Influence of smoking on the prognostic value of cardiovascular computed tomography coronary angiography

The association of metabolic health obesity with incidence of carotid artery plaque in Chinese adults

BACKGROUND AND AIMS

We aimed to evaluate the association between different obese phenotypes with carotid artery plaque (CAP) event.

METHOD AND RESULTS

The current retrospective cohort study was performed in 32,778 Chinese adults (19,221 men and 13,557 women, aged 41.9 ± 11.0 years). Obese phenotypes were assessed based on baseline body mass index (<24.0 vs. ≥24.0 kg/m²) and metabolic characteristics (health vs. unhealth). All the participants were further classified into four groups: metabolic health and normal weight (MHNW), metabolic unhealth and normal weight (MUHNW), metabolic health and overweight (MHO), and metabolic unhealth and overweight (MUHO). Ultrasound B-mode imaging was annually performed to evaluate CAP throughout the study. We have identified 2142 CAP cases during 5-year follow-up. Comparing with the MHNW group, the hazard ratios for the risk of incident CAP was 2.44 (95% CI:1.92 and 3.09) for the MUHNW group, 1.52 (95% CI:1.06 and 2.18) for the MHO group, and 1.8 (95% CI:1.4 and 2.33) for the MUHO group. The association was more pronounced in young adults (<65 y) than that in aged adults (≥65 y). Sensitivity analysis generated similar results with the main analysis.

CONCLUSION

MUHNW, MHO, and MUHO were associated with the risk of CAP.

Effect of smoking status on coronary artery disease among Chinese post-menopausal women

Smoking is a prominent risk factor of cardiovascular diseases. The occurrence of myocardial infarction and mortality in smokers with cardiovascular diseases is several times higher than that in non-smokers. Smoking is associated with gender-independent enhanced mortality. We determined the effect of smoking status on coronary artery disease (CAD) and coronary computed tomography angiography (CCTA) in Chinese post-menopausal women. Among these patients, those with significant CAD (≥50 % luminal narrowing) were further classified into one-, two-, or three-vessel disease according to CCTA results. The following events were recorded: all-cause mortality, non-fatal infarction and unstable angina. 2332 patients evaluated with CCTA included 1668 never smokers (71.5 %), 475 former smokers (20.4 %), and 189 current smokers (8.1 %). The current smokers exhibit greater luminal narrowing as observed on CCTA (p < 0.001) than the other subjects. During the median 685 ± 269.8 days follow-up period, never-smoking women have a low incidence of events, whereas former and current smokers are associated with an increased incidence of such event (p < 0.001). Furthermore, current smoking and the presence of multiple-vessel disease on CCTA are independently associated with the events in the logistic regression analysis. Smoking status is related to significant CAD and luminal narrowing on CCTA in the Chinese post-menopausal smoking women. In addition, current smoking and the presence of multiple-vessel disease on CCTA can independently predict events of all-cause mortality, non-fatal infarction or unstable angina.

Coronary CT angiography findings based on smoking status: Do ex-smokers and never-smokers share a low probability of developing coronary atherosclerosis?

The relationship of coronary artery disease (CAD) in ex-smokers has not been elucidated, although smoking is considered to be one of the major risk factors of CAD. We investigate subclinical coronary atherosclerosis (SCA) in asymptomatic subjects with coronary computed tomography angiography (CCTA), according to smoking status, and determine whether ex-smokers share a low probability of developing CAD with never-smokers. We retrospectively enrolled 6930 self-referred asymptomatic adults who underwent both coronary artery calcium score (CACS) and CCTA. The prevalence and characteristics of SCA were assessed according to smoking status (never-, ex- and current smokers). After adjusting for variable risk factors, we used multivariate logistic regression for adjusted odds ratios (AOR) of high CACS (>100), SCA (any plaque), significant stenosis (>50 % in luminal stenosis) and each plaque type (non-calcified, mixed and calcified plaque) among the three groups. The prevalence of SCA was highest in the ex-smokers (35.4 %) and the prevalence of significant stenosis in ex-smokers (6.9 %) was as high as in current smokers (6.4 %). However, after adjusting for variable risk factors, SCA was significantly correlated with both ex-smokers (AOR; 1.21) and current smokers (AOR; 1.25), whereas significant stenosis was correlated only with current smokers (AOR; 1.91). The association between SCA and ex-smokers is as strong as with current smokers, although significant stenosis is only correlated with current smokers; thus, not only quitting smoking but also never initiating smoking would be helpful to reduce the progression of the SCA.

Association between smoking habits and severity of coronary stenosis as assessed by coronary computed tomography angiography

Smoking promotes arteriosclerosis and is one of the most important coronary risk factors. However, few studies have investigated the association between smoking habits and the severity of coronary stenosis as assessed by coronary computed tomography angiography (CTA). We enrolled 416 patients [165/251 = smoker (past and current)/non-smoker)]. They had all undergone CTA and either were clinically suspected of having coronary artery disease (CAD) or had at least one cardiovascular risk factor. We divided the patients into smoking and non-smoking groups, and evaluated the presence of CAD, the number of significantly stenosed coronary vessels (VD), and the Gensini score as assessed by CTA in the two groups. The incidence of CAD, VD, the Gensini score, and coronary calcification score in the smoking group were all significantly greater than those in the non-smoking group (CAD, p = 0.009; VD, p = 0.003; Gensini score, p = 0.007; coronary calcification score, p = 0.01). Pack-year was significantly associated with VD and the Gensini score, and was strongly associated with multi-vessel disease (2- and 3-VD) (p < 0.05), whereas the duration of cessation in past smokers was not associated with VD or the Gensini score. Pack-year, but not the duration of cessation, may be the most important factor that was associated with the severity of coronary stenosis in terms of VD and the Gensini score.

Attenuated predictive power of a normal myocardial perfusion scan in young smokers

BACKGROUND

The negative predictive value of a normal myocardial perfusion image (MPI) for myocardial infarction or cardiac death is very high. However, it is unclear whether a normal MPI, reflecting non-compromised blood flow in the stable state, would have the same prognostic implications in smokers as in patients who do not smoke.

METHODS

The incidence of total mortality, cardiovascular mortality, and myocardial infarction was evaluated in 11,812 subjects (14.6% of whom were current smokers at the time of the study) with a normal MPI study and no past history of coronary artery disease during the period 1997 to 2008.

RESULTS

During an average follow-up of 72.4 ± 32.4 months the risk for an acute myocardial infarction in current smokers was approximately 50% higher than the corresponding risk in non-smokers, despite a younger average age. Cox proportional regression models show that current smoking was associated with an increased hazard rate for the composite endpoint below age 60 (HR=2.09, 95%CI 1.43-3.07, p<0.001), but not at older ages (HR=1.16, 95% CI 0.81-1.66, p=0.4).

CONCLUSIONS

In individuals below age 60, but not at older ages, current smoking is associated with increased short- and long-term risk of cardiac death and acute myocardial infarction even in subjects with a normal MPI.

Relationship between amount of cigarette smoking and coronary atherosclerosis on coronary CTA in asymptomatic individuals

Current smoking is a powerful independent predictor of coronary atherosclerosis in asymptomatic individuals. Many researchers have suggested a cigarette dose-response relationship between smoking and subclinical coronary atherosclerosis. Our study purposes were (a) to investigate the prevalence and plaque characteristics of coronary atherosclerosis in asymptomatic smokers and (b) to assess the cigarette dose-response relationship between smoking and subclinical coronary atherosclerosis using coronary CT angiography (CTA). We consecutively enrolled 7,104 self-referred asymptomatic subjects who underwent coronary CTA as part of a general health evaluation. Current smokers (n = 1,784) were categorized according to total pack years (TPY) with four grades (A, 0.1-10; B, 10-20; C, 20-30; D, >30), smoking duration (SD, years) with four grades (A, 0.1-10; B, 10-20; C, 20-30; D, >30), and number of cigarettes per day (CPD) with four grades (A, 1-20; B, 10-20; C, 20-40; D, >40). After adjusting for other cardiovascular risk factors, adjusted odds ratios for current smokers versus never-smokers as a control group were estimated for the presence of plaques, significant stenosis, and non-calcified plaques (NCP). Current smokers had a statistically significant higher prevalence of any plaque, significant stenosis, NCP, and coronary artery calcium score >100 than never-smokers. According to each categorization of TPY, SD, and CPD, the subclinical coronary atherosclerosis risk increased as grades increased in asymptomatic current smokers relative to never-smokers after adjusting for variable clinical and chemical risk factors. Our study suggests a cigarette dose-response relationship between current smoking and coronary atherosclerosis in asymptomatic individuals.

Prior smoking status, clinical outcomes, and the comparison of ticagrelor with clopidogrel in acute coronary syndromes-insights from the PLATelet inhibition and patient Outcomes (PLATO) trial

BACKGROUND

Habitual smoking has been associated with increased platelet reactivity, increased risk of thrombotic complications and greater efficacy of clopidogrel therapy over placebo. In the PLATO trial, ticagrelor compared to clopidogrel in patients with acute coronary syndromes (ACS) reduced the primary composite end point of vascular death, myocardial infarction and stroke, without increasing overall rates of major bleeding. We evaluated the results in relation to smoking habits.

METHODS

Interactions between habitual smokers (n = 6678) and in ex/nonsmokers (n = 11,932) and the effects of randomized treatments on ischemic and bleeding outcomes were evaluated by Cox regression analyses.

RESULTS

Habitual smokers had an overall lower risk profile and more often ST-elevation ACS. After adjustment for baseline imbalances, habitual smoking was associated with a higher incidence of definite stent thrombosis (adjusted HR, 1.44 [95% CI, 1.07-1.94]); there were no significant associations with other ischemic or bleeding end points. The effects of ticagrelor compared to clopidogrel were consistent for all outcomes regardless of smoking status. Thus, there was a similar reduction in the primary composite end point for habitual smokers (adjusted HR, 0.83 [95% CI, 0.68-1.00]) and ex/nonsmokers (adjusted HR, 0.89 [95% CI, 0.79-1.00]) (interaction P = .50), and in definite stent thrombosis for habitual smokers (adjusted HR, 0.59 [0.39-0.91]) and ex/nonsmokers (adjusted HR, 0.69 [95% CI, 0.45-1.07]) (interaction P = .61).

CONCLUSIONS

In patients hospitalized with ACS, habitual smoking is associated with a greater risk of subsequent stent thrombosis. The reduction of vascular death, myocardial infarction, stroke, and stent thrombosis by ticagrelor compared to clopidogrel is consistent regardless of smoking habits.

Attitude and efficacy of cardiologists with respect to smoking in patients after acute coronary syndromes

INTRODUCTION AND OBJECTIVES

Smoking is one of the most prevalent risk factors in acute coronary syndrome patients. The aim of this study was to assess the attitudes of cardiologists to the smoking habits of these patients

METHODS

A prospective multicenter registry of acute coronary syndrome patients. The primary endpoint was defined as smoking abstinence and the secondary endpoint as the incidence of all-cause mortality or nonfatal myocardial infarction.

RESULTS

The study population included 715 patients; 365 were current smokers. During follow-up (median, 375.0 days [interquartile range, 359.3-406.0 days]), 110 patients (30.6%) received smoking cessation support (19.7% at hospital discharge and 37.6% at month 3), specialized units and varenicline being the strategies most frequently used. No clinical differences were observed between patients who received smoking cessation support and those who did not, except for a higher prevalence of previous coronary heart disease in those who received support. In the multivariate analysis, the only variable independently associated with receiving smoking cessation support was previous coronary heart disease (odds ratio=3.16; 95% confidence interval, 1.64-6.11; P<.01). The abstinence rate was 72.3% at month 3 and 67.9% at 1 year; no differences were observed between the patients who received smoking cessation support and those who did not. During follow-up, a nonsignificant trend toward a lower incidence of the secondary endpoint was observed among the patients who were smokers at the time of acute coronary syndrome and who achieved abstinence (P=.07).

CONCLUSIONS

Use of smoking cessation support strategies is limited in acute coronary syndrome patients and is more widespread among those with previous coronary heart disease.

Reduced coenzyme Q(10) in female smokers and its association with lipid profile in a young healthy adult population

INTRODUCTION

Cigarette smoking has a negative effect on body reserve of antioxidants and cholesterol metabolism. Coenzyme Q(10) (CoQ(10)), a potent antioxidant synthesized as part of the cholesterol pathway, is a potential biomarker for systemic oxidative stress. We aimed to investigate gender variation in plasma lipid profile and CoQ(10) concentrations in healthy non-smokers and in smokers.

MATERIAL AND METHODS

The study included 55 cigarette smokers (25 females and 30 males) and 51 non-smokers (25 females and 26 males) with the age range from 21 to 45 years, and who had no history of alcohol abuse or chronic diseases such as diabetes mellitus or obesity. Coenzyme Q(10) plasma concentrations were measured by reverse-phase high performance liquid chromatography (HPLC) with ultraviolet detection. Fasting plasma glucose and lipid levels were determined by standard colorimetric methods.

RESULTS

Our results showed that CoQ(10) concentrations were significantly decreased in smokers, especially in females, than their non-smoker counterparts. Female smokers also exhibited a significant decrease in plasma concentrations of total cholesterol (TC), HDL-C, LDL-C, and atherogenic ratios HDL-C/TC and CoQ(10)/LDL-C than male counterparts. Plasma triglyceride concentrations were increased in smokers irrespective of gender. Plasma CoQ(10) was relatively more associated with TC and LDL-C in female smokers than male smokers.

CONCLUSIONS

The adverse effects of smoking on body reserve of antioxidants and cholesterol metabolism are greater in females than in males, partially as a result of decreased CoQ(10) plasma concentrations, HDL-C and total-cholesterol and abnormal atherogenicity indices.