Smoking status and outcome after primary coronary angioplasty for acute myocardial infarction

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

SUCCESSES AND FAILURES OF CARDIOVASCULAR PREVENTION

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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.

A history of smoking is associated with improved survival in patients treated with mild therapeutic hypothermia following cardiac arrest

OBJECTIVES

To assess the association between smoking and survival with a good neurologic outcome in patients following cardiac arrest treated with mild therapeutic hypothermia (TH).

METHODS

We conducted a retrospective observational study of a prospectively collected cohort of 188 consecutive patients following cardiac arrest treated with TH between May 2007 and January 2012. Smoking status was retrospectively collected via chart review and was classified as "ever" or "never". Primary endpoint was survival to hospital discharge with a good neurologic outcome and was compared between smokers and nonsmokers. Logistic regression analysis was used to assess the association between smoking status and neurologic outcome at hospital discharge; adjusting for age, initial rhythm, time to return of spontaneous circulation (ROSC), bystander CPR, and time to initiation of TH.

RESULTS

Smokers were significantly more likely to survive to hospital discharge with good neurologic outcome compared to nonsmokers (50% vs. 28%, p=0.003). After adjusting for age, initial rhythm, time to ROSC, bystander CPR, and time to initiation of TH, a history of smoking was associated with increased odds of survival to hospital discharge with good neurologic outcome (OR 3.54, 95% CI 1.41-8.84, p=0.007).

CONCLUSIONS

Smoking is associated with improved survival with good neurologic outcome in patients following cardiac arrest. We hypothesize that our findings reflect global ischemic conditioning caused by smoking.

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.

["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.

The effects of facilitated primary PCI by guide wire on procedural and clinical outcomes in acute ST-segment elevation myocardial infarction

BACKGROUND

Reperfusion of the infarct related artery (IRA) prior to PCI is prognostically important in patients with acute ST segment elevation myocardial infarction (STEMI). Reperfusion is either achieved spontaneously, facilitated by GP IIb/ IIIa inhibitors, or mechanically by crossing the guide wire beyond the lesion. In order to test the hypothesis that a visible coronary anatomy is independently associated with procedural and clinical outcomes, we evaluated the frequency and prognostic impact of guide wire facilitated reperfusion of the IRA before primary PCI.

METHODS AND RESULTS

We enrolled 311 consecutive patients with successful primary PCI for STEMI (TIMI grade > or =2 flow) within 12 h after onset of symptoms. Among these, 90 patients (28.9%) had a spontaneously reperfused IRA on initial angiogram, 56 patients (18.0%) achieved reperfusion after crossing of the guide wire, and 165 patients (53.1%) successful reperfusion only after PCI. Variables associated with successful guide wire facilitated reperfusion were younger age, no history of arterial hypertension, active smoking status, negative cardiac troponin T on admission, and an infarct in the territory of the right coronary artery. Patients with spontaneous reperfusion or reperfusion after crossing of the guide wire required less fluoroscopic time and less contrast material during angiography and had higher procedural success rates (TIMI grade 3 flow 91.1 vs 79.4%, p=0.048) than patients without initial reperfusion. In addition, patients with reperfusion after crossing the lesion with the guide wire had lower mortality rates at 30 days (3.6 vs 9.1%) and after a median of 16 months (3.6 vs 13.9%, p=0.03) than those with reperfusion after PCI.

CONCLUSIONS

Reperfusion of an occluded IRA by crossing the guide wire is associated with higher procedural success rates and better outcomes. Better roadmapping and device selection represent potential reasons but the exact mechanism for these benefits is still illusive.

Impact of baseline platelet count in patients undergoing primary percutaneous coronary intervention in acute myocardial infarction (from the CADILLAC trial)

Despite the well-recognized role of platelets in the pathogenesis of acute myocardial infarction (AMI) and in the vascular responses to angioplasty, the relation between platelet count and outcomes after primary percutaneous coronary intervention (PCI) in AMI is unknown. We therefore determined the effect of baseline platelet count on clinical and angiographic outcomes of patients with AMI undergoing primary PCI. In the prospective, randomized CADILLAC trial, platelet count on admission was available in 2,021 of 2,082 patients (97.0%). Angiographic results and outcomes at 30 days and 1 year were stratified by quartiles of platelet count. Median platelet count was 231 x 10(9)/L (range 38 to 709). Primary PCI angiographic success rates were independent of platelet count. The 30-day incidence of target vessel thrombosis or reocclusion increased steadily across the higher quartiles of baseline platelet count (0.2%, 0.6%, 1.0%, and 2.0%, p = 0.027). At 1 year, patients with a baseline platelet count >or=234 versus <234 x 10(9)/L had higher rates of death or reinfarction (8.9% vs 4.5%, p <0.0001), death (5.8% vs 3.1%, p = 0.002), and reinfarction (3.4% vs 1.6%, p = 0.008). By multivariable analysis, a higher baseline platelet count was the strongest predictor of 1-year death or reinfarction (hazard ratio [HR] per 10,000 increase in platelet count 1.02, 95% confidence interval [CI] 1.02 to 1.07, p <0.0001) and independently predicted reinfarction (HR 1.06, 95% CI 1.02 to 1.09, p = 0.002) and cardiac mortality (HR 1.03, 95% CI 1.00 to 1.06, p = 0.055) at 1 year. In conclusion, a higher baseline platelet count in patients with AMI is a powerful independent predictor of death and reinfarction within the first year after primary PCI.

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.

Cardiovascular risk factors and clinical presentation in acute coronary syndromes

OBJECTIVE

To investigate the hypothesis that risk factors may be differently related to severity of acute coronary syndromes (ACS), with ST elevation used as a marker of severe ACS.

DESIGN

Cross sectional study of patients with ACS.

SETTING

103 hospitals in 25 countries in Europe and the Mediterranean basin.

PATIENTS

10,253 patients with a discharge diagnosis of ACS in the Euro heart survey of ACS.

MAIN OUTCOME MEASURES

Presenting with ST elevation ACS.

RESULTS

Patients with ACS who were smokers had an increased risk to present with ST elevation (age adjusted odds ratio (OR) 1.84, 95% confidence interval (CI) 1.67 to 2.02). Hypertension (OR 0.65, 95% CI 0.60 to 0.70) and high body mass index (BMI) (p for trend 0.0005) were associated with less ST elevation ACS. Diabetes mellitus was also associated with less ST elevation, but only among men. Prior disease (infarction, chronic angina, revascularisation) and treatment with aspirin, beta blockers, or statins before admission were also associated with less ST elevation. After adjustment for age, sex, prior disease, and prior medication, smoking was still significantly associated with increased risk of ST elevation (OR 1.53, 95% CI 1.38 to 1.69), whereas hypertension was associated with reduced risk (OR 0.75, 95% CI 0.69 to 0.82). Obesity (BMI > 30 kg/m2 versus < 25 kg/m2) was independently associated with less risk of presenting with ST elevation among women, but not among men.

CONCLUSION

Among patients with ACS, presenting with ST elevation is strongly associated with smoking, whereas hypertension and high BMI (in women) are associated with less ST elevation, independently of prior disease and medication.

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.

Cigarette smoking and acute coronary syndromes: A multinational observational study

PURPOSE

To determine the impact of cigarette smoking on the presentation, treatment, and in-hospital outcomes of patients admitted with the full spectrum of acute coronary syndromes.

METHODS

GRACE is a multinational observational registry involving 94 hospitals in 14 countries. This analysis is based on 19,325 patients aged at least 18 years admitted for acute coronary syndromes as a presumptive diagnosis with at least one of the following: electrocardiographic changes consistent with acute coronary syndromes, serial increases in serum biochemical markers of cardiac necrosis, and/or documentation of coronary artery disease. The main outcomes measured were mode of presentation, treatment and in-hospital death in the ST-segment elevation myocardial infarction, non-ST-segment elevation myocardial infarction, and unstable angina groups to assess the impact of smoking status.

RESULTS

Smokers were more frequently diagnosed with ST-segment elevation myocardial infarction (46.0%) than former smokers (27.4%) and non-smokers (30.2%) (P<0.001). Smokers were mostly men, were younger and more aggressively treated than former smokers and non-smokers across the three acute coronary syndrome groups. Unadjusted in-hospital mortality rates were lower in smokers compared with former smokers and non-smokers in the study population (3.3%, 4.5%, and 6.9%, respectively, P<0.001), and in the ST-segment elevation myocardial infarction and non-ST-segment elevation myocardial infarction groups. However, by multivariate logistic analysis, the adjusted in-hospital mortality rate was similar regardless of smoking status.

CONCLUSIONS

There is no survival advantage related to current or prior cigarette smoking in patients admitted with acute coronary syndromes, regardless of presentation. In this large multinational registry, the smokers' paradox does not exist.

Relation between serum lipoprotein (a) and residual lesion stenosis of coronary artery after myocardial Infarction without reperfusion therapy

Lipoprotein (a) (Lp(a)) is an independent risk factor for myocardial infarction (MI). It may also inhibit the fibrinolysis system, and Lp (a) affects the natural course of MI and the results of thrombolytic therapy. The purpose of this study was to investigate the influence of Lp (a) on the residual lesion stenosis of the infarction-related arteries (residual stenosis) in acute MI patients in whom reperfusion therapy was not performed. We studied 129 MI patients not given reperfusion therapy who underwent coronary angiography in the chronic stage. Morning fasting blood was collected and Lp (a), blood sugar, total cholesterol (TC), triglycerides (TG), and hemoglobin A1c (HbA1c) were measured. Residual stenosis was compared between the low Lp(a) group (< 30 mg/dL) and the high Lp(a) group (> or = 30 mg/dL). It was severe in the high Lp(a) group (85.0 +/- 24.9% vs 94.5 +/- 15.5%, P = 0.0044). We also compared residual stenosis and TIMI classification between younger and older, non-DM and DM, non-HT and HT, low-TC (< 220 mg/dL) and high-TC (> or = 220 mg/dL), low-TG (< 150 mg/dL) and high-TG (> or = 150 mg/dL), and low-Lp (a) and high-Lp (a) patients. Only the serum Lp (a) level affected the residual stenosis and TIMI classification (P < 0.05).

CONCLUSION

These findings suggest that elevated Lp (a) levels inhibit fibrinolysis.

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.

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.

[Coronary angioplasty in the acute myocardial infarction: in which patients is it less likely to obtain an adequate coronary reperfusion?]

INTRODUCTION

In patients with acute myocardial infarction treated with primary angioplasty, the inability to achieve successful coronary reperfusion is associated with higher mortality. The objective of the study was to identify which characteristics may predict a lower angiographic success rate in patients with acute myocardial infarction treated with coronary angioplasty.

PATIENTS AND METHODS

The study population is constituted by the 790 patients with acute myocardial infarction that were treated with angioplasty within the 12 hours after the onset of symptoms from 1991 to 1999 at our institution. A successful angiographic result was considered in presence of a residual stenosis < 50% and a TIMI flow 2 or 3 after the procedure.

RESULTS

A successful angiographic result and a final TIMI 3 flow were achieved in 736 (93.2%) and 652 (82.5%) patients, respectively. In-hospital mortality was higher in patients with angiographic failure than in those with angiographic successful result (48 vs. 10%; p < 0.01). Age under 65 (91 vs. 95%; p = 0.02), non smoking (90 vs. 96%; p < 0,01), previous infarction (87 vs. 94%; p < 0.01), angioplasty after failed thrombolysis (83 vs. 94%; p = 0. 02), cardiogenic shock (80 vs. 95%; p < 0.01), undetermined location (67 vs. 93%; p < 0.01), non-inferior location (92 vs. 96%; p = 0.04), left bundle branch block (64 vs. 94%; p < 0.01), multivessel disease (91 vs. 95%; p = 0.02), left ventricular ejection fraction < 0.40 (89 vs. 97%; p < 0.01), no utilization of coronary stenting (90 vs. 96%; p < 0.01), and use of intraaortic balloon counterpulsation pump (82 vs. 95%; p < 0.01) were associated with a lower angiographic success rate. In the multivariable analysis, the following were independent predictors for angiographic failure: left bundle branch block (odds ratio [OR], 12.95; CI 95%, 3.00-53.90), cardiogenic shock (OR, 4.20; CI 95%, 1.95-8.75), no utilization of coronary stent (OR, 3.44; CI 95%, 1.71-7.37), and previous infarction (OR, 2.82; CI 95%, 1.29-5.90).

CONCLUSIONS

Coronary angioplasty allows a successful coronary recanalization in most patients with acute myocardial infarction. Some basic characteristics, however, may identify some subsets in which a successful angiographic result may be more difficult to obtain.

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.

Cigarette smoking status and outcome among patients with acute coronary syndromes without persistent ST-segment elevation: effect of inhibition of platelet glycoprotein IIb/IIIa with eptifibatide. The PURSUIT trial investigators

BACKGROUND

Studies have shown that cigarette smokers constitute a substantial proportion of patients with acute coronary syndromes (ACS) and have platelet-rich coronary thrombi. We characterized the influence of smoking status on outcome of patients with ACS without persistent ST-segment elevation and tested the hypothesis that selective inhibition of the platelet glycoprotein IIb/IIIa receptor with eptifibatide would improve outcomes among cigarette smokers.

METHODS

The study population included patients enrolled in the PURSUIT trial (Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy) with known smoking status presenting with ischemic chest pain </=24 hours and having either ischemic electrocardiographic changes without persistent ST-segment elevation or elevated creatine kinase MB levels. Patients were randomly assigned to receive a bolus and infusion of either eptifibatide or placebo in addition to standard therapy. The primary end point was a composite of death or nonfatal myocardial infarction within 30 days.

RESULTS

Of the 9406 patients with known smoking status, 2677 were current smokers, 3086 were former smokers, and 3643 were nonsmokers. Cigarette smokers had better 30-day outcomes (12.3%, 16.8%, and 15.4% for smokers, former smokers, and nonsmokers, respectively; P =.001). However, after adjusting for differences in baseline clinical variables, smoking status was not a predictor of 30-day outcome (P =.45). There was a reduction in the composite end point overall with eptifibatide compared with placebo (14.3% vs 15. 7%, P =.054) but no interaction between smoking status and treatment strategy (P =.68).

CONCLUSIONS

Among patients with ACS without persistent ST-segment elevation, cigarette smokers had better short-term outcomes because of their more favorable clinical profile. Although prior studies have suggested that smokers more commonly have platelet-rich thrombi than nonsmokers, eptifibatide did not result in more improvement in their outcome compared with former smokers or nonsmokers.