Cardiovascular Disease, Coronary Artery Disease: Scope of Literature

Summary

This review sought to collect and interpret the evidence on home telehealth for management of patients with coronary artery disease. We looked at 3 areas:

• Patients: How is home telehealth used in treating people with coronary artery disease?  Do patients like it?  How clinically effective is it?
• Providers: What is the impact of home telehealth on health human resources?  What are the roles of nurses, general practitioners, and specialists in its delivery?  How do providers characterize their experiences with home telehealth?
• System: How is home telehealth incorporated into the care continuum?  What is the economic impact of incorporating home telehealth into care?  What policies need to be in place for home telehealth to be successful?

In order to answer these questions, we conducted a systematic search for literature published from 2005 to 2010.  This search retrieved 10 studies that met our inclusion criteria.  The quality of the evidence was generally strong.  A final search for publications from 2011 to 2012 found 5 additional studies.  Though findings from these studies were incorporated into the review, be aware that material from the 2011-2012 period was screened and analyzed in a slightly different way than the studies retrieved in our original search.

Details

Number and Location

A search of literature published from 2005-2010 located 10 studies of home telehealth in coronary artery disease management. The purpose of these interventions was primary or secondary prevention of myocardial infarction through education in risk factor management (; Barnason et al., 2006, 2009; Giallauria, 2006; Lindsay et al., 2008, 2009; Miller et al., 2007) and/or ongoing monitoring for detection of critical events ( Al-Khatib et al., 2010; Chiantera et al., 2005;  Morguet et al., 2008; Raatikainen et al., 2008; Waldmann et al., 2008). Lindsay et al. (2008) and Lindsay et al. (2009) formed a case series study; the papers examined the same program and the same sample at 6 months and 9 months, respectively.

Of the studies retrieved, 6 were set in Europe, 2 in Germany (Morguet et al., 2008; Waldmann et al., 2008), 2 in Italy (Chiantera et al., 2005; Giallauria, 2006), 1 in England (Lindsay et al., 2008, 2009), and 1 in Finland (Raatikainen et al., 2008). Subjects were recruited from hospitals in the midwest United States in 2 studies (Barnason et al., 2006, 2009), and from North Carolina in 1 (Al-Khatib et al., 2010). No location was given in Miller et al. (2007).

A scan of material from 2011-2012, a time period not covered by our initial searches, found 5 additional studies that met our inclusion criteria and filled gaps left by the first rounds of searching (Crossley et al., 2011; Dalleck et al., 2011; Petersen et al., 2012; Zimmerman et al., 2011; Zucca et al., 2011). These studies were analyzed in a slightly different way than the studies retrieved in our original search, and their findings were incorporated into this review in a limited fashion. For more details, please see Methods.

Study Design

The Oxford 2011 Levels of Evidence were used to assess the strength of the evidence base.[1] Studies were placed on a scale running from Level 1,[2] considered the highest level of evidence, through to Level 5.[3] Levels are based primarily on study design. Studies were also assigned scores for quality of execution and reporting. Low execution/reporting scores resulted in downgrading.

The Oxford 2011 Levels of Evidence are intended to provide guidance rather than absolute judgments, and do not obviate the need for careful appraisal of local needs and context. The quality of studies within a given level can vary, as can their applicability to select populations. Furthermore, this system is not suitable for all forms of assessment. In the text that follows, the Oxford 2011 Levels of Evidence are used only when discussing clinical outcomes.

The evidence base for use of home telehealth in the management of coronary artery disease was generally strong, although execution/reporting scores tended to be unexceptional.[4] Use of control groups and randomization with prospective measurement of exposure and outcomes resulted in 7 studies being classified as Level 2 evidence (Al-Khatib et al., 2010; Barnason et al., 2006, 2009; Lindsay et al., 2008, 2009; Miller et al., 2007; Waldmann et al, 2008). However, 1 was subsequently downgraded to Level 3 for a low execution/reporting score (Chiantera et al., 2005). The remaining studies received Level 4 ratings; 2 were case series studies (Morguet et al., 2008; Raatikainen et al., 2008) and 1 was a non-randomized controlled study that, like Chiantera et al. (2005), was downgraded a level due to a low execution/reporting score (Giallauria et al., 2006). Industry involvement was disclosed in 1 study (Raatikainen et al., 2008).

The number of participants enrolled ranged from 41 to 1541, although somewhere between 40 and 80 was most common. Study duration followed a roughly bimodal distribution, with 4 studies lasting 9-12 months, and 6 running for 1-3 months.

The majority of patients in every study, without exception, were male. In 4 studies, the percentage of females was under 20% (Giallauria, 2006; Raatikainen et al., 2008; Chiantera et al., 2005; Barnason et al., 2009). The mean age of participants was generally between 60 and 70 years. Apart from age and sex, most authors provided little non-clinical information about patients. Only 1, for example, mentions computer literacy (Lindsay et al., 2008, 2009).

Population Characteristics: Clinical Characteristics

Notable clinical characteristics include:

1) High rates of previous myocardial infarctions and/or coronary artery bypass surgeries. In 4 of the 5 studies reporting this figure, over 50% of patients had previously experienced myocardial infarction and/or coronary artery bypass surgery (Miller et al., 2007; Waldmann et al., 2008; Chiantera et al., 2005; Raatikainen et al., 2008).

2) High levels of co-morbidities (30-100%) were reported in studies that recorded co-morbidites (Waldmann et al., 2008; Al-Khatib et al., 2010; Miller et al., 2007). Most commonly cited were diabetes, hypertension, and hyperlipidemia. Barnason et al. (2009), while not providing a detailed breakdown of co-morbidities, examined a sub-group of a larger study that met criteria for high pre-operative disease burden. Eligibility criteria for Miller et al. (2007) included a diabetes diagnosis.

Interestingly, only 1 of 10 studies gave New York Heart Association classification information for participants (Raatikainen et al., 2008). This is a far lower percentage than that found in the heart failure sub-category of cardiovascular disease, where 11 of 26 studies report on NYHA classifications.