Recruitment

Included studies that are complete with data available were conducted in the USA (Southard 2003; Zutz 2007), Canada (Lear 2014; Reid 2012), the UK (Devi 2014; Lindsay 2009), the Netherlands (Vernooij 2012), Belgium (Frederix 2015), Norway (Antypas 2014), New Zealand (Maddison 2014), and Australia (Varnfield 2014). Four trials recruited participants from conventional cardiac rehabilitation programmes (Antypas 2014; Frederix 2015; Varnfield 2014; Zutz 2007). One trial was set in tertiary care and recruited people who had undergone percutaneous coronary revascularisation and were not planning on taking part in cardiac rehabilitation (Reid 2012). One trial recruited cardiac inpatients from both a tertiary and a regional hospital (Lear 2014). One trial recruited participants from two metropolitan hospitals, through outpatient clinics (Maddison 2014). Two trials recruited participants from primary care general practitioner practices (Devi 2014; Lindsay 2009), one trial recruited from primary and community health services (Varnfield 2014), and two trials recruited from both primary and secondary care (Southard 2003; Vernooij 2012).

A total of 1392 participants were recruited, with sample sizes ranging from 15 to 330 participants. Ten studies reported the mean age of study participants, which ranged from 54.9 to 66.27 years, and one trial reported the median age of participants in the control and experimental group as 58.4 years and 61.7 years, respectively (Lear 2014). In six studies, over 80% of participants were male (Frederix 2015; Lear 2014; Maddison 2014; Reid 2012; Varnfield 2014; Zutz 2007), and in five studies over 70% of participants were male (Antypas 2014; Devi 2014; Lindsay 2009; Southard 2003; Vernooij 2012).

Southard 2003 recruited participants diagnosed with CHD, congestive heart failure, or both. The medical characteristics of participants recruited are described, amalgamating those with multiple diagnoses. In the sample 9.6% had a past medical history of congestive heart failure, and therefore the sample consisted of mostly people with CHD. Reid 2012 recruited a mixture of percutaneous coronary intervention (PCI), acute myocardial infarction (AMI), and coronary artery bypass grafting (CABG) patients. Vernooij 2012 sample included a mixture of coronary artery disease, cerebrovascular disease, abdominal aortic aneurysm, and peripheral vascular disease, and Frederix 2015 sample included post‐PCI and post‐CABG patients. Lear 2014 recruited cardiac inpatients admitted for either acute coronary syndrome or revascularisation procedure. Zutz 2007 recruited a mixture of myocardial infarction (MI), PCI, CABG, and diabetes mellitus patients. Devi 2014 recruited a stable angina population, Maddison 2014 recruited both angina and MI patients, and Varnfield 2014 recruited post‐MI patients. Lindsay 2009 and Antypas 2014 did not provide specific details of CHD diagnosis. Three trials described participants' ethnicity: Southard 2003 and Devi 2014 samples consisted of 97.1% and 91% white participants, respectively, and Maddison 2014 recruited predominately European New Zealanders (76%).

Interventions

Of the 11 completed trials, seven interventions were broad, targeting the general management of CHD (Devi 2014; Lear 2014; Lindsay 2009; Southard 2003; Varnfield 2014; Vernooij 2012; Zutz 2007), and four interventions were focused on physical activity promotion (Antypas 2014; Frederix 2015; Maddison 2014; Reid 2012). Seven interventions were delivered using the Internet only (Devi 2014; Lear 2014; Lindsay 2009; Reid 2012; Southard 2003; Vernooij 2012; Zutz 2007), and four interventions were delivered through both the Internet and mobile telephone technology (Antypas 2014; Frederix 2015; Maddison 2014; Varnfield 2014).

The intervention evaluated by Lindsay 2009 was an online heart care support community, where participants interacted with each other in one of five discussion forums moderated by researchers. The intervention also contained information resources about CHD, diet, exercise, and smoking. The web‐based programme evaluated by Southard 2003 was based around educational modules and involved interactive features such as multiple‐choice self test questions, an online discussion group, and a feature that allowed participants to upload health information, for example exercise and blood pressure. The health information provided by the user was then used to produce graphic feedback which showed the user's progress over time. The intervention evaluated by Vernooij 2012 was a personalised website containing an overview of participants' risk factors and self management information about different CHD risk factors. The intervention evaluated by Devi 2014 involved tailored goal‐setting for exercise, diet, anxiety and emotions, and smoking. Depending on the participant’s performance, these goals were modified/made increasingly difficult throughout the programme. Programme users also had to complete an online interactive exercise diary, uploading the daily number of exercise minutes carried out. The intervention evaluated by Varnfield 2014 used a smartphone to monitor health and exercise and to deliver motivational and educational materials via text messages and through audio or video files. The health and exercise daily diary entries were synchronised to a web portal, which mentors could access and review to give feedback during a weekly scheduled telephone consultation. The web‐based programme evaluated by Zutz 2007 comprised weekly education sessions, scheduled one‐on‐one chat sessions with various healthcare professionals, and monthly 'ask an expert' group chat sessions. Participants were also required to upload exercise levels, heart rate, weight, blood pressure, and glucose levels (if diabetic) data to the website. The trial carried out by Lear 2014 evaluated an intervention consisting of weekly education sessions (in the form of interactive slide presentations), a feature to upload participant health data, progress notes (for healthcare professionals), scheduled one‐on‐one chat sessions with a healthcare professional, and monthly 'ask an expert' group chat sessions.

Trials carried out by Antypas 2014, Frederix 2015, Maddison 2014, and Reid 2012 focused on promoting physical activity only. Both Antypas 2014 and Frederix 2015 investigated the effectiveness of an Internet‐ and mobile phone‐based intervention offered to participants after completing traditional cardiac rehabilitation. Antypas 2014 offered participants tailored motivation and support through both a website and text messaging, physical activity goal‐setting, and access to generic information. In Frederix 2015, participants wore a physical activity monitor, and uploaded weekly data via a USB connection to an online participant account, from which they received automated personalised feedback weekly via email or text messages. Similar to both Antypas and Frederix, Maddison 2014 aimed to increase moderate and vigorous aerobic exercise in those with CHD with an intervention comprised of personalised automated text messages, pedometer‐based step counts feedback, personalised feedback on a website, video messages, motivational messages, and weekly health and exercise tips. Reid 2012 aimed to increase levels of physical activity in those not taking part in traditional cardiac rehabilitation; intervention participants uploaded their daily physical activity data onto the intervention website and completed a series of online tutorials, which generated new physical activity plans.

The length of the interventions ranged from six weeks, in Devi 2014, to one year (Antypas 2014; Vernooij 2012). The duration of the other interventions was three months (Zutz 2007), four months (Lear 2014), four and a half months (Frederix 2015), six months (Maddison 2014; Reid 2012; Southard 2003), and nine months (Lindsay 2009). The intervention evaluated by Varnfield 2014 consisted of a six‐week intervention, which was followed by a six‐month self management phase. Participants received training on how to use the intervention in 10 trials (Antypas 2014; Devi 2014; Frederix 2015; Lear 2014; Lindsay 2009; Maddison 2014; Reid 2012; Varnfield 2014; Vernooij 2012; Zutz 2007). Details of how the intervention was introduced to participants was not described by Southard 2003.

In eight interventions, participants were able to initiate communication with a healthcare professional (Antypas 2014; Devi 2014; Lear 2014; Reid 2012; Southard 2003; Varnfield 2014; Vernooij 2012; Zutz 2007). Communication was through email access (Devi 2014; Reid 2012; Zutz 2007), private‐messaging function on the website (Antypas 2014; Southard 2003; Vernooij 2012; Zutz 2007), one‐to‐one chat facility (Lear 2014), a synchronised group chat (Devi 2014; Lear 2014; Zutz 2007), an online discussion forum (Lindsay 2009; Southard 2003), or telephone consultations (Varnfield 2014). The healthcare professionals communicating with participants were exercise specialists (Lear 2014; Reid 2012; Zutz 2007), dietitians (Lear 2014; Southard 2003; Zutz 2007), nurse practitioners (Lear 2014; Vernooij 2012; Zutz 2007), cardiac rehabilitation specialists (Devi 2014), or a physiotherapist (Antypas 2014). Varnfield 2014 did not describe the professional background of those delivering the telephone consultation component of the intervention. Only one intervention included a prompt feature, in which a nurse practitioner could message a participant, or telephone participants who had not recently logged on to the programme (Vernooij 2012).

The intervention user was able to communicate with other intervention users in four studies, either through online discussion forums (Lindsay 2009; Southard 2003), messaging on other users' profile pages (Antypas 2014), via an online synchronised group chat (Devi 2014; Lear 2014), or through email (Southard 2003).

Control groups

In all studies, the web‐based intervention was evaluated in two‐arm trials.

Usual care was the comparison group in six trials. One study did not provide details of usual care (Southard 2003), and in the others it was usual general practitioner care (Devi 2014; Lear 2014; Vernooij 2012), no intervention (Frederix 2015), or wait‐list control (Zutz 2007).

In three trials, control group participants received a minimal intervention consisting of a static, non‐tailored web‐based programme (Antypas 2014), weekly drop‐in sessions (Lindsay 2009), or general physical activity guidance and an educational booklet (Reid 2012). In two trials, the comparison group was traditional cardiac rehabilitation (Maddison 2014; Varnfield 2014).

Use of the intervention by participants

Five trials reported the frequency of website login. Southard 2003 reported that on average participants logged into the website 58 times over the six‐month intervention period, which was equivalent to twice per week. Devi 2014 reported an average of 19 logins per participant over the six‐week intervention, with an average of three logins per week. In Zutz 2007, the average number of logins over the 12‐week programme was 50, which averaged to 4.2 times per week. Vernooij 2012 and Lear 2014 did not report average values, instead reporting median and range values, respectively. In Vernooij 2012, participants logged in a median of 56 (interquartile range 35 to 83) times during the 12‐month intervention, and in Lear 2014, weekly logins ranged from one participant not logging in to the website at all to other participants logging in more than eight times per week.

Mortality

Six trials reported this as an outcome, with a total of 895 participants randomised (Analysis 1.1). A total of four deaths were reported across three of these trials, all in the control groups (Lear 2014; Reid 2012; Vernooij 2012). Vernooij 2012 reported one death described as a "fatal cerebrovascular event", Lear 2014 reported one death as a non‐cardiovascular disease death, and Reid 2012 reported two cases of mortality with no reasons provided. The odds ratio (OR) was 0.27 (95% confidence interval (CI) 0.04 to 1.63), P = 0.15 (Analysis 1.1), with low‐quality evidence (summary of findings Table for the main comparison).

Only one trial reported a case of cardiovascular‐related mortality; Vernooij 2012 reported one cardiovascular‐related death in the control group.

Non‐fatal re‐infarction

No studies reported any incidences of non‐fatal re‐infarction.

Revascularisation

Six studies contributed to the analysis with 895 participants randomised (Analysis 1.2). In total, 18 revascularisations were reported amongst the intervention groups in three studies (Lear 2014; Maddison 2014; Vernooij 2012), and 26 in the control groups across five studies (Frederix 2015; Lear 2014; Maddison 2014; Reid 2012; Vernooij 2012), with no evidence of an effect of the intervention (OR 0.69 (95% CI 0.37 to 1.27), P = 0.23) (Analysis 1.2, Figure 4), and with low‐quality evidence (summary of findings Table for the main comparison).

Figure 4

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Forest plot of comparison: 1 Cardio events, outcome: 1.1 Revascularisation.

Lipid levels

Six trials assessed the impact of web‐based interventions on total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides (Frederix 2015; Lear 2014; Southard 2003; Varnfield 2014; Vernooij 2012; Zutz 2007). We were unable to combine data from Southard 2003 and Lear 2014. Southard 2003 did not report variance values, and we were unable to obtain these from the authors, and Lear 2014 reported data in terms of medians and interquartile ranges. At six months' follow‐up, Southard 2003 reported no statistically significant changes in cholesterol levels, and Lear 2014 reported statistically significant group differences between the control and intervention group for total cholesterol (P = 0.026) and LDL cholesterol (P = 0.022), although not for HDL cholesterol (P = 0.075) and triglycerides (P = 0.715). For total cholesterol, the median values in the control group at baseline, four months, and 16 months were 3.45 mmol, 3.77 mmol, and 3.66 mmol, respectively, and experimental group median values were 3.54 mmol, 3.68 mmol, and 3.60 mmol, respectively, P = 0.026. For LDL cholesterol, the median values in the control group at baseline, four months, and 16 months were 1.79 mmol, 1.99 mmol, and 1.82 mmol, respectively, and experimental group values were 1.74 mmol, 1.79 mmol, and 1.69 mmol, respectively, P = 0.022.

There were four studies where data could be combined, there was moderate heterogeneity for the outcome total cholesterol and a random‐effects model was used (I² = 41%) showing no effect of the intervention on total cholesterol (mean difference (MD) 0.00 (95% CI ‐0.27 to 0.28) mmol/L, P = 0.98, four studies, 439 participants) (Analysis 2.1, Figure 5) with low‐quality evidence (summary of findings Table 2). Similarly, there were no intervention effects for HDL cholesterol (MD 0.01 (95% CI ‐0.06 to 0.07) mmol/L, P = 0.82, four studies, 437 participants) (Analysis 3.1, Figure 6) with low‐quality evidence (summary of findings Table 2). There was considerable heterogeneity for the LDL cholesterol outcome, and results were not pooled statistically (I² = 77%) (Analysis 4.1, Figure 7), low‐quality evidence (summary of findings Table 2). Of these studies, one reported a difference in LDL cholesterol between groups at 12 months' follow up (MD ‐0.3 (95% CI ‐0.5 to ‐0.1) (Vernooij 2012) other trials reported no effect on LDL levels (Frederix 2015; Varnfield 2014; Zutz 2007). For triglycerides, there were again no intervention effects (MD 0.01 (95% CI ‐0.17 to 0.19) mmol/L, P = 0.91, four studies, 439 participants) (Analysis 5.1, Figure 8).

Figure 5

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Forest plot of comparison: 2 Total cholesterol, outcome: 2.1 Total Cholesterol.

Figure 6

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Forest plot of comparison: 3 HDL cholesterol, outcome: 3.1 HDL Cholesterol.

Figure 7

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Forest plot of comparison: 4 LDL cholesterol, outcome: 4.1 LDL Cholesterol.

Figure 8

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Forest plot of comparison: 5 Triglycerides, outcome: 5.1 Triglycerides.

Blood pressure

In total, seven studies measured systolic (SBP) and diastolic (DBP) blood pressure (Devi 2014; Lear 2014; Maddison 2014; Southard 2003; Varnfield 2014; Vernooij 2012; Zutz 2007). We were unable to combine data from two studies due to variance data not being reported (Southard 2003), and due to data being presented using median values (Lear 2014). Southard 2003 reported no effects for SBP or DBP between groups at a six months' follow‐up (P values not provided), and Lear 2014 reported a between‐group difference over time for SBP (P = 0.051), although not for DBP (P = 0.776). The median SBP values in the control group at baseline, four months', and 16 months' follow‐up were 112 mmHg, 114 mmHg, and 117 mmHg, and the experimental group median values were 121 mmHg, 126 mmHg, and 121 mmHg, respectively.

For the remaining five trials, heterogeneity was substantial (I² = 63% for SBP, 58% for DBP), and so we did not pool results statistically (Analysis 6.1, Figure 9; Analysis 7.1, Figure 10). In Vernooij 2012, the difference in SBP at 12 months' follow‐up in the intervention group was ‐3 (standard deviation (SD) = 17.52) mmHg, and in the control group the difference was 2 (SD = 18.52) mmHg; this was reported within a 95% CI of ‐7.6 to 0.2. For DBP, the difference at a 12 months' follow‐up in the intervention group and the control group was ‐1 (SD = 9.54) mmHg, and 1 (SD = 10) mmHg, respectively; this was reported with a 95% CI of ‐4.4 to 0.4 (Vernooij 2012). Varnfield 2014 reported six weeks' follow‐up data in the published findings; we contacted the authors for the six months' follow‐up data, however this was not made available. At six weeks' follow‐up, Varnfield 2014 reported an intervention effect for DBP (P = 0.03), while the intervention effect on SBP was not significant (P = 0.4). Maddison 2014 measured DBP and SBP, which is not reported in the published findings; the authors were contacted and the findings provided. At six months' follow‐up, the change in SBP in the intervention group was 4.77 (SD = 13.39) mmHg, and in the control group 0.29 (SD = 13.37) mmHg. The change in DBP at six months' follow‐up in the intervention group was 1.23 (SD = 9.27) mmHg and in the control group ‐1.73 (SD = 10.16) mmHg. Both Devi 2014 and Zutz 2007 reported no significant SBP and DBP effects between the intervention and control groups at six months', and 12 weeks' follow‐up, respectively.

Figure 9

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Forest plot of comparison: 6 Systolic blood pressure, outcome: 6.1 Systolic Blood Pressure.

Figure 10

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Forest plot of comparison: 7 Diastolic blood pressure, outcome: 7.1 Diastolic Blood Pressure.

Health‐related quality of life

Five studies measured changes in health‐related quality of life (HRQOL) (Devi 2014; Maddison 2014; Reid 2012; Southard 2003; Varnfield 2014). Due to a lack of homogeneity in instruments used across studies, we could not combine these findings in a meta‐analysis. Southard 2003 used the Dartmouth COOP, however only baseline data was described, and no follow‐up findings reported. We contacted the authors, and unfortunately this data is no longer available. Both Devi 2014 and Reid 2012 used the MacNew to measure HRQOL; we were unable to combine this data as Reid 2012 did not report baseline scores. Devi 2014 showed that compared to a control group the experimental group demonstrated statistically significant improvements in emotional HRQOL (P = 0.04, 95% CI 0.01 to 0.54) at six weeks' follow‐up and statistically significant improvements in social HRQOL at six months' follow‐up (P = 0.018, 95% CI 0.05 to 0.54). In addition, Maddison 2014 reported statistically significant intervention effects in the general health domain of the 36‐Item Short Form Health Survey at 24 weeks (mean difference 2.1, 95% CI 0.1 to 4.1; P = 0.03), while there were no statistically significant differences in other HRQOL domains. Varnfield 2014 reported a statistically significant improvement between groups in HRQOL measured using the EQ‐5D index at six weeks' follow‐up (adjusted MD ‐0.08, 95% CI ‐0.14 to ‐0.02, P = 0.01), however this improvement was not maintained at six months' follow‐up. Reid 2012 reported that the differences between groups over time at six and 12 months' follow‐up in HRQOL domains were not statistically significant.

Diet

Five trials assessed dietary outcomes (Devi 2014; Lear 2014; Lindsay 2009; Southard 2003; Varnfield 2014), and findings were inconclusive. Southard 2003 used MEDFICTS, a measure of fat and cholesterol intake, and reported no statistically significant changes at six months' follow‐up. Devi 2014 measured diet using the DINE (Dietary Instrument for Nutrition Education) and reported no statistically significant dietary effects at both six weeks' and six months' follow‐up. Varnfield 2014 assessed diet using Dietary Habits Questionnaire; this study did not report six months' follow‐up data, and at six weeks reported no statistically significant differences between groups in fat intake (P = 0.4), fibre intake (P = 0.7), sodium (P = 0.4), or alcohol (P = 0.6). Lear 2014 reported no significant group differences over time in carbohydrate (P = 0.224) and fat (P = 0.451) intake, but reported statistically significant intervention effects in protein (P = 0.044) and saturated fat (P = 0.018) intake. Lindsay 2009 also demonstrated a positive finding. This study measured the frequency of unhealthy foods eaten using variables from the Health Survey for England and reported that after six months of using the intervention, the experimental group ate unhealthy foods less often compared to the control group (P = 0.014); this change was not sustained at nine months' follow‐up (P = 0.517).

Physical activity

Eight trials assessed physical activity effects. Six studies used self report measures (Antypas 2014; Lear 2014; Lindsay 2009; Maddison 2014; Southard 2003; Zutz 2007), one used an objective measure (Devi 2014), and one used both an objective and a self report measure (Reid 2012).

Of the studies using self report measures, two used the International Physical Activity Questionnaire (IPAQ) (Antypas 2014; Maddison 2014), two used the Minnesota Leisure Time Physical Activity Questionnaire (Lear 2014; Zutz 2007), and two used unstandardised measures (Lindsay 2009; Southard 2003). In both Southard 2003 and Lindsay 2009, there were no significant physical activity effects.

Even though Maddison 2014 and Antypas 2014 both used the IPAQ, we could not combine the data, as Maddison 2014 reported means and standard deviations, and Antypas 2014 reported median and interquartile range values. Maddison 2014 reported a statistically significant increase in self reported leisure time physical activity (mean difference 110.2 min/week, 95% CI ‐0.8 to 221.3; P = 0.05) and walking (mean difference 151.4 min/week, 95% CI 27.6 to 275.2; P = 0.02) at 24 weeks in favour of the intervention group, which represents increases of 40% and 42%, respectively. Maddison 2014 reported no statistically significant differences for the other activity domains (total activity, active transport, domestic/gardening, and reduced sitting time). Antypas 2014 reported that at three months' follow‐up the intervention group had a significantly higher IPAQ score than the control group, P = 0.02, and higher levels of walking than the control group (P value not reported). There were no significant differences between groups in moderate and vigorous activity or time spent sitting at a one and three months' follow‐up (Antypas 2014).

Although Lear 2014 and Zutz 2007 both used the Minnesota Leisure Time Physical Activity Questionnaire, we were unable to combine their findings as Zutz 2007 reported mean values, and Lear 2014 reported median values. Zutz 2007 reported no statistically significant differences between groups (P value not reported). Similarly, Lear 2014 reported that the group differences over time in leisure time physical activity were not statistically significant (P = 0.191).

Two of the included studies used an objective measure to evaluate physical activity. Devi 2014 used an accelerometer to measure a range of outcomes, and reported statistically significant improvements in daily step count (intervention group n = 35, control group n = 40, P = 0.016, 95% CI 263 to 2451), energy expenditure (intervention group n = 35, control group n = 40, P = 0.01, 95% CI 43.93 to 309.98), duration of sedentary activity (intervention group n = 35, control group n = 40, P = 0.012, 95% CI ‐55.01 to ‐7.01), and duration of moderate activity (intervention group n = 35, control group n = 40, P = 0.014, 95% CI 6.01 to 51.20) at six weeks' follow‐up. There were no statistically significant effects at a six months' follow‐up (Devi 2014). Reid 2012 used both an objective (pedometer) and a self reported measure (a modified version of the Godin Leisure‐Time Exercise Questionnaire); however this study did not collect pedometer data at baseline, and only collected data at the six‐ and 12‐month follow‐ups. This study reported that the difference between groups over time in pedometer‐measured activity (P = 0.656) and self reported moderate and vigorous physical activity levels (P = 0.782) was not significant.