SMARTphone-based, early cardiac REHABilitation in patients with acute coronary syndromes [SMART-REHAB Trial]: a randomized controlled trial protocol

Coronary heart disease (CHD) is the leading cause of mortality and morbidity in the world [1]. In 2012 CHD accounted for approximately 7.4 million lives, an increase of 23 % (1.4 million) from CHD deaths in 2000 [1]. Patients at highest risk of premature death, myocardial infarction and re-hospitalization are those with known CHD [2]. Consequently international guidelines strongly advocate proven secondary prevention strategies such evidence-based pharmacological therapy, cardiovascular risk factor optimization, cardiac rehabilitation and adherence to diet and physical activity recommendations [3].

Cardiac rehabilitation provides a comprehensive secondary prevention framework based on extensive scientific evidence. A recent Cochrane review revealed cardiac rehabilitation was associated with a 13 % decrease in all-cause mortality and a 26 % decrease in cardiovascular mortality [4]. This result is consistent with several other meta-analyses [5‐7].

However, there is poor translation of scientific evidence into clinical practice. Cardiac rehabilitation services are underutilized as highlighted by low referral rates and even lower completion rates [8‐12]. In addition, utilization of recommended pharmacological therapy and compliance with dietary and physical activity guidelines is suboptimal [13‐16]. Lastly, outpatient cardiac rehabilitation often starts weeks to months after the index event, even with the utilization of new technology [17]. This delay creates a missed opportunity to immediately reinforce the importance of physical activity and lifestyle changes. Furthermore, the delay in cardiac rehabilitation has been associated with delayed resumption of work [18].

The drawbacks of conventional cardiac rehabilitation have resulted in the development of innovative models of care. In the seminal paper by Vale et al, regular personal coaching via telephone has been shown to be effective in reducing total cholesterol levels and other cardiovascular risk factors [19]. Systematic reviews and meta-analyses have shown telehealth interventions for secondary prevention, limited to telephone calls, internet and videoconferencing technologies, offer an effective alternative model of secondary prevention care [20, 21].

Most recently, the Tobacco, Exercise and Diet Messages (TEXT ME) study showed a lifestyle-focused text-messaging service lowered LDL-cholesterol level, and blood pressure while increasing smoking cessation rates and physical activity in patients with known CHD [22].

Smartphone technology is an advance on previous telehealth and text-message based technologies. It has the potential to revolutionize the landscape of secondary prevention as it can provide a platform for a patient-centred program with the capacity to incorporate education, real-time feedback, motivation, reminders and support. Furthermore, it is a tool that can be used to monitor diet, physical activity, medications and cardiovascular risk factor parameters. Lastly and most importantly, a smartphone-based program can be started immediately, delivered from anywhere at any time and for extended periods of time.

Four studies have been published incorporating smartphone technology for the delivery of cardiac rehabilitation. Worringham et al. assessed a walking-based cardiac rehabilitation program with single-lead ECG, heart rate and GPS-based speed and location transmitted via smartphone for real-time monitoring by a qualified exercise scientist. [23] Six patients were evaluated in 134 exercise sessions with improvements in exercise capacity (improvement in 6-minute walk test from 524 m to 637 m, p < 0.01) and health status measured by SF-36 form. Korzeniowska-Kubacka et al. assessed a mobile device with preprogrammed exercise training sessions with audio and visual clues and a 3-lead ECG monitor [24]. In this non-randomized trial, 30 patients were assigned to the mobile device intervention with 10 supervised exercise sessions and 14 sessions with the mobile device at home. The control group of 32 patients had 24 supervised exercise sessions. There was in improvement in exercise capacity in the mobile arm (p < 0.05) but no difference in blood pressure. Blasco et al. assessed a web-based telemonitoring system that provided patients with self-measurement devices and connected them to a cardiologist who accessed the data and sent recommendations via short message service (SMS) [25]. In this single-blinded, randomized controlled trial of 203 acute coronary syndrome survivors, patients in the telemonitoring group were more likely to improve at least one risk factor (RR 1.4, 95 % CI 1.1–1.7) and achieve targets for BP (62.1 % vs 42.9 %, p = 0.01) and HbA1c (86.4 % vs 54.2 %, p = 0.02). Varnfield et al. compared the effectiveness of smartphone-based cardiac rehabilitation versus traditional care on cardiac rehabilitation uptake, adherence and completion in a randomized controlled trial [17]. 120 patients were randomized to the two groups for a 6-week cardiac rehabilitation program followed by a 6-month self-maintenance period. The smartphone based model included health and exercise monitoring, motivational and educational material delivery and weekly mentoring consultations. The trial met its primary end point with the smartphone based rehabilitation program showing significantly higher uptake (94 % vs. 68 %, P <0.05) and completion (80 % vs. 47 %, p <0.05).

The exponential growth and availability of smartphone technology provides a novel opportunity to optimize secondary prevention of coronary heart disease [26]. However, further studies are needed to examine the value of this approach and to demonstrate improvements in objective outcomes.

The study design is single-blinded, two-arm, parallel, randomized control trial. The study design is displayed in Fig. 1. The protocol conforms to the SPIRIT 2013 statement and the intervention is described in accordance with the CONSORT-EHEALTH checklist. [27‐30]

This novel study aims to evaluate the impact of a smartphone based secondary prevention program on functional capacity of patients with acute coronary syndromes. The benefit of comprehensive secondary prevention programs incorporating physical activity is well recognised. Smartphone technology could hold the key to bridging the well documented gap between scientific evidence and clinical practice.

This randomised clinical trial also aims to build the scientific base supporting alternative models of secondary prevention care in patients post acute myocardial infarction. Of particular note, is the initiation of this program as soon as the patient is discharged from hospital post their index event. This is a crucial period of recovery and immediate initiation of smartphone based secondary prevention program may facilitate early physical activity and return to normal daily function, including resumption of work.

The primary endpoint aims to objectively assess improvement in physical activity through the use of the six-minute walk test. Near maximal exercise testing is safe in patients with uncomplicated myocardial infarction prior to discharge and thus early mobilisation should be encouraged [37, 38]. The superiority trial design is suitable to detect a minimal clinically important difference in 6-minute walk distance [31]. It is postulated the improvement will be due to earlier initiation of an exercise program and increase in uptake and adherence with cardiac rehabiliation.