Author + information
- Michelle C. Williams, MD, PhD,
- David E. Newby, MD∗ (, )
- SCOT-HEART Trial Investigators
- ↵∗University/BHF Centre for Cardiovascular Science, Chancellor’s Building, SU315, 49 Little France Crescent, Edinburgh EH16 4SA, United Kingdom
We are very grateful for the positive comments regarding our recent study (1) and the SCOT-HEART trial.
We agree with Drs. Garcia-Garcia and de Araújo Gonçalves that the culprit plaque in myocardial infarction is not necessarily the same as those causing symptoms of angina. Indeed, the majority of culprit plaques are not flow limiting, and most patients presenting with myocardial infarction do not have a history of antecedent angina pectoris. Using positron emission tomography (2), we are currently exploring whether the identification of high-risk or vulnerable plaque has additive prognostic utility (NCT02278211). Increasing calcium score and plaque burden scores are both associated with an increased likelihood of coronary events. In addition to plaque burden, a variety of other coronary computed tomography angiography (CCTA) features have been suggested to identify potentially vulnerable atherosclerotic plaques (3). We are in the process of assessing a range of these features in the participants of the SCOT-HEART (Scottish COmputed Tomography of the HEART) trial. Once completed, we intend to publish these data.
Drs. Cremer and Jaber highlight that the SCOT-HEART trial was a pragmatically designed study in which medications were not mandated. This is real-world practice, and we believe this is a strength of our study. Nevertheless, patients were managed with reference to local and national guidelines for optimal medical treatment and referral for coronary revascularization. Fractional flow reserve assessment during invasive coronary angiography was performed when clinically indicated by the attending interventional cardiologist. Although adherence to optimal medical therapy cannot be guaranteed, the randomized design of this study means that the effect of this is likely to be similar between the 2 groups. Moreover, in the standard care arm of the study, clinicians received a communication stating the patients’ cardiovascular risk and were encouraged to prescribe preventative therapies where indicated. This was introduced to control for the similar communication regarding the CCTA result in those randomized to CT scanning where clinicians were encouraged to prescribe preventative therapies for both nonobstructive and obstructive disease. We, therefore, believe the comparisons remain relevant and valid because they represent the clinical scenario facing physicians and patients with appropriate prompts to ensure adherence to best medical therapy.
A major advantage of the SCOT-HEART study is the national health record data linkage that allows us to assess clinical outcomes, hospitalizations, revascularization, and prescriptions. This also includes assessing serious adverse events that may be attributable to preventative drug therapies. We fully intend to perform longer-term follow-up when substantially more events will have accrued so that we can undertake further detailed analysis to better define the potential benefits and risks of CCTA.
We believe that the SCOT-HEART trial will change the management of patients with chest pain of suspected cardiac origin. The SCOT-HEART and other trials have already led to proposed changes in National Institute of Health and Care Excellence (NICE) guidelines for the assessment of chest pain of recent onset in the United Kingdom. Longer-term follow-up and further planned analyses will give us greater power to determine clinical impact and help define the mechanisms behind the clinical effects of CCTA in the management of patients with suspected angina due to coronary artery disease.
Please note: Prof. Newby has received honoraria and consultancy fees from Toshiba Medical Systems. Dr. Williams has reported that she has no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation
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