Smoking and prognosis after acute myocardial infarction in the thrombolytic era (Israeli Thrombolytic National Survey)

Smoking paradox in coronary function and structure of acute ST-segment elevation myocardial infarction patients treated with primary percutaneous coronary intervention

BACKGROUND

The Smoking paradox has generated inconsistent findings concerning the clinical prognosis of acute ST-segment elevation myocardial infarction (STEMI) patients, while providing limited insights into coronary anatomy and function which are crucial prognostic factors. Therefore, this study aimed to further investigate the existence of smoking paradox in coronary anatomy and function.

METHODS

This study divided STEMI patients into smokers and non-smokers. Quantitative coronary angiography, angiography‑derived microcirculatory resistance (AMR) and quantitative flow ratio (QFR) were utilized to analyze coronary anatomy and function. These parameters were compared using multivariable analysis and propensity score matching. The clinical outcomes were evaluated using Kaplan-Meier curve and Cox regression.

RESULTS

The study included 1258 patients, with 730 in non-smoker group and 528 in smoker group. Smokers were significantly younger, predominantly male, and had fewer comorbidities. Without adjusting for confounders, smokers exhibited larger lumen diameter [2.03(1.45-2.57) vs. 1.90(1.37-2.49), P = 0.033] and lower AMR [244(212-288) vs. 260(218-301), P = 0.006]. After matching and multivariate adjustment, smokers exhibited inversely smaller lumen diameter [1.97(1.38-2.50) vs. 2.15(1.63-2.60), P = 0.002] and higher incidence of coronary microvascular dysfunction [233(53.9%) vs. 190(43.6%), P = 0.002], but showed similar AMR and clinical outcomes compared to non-smokers. There was no difference in QFR between two groups.

CONCLUSION

Smoking among STEMI patients undergoing pPCI was associated with smaller lumen diameter and higher occurrence of coronary microvascular dysfunction, although it had no further impact on clinical prognosis. The smoking paradox observed in coronary anatomy or function may be explained by younger age, gender, and lower prevalence of comorbidities.

Impact of Smoking Status on Mortality in STEMI Patients Undergoing Mechanical Reperfusion for STEMI: Insights from the ISACS-STEMI COVID-19 Registry

The so-called “smoking paradox”, conditioning lower mortality in smokers among STEMI patients, has seldom been addressed in the settings of modern primary PCI protocols. The ISACS−STEMI COVID-19 is a large-scale retrospective multicenter registry addressing in-hospital mortality, reperfusion, and 30-day mortality among primary PCI patients in the era of the COVID-19 pandemic. Among the 16,083 STEMI patients, 6819 (42.3%) patients were active smokers, 2099 (13.1%) previous smokers, and 7165 (44.6%) non-smokers. Despite the impaired preprocedural recanalization (p < 0.001), active smokers had a significantly better postprocedural TIMI flow compared with non-smokers (p < 0.001); this was confirmed after adjustment for all baseline and procedural confounders, and the propensity score. Active smokers had a significantly lower in-hospital (p < 0.001) and 30-day (p < 0.001) mortality compared with non-smokers and previous smokers; this was confirmed after adjustment for all baseline and procedural confounders, and the propensity score. In conclusion, in our population, active smoking was significantly associated with improved epicardial recanalization and lower in-hospital and 30-day mortality compared with previous and non-smoking history.

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

Background

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

Methods

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

Results

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

Conclusions

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

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

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

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

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

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

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

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

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

BACKGROUND

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

OBJECTIVES

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

DESIGN

Retrospective review of medical records.

SETTING

Multicenter registry in South Korea.

PATIENTS AND METHODS

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

MAIN OUTCOME MEASURES

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

SAMPLE SIZE

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

RESULTS

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

CONCLUSION

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

LIMITATIONS

Retrospective design.

CONFLICTS OF INTEREST

None.

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Usefulness of Calculation of Cardiovascular Risk Factors to Predict Outcomes in Patients With Acute Myocardial Infarction

Cardiovascular risk factors contribute differently to short-term prognosis of acute myocardial infarction (AMI); hypertension and diabetes increase adverse outcomes, whereas hyperlipidemia, smoking, and obesity seem to paradoxically decrease these in post-MI patients. We aimed to investigate whether a simple calculation of conventional risk factors, PARADOCS (Pressure of ARtery elevAtion, Diabetes, Obesity, Cholesterol, Smoking) score, would improve the ability to predict major adverse cardiac and cerebrovascular events (MACCEs) in post-MI patients. Between November 2011 and December 2015, 13,104 patients with diagnosis of AMI were analyzed in this study from Korean AMI Registry - National Institute of Health database. PARADOCS score was calculated as follows: (number of nonparadoxical risk factors - number of paradoxical risk factors) + 3 where nonparadoxical risk factors are hypertension and diabetes, and paradoxical risk factors are hyperlipidemia, smoking, and obesity. PARADOCS score was significantly greater in patients with 1-year MACCEs compared with those without MACCEs (3.43 ± 1.03 vs 2.88 ± 1.11, p <0.001). In Cox proportional hazards model, PARADOCS score was an independent predictor of 1-year MACCEs (hazards ratio 1.23, 95% confidence interval 1.16 to 1.30; p <0.001) after adjusting for confounding variables. In Kaplan-Meier survival curve, patients with greater PARADOCS score had worse clinical outcome. In conclusion, although it needs more validation, a simple calculation of risk factors, PARADOCS score, could provide useful prognostic information of MI patients to clinicians.

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.

Gender but not diabetes, hypertension or smoking affects infarct evolution in ST-elevation myocardial infarction patients - data from the CHILL-MI, MITOCARE and SOCCER trials

BACKGROUND

Infarct evolution rate and response to acute reperfusion therapy may differ between patients, which is important to consider for accurate management and treatment of patients with ST-elevation myocardial infarction (STEMI). The aim of this study was therefore to investigate the association of infarct size and myocardial salvage with gender, smoking status, presence of diabetes or history of hypertension in a cohort of STEMI-patients.

METHODS

Patients (n = 301) with first-time STEMI from the three recent multi-center trials (CHILL-MI, MITOCARE and SOCCER) underwent cardiac magnetic resonance (CMR) imaging to determine myocardium at risk (MaR) and infarct size (IS). Myocardial salvage index (MSI) was calculated as MSI = 1-IS/MaR. Pain to balloon time, culprit vessel, trial treatments, age, TIMI grade flow and collateral flow by Rentrop grading were included as explanatory variables in the statistical model.

RESULTS

Women (n = 66) had significantly smaller MaR (mean difference: 5.0 ± 1.5% of left ventricle (LV), p < 0.01), smaller IS (mean difference: 5.1 ± 1.4% of LV, p = 0.03), and larger MSI (mean difference: 9.6 ± 2.8% of LV, p < 0.01) compared to men (n = 238). These differences remained significant when adjusting for other explanatory variables. There were no significant effects on MaR, IS or MSI for diabetes, hypertension or smoking.

CONCLUSIONS

Female gender is associated with higher myocardial salvage and smaller infarct size suggesting a pathophysiological difference in infarct evolution between men and women.

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.

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.

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'.

"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.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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

The bizzare phenomenon of smokers' paradox in the immediate outcome post acute myocardial infarction: an insight into the Malaysian National Cardiovascular Database-Acute Coronary Syndrome (NCVD-ACS) registry year 2006-2013

Background

‘Smoker’s paradox’ is a controversial phenomenon of an unexpected favourable outcome of smokers post acute myocardial infarction. There are conflicting evidences from the literature so far. We investigate for the existence of this phenomenon in our post acute myocardial infarction patients.

Methods

We analysed 12,442 active smokers and 10,666 never-smokers diagnosed with STEMI and NSTEMI from the Malaysian National Cardiovascular Database-Acute Coronary Syndrome (NCVD-ACS) year 2006–2013 from 18 hospitals across Malaysia. Comparisons in the baseline characteristics, clinical presentation, in-hospital treatment and short term clinical outcome were made between the two groups. To compare the clinical outcome, an extensive multivariate adjustment was made to estimate the allcause mortality risk ratios for both groups.

Results

The active smokers were younger (smokers 53.7 years vs non-smokers 62.3 years P < 0.001) and had lower cardiovascular risk burden and other co-morbidities. STEMI is more common in smokers and intravenous thrombolysis was the main reperfusion therapy in both groups. Smokers had a higher rate of in-hsopital coronary revascularisation in NSTEMI group (21.6 % smokers vs 16.7 % non-smokers P < 0.001) but similar to non-smokers in the STEMI group. Multivariate adjusted mortality risk ratios showed significantly lower mortality risks of smokers at both in-hospital (RR 0.510 [95 % CI 0.442–0.613]) and 30-day post discharge (RR 0.534 [95 % CI 0.437–0.621]).

Conclusion

Smoking seems to be associated with a favourable outcome post myocardial infarction. The phenomenon of ‘smoker’s paradox’ is in fact a reality in our patients population. The definitive explanation for this unexpected protective effect of smoking remains unclear.

Smoker's Paradox in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

Prior studies have found that smokers undergoing thrombolytic therapy for ST-segment elevation myocardial infarction have lower in-hospital mortality than nonsmokers, a phenomenon called the "smoker's paradox." Evidence, however, has been conflicting regarding whether this paradoxical association persists in the era of primary percutaneous coronary intervention.

METHODS AND RESULTS

We used the 2003-2012 National Inpatient Sample databases to identify all patients aged ≥18 years who underwent primary percutaneous coronary intervention for ST-segment elevation myocardial infarction. Multivariable logistic regression was used to compare in-hospital mortality between smokers (current and former) and nonsmokers. Of the 985 174 patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention, 438 954 (44.6%) were smokers. Smokers were younger, were more often men, and were less likely to have traditional vascular risk factors than nonsmokers. Smokers had lower observed in-hospital mortality compared with nonsmokers (2.0% versus 5.9%; unadjusted odds ratio 0.32, 95% CI 0.31-0.33, P<0.001). Although the association between smoking and lower in-hospital mortality was partly attenuated after baseline risk adjustment, a significant residual association remained (adjusted odds ratio 0.60, 95% CI 0.58-0.62, P<0.001). This association largely persisted in age-stratified analyses. Smoking status was also associated with shorter average length of stay (3.5 versus 4.5 days, P<0.001) and lower incidence of postprocedure hemorrhage (4.2% versus 6.1%; adjusted odds ratio 0.81, 95% CI 0.80-0.83, P<0.001) and in-hospital cardiac arrest (1.3% versus 2.1%; adjusted OR 0.78, 95% CI 0.76-0.81, P<0.001).

CONCLUSIONS

In this nationwide cohort of patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction, we observed significantly lower risk-adjusted in-hospital mortality in smokers, suggesting that the smoker's paradox also applies to ST-segment elevation myocardial infarction patients undergoing primary percutaneous coronary intervention.

Association of smoking with myocardial injury and clinical outcome in patients undergoing mechanical reperfusion for ST-elevation myocardial infarction

AIMS

There is evidence suggesting a positive effect of cigarette smoking on myocardial tissue reperfusion and clinical outcomes in patients with myocardial infarction ('smoker's paradox'). We aimed to evaluate the relationship of smoking with cardiac magnetic resonance (CMR)-determined myocardial salvage and damage as well as clinical outcomes in patients undergoing primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction (STEMI).

METHODS AND RESULTS

This multicentre study included 727 consecutive STEMI patients reperfused within 12 h after symptom onset. CMR imaging parameters [area at risk (AAR), infarct size (IS), myocardial salvage index (MSI), and microvascular obstruction (MVO) and intramyocardial haemorrhage (IMH)] were compared according to admission smoking status. Major adverse cardiac event (MACE) rates at 12 months after infarction were compared between groups. Three hundred and thirty-nine (46.6%) patients were current smokers. There was no difference in the extent of AAR [35 (24-47) vs. 37 (27-49) % of left ventricular volume (LV), P = 0.10], IS [16 (8-25) vs. 17 (10-26) %LV, P = 0.21], MSI [53 (29-70) vs. 52 (34-71), P = 0.47], MVO [0 (0-1.7) vs. 0 (0-1.6) %LV, P = 0.91], or in the frequency of IMH (42 vs. 39%, P = 0.58) between smokers and non-smokers. Smokers had lower MACE (3.8 vs. 8.2%, P = 0.01) rates. However, adjustment for differences in baseline risk factors attenuated the association of smoking with MACE markedly (hazard ratio = 0.71, 95% confidence interval 0.36-1.38, P = 0.31).

CONCLUSION

Smoking is not associated with PPCI efficacy (myocardial salvage) or irreversible myocardial damage in patients with STEMI. The lower MACE rate of smokers was entirely explained by differences in baseline risk characteristics, thus challenging the existence of a smoker's paradox.

Unplanned Inpatient and Observation Rehospitalizations After Acute Myocardial Infarction: Insights From the Treatment With Adenosine Diphosphate Receptor Inhibitors: Longitudinal Assessment of Treatment Patterns and Events After Acute Coronary Syndrome (TRANSLATE-ACS) Study

BACKGROUND

Previous studies examining early readmission after acute myocardial infarction have focused exclusively on inpatient readmissions. However, from a patient's perspective, any unplanned inpatient or observation rehospitalization after acute myocardial infarction represents a significant event; these unplanned rehospitalizations have not been well characterized.

METHODS AND RESULTS

We examined all patients with acute myocardial infarction treated with percutaneous coronary intervention and discharged alive from 233 hospitals in the Treatment With Adenosine Diphosphate Receptor Inhibitors: Longitudinal Assessment of Treatment Patterns and Events After Acute Coronary Syndrome (TRANSLATE-ACS) study from 2010 to 2012. Our primary outcome was unplanned rehospitalizations (inpatient or observation status) within 30 days after discharge. We identified factors associated with unplanned rehospitalizations using multivariable logistic regression. Among 12 312 patients, 1326 (10.8%) had 1483 unplanned rehospitalizations within 30 days of the index event: 1028 (69.3%) were inpatient readmissions, and 455 (30.7%) were observation stays. The majority of unplanned rehospitalizations (72%) were for cardiovascular reasons. Variation in hospital rates of 30-day unplanned rehospitalization ranged from 5.4% to 20.0%, with a median of 10.7%. After multivariable modeling, the factors most strongly associated with unplanned rehospitalization were baseline quality of life and depression, followed by index hospital length of stay.

CONCLUSIONS

Early unplanned rehospitalizations are common after acute myocardial infarction, and close to one third were classified as an observation stay. Predischarge and postdischarge assessments of overall, not just cardiovascular, health and strategies to optimize patient functional status may help to reduce unplanned rehospitalizations.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01088503.

Risk factors for long-term outcome of drug-eluting stenting in adults with early-onset coronary artery disease

OBJECTIVE

We lack data on the long-term outcome of drug-eluting stenting in patients with early-onset coronary artery disease (CAD). Here, we investigated the association of traditional risk factors and major adverse cardiovascular events (MACEs) after drug-eluting stenting in patients with CAD who were < 50 years old.

METHODS

We enrolled 437 consecutive CAD patients < 50 years old who underwent drug-eluting stenting and 132 subjects who were age- and sex-matched and angiographically shown to be disease free as controls. MACEs were analyzed in CAD patients for a median of 24 months [interquartile range 14-34 months].

RESULTS

Male patients accounted for 90.4% of cases. As compared with controls, patients with early-onset CAD had higher body mass index and rates of smoking, family history of CAD, and diabetes and hypercholesterolemia. During the hospital stay, 1 patient died, and the incidence of MACEs was 1.1%. At the end of follow-up, the overall death rate was 0.7%. MACEs were observed in 54 patients (12.4%). On Cox proportional hazard analyses, positive family history and diabetes were independent risk factors of MACEs (HR 2.61, 95% confidence interval 1.29-4.00, p = 0.002; and HR 2.48, 95% confidence interval 0.86-3.14, p = 0.004, respectively).

CONCLUSIONS

Drug-eluting stenting is a reliable treatment for patients with early-onset CAD. Positive family history of CAD and diabetes are independent risk factors of adverse cardiovascular events in this subgroup of patients after drug-eluting stent implantation.

Smoking and infarct size among STEMI patients undergoing primary angioplasty

BACKGROUND

Prior studies have found that smokers with STEMI have lower mortality rates and a more favorable response to fibrinolytic therapy than nonsmokers, phenomenon defined as "the smoker's paradox". Still poorly explored is the impact of cigarette smoking in patients undergoing primary percutaneous coronary intervention. Aim of the current study was to evaluate the impact of cigarette smoking on scintigraphic infarct size in STEMI patients undergoing primary PCI.

METHODS

Our population is represented by 830 STEMI patients undergoing primary PCI. Infarct size was evaluated at 30 days by technetium-99m-sestamibi.

RESULTS

Smoking was associated with younger age (p < 0.001), a lower prevalence of female gender (p < 0.001), hypertension (p < 0.001), diabetes (p = 0.003), shorter ischemia time (p = 0.037), but higher rates of previous PCI (p = 0.016). No differences were observed in other clinical or angiographic characteristics. In particular, smoking did not affect the rate of postprocedural TIMI 3 flow. As shown in Fig. 1, smoking did not affect infarct size (12.5% [3.3%-23.7%] vs 12.7% [4.9%-25.9%], p = 0.12). Similar results were observed in subanalyses according to infarct location (anterior STEMI, p int = 0.33), gender (p int = 0.95) age, (p Int = 0.96), diabetes (p int = 0.85). The absence of any impact of smoking on infarct size was confirmed after correction for baseline characteristics, such as age, gender, hypertension, diabetes, previous PCI, ischemia time (OR [95% CI] = 0.80 [0.59-1.09], p = 0.15).

CONCLUSIONS

This study shows that among STEMI patients undergoing primary PCI smoking status does not affect infarct size.

Paradoxical association of smoking with in-hospital mortality among patients admitted with acute ischemic stroke

BACKGROUND

Compared to those who never smoked, a paradoxical effect of smoking on reducing mortality in patients admitted with myocardial ischemia has been reported. We sought to determine if this effect was present in patients hospitalized with ischemic stroke.

METHODS AND RESULTS

Using the local Get with the Guidelines-Stroke registry, we analyzed 4305 consecutively admitted ischemic stroke patients (March 2002-December 2011). The sample was divided into smokers versus nonsmokers. The main outcome of interest was the overall inpatient mortality. Compared to nonsmokers, tobacco smokers were younger, more frequently male and presented with fewer stroke risk factors such as hypertension, hyperlipidemia, diabetes, coronary artery disease, and atrial fibrillation. Smokers also had a lower average NIH Stroke Scale (NIHSS) and fewer received tissue plasminogen activator (tPA). Patients in both groups had similar adherence to early antithrombotics, dysphagia screening prior to oral intake, and deep vein thrombosis (DVT) prophylaxis. Smoking was associated with lower all-cause in-hospital mortality (6.6% versus 12.4%; unadjusted OR 0.46; CI [0.34 to 0.63]; P<0.001). In multivariable analysis, adjusted for age, gender, ethnicity, hypertension, diabetes mellitus, hyperlipidemia, CAD, atrial fibrillation, NIHSS, and tPA, smoking remained independently associated with lower mortality (adjusted OR 0.64; CI [0.42 to 0.96]; P=0.03).

CONCLUSIONS

Similar to myocardial ischemia, smoking was independently associated with lower inpatient mortality in acute ischemic stroke. This effect may be due to tobacco-induced changes in cerebrovascular vasoreactivity, or may be due in part to residual confounding. Larger, multicenter studies are needed to confirm the finding and the effect on 30-day and 1-year mortality.

Impact of smoking status on cardiovascular outcomes following percutaneous coronary intervention

BACKGROUND

Many military veterans in the United States with coronary artery disease continue to smoke despite undergoing percutaneous coronary intervention (PCI). Previous studies have described improved cardiovascular outcomes in smokers, the so-called "smokers' paradox." In this study, we examined the effects of smoking on cardiovascular outcomes following PCI.

HYPOTHESIS

Do patients who smoke have different post-PCI outcomes than nonsmokers?

METHODS

All patients who underwent PCI at a single US Veterans Administration hospital from 2004 to 2009 were followed. Outcomes of interest included myocardial infarction, unplanned coronary intervention, unplanned cardiac hospitalization, death, and a composite of events for 6 months after PCI. Changes in traditional risk factors were also assessed.

RESULTS

Unadjusted analysis revealed that in almost all categories, smokers had lower incidence of adverse events than nonsmokers. However, after adjusting for the older age of the nonsmokers, no favorable statistical trend toward smokers was seen. Significant improvement in blood pressure and lipid levels were seen in both groups.

CONCLUSIONS

After adjusting for differences in age, there did not appear to be any protective effect of smoking on cardiovascular outcomes following PCI. Smokers achieved similar degrees of risk factor optimization during the follow-up period as their nonsmoker counterparts. Aggressive efforts to decrease the prevalence of smoking must be maintained.

Cigarette smoking is paradoxically associated with low mortality risk after acute myocardial infarction

BACKGROUND

Cigarette smoking has been shown to be associated with a decreased risk of death after acute myocardial infarction (AMI), which is also known as the "smokers' paradox." This study aimed to investigate the relationship between smoking and all-cause mortality after AMI.

METHODS

We extracted the data of patients who were hospitalized for AMI between November 2005 and September 2010 from nationwide multicenter prospective registries in Korea.

RESULTS

Among a total of 29,199 patients with AMI, 10,251 (42.3%) were current smokers, and 14,006 (57.7%) were nonsmokers. Current smokers were younger, more likely to be male, and had lower frequencies of hypertension, diabetes mellitus, dyslipidemia, and previous history of ischemic heart disease than nonsmokers. The initial presentation was less severe in terms of hemodynamic status, and angiography showed less complex coronary involvement in smokers. The overall mortality rate was 5.4% for current smokers and 9.9% for nonsmokers (hazard ratio [HR], 0.52; 95% confidence interval [CI], 0.47-0.58; p < .001). The gap in risk was attenuated after multivariable adjustment but remained statistically significant (HR, 0.85; 95% CI, 0.76-0.95; p = .005). Propensity score matching corroborated the results of reduced mortality among current smokers (6.7% vs. 7.6%; p = .005).

CONCLUSIONS

In this study, in which the patients received up-to-date treatment options, smoking was associated with a 48% decrease in the risk of all-cause mortality at 1 year after AMI.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Influence of smoking on the location of acute myocardial infarctions

Objective. To determine whether there is an association between smoking and the location of acute myocardial infarctions. Methods. Using a cohort from our hospital and published cohorts from Ireland, Uruguay, and Israel, we calculated odds of having an inferior wall as opposed to an anterior wall acute myocardial infarction among smokers and nonsmokers. Results. In our cohort, there was a higher proportion of smokers than nonsmokers in patients with inferior acute myocardial infarctions than in patients with anterior infarctions. This difference was also present in each of the other cohorts. Odds ratios for an inferior versus an anterior acute myocardial infarction among smokers ranged from 1.15 to 2.00 (median odds ratio, 1.32). When the cohorts were combined (n = 3, 160), the pooled odds ratio for an inferior as opposed to an anterior acute myocardial infarction among smokers was 1.38 (95% confidence interval, 1.20 to 1.58) (P < .002). Conclusions. Cigarette smoking increases the risk of inferior wall acute myocardial infarction more than the risk of anterior wall infarction. Smoking thus appears to adversely affect the right coronary arterial circulation to a greater extent than the left coronary arterial circulation by a mechanism not yet understood.

Risk of all-cause mortality, recurrent myocardial infarction, and heart failure hospitalization associated with smoking status following myocardial infarction with left ventricular dysfunction

Patients with left ventricular (LV) systolic dysfunction after myocardial infarction (MI) are at particularly high risk for recurrent adverse outcomes. The magnitude of the decrease in risk associated with smoking cessation after MI has not been well described in patients with LV dysfunction after MI. We aimed to quantify the risk decrease associated with smoking cessation in subjects with LV dysfunction after MI. The Survival and Ventricular Enlargement (SAVE) trial randomized 2,231 subjects with LV dysfunction 3 to 16 days after MI. Smoking status was assessed at randomization and at regular intervals during a median follow-up of 42 months. Propensity score-adjusted Cox proportional hazard models were used to quantify the decrease in risk of all-cause mortality, death or recurrent MI, and death or heart failure (HF) hospitalization associated with smoking cessation. In baseline smokers who survived to 6 months without interval events, smoking cessation at 6-month follow-up was associated with a significantly lower adjusted risk of all-cause mortality (hazard ratio [HR] 0.57, 95% confidence interval [CI] 0.31 to 0.91), death or recurrent MI (HR 0.68, 95% CI 0.47 to 0.99), and death or HF hospitalization (HR 0.65, 95% CI 0.46 to 0.92). In conclusion, in patients with LV dysfunction after MI, smoking cessation is associated with a 40% lower hazard of all-cause mortality and a 30% lower hazard of death or recurrent MI or death or HF hospitalization. These findings indicate that smoking cessation is beneficial after high-risk MI and highlight the importance of smoking cessation as a therapeutic target in patients with LV dysfunction after MI.

Smoking, clopidogrel, and mortality in patients with established cardiovascular disease

BACKGROUND

Smoking increases platelet aggregability and the degree of platelet inhibition by clopidogrel on ex vivo platelet function tests. Whether smoking status affects the relationship between clopidogrel and clinical outcomes is unknown.

METHODS AND RESULTS

We evaluated the relationship between smoking status (current smoker, former smoker, or never-smoker) and treatment with clopidogrel on the risk of all-cause, cardiovascular, and cancer mortality among the 12 152 participants from the CHARISMA (Clopidogrel for High Atherothrombotic Risk and Ischemic Stabilization, Management, and Avoidance) trial who had established cardiovascular disease. Current smoking was associated with an increase in all-cause (adjusted hazard ratio [HR] 2.58, 95% confidence interval [CI] 1.85 to 3.60), cardiovascular (HR 2.26, 95% CI 1.48 to 3.45), and cancer (HR 3.56, 95% CI 1.96 to 6.46) mortality compared with never smoking. The impact of clopidogrel on mortality differed by smoking status (P for interaction=0.018 for current smokers). Among current smokers, clopidogrel was associated with a reduction in all-cause mortality (HR 0.68, 95% CI 0.49 to 0.94); clopidogrel did not reduce all-cause mortality among former smokers (HR 0.95, 95% CI 0.75 to 1.19) or never-smokers (HR 1.14, 95% CI 0.83 to 1.58). A similar pattern was noted for cardiovascular mortality. As expected, no relationship was observed between clopidogrel and cancer mortality by smoking status. The risk of bleeding appeared to differ according to smoking status; randomized clopidogrel was associated with a significantly increased risk of severe or moderate bleeding (HR 1.62, P=0.04) among current smokers but a smaller and nonsignificant increase among never-smokers (HR 1.31, P=0.15).

CONCLUSIONS

Clopidogrel therapy may be more effective in current smokers, but it may also confer a greater bleeding risk than in nonsmokers. Further studies are needed to investigate this possibility.

Differences in cardiovascular mortality in smokers, past-smokers and non-smokers: findings from the FRENA registry

BACKGROUND

The influence of smoking on outcome in patients with coronary artery disease (CAD) is controversial. Even less is known about its influence in patients with cerebrovascular (CVD), or peripheral artery (PAD) disease.

PATIENTS AND METHODS

FRENA is an ongoing, observational registry of consecutive outpatients with symptomatic CAD, CVD, or PAD. We reviewed their cardiovascular mortality according to smoking status.

RESULTS

As of May 2008, 2501 patients had been enrolled in FRENA. Of these, 439 (18%) were current smokers, 1086 (43%) past-smokers, 976 (39%) had never smoked. Current- and past-smokers were 10 years younger, more often males, and more likely to have chronic lung disease, but had diabetes, hypertension, heart failure, or renal insufficiency less often than non-smokers. Over a mean follow-up of 14 months, 123 patients died (cardiovascular death, 68). On univariate analysis, current smokers had a significantly lower rate of cardiovascular death: 1.1 (95% CI: 0.4-2.4) per 100 patient-years in current smokers; 1.9 (95% CI: 1.2-2.8) in past-smokers; 3.5 (95% CI: 2.5-4.7) in non-smokers, with no differences between patients with CAD, CVD or PAD. Mean age at cardiovascular death was 82+/-6.4; 70+/-9.9 and 67+/-15 years, respectively. On multivariate analysis, smoking status was not independently associated with a lower risk for cardiovascular death.

CONCLUSIONS

Current and past-smokers with CAD, CVD or PAD had a less than half cardiovascular mortality than those who never smoked, but this may be explained by the confounding effect of additional variables. They died over 10 years younger than non-smokers.

Incidence and prognosis of non-Q-wave vs. Q-wave myocardial infarction following catheter-based reperfusion therapy

BACKGROUND

The clinical importance of classifying myocardial infarction (MI) into non-Q-wave (NQWMI) vs. Q-wave (QWMI) subsets is controversial and might depend on the therapeutic reperfusion strategy employed. The prognostic implications of NQWMI development following primary percutaneous coronary intervention (PCI) have not been reported.

AIM

To examine the incidence, determinants and prognostic implications of NQWMI vs. QWMI development following primary PCI.

DESIGN

The ACSIS Registry, a 2-month nationwide survey conducted biennially, prospectively collects data from all MI admissions in Israel.

METHODS

Outcomes were compared among patients managed by primary PCI who subsequently developed NQWMI vs. QWMI. Independent predictors of Q-wave development and 1-year mortality were determined by multivariate stepwise logistic regression analysis and Cox proportional hazard model, respectively.

RESULTS

Of 4537 MI patients with ST-segment elevation on admission, 1230 (27%) were treated with primary PCI. A discharge diagnosis of NQWMI was made in 259 (21.1%) patients. The baseline features and PCI strategies employed were similar among NQWMI vs. QWMI patients, though peak creatine kinase levels were higher (median 795 U/l vs. 1681 U/l, P = 0.0001) and severe left ventricular ejection fraction (LVEF) impairment (<40%) more frequent (22.6% vs. 43.9%, P < 0.0001), in the latter group. Mortality at 1-year was significantly lower in NQWMI vs. QWMI patients (3.9% vs. 10.8%, P log-rank = 0.001). By Cox proportional hazard analysis, NQWMI vs. QWMI was an independent predictor of freedom from 1-year mortality [HR = 0.34 (95% CI: 0.15-0.79), P = 0.01].

DISCUSSION

The diagnosis of NQWMI after primary PCI is associated with an excellent prognosis independent of established prognosticators, including LVEF.

Cumulative burden of atherosclerotic risk genotypes and the age at onset of a first myocardial infarction: a case-only carriership approach

BACKGROUND

Previously identified atherosclerotic genetic factors have been studied mostly in case-control studies and in nonuniform ethnic populations, whereas data on the cumulative contribution of genetic factors to an earlier onset of a first myocardial infarction (MI) are limited. We hypothesized that several genetic atherosclerotic single nucleotide polymorphisms (SNPs) may exert an additive effect on the earlier occurrence of coronary atherothrombotic disease after adjustment for clinical factors.

METHODS

Eighteen atherosclerotic high-risk SNPs were selected based upon meta-analyses of 614 published reports, and were incorporated into a carriership model. Multivariate regression analysis was used to identify the independent contribution of selected genotypes to the age at onset of a first MI in a cohort of 814 white (n = 622) and nonwhite (n = 192) patients enrolled in the Thrombogenic Factors and Coronary Events Study.

RESULTS

The analysis demonstrated that selected genotypes were significantly associated with an earlier occurrence of a first MI among white patients (an average of 0.6 year reduction per carried genotype; P = 0.027), whereas the contribution of genotypes to MI onset among nonwhite patients was not significant (an average of 0.7 year increase per carried genotype; P = 0.16), with a significant ethnic x genotype interaction effect (P = 0.02).

CONCLUSIONS

Our findings suggest that currently identified atherosclerotic genetic factors confer an independent additive contribution to the earlier onset of coronary atherothrombotic disease among white patients. The lack of a significant association between these genotypes and outcome in other ethnic groups suggests that cardiovascular genetic risk should be studied directly in these populations.

High-risk myocardial infarction in the young: the VALsartan In Acute myocardial iNfarcTion (VALIANT) trial

BACKGROUND

Advanced age is a well-established prognostic risk factor after acute myocardial infarction (AMI), yet approximately 10% of MIs occur in patients <45 years. We examined characteristics, cardiovascular outcomes, and the influence of risk factors on outcomes in young survivors of AMI.

METHODS

Fourteen thousand seven hundred three patients enrolled in the VALsartan In Acute myocardial iNfarcTion (VALIANT) trial were divided into 3 age groups: 18 to < 45 (n = 803), 45 to < 65 (n = 6185), > or = 65 years (n = 7715). Multivariate Cox regression was used to compare cardiovascular event rates and assess the impact of risk factors on outcomes.

RESULTS

The youngest patients had less diabetes, hypertension, and history of MI and were more likely to be male (18 to < 45 years, 88%; > or = 65 years, 59.1%), nonwhite (18 to < 45 years, 9.6%; > or = 65 years, 5%), current smokers (18 to < 45 years, 73.7%; > or = 65 years, 15.9%), obese (18 to < 45 years, 37.9%; > or = 65 years, 25.1%), and dyslipidemic at randomization (18 to < 45 years, 43.1%; > or = 65 years, 32.7%). Adjusted relative risks of smoking (18 to < 45 years, hazard ratio [HR] 1.6 [95% confidence interval {CI} 1.1-2.5]; > or = 45 years, HR 0.9 [95% CI 0.9-1.1]; P =.014) and hypertension (18 to < 45 years, HR 1.8 [95% CI 1.3-2.6]; > or = 45 years, HR 1.2 [95% CI 1.1-1.3]; P = .044) were higher in the young, with significant interactions observed between age and these risk factors.

CONCLUSIONS

After AMI, risk factors and outcomes of the young differ substantively from their older counterparts. The influence of hypertension and smoking is more profound in the young, underscoring the need for aggressive risk factor modification post-AMI.

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.

Sex and classic risk factors after myocardial infarction: a community study

BACKGROUND

Sex-specific data on classic risk factors and their impact after myocardial infarction (MI) in the community are lacking. We evaluated the prevalence and association of classic risk factors with recurrent ischemic events in patients with MI and tested the hypothesis that they differed by sex.

METHODS

All patients (1104, 45% women) from Olmsted County, Minnesota, hospitalized with an incident MI between 1990 and 1998 were identified using standardized criteria and followed-up (mean 3.7 years) for recurrent ischemic events, defined as recurrent MI, ischemic stroke, or coronary death. Data on hypertension, diabetes, hypercholesterolemia, smoking, and obesity at index hospitalization were analyzed individually and in clusters.

RESULTS

Women were older than men (73 vs 64 years, P < .001) and had more risk factors. During follow-up, 423 events occurred. For women, the adjusted risk of recurrent events increased with hypertension, diabetes, and hypercholesterolemia. For men, no increase in risk was detected with any risk factor. The population attributable risk of all risk factors combined was 46% (95% CI 29%-62%) in women and 19% (95% CI 6%-35%) in men. As the number of risk factors increased from 1 to > or = 4, compared with no risk factors, the adjusted hazard ratio in women increased progressively (1.12, 1.82, 2.34, and 2.68, respectively), whereas no trend was detected in men (1.40, 1.27, 1.24, and 1.37, respectively) (P = .01 for effect modification by sex).

CONCLUSIONS

Classic risk factors are highly prevalent and often clustered in MI, especially among women. Although their predictive value for recurrent ischemic events is marginal in men, strong associations exist in women, which define secondary prevention opportunities.

Hypertension and Smoking Are Associated With Reduced Regional Left Ventricular Function in Asymptomatic Individuals

OBJECTIVES

This study sought to test the hypothesis that reduced regional left ventricular (LV) function is associated with traditional risk factors including hypertension, hypercholesterolemia, and smoking in asymptomatic individuals.

BACKGROUND

Coronary artery disease is the main etiology of congestive heart failure in the U.S. and Europe. However, the relationship between risk factors for coronary artery disease and decreased myocardial function has not been studied systematically in asymptomatic individuals.

METHODS

The Multi-Ethnic Study of Atherosclerosis (MESA) is a cohort study designed to investigate the nature of atherosclerosis in asymptomatic individuals. A total of 1,184 participants (45 to 84 years old) underwent tagged cardiac magnetic resonance imaging. Regional LV function was quantified by analyzing peak systolic circumferential strain (Ecc) in regions corresponding to the left anterior descending (LAD), circumflex (LCX), and right coronary (RCA) territories. The association between risk factors and strains was studied using multiple linear regression.

RESULTS

Higher diastolic blood pressure (DBP) was associated with lower Ecc (p < or = 0.002). The Ecc's in the LAD territory of participants with DBP <80, 80 to 84, 85 to 89, and > or =90 mm Hg were -15.6%, -14.8%, -14.2%, and -13.7%, respectively (p < 0.001). Similar results were documented in other territories and after multivariable analysis. Smokers had lower Ecc in the LAD and RCA regions compared with nonsmokers. Furthermore, dose response relationship between cigarette consumption measured in pack-years and regional LV dysfunction by Ecc was noted (p < or = 0.01 in LAD and RCA territories). Finally, combined diastolic hypertension and smoking was associated with a greater reduction of regional LV function.

CONCLUSIONS

Higher diastolic blood pressure and smoking are associated with decreased regional LV function in asymptomatic individuals.

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.

Depression and smoking in coronary heart disease

OBJECTIVE

This review examines the relationship between depression and smoking in coronary heart disease (CHD). It summarizes relevant findings from general population and smoking cessation studies and discusses the few studies that have investigated whether smoking confounds, mediates, or moderates the effect of depression on cardiac morbidity and mortality.

METHODS

Qualitative review of research literature.

RESULTS

Although many studies of the prognostic importance of depression in CHD have adjusted for smoking, there is no convincing evidence that smoking actually confounds the relationship between depression and CHD. There is also no evidence that smoking moderates this relationship. There is, however, limited evidence that smoking may partially mediate the effect of depression on morbidity and mortality in CHD.

CONCLUSION

We need more research on the relationship between depression and smoking in CHD to develop a more complete model of the mechanisms linking depression to cardiac morbidity and mortality.

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

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

Mortalidad del infarto de miocardio en el registro PRIMVAC. Factores pronósticos

BACKGROUND AND OBJECTIVE

The aim of this study was to determine the mortality due to acute myocardial infarction in the coronary units from Comunidad Valenciana (Spain) and the prognostic factors associated with a higher mortality.

PATIENTS AND METHOD

Demographic characteristics, coronary risk factors, electrocardiographic ischemic signs, complications and mortality of patients with acute myocardial infarction admitted in the coronary units were collected. The study period comprised January 1995-December 1999. Death incidence was measured during coronary unit's stay. Factors associated with poor prognosis were analyzed.

RESULTS

10.213 patients entered into the study. Mean age at admission was 65 12 years. 23.8% were females (76.2% males). Global mortality in coronary units was 13.3%. Independent variables associated with higher mortality were (p < 0.05): advanced age (OR=1.06 [1.05-1.06]), female sex (OR=1.45 [1.26-1.66]), diabetes mellitus (OR=1.53 [1.35-1.74]), previous myocardial infarction (OR=1.46 [1.23-1.70]), previous angor pectoris (OR=1.29 [1.13-1.49]) and Q-wave infarction (OR=1.23 [1.03-1.43]). Factors associated with lower mortality were: hypercholesterolemia (OR=0.76 [0.66-0.78]), smoking (OR=0.65 [0.57-0.74]) and thrombolysis (OR=0.85 [0.78-0.92]).

CONCLUSIONS

At present, in the reperfusion therapy era, acute myocardial infarction has a high mortality after coronary unit admission. Several clinical factors are associated with a worse prognosis.

Old and new cardiovascular risk factors: from unresolved issues to new opportunities

With the aim of identifying areas that may deserve some further thinking the present review deliberately points out controversial issues in cardiovascular research and risk assessment. In the first part of the review general aspects are addressed regarding the evaluation of risk factors. A first point of concern is the frequent practice of combining different vascular events and effects in different vascular beds into a single endpoint. Furthermore, verification of vascular events in clinical reality may be surprisingly inaccurate. Problems in risk assessment also arise from overlapping properties (shared pathophysiological pathways) of traditional risk factors like hypertension, obesity and diabetes. In the second part of the review unresolved issues concerning selected established and emerging risk factors are discussed. The difficulty of establishing causality in cardiovascular disease is addressed, using modification of LDL cholesterol and accumulating evidence for pleiotropic effects of the LDL cholesterol-lowering statins as an example. As an alternative or supplement to the notion of LDL-related cardiovascular risk it is proposed to distinguish between statin-sensitive and statin-insensitive cardiovascular risk. Finally the future prospects of selected new and emerging risk factors like CRP, homocysteine, asymmetrical dimethylarginine (ADMA), oxLDL, and isoprostanes are evaluated. In summary, imprecise terminology and varying definitions of "cardiovascular risk" may lead to a considerable blurring of our current risk estimates, which may also explain some presently controversial issues. With several new risk factors and substantial changes in lifestyle and treatment patterns on the horizon major changes in the hierarchy of risk factors may be inevitable.

Epidemiology of smoking-induced cardiovascular disease

Cigarette smoking is a major cause of coronary heart disease, stroke, aortic aneurysm, and peripheral vascular disease. The risk is manifest both as an increased risk for thrombosis of narrowed vessels and as an increased degree of atherosclerosis in those vessels. The cardiovascular risks owing to cigarette smoking increase with the amount smoked and with the duration of smoking. Risks are not reduced by smoking cigarettes with lower machine-measured yields of tar and nicotine, but those who have only smoked pipes or cigars seem to have a lower risk for cardiovascular diseases. Cessation of cigarette smoking reduces disease risks, although risks may remain elevated for a decade or more after cessation.

Implications of cigarette smoking for the management of patients with acute coronary syndromes

Smokers differ from nonsmokers in the way they present with acute coronary syndromes and in how they respond to treatment. Although smoking increases the risk of a coronary event and accelerates the progression of established atherosclerosis, paradoxically, smokers have better short-term survival after an acute myocardial infarction, mainly because they are younger and have more favorable coronary anatomy. Thrombolysis appears to be a better treatment in smokers than in nonsmokers, probably because thrombosis plays a more important role in the pathogenesis of acute coronary events in smokers. Patients who continue to smoke after angioplasty or bypass surgery have a worse outcome than nonsmokers or quitters. The 2.5- to 3-fold increase in risk for myocardial infarction or stroke in smokers compared with nonsmokers decreases exponentially after smoking cessation. By 4 years the risk is only slightly higher than the risk of a subject who never smoked.

Genetic influence on cigarette-induced cardiovascular disease

Cigarette smoking as an addictive habit has accompanied human beings for more than 4 centuries. It is also one of the most potent and prevalent environmental health risks human beings are exposed to, and it is responsible for more than 1000 deaths each day in the United States. With recent research progress, it becomes clear that cigarette smoking can cause almost all major diseases prevalent today, such as cancer or heart disease. These detrimental effects are not only present in active smokers who choose the risk, but also to innocent bystanders, as passive smokers, who are exposed to cigarettes not-by-choice. While the cigarette-induced harm to human health is indiscriminate and severe, the degree of damage also varies from individual to individual. This intersubject variability in cigarette-induced pathologies is partly mediated by genetic variants of genes that may participate in detoxification process, eg, cytochrome P450 (CYP), cellular susceptibility to toxins, such as p53, or disease development. Through population studies, we have learned that certain CYP1A1 variants, such as Mspl polymorphism, may render the carriers more susceptible to cigarette-induced lung cancer or severe coronary atherosclerosis. The endothelial nitric oxide synthase intron 4 rare allele homozygotes are more likely to have myocardial infarction if they also smoke. In vitro experimental approach has further demonstrated that cigarettes may specifically regulate these genes in genotype-dependent fashion. While we still know little about genetic basis and molecular pathways for cigarette-induced pathological changes, understanding these mechanisms will be of great value in designing strategies to further reduce smoking in targeted populations, and to implement more effective measures in prevention and treatment of cigarette-induced diseases.

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

BACKGROUND

Despite increased risk for coronary artery disease and acute myocardial infarction (AMI), smokers have a paradoxically lower mortality after thrombolysis for AMI than non-smokers. We determined the clinical risk profiles and coronary flow characteristics of patients in the TIMI trials according to smoking status, focusing on microvascular flow.

METHODS

Among 2,573 patients in the TIMI 4, 10A, 10B and TIMI 14 trials, epicardial flow post-thrombolysis was measured using angiographic TIMI flow grades and the corrected TIMI frame count (CTFC). Microvascular flow was measured by TIMI Myocardial Perfusion Grade (TMPG) and, in TIMI 14, the percentage of ST segment resolution.

RESULTS

Clinically, the mean age (54 vs. 62 years), the prevalence of diabetes mellitus (11% vs. 16%) and hypertension (26% vs. 40%), and the 30-day mortality (2.6% vs. 6.2%) were lower among smokers than non-smokers (all p < or = 0.001). Angiographically, single-vessel disease (48% vs. 40%) and non-left anterior descending infarct arteries (65.4% vs. 60.8%) were more common among smokers (both p < or = 0.01). Epicardial TIMI grade 3 flow was achieved more often in smokers than non-smokers (61% vs. 56%) and the CTFC was faster (34 vs. 37 frames/sec, both p < or = 0.01), especially in LAD lesions. However, the frequency of normal microvascular flow (TMPG 3) was similar among smokers and non-smokers (24% vs. 29%, p = 0.16), as was the frequency of complete ST segment resolution (50% vs. 46%, p = 0.29).

CONCLUSIONS

Smokers have lower mortality after AMI than non-smokers, due in large part to lower clinical risk profiles and faster epicardial flow. Differences in tissue-level perfusion do not appear to contribute to lower mortality in smokers.

Effects of smoking on myocardial injury in patients with conservatively treated acute myocardial infarction: a study with resting 123I-15-iodophenyl 3-methyl pentadecanoic acid/201Tl myocardial single photon emission computed tomography

Many reports have demonstrated that smokers who have suffered an acute myocardial infarction (AMI) have a better prognosis than nonsmokers. The present study investigated the effects of current smoking on myocardial injury with resting 123I-15-iodophenyl 3-methyl pentadecanoic acid (BMIPP)/201Tl myocardial single photon emission computed tomography in 103 patients with conservatively treated AMI. The left ventricular myocardium was divided into 9 segments and BMIPP and 201Tl defects were scored using a 5-point grading system (0 = normal and 4 = no uptake). The sum of the defect scores was defined as the total defect score. There was no significant difference in either the baseline severity of the coronary artery disease or the total defect scores for BMIPP and 201Tl between the current smoker and nonsmoker groups. The difference between the total defect scores for BMIPP and 201Tl tended to be larger in the current smoker group than in the nonsmoker group (2.0 +/- 1.9 vs 1.3 +/- 1.6, p = 0.056). Forty-one (53%) of 77 patients in the current smoker group exhibited a BMIPP/201Tl mismatch, whereas only 8 (31%) of 26 patients in the nonsmoker group did (p = 0.047). In conclusion, current smokers had more likelihood of salvageable myocardium in areas at risk, as demonstrated by BMIPP/201Tl mismatch, in AMI than nonsmokers.