower case-fatality. In fatal cases, recent former smokers presented a lower risk of out-of-hospital death than never-smokers (odds ratio=0.47; 95% confidence interval: 0.29-0.77), whereas current smoking was marginally associated with out-of-hospital death (odds ratio=1.22; 95% confidence interval: 0.99-1.50).

CONCLUSIONS

Current smoking is associated with lower 28-day case-fatality in hospitalized myocardial infarction patients. This association held at population level. Among fatal cases, smoking is associated with higher and recent former smoking with lower risk of dying out-of-hospital.

Planned versus provisional use of glycoprotein IIb/IIIa inhibitors in smokers undergoing percutaneous coronary intervention

Postmortem and angiographic studies have demonstrated that thrombosis is the primary cause of coronary artery occlusion in smokers. Further, smokers have high levels of fibrinogen, increased platelet aggregation, and more platelet-dependent thrombin generation than do nonsmokers, suggesting that glycoprotein (GP) IIb/IIIa inhibitor use during percutaneous coronary intervention (PCI) may be especially useful among smokers. We evaluated a subpopulation of active smokers in the REPLACE-2 trial to assess the effect of treating smokers with bivalirudin and provisional GP IIb/IIIa blockade compared with heparin and planned GP IIb/IIIa blockade. The REPLACE-2 trial enrolled 1,558 smokers and 4,305 nonsmokers. Smokers who were treated with bivalirudin had an absolute 3.2% increase in the composite end point of death and myocardial infarction at 48 hours compared with smokers who were treated with heparin and GP IIb/IIIa inhibitors (7.7% vs 4.5%, p=0.008, interaction p=0.016). This difference was ameliorated when GP IIb/IIIa inhibitors were used consistently in a previous trial that compared bivalirudin with heparin during PCI (4.6% vs 6.7%, p=0.322). In conclusion, these results suggest that smokers may derive particular benefit with GP IIb/IIIa inhibitors for decreasing myocardial infarction and death after PCI. These findings require further validation from other large, randomized trials.

Effect of smoking status on outcome after acute ischemic stroke

BACKGROUND

The status of smoking as a risk factor for the occurrence of stroke is well established. However, there is a paucity of data on the relationship between smoking status and acute stroke outcomes. We evaluated the role of recent smoking as a prognostic factor following acute ischemic stroke.

METHODS

We analyzed data from patients enrolled in the Intravenous Magnesium Efficacy in Stroke (IMAGES) trial. Outcome measures studied included change in IMAGES stroke score, poor functional outcomes at day 30 and 90 (defined as Rankin Scale >1 and Barthel Index <95), and survival over the first 3 months after stroke. The independent effect of smoking status (subjects who had smoked in the past year) on outcome was evaluated by logistic regression analysis and Cox's proportional hazards model, adjusting for variables known to predict outcome after ischemic stroke.

RESULTS

There were 2,386 subjects in the IMAGES efficacy dataset, including 615 recent or current smokers and 1,771 nonsmokers, among whom smokers were younger (p < 0.0001). After adjusting for covariates, smokers had increased odds of poor 90-day functional outcome independently of other statistically significant predictor variables, as assessed by Rankin Scale (odds ratio 1.38; 95% confidence interval 1.09-1.75) and Barthel Index (odds ratio 1.42; 95% confidence interval 1.13-1.79) at day 90. Smoking status did not affect survival at day 90.

CONCLUSIONS

Current or recent smokers experience poorer functional outcomes than nonsmokers 3 months after acute ischemic stroke.

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

OBJECTIVES

We sought to determine the relationship between cigarette smoking and outcomes after mechanical reperfusion therapy in acute myocardial infarction (AMI).

BACKGROUND

Prior studies have found that smokers with AMI have lower mortality rates and a more favorable response to fibrinolytic therapy than nonsmokers. The impact of cigarette smoking in patients undergoing primary percutaneous coronary intervention has not been examined.

METHODS

In the CADILLAC trial, 2082 patients with AMI were randomized to percutaneous transluminal coronary angioplasty +/- abciximab versus stenting +/- abciximab. Data on smoking status were prospectively collected and follow-up continued for 1 year.

RESULTS

At the time of presentation, 638 (31%) patients had never smoked, 546 (26%) were former smokers, and 898 (45%) were currently smoking. In comparison to nonsmokers, current smokers were younger, more often men, and less frequently had diabetes, hypertension, prior AMI, and triple-vessel coronary disease. Procedural success rates were unrelated to smoking status. Mortality was lowest in current smokers, intermediate in former smokers, and highest in nonsmokers at 30 days (1.3% vs 1.7% vs 3.5%, respectively, P = .02) and 1 year (2.9% vs 3.7% vs 6.6%, P = .0008). After multivariate correction for differences in baseline variables, however, current smoking status was no longer protective from late mortality (hazard ratio 0.96, 95% CI 0.52-1.76, P = .89).

CONCLUSIONS

The "smoker's paradox" extends to patients undergoing primary PCI for AMI, with increased survival seen in current smokers, an effect entirely explained by differences in baseline risk and not smoking status per se. The deleterious effects of smoking are expressed in the occurrence of AMI nearly a decade earlier than in nonsmokers, with similar age-adjusted risk, mandating intensive primary and secondary cigarette-cessation efforts.

Fifteen-year trend in the treatment and outcome of acute myocardial infarction in Japan

To assess the changes in treatment and outcome of acute myocardial infarction (AMI) over a 15-year period, the medical records of 1,437 patients with AMI who underwent emergency coronary angiography within 24h of the onset of chest pain at Hiroshima City Hospital from 1985 to 1999 were reviewed. The patients were divided into 3 groups in chronological order: group 1 (1985-89, n=439), group 2 (1990-94, n=453) and group 3 (1995-99, n=545). Conventional balloon angioplasty and thrombolysis were frequently performed in group 1 (56% and 29%, respectively) and group 2 (71% and 13%, respectively), whereas coronary stenting and conventional balloon angioplasty were more often performed in group 3 (57% and 23%, respectively). The achievement of TIMI grade 3 flow improved in the chronological order (62%, 80% and 85%, respectively; p<0.001). The incidence of reinfarction was lower in group 3 (4.2%) than groups 1 and 2 (8.0% and 7.5%, respectively; p=0.007), and in-hospital mortality decreased from group 1 to group 3 (11.8%, 8.2% and 5.5%, respectively; p=0.002). Stenting is now the most frequently chosen treatment for AMI and sustained TIMI grade 3 flow is obtained in most of the cases, with the result that mortality has reduced by 50% in the past decade.

Current smokers develop more posterior myocardial infarctions probably due to increased tendency to thrombosis

This investigation was carried out to determine whether smokers developed smaller infarcts as assessed by peak enzyme levels and also to what extent smoking could modify infarct localization. The study included 753 patients, of whom 351 had no history of previous coronary heart disease (CHD) (angina pectoris and/or myocardial infarction (MI)). The investigation was designed as an exposed (smoking) versus non-exposed (non-smoking) cohort study. Outcome was infarct size, posterior versus non-posterior MI and non-Q-wave versus Q-wave infarcts. In the total cohort of patients, 312 (41%) were smokers, the corresponding number in the restricted cohort of patients without a previous CHD (CHD-0-pts) was 169 (48%). Smokers were younger than non-smokers, and more of them were males. It was found that infarct size was similar in smokers and in non-smokers (crude and adjusted effects). Crude effects showed that smokers developed significantly more posterior infarcts than non-smokers; odds ratio (OR) for developing a posterior MI was 1.95 (2p < 0.001) (all patients) and 2.34 (2P < 0.001) (CHD-0-pts), respectively. After adjusting for confounders (logistic regression model), OR in the two groups was 1.24 (2p = 0.256) and 1.95 (2p = 0.01), respectively. The study shows that current smokers were younger, and indicates that in those without a previous CHD, significantly more of them developed a posterior MI.

Influence of previous aspirin treatment and smoking on the electrocardiographic manifestations of injury in acute myocardial infarction

OBJECTIVE

To examine demographic and clinical characteristics of patients with acute myocardial infarction in order to identify factors affecting the electrocardiographic evolution of injury.

METHODS

Prospective cohort study of 1399 consecutive patients with a first myocardial infarction. Baseline clinical data associated with ST elevation and Q wave development were identified and 12 month survival was estimated.

RESULTS

Smoking had complex effects on the evolution of injury, increasing the odds of ST elevation (odds ratio (OR) 1.61; 95% confidence interval (CI) 1.08 to 2.36), but reducing the odds of Q wave development (OR 0.69, 95% CI 0.49 to 0.96). The effects of previous aspirin treatment were more consistent with reductions in the odds of ST elevation (OR 0.57, 95% CI 0.35 to 0.94) and Q wave development (OR 0.53, 95% CI 0.34 to 0. 84). ST elevation and Q wave development were both associated with an adverse prognosis, with estimated 12 month survival rates of 80. 6% (95% CI 78.2% to 83.1%) and 80.0% (95% CI 77.5% to 82.5%), respectively, compared with 86.5% (95% CI 81.2% to 91.9%) and 89.9% (95% CI 86.2% to 93.7%) for patients without these ECG changes.

CONCLUSIONS

The thrombogenicity of the blood may be a major determinant of infarct severity. Smoking increases thrombogenicity and the likelihood of ST elevation, but because coronary occlusion is relatively more thrombotic in smokers, responses to both endogenous and exogenous thrombolysis are better, reducing the risk of Q wave development. Previous aspirin treatment reduces thrombogenicity, protecting against ST elevation and Q wave development.