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New Emirates Medical Journal

Volume 1, 2 Issues, 2020
ISSN: 0250-6882 (Online)
This journal supports open access

Open Access Article

Effects of Coronary Computer Tomography Angiography Screening on Smoking Habits in Asymptomatic Individuals with Family History of Premature Coronary Heart Disease



Nadim Shah1, 2, *, Mohamed Abdulla Alraqabani Almteiri1, Samer Noaman2, Nicholas Cox2, Chiew Wong2, Anne-Maree Kelly2, 3, Kean Soon2
1 Department of Cardiology, Rashid Hospital, Dubai Health Authority, Dubai, United Arab Emirates.
2 Department of Medicine, Melbourne Medical School - Western Precinct, The University of Melbourne, Melbourne, Victoria, Australia.
3 Joseph Epstein Center for Emergency Medicine Research, Western Health, Victoria, Australia.

Abstract

Background:

The Screening for Asymptomatic Coronary Heart disease in the Siblings of young Myocardial Infarction patients study (SACHSMI) investigated the association between index myocardial infarction patient sibling(s) and obstructive coronary heart disease as detected by coronary computer tomography angiography (CCTA). The results of SACHSMI described a statistically significant association between smoking and the prevalence of stenosis detected by CCTA. Data is lacking, however, regarding CCTA screening effects on smoking habits of young individuals.

Methods:

Fifty asymptomatic siblings of prospectively identified index myocardial infarction patients, aged 55 years or younger, were screened. These 50 sibling participants were shown and explained their CCTA results. The participants were followed up on telephone calls at 1 and 12 months after screening to assess any change in their smoking habits. The primary outcome of interest was to identify any change in the smoking habit among the participants of the SACHSMI study undergoing CCTA 1 and 12 months post scanning.

Results:

Of the 50 participants, 20 (40%) had a history of smoking. One month post CCTA, 12 (60%; 95% confidence interval (CI): 36% to 81%) participants either stopped smoking (7/20 (35%; 95% CI: 15% to 59%)) or reduced (5/20 (25%; 95% CI: 9% to 49%)) the number of cigarettes smoked daily. At 12 months post CCTA, 11 (55%; 95% CI: 32% to 77%) participants either stopped smoking (6/20 (30%; 95% CI: 12% to 54%)) or reduced (5/20 (25%; 95% CI: 9% to 49%)) the number of cigarettes smoked daily.

Conclusion:

Screening individuals with a family history of premature CHD via CCTA may have the additional benefit of reducing smoking in the short term.

Keywords: Coronary heart disease, Coronary computer tomography angiography, Screening, Smoking, Cessation, Young adult.


Article Information


Identifiers and Pagination:

Year: 2020
Volume: 1
Issue: 2
First Page: 49
Last Page: 53
Publisher Id: nemj-1-49
DOI: 10.2174/0250688201999200415094822

Article History:

Received Date: 23/02/2020
Revision Received Date: 30/03/2020
Acceptance Date: 30/03/2020
Electronic publication date: 15/07/2020
Collection year: 2020

© 2020 Shah et al.

open-access license: This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International Public License (CC-BY 4.0), a copy of which is available at: (https://creativecommons.org/licenses/by/4.0/legalcode). This license permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


* Address correspondence to this author at the Department of Cardiology, Rashid Hospital, Dubai Health Authority, Dubai, United Arab Emirates; Tel: +971 4 219 1000; E-mail: nadim.shah@gmail.com




1. BACKGROUND

Coronary computer tomography angiography (CCTA) is being increasingly used as a non-invasive diagnostic test for coronary heart disease (CHD) with similar clinical outcome predictions when compared with stress testing [1]. The Screening for Asymptomatic Coronary Heart disease in the Siblings of young Myocardial Infarction patients [SACHSMI, Australian New Zealand clinical trial registry number ACTRN12614000105640) study investigated the prevalence of obstructive CHD as detected by CCTA in the siblings of young myocardial infarction (MI) patients. It has been previously presented and published [2]. Fifty asymptomatic participants underwent CCTA and the results described a statistically significant association between obstructive stenosis as detected by CCTA and smoking [2].

A considerable proportion of the young is affected by CHD [3, 4] and cigarette smoking has been reported in 73% of patients younger than 45 years versus 46% of older patients with MI [5]. With a high prevalence of tobacco smoking in young populations worldwide and a phenomenon of unrealistic optimism whereby “people have an optimistic bias concerning personal risk” [6], it becomes a necessity to investigate effective means of modifying smoking behaviour in the primary prevention setting to reduce the burden of CHD. Previous studies have linked patients’ perception of their illness and clinical outcomes [7, 8], calcium scoring and a composite measure of risk [9], psychosocial interventions and smoking cessation [10]. Lederman et al., described the influence of CCTA on cardiac risk reduction in postmenopausal women [11], however, little is known about the effects of CCTA screening on the individual’s health perception and smoking habits in young individuals.

This is a sub-study of SACHSMI aiming to demonstrate any association that exists between individuals with a family history of ischaemic heart disease undergoing cardiac risk assessment using CCTA and their smoking habits pre and post-screening. We predicted that participants who underwent CCTA would report a significant change in their smoking habits.

2. METHODS

2.1. Participant Selection

Patients aged 55 years or younger presenting with acute MI due to primary coronary atherosclerosis and at least 50% stenosis demonstrated in at least 1 epicardial coronary artery via diagnostic coronary angiography to Western Health, Melbourne, Victoria, Australia were prospectively identified. This group comprised the index MI cohort. Those less than 18 years of age were excluded.

These patients were then contacted to determine if they had siblings aged between 30 and 55 years if male and 30 and 60 years if female. Subsequently, the siblings were invited to participate in the study following informed consent. The siblings are the participants for this study. Exclusion criteria included symptoms of CHD, known history of CHD, refusal to consent, intolerance to intravenous contrast, chronic renal impairment, atrial fibrillation, thyrotoxicosis, pregnancy, ventricular pacing, left bundle branch block, severe valvular heart disease and malignancy.

The current smokers were identified from this group and we investigated the effects of undergoing screening CCTA on smoking habits in this asymptomatic group via telephone call 1 and 12 months after inclusion. The local human research ethics committee approved the study.

2.2. Screening

The participants underwent CCTA but were not blinded to the results of each of the studies. Each participant was shown and explained the results of their CCTA. A low radiation dose (<5mSv) CCTA algorithm was performed in compliance with the National Health and Medical Research Council guidelines [12]. All CCTAs were performed with the General Electric 64 slice VCT scanner using a low radiation dose scanning protocol with prospective gating step and shoot scanning mode with 100kvp. Coronary calcium score and CCTA reformatted images were obtained from the CCTA study for further analysis. Two-level II (or higher) CCTA reporters (verified by the Society of Cardiac Computer Tomography) reported all studies.

2.3. Definitions

Current smoking was defined as having smoked at least 100 cigarettes during the participants’ lifetime and at least 1 in the 30 days prior to inclusion. CHD by CCTA was considered present if there was at least 1 epicardial coronary artery with stenosis. The severity of CHD by CCTA was defined as none (0% luminal stenosis), mild (<50% luminal stenosis), moderate (50-69% luminal stenosis) and severe (≥70% luminal stenosis) in at least 1 epicardial coronary artery. Obstructive CHD by CCTA was defined as the presence of either moderate or severe stenosis in at least 1 epicardial coronary artery.

The participants were asked if they were interested to see the images of their CCTA. All of the participants accepted the invitation and reviewed their CCTA images while being explained by one of the CCTA reporters.

2.4. Outcomes of Interest

The primary outcome of interest was to identify any change in smoking habits among the participants of the SACHSMI study undergoing CCTA 1 and 12 months post scanning. In addition, we wished to know whether there was any association between the results of screening CCTA and change in the smoking habit.

2.5. Statistical Analysis

Categorical variables were expressed as numbers and percentages, while continuous variables were expressed as mean with standard deviation or median with first and third quartiles. Odds Ratios (OR) were calculated using binary logistic regression. Statistical tests were performed using Minitab 17 Statistical Software (2010) and a 2 sided p-value ≤ 0.05 was considered statistically significant. Data capture was complete with no identifiable missing information.

3. RESULTS

We identified 167 acute MI patients who met inclusion criteria over a period of 18 months. Fifty asymptomatic siblings of these patients were recruited and were included as participants in the SACHSMI study. Twenty (40%) of the participants had a history of current smoking. (Table 1) lists participant demographics, clinical risk factors and medications. Among the smokers, males were more predominant. There was equipoise with respect to the clinical risk factors among the total cohort, smokers and non-smokers. In the asymptomatic cohort, the prevalence of prescribed cardiovascular medications was low.


Table 1
Participant demographics, clinical risk factors and medications.

Table 2
Participant CCTA results.

The CCTA findings of the participants of the SACHSMI study are listed in Table 2. The overwhelming majority of smokers had some degree of CHD detected by CCTA. Five times more smokers had obstructive CHD compared to non-smokers. A calcified plaque was more evident among the smokers by approximately a factor of four compared to non-smokers.

One month following their screening, CCTA 12 (60%; 95% confidence interval (CI): 36% to 81%) participants either stopped smoking or reduced the number of cigarettes smoked daily. Seven (35%; 95% CI: 15% to 59%) participants stopped smoking altogether and 5 (25%; 95% CI: 9% to 49%) reduced. None of the 30 participants who were not current smokers commenced smoking 1 month following their screening CCTA.

At 12 months post-screening CCTA, 11 (55%; 95% CI: 32% to 77%) out of the original 20 participants who smoked either stopped smoking or reduced the number of cigarettes smoked daily. Of these 6 (30%; 95% CI: 12% to 54%) participants stopped smoking altogether and 5 (25%; 95% CI: 9% to 49%) reduced. At 12 months post-screening CCTA, 10 (83%; 95% CI: 52% to 98%) out of the 12 participants who either stopped or reduced the number of cigarettes smoked daily at 1 month maintained this status. Two participants (17%; 95% CI: 21% to 48%) who quit smoking at one month, unfortunately, returned to smoking within 12 months.

There was a trend for those participants who had obstructive CHD detected on their CCTA to stop or reduce smoking in comparison to those with no obstructive CHD, at 1 month (OR 7.0; 95% CI: 0.6 to 75.7, p=0.109) and 12 months (OR 9.6; 95% CI: 0.9 to 105.2, p=0.064) post CCTA although this did not achieve statistical significance. There was a weaker trend demonstrating the presence of having any stenosis on CCTA and the likelihood of stopping or reducing smoking at 1 (OR 1.6; 95% CI: 0.1 to 29.4, p=0.762) and 12 (OR 1.3; 95% CI: 0.1 to 23.3, p=0.881) months but again this did not reach statistical significance. A trend for males being more likely to stop or reduce smoking at 1 month was detected but this again was not statistically significant (OR 2.0; 95% CI: 0.3 to 12.5, p=0.459).

4. DISCUSSION

The majority of the participants of the SACHSMI study who smoked, all of those who underwent screening CCTA, either reduced smoking or stopped smoking both at 1 and 12 months. Previous studies investigating the role of CCTA in changing smoking habits have been neutral at best [9, 11]. However, data investigating this particular topic is lacking. Computer tomography is also used for lung cancer screening and there is some data to suggest it may influence smoking habits in this group [12-14]. It was of interest that none of the participants who were not current smokers commenced smoking following their screening CCTA especially considering the vast majority of them did not have obstructive CHD detected by CCTA. This finding is interesting but not particularly surprising, given the motivation required to participate in such a study likely also indicates a strong willingness to avoid risks of developing or increasing CHD.

Specific therapies are available to increase smokers’ chances of reducing or even leaving smoking. Nicotine replacement therapy is widely available and has been extensively investigated. Treatment with nicotine replacement therapy for 6 - 18 months is estimated to achieve a reduction rate of approximately 22% for a follow-up period of between 12 – 26 months [15]. This is far below the rate achieved in our study, but of course, our follow up period of up to 12 months may account for relapses that may occur beyond this period.

Nearly half of the study participants were active smokers. This is alarming, considering the prevalence of smoking in Australia, it was only 14.5% in those aged 18 years and above between 2014 – 2015 [16]. Even in the young, defined as aged between 18 – 44 years, the prevalence was only 16.3% between 2014 – 2015 [16]. Hence any strategy that can identify such a high prevalence and may help in its reduction should be investigated further. The potential for gain in such a young and high-risk group should not be underestimated.

The prevalence of any stenosis, obstructive CHD and a calcified plaque was higher among smokers compared to non-smokers but despite this, no statistically significant association was found between the severity of disease on CCTA and a participant’s likelihood of reducing or stopping smoking. The small numbers of smokers in our study may explain the lack of statistical significance. Alternatively, motivation is required to participate in such a study and it maybe hypothesized that this makes our participants more likely to reduce their modifiable risk factors for CHD irrespective of undergoing CCTA or knowledge of the results. To investigate this further, a case control study would be required. It is known, however, from previous data investigating screening for lung cancer via computer tomography that the rate of abstinence is increased among smokers with abnormal findings [13]. Participation in itself in general cardiovascular screening appears to be an important factor in helping smokers quit smoking irrespective of the results of the screening program [17].

The majority (60%) of the smokers in our study were male but men only comprised 40% of the entire cohort. There was a trend for males to stop or reduce smoking at 1 month compared to females, but this did not reach statistical significance likely due to our small sample size. Previous data, however, does not appear to highlight an association between gender and smoking cessation [18].

5. STUDY LIMITATIONS

Given the single center observational nature of this study, it is prone to multiple confounders. In addition, the sample size was relatively small. Extending the study by recruiting more participants could potentially improve the findings of some of the outcomes that are currently not statistically significant.

CONCLUSION

Two-fifths of the young asymptomatic participants of the SACHSMI study, who have a family history of premature CHD, were smokers. The majority of these participants either reduced or stopped smoking at 1 and 12 months following their screening CCTA. Hence screening CCTA may have the added benefit of motivating participants to reduce or stop smoking. This potential benefit, however, requires further investigations.

LIST OF ABBREVIATIONS

CCTA  = Coronary Computer Tomography Angiography
CHD  = Coronary Heart Disease
CI  = Confidence Interval
HDL  = High-Density Lipoprotein
LDL  = Low-Density Lipoprotein
MI  = Myocardial Infarction
OR  = Odds Ratio
SACHSMI  = The Screening for Asymptomatic Coronary Heart disease in the Siblings of young Myocardial Infarction patients study

ETHICS APPROVAL AND CONSENT TO PARTICIPATE

This study has been approved by the Melbourne Health Human Research Ethics Committee, Melbourne, Australia, under approval number 2014.002.

HUMAN AND ANIMAL RIGHTS

No animals were used in this research. All human procedures were followed in accordance with the ethical standards of the committee responsible for human experimentation (institutional and national), and with the Helsinki Declaration of 1975, as revised in 2013 (http://ethics.iit.edu/ecodes/node/3931).

CONSENT FOR PUBLICATION

Informed consent was obtained from the patients.

AVAILABILITY OF DATA AND MATERIALS

The authors confirm that the data supporting the findings of this study are available within the article.

FUNDING

None.

CONFLICT OF INTEREST

The author declares no conflict of interest, financial or otherwise.

ACKNOWLEDGEMENTS

Declared none.

REFERENCES

[1] Douglas PS, Hoffmann U, Patel MR, et al. Outcomes of anatomical versus functional testing for coronary artery disease. N Engl J Med 2015; 372(14): 1291-300.
[http://dx.doi.org/10.1056/NEJMoa1415516] [PMID: 25773919]
[2] Shah N, Wong C, Cox N, Kelly AM, Soon K. Prevalence of asymptomatic coronary heart disease in the siblings of young myocardial infarction patients as detected by coronary computer tomography angiography: A pilot study. Heart Lung Circ 2018; 27(2): 205-11.
[http://dx.doi.org/10.1016/j.hlc.2017.03.160] [PMID: 28506456]
[3] Doughty M, Mehta R, Bruckman D, et al. Acute myocardial infarction in the young--The University of Michigan experience. Am Heart J 2002; 143(1): 56-62.
[http://dx.doi.org/10.1067/mhj.2002.120300] [PMID: 11773912]
[4] Loughnan ME, Nicholls N, Tapper NJ. Demographic, seasonal, and spatial differences in acute myocardial infarction admissions to hospital in Melbourne Australia. Int J Health Geogr 2008; 7: 42.
[http://dx.doi.org/10.1186/1476-072X-7-42] [PMID: 18664293]
[5] Chen L, Chester M, Kaski JC. Clinical factors and angiographic features associated with premature coronary artery disease. Chest 1995; 108(2): 364-9.
[http://dx.doi.org/10.1378/chest.108.2.364] [PMID: 7634868]
[6] Harris AJ, Hahn U. Unrealistic optimism about future life events: A cautionary note. Psychol Rev 2011; 118(1): 135-54.
[http://dx.doi.org/10.1037/a0020997] [PMID: 21058872]
[7] Frostholm L, Fink P, Christensen KS, et al. The patients’ illness perceptions and the use of primary health care. Psychosom Med 2005; 67(6): 997-1005.
[http://dx.doi.org/10.1097/01.psy.0000189164.85653.bc] [PMID: 16314606]
[8] French DP, Cooper A, Weinman J. Illness perceptions predict attendance at cardiac rehabilitation following acute myocardial infarction: A systematic review with meta-analysis. J Psychosom Res 2006; 61(6): 757-67.
[http://dx.doi.org/10.1016/j.jpsychores.2006.07.029] [PMID: 17141663]
[9] O’Malley PG, Feuerstein IM, Taylor AJ. Impact of electron beam tomography, with or without case management, on motivation, behavioral change, and cardiovascular risk profile: A randomized controlled trial. JAMA 2003; 289(17): 2215-23.
[http://dx.doi.org/10.1001/jama.289.17.2215] [PMID: 12734132]
[10] Barth J, Critchley J, Bengel J. Psychosocial interventions for smoking cessation in patients with coronary heart disease. Cochrane Database Syst Rev 2008; (1): CD006886
[http://dx.doi.org/10.1002/14651858.CD006886] [PMID: 18254119]
[11] Lederman J, Ballard J, Njike VY, Margolies L, Katz DL. Information given to postmenopausal women on coronary computed tomography may influence cardiac risk reduction efforts. J Clin Epidemiol 2007; 60(4): 389-96.
[http://dx.doi.org/10.1016/j.jclinepi.2006.07.010] [PMID: 17346614]
[12] The National Health and Medical Research Council tARCatAV-CC. National Statement on Ethical Conduct in Human Research 2007.
[13] Poghosyan H, Kennedy Sheldon L, Cooley ME. The impact of computed tomography screening for lung cancer on smoking behaviors: A teachable moment? Cancer Nurs 2012; 35(6): 446-75.
[http://dx.doi.org/10.1097/NCC.0b013e3182406297] [PMID: 22209869]
[14] Cox LS, Clark MM, Jett JR, et al. Change in smoking status after spiral chest computed tomography scan screening. Cancer 2003; 98(11): 2495-501.
[http://dx.doi.org/10.1002/cncr.11813] [PMID: 14635086]
[15] Moore D, Aveyard P, Connock M, Wang D, Fry-Smith A, Barton P. Effectiveness and safety of nicotine replacement therapy assisted reduction to stop smoking: systematic review and meta-analysis. BMJ 2009; 338: b1024.
[http://dx.doi.org/10.1136/bmj.b1024] [PMID: 19342408]
[16] Statistics ABo. 4364055001 - National Health Survey: First Results, 2014-15 2015.
[17] Bretteville-Jensen AL, Biorn E, Selmer R. Does screening participation affect cigarette smokers’ decision to quit? A long-horizon panel data analysis. Nord Alkohol- Narkotikatidskrift 2014; 31: 141-60.
[http://dx.doi.org/10.2478/nsad-2014-0012]
[18] Cengelli S, O’Loughlin J, Lauzon B, Cornuz J. A systematic review of longitudinal population-based studies on the predictors of smoking cessation in adolescent and young adult smokers. Tob Control 2012; 21(3): 355-62.
[http://dx.doi.org/10.1136/tc.2011.044149] [PMID: 21846777]

Editor-in-Chief

Abdullah Shehab
Emirates Cardiac Society
Emirates Medical Association
Dubai
(UAE)

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