Think-aloud test of online education for patients with cardiac diseases: do they meet the needs of women?

Abstract

Patient education is a core component of cardiovascular rehabilitation (CR). Recent guidelines call for tailored materials to support women, given their unique needs and preferences. This study investigated women patient’s perspectives of online CR educational materials (Cardiac College, Toronto). Through a cross-sectional design, a think-aloud protocol followed by semistructured qualitative interviews was used to collect data on women’s perceptions of the comprehensive educational webpages with regard to content, format, visuals, length/volume, difficulty, applicability, implementability and suggestions for improvement. Thirty-eight current and previous CR program participants completed 1-h Zoom interviews. Transcripts were coded thematically using best practices in NVivo by two researchers independently. Four themes emerged: (I) materials met their needs (content, presentation, and empowerment), (II) suggestions for improvement in presentation (website design, text, and visuals), (III) content (volume, additions, and difficulty), and (IV) optimizing reach and implementability (inclusiveness, barriers, and dissemination). Overall, the education content met women’s needs and was relatable, but should be updated for currency, visual appeal, and searchability. Cardiac College for Women may meet these needs and preferences.

Introduction

Cardiovascular diseases (CVDs) are the second leading cause of disability globally and the leading cause of death among women [1]. Patients suffering from CVDs are at increased risk of subsequent morbidity and mortality compared to those without CVDs [2]. For these reasons, secondary prevention is key. Cardiovascular rehabilitation (CR) is an outpatient model of chronic disease management, which is proven to ameliorate CVD patient outcomes [3].

In CR programs, internationally agreed core components are delivered to patients, including risk factor management, structured exercise, psychosocial counseling, and, of importance here, patient education [4]. While patient education is necessary but not sufficient to support risk-reducing lifestyles, rigorous reviews demonstrate the beneficial impacts of patient education for CVD patient outcomes [5, 6].

To support comprehensive, evidence-based delivery of CR [4, 7, 8], Cardiac College was developed and is available open access to support patients and programs globally [9, 10]. Since its launch in 2012, not only have there been advances in cardiac care necessitating an update [11], but further evidence on gaps in CR patient education has also accumulated [12]. Of relevance herein, clinical guidelines have been released on the need to tailor CR for women [13] and to better engage this under-represented group [14]. One of the guideline recommendations is to ensure that education addresses women’s unique information needs and preferences, which include tailored delivery methods, comprehensive coverage of women-specific CVD issues, and consideration of individual barriers and support systems [13]. Therefore, the objectives of this study were to investigate women’s perceptions of Cardiac College [9] (i.e. content satisfaction, visuals, length, volume, format, level of difficulty, applicability, usability, and implementability) and to explore how it could be improved to better meet their needs.

Methods

This study was cross-sectional in design, using a think-aloud protocol with subsequent semistructured interviews [15]. The protocol was approved by the University Health Network (UHN) Quality Improvement Review Committee (23-0619). Data were collected between December 2023 and March 2024. All participants provided signed informed consent.

Setting: education

Cardiac College was developed at UHN’s CR program of Toronto Rehabilitation Institute, Canada, as described elsewhere [10]. In brief, it is a theoretically informed, codesigned curriculum based on principles of adult learning, in plain language. There have been many studies assessing Cardiac College, demonstrating across many settings that utilization results in increased patient knowledge as well as heart health behavior changes [16–20].

Online education materials were investigated in this study, which are used to supplement weekly group education classes at the center. The website comprises sections on the following: tests for, types of, and treatments for heart diseases (including procedures and medications), exercise (aerobic and resistance, safety), nutrition, psychosocial well-being (stress, depression, sleep, and support), as well as self-management. Content is primarily text based, with some images as well as embedded links to videos.

Cardiac College has been translated to several languages, but only the English version was assessed as part of this study. The recently launched Cardiac College for Women was also not assessed in the current study as it underwent a separate development and rigorous evaluation process [21, 22].

Participants

Past and current female UHN CR program participants (any model) were eligible for participation. Inclusion criteria are as follows: ≥18 years of age, self-reported proficiency in English language, cognitive capacity to consent and evaluate written education materials, and access to an internet-enabled technological device at home with a large screen (e.g. laptop and tablet); patients with only a phone were excluded.

Procedure

A list of Cardiac College webpages was tabulated and parsed into related content of manageable quantity to review fulsomely in a 1-h session. Several pilot data collection sessions were held by the senior authors to confirm volume of information (i.e. approximately three webpages per session) and standard operating procedures; these sessions also served to train the Rehabilitation Science graduate students in data collection and initial analytic coding calibration. Thirty-four interviews were planned; note that some of the content updates undertaken to coincide with this initiative were delayed and hence those pages were not assessed (e.g. newer classes of medications for heart failure).

Recruitment strategies were manifold. Current female participants in co-ed classes were approached in person at their classes by their CR supervisor and directed to be in touch with the study coordinator if they were interested in learning more. The study coordinator presented about the study to active women-only CR classes during the period of study to recruit interested participants. Female CR graduates who consented to be contacted for research at initial intake were contacted via e-mail. Recruitment continued until one participant was assigned per interview.

Consenting patients were directed to complete an online survey assessing sociodemographic characteristics, as well as clinical characteristics such as cardiac risk factors, diagnosis, procedures, and comorbidities. The latter was used to allocate participants to interview topics, ensuring relevance.

A mutually agreeable 1-h interview time was scheduled via Zoom. The interviewers were not known to interviewees. The interviewer had their camera on, and participants were invited to turn theirs on as well to facilitate observation of nonverbal communication and notate it. The interviewer shared the first webpage on their screen and ensured that the participants could view it clearly and that they had glasses if needed. To optimize legibility where helpful, the weblinks were shared with participants via the chat box to open on their screen and share with the interviewer. Auto-transcription and recording were begun with consent.

For the think-aloud protocol, participants were directed to view the content and state their impressions out loud “as they go along” (Supplementary File 1). They were directed to forthrightly state if information was unclear or missing, for example. Subsequently, a semistructured interview was held; this retrospective questioning ensured fulsome feedback and supported triangulation. Interview recording transcripts were cleaned to be verbatim except to preserve anonymity.

Measures

The initial sociodemographic and clinical questionnaire comprised investigator-generated items with closed-ended responses. The think-aloud protocol and interview guide (Supplementary File 1) were developed by the senior authors. The interview guide aimed to query content satisfaction, visuals, length, volume, format, level of difficulty, applicability, usability, implementability, and suggestions for improvement. It was piloted with several participants until they were comfortable desired information was being solicited.

Analysis

The Rehabilitation Science graduate students underwent formal coursework in qualitative methods, in addition to training by the senior authors. The transcripts of the think-aloud protocol and subsequent interviews were segmented into sensible chunks or communication units, which—after calibration—were thematically coded independently by two graduate student authors (E.A.G., E.S., S.B., J.H., A.E., and R.P.C.) in accordance with best practices [23–25]. The coding of the think-aloud utterances focused on thoughts reflecting ways in which the education met their needs as women, or not, and could be improved. The coding of the subsequent interviews focused on validating interpretation of the think-aloud utterances and, as stated earlier, capturing fulsome feedback [26]. Coding was undertaken in NVIVO (version 12).

Coding of each interview was reconciled between the two coders using consensus discussions, with any discrepancies brought to the senior author for resolution. Once all the individual interview coding was reconciled, the senior author led a session where all coders reconciled major themes and corresponding subthemes across all interviews. Exemplary quotes were then selected by the graduate student interviewers to illustrate each subtheme and reviewed by the senior authors.

Results

A total of 38 interviews were conducted. Sociodemographic questionnaires were completed by 34 (89.5%) participants; characteristics are shown in Table I. As shown, one-third were former program graduates.

Table I.

Self-reported participant characteristics, n = 34

Characteristic	n (%)a/mean ± SD
Sociodemographic
Age (years)	69.3 ± 11.5
Language most commonly spoken (% English)	33 (97.1%)
Work status
Retired	18 (52.9%)
Full or part-time	10 (29.4%)
Other	6 (17.6%)
Currently partnered (% yes)	17 (50%)
Highest level of education
Some postsecondary or greater	29 (85.3%)
High school diploma or less	3 (8.8%)
Other	1 (2.9%)
Prefer not to say	1 (2.9%)
Comfort level viewing health education materials on websites (/5b)	4.5 ± 1.1
Clinical
CR indicationc
Heart rhythm issues	18 (52.9%)
Stent/percutaneous coronary intervention	12 (35.3%)
Heart attack/acute coronary syndrome	12 (35.3%)
Valve issues	10 (29.4%)
Heart failure	5 (14.7%)
Heart bypass surgery	2 (5.9%)
Risk factors and comorbiditiesc
Postmenopausal	27 (79.4%)
Autoimmune disease	9 (26.5%)
Tobacco use	7 (20.6%)
Cancer	7 (20.6%)
Bone disease	6 (17.6%)
More than four alcoholic drinks per week and/or use of cannabis	5 (14.7%)
PCOS	1 (2.9%)
How many cardiac rehab sessions do you estimate you have attended in your lifetime?
1–25	31 (91.2%)
26 or more	3 (8.8%)
How much do you know about managing your heart health?
Some	32 (97.1%)
None	1 (2.9%)
How recently have you learned about heart health?
In the last 2–6 months	13 (42.0%)
Not in over 6 months	10 (32.2%)
In the last month	8 (25.8%)

a

Valid percentages are reported.

b

Scored from 1 “not comfortable” to 5 “very comfortable.”

c

Check all that applies.

Abbreviations: PCOS, polycystic ovary syndrome; SD, standard deviation.

Four themes emerged from the interviews; these are depicted in Fig. 1 with corresponding subthemes. These are also exemplified with illustrative quotes in Table II.

Fig. 1.

Four main themes pertaining to women’s perceptions of Cardiac College online cardiac rehabilitation education with corresponding subthemes.

Table II.

Illustrative quotes supporting themes and subthemes

Theme	Subtheme	Illustrative quotes (number of participants)
Education Materials Met Patient’s Needs	Satisfaction with content	“I thought I pretty much covered everything that like I’ve looked up or read about or gone looking for.” (#1)
		“No, just to definitely say that I think the Cardiac College is great. It’s really helpful. There’s a lot of good information in all of the categories. Yeah. I thought it was well set out. I thought it was interesting and clear. And you know, I think it’s very helpful, especially probably for somebody who’s sort of new to the whole program. It’s helpful information.” (#23)
		“Gives a lot of information. Tells you how to develop a plan that you know and how frequently to do it.” (#34)
	Satisfaction with presentation	“I love that you have the dropdown menus, and that you tell people it’s a dropdown on the left hand side.” (#22)
		“Very well presented, simple, with, you know, lots of spacing and clear, clear language.” (#16)
		“Yeah, I really like the fact that you know there’s ‘treat heart diseases’. Then you get in to ‘get active’, ‘eat healthy’, you know. So you have that bar there, so you can choose right away but that but that you also have these 2 important questions right there at the front? Because they are, I think the questions most people have.” (#16)
		“Okay, so this page has some pictures of food and some little things. So it is more engaging. Yeah, and a picture of chips is interesting, I wouldn’t have associated chips with fibers. So that’s interesting.” (#22)
	Patient empowerment	“I think it would help me a lot, and it’s even got the link to suggested to lifestyle changes and recipes, you know, most of which I’m trying to implement.” (#26)
		“I think this information is really good. I mean, it will trigger a lot of thought to have that conversation….” (#29)
		“And … I think it’s very applicable, you know, especially when you’re first getting into the system and you know, you’re kind of hyper-vigilant about everything. and I think it’s a very good time. People are very open to ‘what should I do? What should I do?’ and I think that this is really helpful. It’s very clear it’s not anything that is difficult to do.” (#23)
Suggestions for Improvement in Presentation	Website design and structure	“There has to be a consistency between one page and the other, so that the pages flow. So if there’s a different design on each page that doesn’t show.” (#12)
		“I thought the information was adequate. It was with the arrangement of it that I had questions.” (#15)
		“It looks weird that you have back to the top right after frequency. But you don’t have it after intensity.” (#14)
		“I don’t know if there’s a way to lead people through it, like, for example, we’ve got that left hand menu panel. And it’s ordered from top to bottom, and that’s presumably the way you would want people to go through it, whatever the top to the bottom is.” (#24)
		“The one thing is, was, I did find at times searching for information was not as easy.” (#18)
		“Just yeah, the way it’s presented. Just could anybody look at this? Yeah, spacing consistency like that is… there’s some really good information. I just feel like the functionality will prevent that. You know the how it’s laid out prevents… So I think form is getting in the way of function actually.” (#22)
		“There’s one thing, I noticed you don’t have categories for the food. It’s kinda, I don’t know if you guys need to categorize it somehow. Cause you just had like recipes there, if you had more of them, you could organize them.” (#21)
	Text and visuals (font, color)	“Yeah, the font could be a little bit better, a little bit bigger” (#29)
		“It’s also very small print. But then I you know. I mean, I wear glasses. I can read it, but it is very small.” (#15)
		“I think the vibrancy of the pictures is a little dull like the whole site is a little dull, like maybe a little bit more vibrant.” (#22)
		“I think the grey is a little light. This is hard to be right, little colors too light.” (#14)
		“It’s not particularly colorful in terms of pictures of fiber or something.” (#23)
	Text and visuals (images)	“Here you’re talking about walking and cycling; maybe show pictures of walking or cycling.” (#12)
		“Yeah, something that grabs your attention and kinda says ‘I don’t want this to happen inside of my body’. I would say, I really think a visual will help get across the importance of this type of stuff.” (#24)
		“I would say pictures would be helpful.” (#22)
Suggestions for Content Improvements	Volume of information	“There’s a lot of headings for very little content. So it’s like finding the right balance between not having too much content in the way it looks that it’s overwhelming, but like I probably wouldn’t bother to come and read this. Like I think I know enough about cholesterol and food, so I’m like skimming, and I’m not getting anything from it.” (#22)
		“I guess the first impression I have is that, and I imagine this is because it’s an information page. It’s a little more dense than I think, you know, people have been expecting from the Internet these days.” (#24)
		“It potentially could be edited a little bit. Just to make sure you’re not using more words than you need to get the idea across. Everybody’s busy. So they wanna get through things as quickly as they can.” (#24)
	Desired additions	“I could see maybe a day in the life. Right? Here’s your breakfast. And then, you know, after breakfast you go for a walk and some way of maybe combining everything together.” (#24)
		“Also, when you have things like glaucoma or high blood pressure you might want to make it an active link. So you have a definition. So heck, you’re talking about some of those technical terms those are all set of exercise repetitions. There’s different ways. You can do charts. You can do different things. People don’t always just read words.” (#14)
		“You could do, maybe a quick ‘true or false’ or a quick something to engage.” (#13)
	Level of difficulty	“You have to explain what that means. It’s good to be where you can do lower level. What is the lower levels? It says sports or recreation. But you know, if you’re playing soccer or some love it.” (#19)
		“I don’t understand these because they don’t mean a lot to me, so… a ‘Standing Bird dog’; I don’t know how.” (#15)
Optimizing Reach and Implementability	Diversity and inclusion	“But a lot of black women, for example, women have, you know, from that background. They have a different history of heart conditions, you know. So I’m wondering whether that might be of interest to you as well, is to look at some of the other ethnic groups and culturally different groups that you know that, that you know the heart disease.” (#16)
		“Well, I did wonder, as you went through, whether everybody needs the same things. Everybody in like the Mediterranean diet, I assume, is covered earlier in the other pieces. So it’s already that sort of the cultural considerations of who eats what kind of thing, but I think that that the vegetable list and stuff seemed to have vegetables that are common to this culture and common to that culture, so it’s not just, you know, just sort of a one blah blah shopping experience kind of thing. … I don’t know if there are any specific differences in fiber and all that kind of thing, and you know people from different parts of the world. I assume our bodies are pretty much the same, so it would be applicable. But I don’t really know whether there’s anything that should be added in that way, I mean.” (#23)
		“Racialized women are often left out… racialized, indigenous. You know the term BIPOC? But you don’t want to have a page or content that screams ‘BIPOC, BIPOC’, or ‘information for queer women’. You might. I mean, you want something that’s inclusive.” (#29)
		“It doesn’t go across demographics very well. She is a woman who is standing in a very fancy kitchen that has 2 double ovens. And I’m just like, yeah, you’ve got like fresh herbs behind you. You’re of a specific socioeconomic class. So right off the bat that would, I think make a lot of people feel like, ‘Okay, this is not helpful for me’.” (#22)
	Barriers to implementation	“Yeah, the information has to be engaging because if it is simply just information sharing, then I think people won’t come back after. Like you look at it once, and then you’ll never come back. If there’s a way to get people to want to come to the site and like, actually do stuff on the site, or think like, ‘Oh, yeah, there was that really good recipe’, or whatever or like ‘that worksheet that I didn’t do already, maybe I should go back and do that’.” (#22)
		“One of the thoughts that I had while I was watching it, was around you know, food prices these days is a big issue. And even before the inflation that started after COVID, access to healthy food was already an issue for people with lower incomes. … So if we look, there’s somewhere here where there’s a traditional description of Mediterranean diet, maybe think about the cost associated to what is being presented and think about well, how can we potentially suggest, like a lower cost alternative for people who maybe can’t afford to eat the ways being described.” (#24)
		“And so, this is also very culturally specific. So, like the food; corned beef brisket. Things that I didn’t grow up eating. I couldn’t tell you what brisket it was. Chicken wings, sausages like. It’s very sort of like Canadian food or white food. I don’t know how to say that: It doesn’t feel like there’s any ethnic examples of what could be a fatty meat.” (#22)
		“Is there another way to convey that information without me, thinking that in order for me to have a healthy heart, I need to spend 4 hours a day just trying to figure out what I’m eating.” (#22)
	Dissemination	“maybe make TikTok or something” (#11)
		“I and again, between the time of your surgery and the time you actually get into a rehab program is several months. That’s a good time to be introduced to some of this material.” (#33)
		“So, all I think is important is that that you somehow promote this this website.” (#15)

The first theme reflected the ways in which the Cardiac College online education met women patient’s needs and comprised three subthemes. Women reported being satisfied with the content, in terms of relevance to their lives and appreciating the practical advice forwarded. Women were also satisfied with the presentation of information, noting the user-friendliness of the dropdown menus, enabling immediate access to essential topics. They were satisfied with the organization of the content, rendering it easy to find important sections. They liked the layout, describing it as “clean” and “simple,” with adequate spacing and use of clear language. The final subtheme was patient empowerment. Women reported that the content fulfilled gaps in their knowledge, was relatable, promoted reflection and behavior change as well as provided the groundwork for discussions and ultimately decision-making about their cardiac management.

The second theme pertained to patient suggestions for improvement in content and comprised two subthemes. First, with regard to the website design and structure, participants remarked that there could be more consistency in the design and layout of content across the webpages. They also desired user-friendly search functionality, to enable them to locate information, ultimately improving content accessibility. Participants suggested a feature be added where they could see what sections they had completed, to map out their learning journey. The second subtheme for Theme 2 pertained to font as well as images/videos. With regard to font, they perceived the visual appeal and readability of the content pages could be improved with some vibrant colors, color coordination, and better color contrast, particularly in relation to emphasis in headings versus text body. With regard to images, they desired more vibrant, attention-grabbing, and high-quality pictures to illustrate important points.

The third theme pertained to suggestions for content improvements and comprised three subthemes. The first subtheme related to volume of content or information on the webpages. While some women were satisfied with the volume of information, others had conflicting feedback, such that the volume was too high (e.g. they reported feeling overloaded), too low, or repetitive in some cases. They suggested that this could be rectified in many cases by simplifying the text or using bullet points, for example. The second subtheme pertained to desired additions, created in a way that engaged visitors to want to read and learn more. Some of the desired additional content was covered on pages not assessed by the individual patients, but examples of desired additional information included self-compassion, managing responsibilities, myths about exercise, and community supports. The final subtheme related to level of difficulty; again some interviewees expressed satisfaction in this regard, but others noted areas where further explanations or definitions of terms were needed.

The final major theme pertained to optimizing the online CR education reach and implementability and comprised three subthemes. First, participants suggested that by considering diversity and using inclusive language, reach and implementability could be attained. They desired images and stories that reflect a diverse range of experiences and intersectional backgrounds. Secondly, participants stated they desired that potential barriers to implementation of recommended behaviors for self-management were candidly acknowledged and identified, with potential solutions offered. Third and finally, participants spoke of ways the education could be disseminated to optimize use. They suggested leveraging various channels to improve awareness of the sites, such as social media, newsletters, and healthcare provider endorsements. They suggested spreading the word about the website to patients at the time they would be starting CR. They also suggested listing reputable online sources for patients to get further information where desired.

Discussion

Patient education is central to enlightening heart patients and supporting them to self-manage their disease and to mitigate downstream morbidity and mortality. To our knowledge, this is the first study to use a think-aloud protocol to assess patient perceptions of CR education and, in particular, to solicit women’s perceptions of such education and whether it meets their needs. Four themes emerged, pertaining to satisfaction with the materials, suggestions for improvement, and means to optimize dissemination and implementability. While further research is warranted, overall results suggest that women are satisfied with Cardiac College, perceiving the content to be relevant to their experience and empowering for self-management of their disease.

Comparing our findings with the existing literature on cardiac education evaluation, similarities and differences are evident. Prior studies have consistently demonstrated the positive impact of patient education on improving knowledge and promoting heart-healthy behaviors among CVD patients [5, 6]. However, the use of a think-aloud protocol in our study provided unique, real-time insights into the cognitive processes of women as they engaged with the educational materials, an aspect less explored previously. Additionally, previous evaluations of cardiac education programs often focus on generalized patient populations without distinguishing between genders [16–19]. This study’s emphasis on women revealed specific needs and preferences, such as the desire for more consistent design, user-friendly search functionalities, and inclusive, relatable content. These findings align with recent recommendations to tailor CR programs to better engage women by addressing their unique information needs and barriers [13]. Therefore, while general satisfaction with CR education is supported by the existing literature [27, 28], our study highlights critical areas for improvement and personalization to enhance the effectiveness of educational interventions for women CVD patients.

Implications

The invaluable feedback proffered by women CR patients can be used to improve the Cardiac College website. Overall, with funding, suggested changes to the text, graphics, and navigation on the site should be made. With the high-level summary of results offered herein, some conflicting feedback was raised; notations were made on specific pages where, e.g., volume of information was perceived to be too high or too low, so specific revisions can be made to webpages accordingly. Moreover, given that each participant did not review all the content for each interview, while they noted issues of potential repetition, the team should review the website in its entirety to identify areas of repetition and ensure that information is stated in the most applicable section and only cross-referenced elsewhere. Finally, it was encouraging that where women raised additional content they would like to see, much of it is available in the recently launched and open access Cardiac College for Women online assets [21, 22].

Limitations

Caution is warranted in interpreting these results. Generalizability is limited as this was a single-center study, assessing patient perceptions of online CR education content from one CR program. Generalizability may also be limited to older/postmenopausal, educated, English-speaking, health literate women. The perceptions of cardiac patients who have not accessed a CR program cannot be extrapolated from this study. Moreover, there may have been selection bias as a convenience sample was used; for reasons of confidentiality, it is not known how many current participants were approached and were not interested in participating, and the contact information for many CR graduates e-mailed was out of date.

In order to minimize participant burden, each patient could not review all the Cardiac College education content, and therefore patients provided feedback on only small sections of the site. Therefore, results are limited in that no over-arching conclusions about women’s patient perceptions of Cardiac College can be made, and suppositions drawn should be subject to replication. Moreover, because of this approach, whether the sample size was sufficient to amass fulsome perspectives of women cannot be determined. However, through the reconciliation process, the coders deemed that other themes were not emerging, and saturation was considered to have been achieved.

Directions for future research

With content updates complete and edits made based on this feedback, reassessment of women’s perceptions of the Cardiac College is warranted. Assessment of the education in patients who cannot access CR is warranted to determine whether the education as a stand-alone resource can meet women’s needs. Evaluation of the education by patients in other groups, which are known to be under-represented in CR, such as those of low health literacy, low socioeconomic status, older patients, and ethnocultural minorities, is also needed.

In conclusion, this is the first study to have examined the applicability of and women’s satisfaction with co-educational CR education. Overall results suggest that the content met women’s needs and was relatable, but that the presentation of information could be updated for currency and visual appeal. The recently launched Cardiac College for Women does address most of the outstanding needs raised by women, and thus this research reinforces the utility of UHN’s open access resources for CR programs. It is hoped that by leveraging dissemination strategies of participating women, the education can reach more women in need, resulting in more empowered women patients self-managing their disease and thriving.

Acknowledgements

The authors would like to acknowledge Crystal Aultman, Paul Oh, Gayl MacKinley, and the Patient Education and Engagement Program at UHN that supported the development of Cardiac College for Women.

Supplementary data

Supplementary data are available at Journal name HEAL online.

Funding

This work was supported by the Canadian Institutes of Heart Research (CIHR #487149).

Conflict of interest

None declared.