A systematic literature search was conducted using the following electronic databases: PubMed, SCOPUS, PsychINFO and CINAHL. The search terms comprised subject headings specific to databases where applicable, such as Medical Subject Headings (MeSH) in PubMed, as well as synonyms for these terms generated by the authors or listed in the databases. These searches were supplemented by citation screening of retrieved records and additional hand searching.

Records retrieved were those containing search terms related to ACS, patient discharge/post-discharge management, and either primary care, secondary prevention, and/or cardiac rehabilitation (CR). CR was included as a domain in the search strings because, although generally defined as medically supervised programs, CR services are sometimes expanded to include many different aspects of post-discharge management of ACS [24]. The literature search was limited to studies conducted in Australia or New Zealand and to journal articles published in the English language from the year 2000 onwards.

The literature search was last conducted on August 18^th, 2015. An example of a search string is presented in Additional file 1.

Duplicates were identified and removed. The remaining titles and abstracts were screened for eligibility and those that did not meet the inclusion criteria (Table 2) were excluded. Two reviewers (JW and MB) conducted this initial screening process independently, with any discrepancies resolved by discussion. Full-texts of the remaining publications were retrieved and assessed by three authors (MB, MD, JW) against the inclusion and exclusion criteria. A flow diagram of the literature search and selection process is presented in Fig. 1.

Data extraction was undertaken by all authors utilising a template with studies grouped according to the type of evidence-based primary care intervention they described. Studies were assessed for quality by one author (MB) based on the Mixed Methods Appraisal Tool (MMAT) [25], a method of appraising studies of various designs, in consultation with a second author (JW).

Six studies explored various aspects of pharmacological management of ACS in primary care. One recent Australian observational study reported outcomes of patients (n = 12813) following a percutaneous coronary intervention (PCI), the majority in the context of ACS [26]. In 2010, 75 % of patients were taking ≥ 4 classes of drugs at 12 month follow-up. The study also analysed trend data from 2005 to 2010 and found an increase over time in receipt of all drug classes investigated (p < 0.01). Finally, the same study found that females and patients aged > 75 years had significantly lower rates of medication usage than males and younger patients. Medication use was determined either by patient report or record review. An observational study conducted in New Zealand [27] reported similar rates of medication use at 3-year follow-up (n = 112). However, another New Zealand study reported lower rates of medication use in a cohort of coronary artery bypass grafting (CABG) patients (n = 109) at three-year follow-up [28]. Wachtel et al. [29] conducted a retrospective analysis of hospital and GP medical records (n = 34 patients), and found that GPs generally increased the prescription of evidence-based medications compared to prescription rates at hospital discharge.

Two interventional studies used medication prescription rates at GP follow-up as a clinical indicator to evaluate programs designed to improve post-ACS care [30, 31]. Hickey et al. [30] examined a quality improvement initiative known as the Brisbane Cardiac Consortium (BCC). The intervention included recurrent GP performance feedback from researchers in addition to GP liaison with hospitals regarding patient management. Though the study showed significant improvements in some clinical indicators, it did not report a significant change in prescription rates of medications in primary care follow-up post-intervention (n = 89 and n = 104 for 3- and 6- month follow-up, respectively). Scott et al. [31] examined the efficacy of a multi-faceted intervention that included clinical decision support, educational interventions, regular performance feedback, patient self-management strategies, and hospital-community integration. The study found greater prescription rates of aspirin at 3 months post-discharge in intervention patients compared to patients that received usual care (p = 0.05), and high rates of aspirin (p = 0.03) and β-blocker (p = 0.05) continuation among those prescribed these medications at discharge (n = 344). The intervention described in Scott et al. [31] also received generally positive feedback from patients.

In addition, Wai et al. [20] reported baseline results of medication use across Australia before a quality improvement initiative. This study reported that only 48 % of patients used four or more evidence-based drugs at a median of 96-day follow-up (n = 1319). When medication was stopped post-discharge, “the GP stopped it” was a major reason cited for discontinuation. The subsequent study to these baseline findings [32] did not report any medication usage rates in follow-up.

Two studies examined rates of lipid-lowering therapy (LLT) use in primary care follow-up. Mudge et al. [33] found that 66 % of post-ACS patients were on LLT 6–18 months post-discharge, and that 18 % of post-ACS patients with cholesterol levels over target did not receive LLT (n = 282). Toms et al. [34] measured a 50 % LLT prescription rate 18–36 months post-discharge, and that more than 50 % of study participants had total serum cholesterol levels above target (n = 93).

Five studies described behaviour change related to ACS in primary care. Gallagher et al. [35] studied an all-female population to determine predictors of completion of CR (n = 196). This descriptive study surveyed patients 12 weeks post-discharge, and found that two-thirds of women were referred to CR, and that CABG patients were more likely to be referred to CR than were myocardial infarction (MI) patients (though statistical analysis was not provided).

Rushford et al. [36] examined Australian female ACS patients and reported that recall by patients of CR referral by physicians, physiotherapists, nurse practitioners, or dietitians was correlated with attendance (p = 0.001) in this cohort (n = 212). Schulz et al. [37] found CR referral to be the single biggest influencer of attendance, and also found that being younger (p = 0.032) or married (p = 0.03) or living with a partner (p = 0.05) made patients more likely to be referred to CR (n = 79). Gender was not determined by this study to be a factor influencing CR attendance. Toms et al. [34] compared CR participants with non-participants in a observational study, and found that non-participants cited non-referral most commonly as the reason for their non-attendance, and that younger patients were more likely to be participate in CR. In results from a 2012 Australia-wide quality improvement study [32], both GPs and patients reported a 6 % increase in CR referral by GPs post-educational intervention (n = 636, p-values = 0.05 and 0.001 for GPs and patients, respectively).

The same interventional study examined the effect of an education intervention across the continuum of care on patients’ possession of an ACS management plan [32], which is an evidence-based guideline recommended for all post-ACS patients [5]. Compared to baseline, Peterson et al. [32] found that more patients had documented ACS management plans (n = 1589, p = 0.01), and of these, more plans contained a chest pain action plan (n = 1383, p < 0.0001). This intervention also increased communication of this management plan to the GP (n = 1589, p = 0.0001).

Psychological management in primary care was described in four studies. Fernandez et al. [38] described significant levels of depression, anxiety and documented stress in an observational study of patients 12–18 months after a percutaneous coronary intervention (PCI) (n = 202). Reddy et al. [39] described a lack of consistency in GP adherence to a protocol regarding depression screening, and that in a study of GPs, “about half” of the GPs were prepared to prescribe antidepressants (n = 18). In this same study, few GPs asked patients about depression, despite having received information about their patient’s depression score. Wachtel et al. [40] found that no ACS patients received any relevant behavioural interventions by a GP (n = 55), and no ACS patients received a social support or living condition intervention by a GP (n = 45). A randomised controlled trial conducted by Schrader et al. [41] documented that a GP intervention involving a telephone consult with a psychiatrist was the most effective psychological intervention and resulted in a reduced relative risk of having moderate to severe depression (n-237, 95 % CI). The same study found that non-consent to study procedures was associated with being older (p < 0.001) and female (p < 0.001).

Seven studies discussed management of lifestyle and behavioural risk factors. Fernandez et al. [38] documented that 46 % of female and 25 % of male patients had two or more modifiable risk factors one year after a PCI (n = 202). The same study found that patients underestimated their possession of risk factors: for both hypertension and hypercholesterolaemia, the portion of patients that reported these conditions were 9 % and 40 % lower than the portion of patients who had blood pressure and total cholesterol levels above target, respectively [38].

One study in Canberra reported that 12 % of CR participants, 53 % of CR non-participants, and 28 % of all studied patients still smoked 18–36 months after an MI (n = 93) [34]. Another observational study in Sydney [38] reported that 15 % of PCI patients were active smokers at 12- to 18- month follow-up post-PCI. A cross-sectional study in Auckland (n = 202) [27], found that 52 % of smokers had quit 3 years post-discharge from an ACS after an implicit intervention by the GP, resulting in an 11 % decrease in smoking in the study population.

A cohort study conducted by Wachtel et al. [29] reported that 45 % of patients received a smoking intervention in their GP clinics, while none received this intervention in the hospital setting (n = 34). A larger cross-sectional study [42] found that 88 % of post-ACS smokers received advice to quit (n = 674). One cross-sectional study [30] reported a significant improvement of smoking cessation at 3- and 6- month post- ACS event (n = 89 and n = 104, respectively) after a quality improvement program which included an education intervention targeting hospitals and GPs (p ≤ 0.05 for both).

A qualitative study [43] which described how Australian smokers and ex-smokers viewed the role of their GPs post-ACS found that many of the participants expressed a negative reaction to GP advice about smoking cessation, especially when it was unsolicited (n = 41). Some participants expressed that smoking advice was hard to receive when they were unwell or frightened. Patients in the study expressed feeling distressed when GPs attributed all their health problems to smoking, and some admitted to lying to their GP about quitting. Participants often described the manner in which GPs spoke to them about smoking cessation as significant: doctors who had quit smoking or had personal experiences with smoking were more likely to be persuasive.

Other studies described management of physical activity in primary care. The observational study conducted by Fernandez et al. [38] documented that 12 % of patients performed no physical activity 12–18 months after a PCI (n = 202), while the Toms et al. study [34] found that 65 % of MI patients exercised less than 3 times a week 18–36 months post-MI (n = 93). Ford et al. [27] found that in New Zealand, 47 % patients exercised 4 or more times a week 3 years after their ACS event (n = 112). Johnson et al. [42] reported that 76 % of patients were told to increase physical activity by a primary care professional (n = 4330), while another study [40] found that only 3 % of patients had an intervention in their GP clinic regarding physical activity (n = 34).

Fernandez et al. [38] reported 18 % of patients had hypercholesterolaemia 12–18 months after a PCI (n = 200). A cross-sectional study [27] showed a 0.8 mmol/L decrease in total cholesterol levels 3 years after ACS discharge (P < 0.001) compared to pre-PCI values (n = 112). One study found that 60 % of patients received advice in a primary care setting to follow a modified fat diet (n = 4347) [42] while another found that only 6 % of patients (n = 34) reported receiving advice regarding their dietary habits in a GP clinic [40]. The same study also describes that 7 % (n = 29) of patients reported receiving a GP intervention about being obese or overweight, while 3 % (n = 33) reported receiving an intervention for alcohol intake.

Besides the four categories outlined by the National Heart Foundation of Australia (NHFA), one study also examined hospital communication as a barrier to primary care management of ACS. As reported by Wai et al. [20], only 77 % of GPs (n = 731) reported receiving discharge summaries of ACS patients from hospitals at baseline. In addition, not all discharge summaries included prescribed medications (88 %) and risk factor management details (55 %). Only 65 % participating in the GP survey considered the quality of hospital information provided as “very good” or “excellent”. A subsequent educational intervention did not significantly improve the quality of these discharge summaries [32].

This review is unique in its summary of the knowledge base of primary care of coronary artery disease post-ACS in Australia and New Zealand. The 19 peer-reviewed publications show there is fragmented understanding of post-ACS care by GPs in Australia and New Zealand. Since the studies are diverse in study design, quality, analytical methods, setting, and time frame, it is difficult to discern any emerging patterns. However, some strengths and weaknesses do arise.

Studies of medication prescription rates post-ACS report mostly high rates of antiplatelet therapy prescription [20, 26, 27, 31], with one study reporting an encouraging positive trend in medication prescription over time [26]. However, the prescription rates of other evidence-based medications demonstrate room for improvement, especially angiotensin-converting enzyme inhibitor/angiotensin-II receptor blockers (ACEi/ARBs) and glycerol trinitrate (GTN) spray [27, 28]. Out of two interventional studies aiming to improve medication prescription rates, only one reported a significant positive impact [31]. The limited number and success of interventional studies and the diverse range of medication prescription rates (as described in Table 3) highlight the need for further research in ways to improve medication prescription by GPs in primary care.

Studies examining CR paid little attention to the role of GPs in influencing CR attendance: only one intervention sought to improve CR referral by GPs [32]. This is a matter of concern, especially since studies reported low referral rates [35, 37] and a strong relationship between referral and attendance [36]. Since studies highlighted that female [35], elderly, and single [37], patients are less likely to be referred to CR, interventions that focus on the needs of these special populations are indicated. In addition, since an educational intervention was found to have a significant positive impact on GP referral to CR and to creation of ACS management plans [32], the wider implementation of this quality improvement initiative has the potential to improve outcomes. Johnson and colleagues strongly recommended that non-referred patients be identified by their GP and be referred to CR and those who were referred but did not attend be identified and encouraged to participate in an alternative home-based CR program [42].

Although Fernandez et al. [38] clearly highlighted the need for psychological management of patients with ACS, there is little consensus or study of psychological assessment in primary care. Two descriptive studies found a complete lack of intervention [29] and inconsistent beliefs regarding depression screening in the primary care setting [39], highlighting an urgent need for more research to enhance primary care psychological management of coronary disease. Both studies also used small sample sizes, so research studying psychological assessment on a larger scale would be advantageous. The single randomised controlled trial that examined depression management found that a telephone consultation with a psychiatrist was effective [41], suggesting that larger scale implementation of this practice in primary care could be effective.

In studies where lifestyle management was studied, the possession of multiple modifiable risk factors post-ACS patients was common [33, 34, 38], while GP advice or intervention regarding these risk factors was inconsistent [27, 42] and sometimes severely lacking [40]. One promising interventional study found success in increasing GP interventions regarding smoking cessation post-ACS [30], but the success of these interventions in actually causing patients to quit smoking is still unclear. A qualitative study highlighted the complexity of GP involvement in smoking cessation [43], as advice regarding smoking cessation was not always regarded positively, and opinions were inconsistent regarding the productivity of such advice.

Hypercholesterolaemia management through modified diet advice and LLT was generally lacking [38, 42]. In addition, though body mass index (BMI) was not widely addressed, two studies reported alarming rates of obese and overweight post-ACS patients [29, 38], while advice from GPs regarding physical activity was imperfect [42]. Little is known about GP management and advice regarding alcohol intake in the context of post-ACS care. Besides depression management and a single study of a diabetic cohort, included publications failed to address in detail the complexities of handling ACS patients with other relevant comorbidities. Research in this area would assist a GP in adequately managing such complex cases. Surprisingly, there were few studies for whom the provision and effectiveness of lifestyle management advice was assessed, and these had small sample sizes. Concerns regarding the efficacy of GP advice in risk factor modification have the potential to influence the rate at which GPs deliver such advice, and so the development of robust strategy regarding GP advice to reduce patient possession of modifiable risk factors would be beneficial. This is an area where practice nurses with chronic disease expertise and ancillary allied health practitioners working within a general practice setting could offer opportunities for improved patient advice and outcomes.

Wai et al. [20] highlighted a need for increased communication between hospitals and GPs post-ACS. A subsequent quality intervention across the continuum of care was promising [32], and has the potential to improve multiple areas of evidence-based management of post-ACS care.

While Indigenous populations are identifiable as collectively having poorer health status in Australia and New Zealand [45], no published studies focused exclusively on the primary care management of Indigenous populations that have suffered an ACS. This is despite documentation that Indigenous populations of both nations face a disproportionate cardiovascular disease burden and experience culture-specific barriers to care [46]. Besides Indigenous populations, no Australian studies examined post-discharge ACS management in any non-Indigenous minority populations, although these groups were better addressed in publications from New Zealand [20, 28, 32]. Rural populations face unique barriers to care, and yet only five studies examined different aspects of patient care and follow-up in this setting. This is noteworthy because a significant portion of both Australia and New Zealand’s populations reside in rural areas. In addition, while many included studies reported patient populations that were overwhelmingly male, there was limited analysis of gender-based differences in primary care management of ACS. This is significant because post-ACS care decisions have historically been gendered. Overall, though age- and gender-related data was consistently collected, limited analysis of this data was reported. Overwhelmingly, studies followed patients from hospital rather than focusing on GP care. Published literature was also lacking in qualitative data, which could expose underlying attitudes and beliefs that affect patient care.

Out of 17 unique studies, 13 received MMAT scores ≥ 75 %, indicating that studies were of generally good quality. No study received a score below 50 %, though the MMAT score of one study [39] could not be assessed, since its study protocol was not fully reported.

This review highlights the challenges of and potential opportunities for improvement in post-ACS management in primary care in Australia and New Zealand. As ACS management, as specified by the NHFA and the CSANZ [5] and supplemented by the Cardiovascular Therapeutic Guidelines [6], covers such a broad range of treatment and care, this study is unique reporting on the status of primary care management and research in this area. This review is strengthened by its thorough literature search of multiple databases, and by the quality appraisal of publications in the MMAT format.

Several factors limit the definitive conclusions that can be drawn from the review. In the literature selection process, the possibility exists that relevant article(s) were not identified by the literature search because of gaps in implemented database search strings, although search strings for each database were developed with careful consideration and input from multiple authors, they were not proofread by any third-party assistant or librarian. The decision to limit this review to peer-reviewed publications additionally creates the potential of publication bias [47], especially since studies of populations often neglected by peer-reviewed publications, like Indigenous or rural populations, may be conducted by organisations that lack the financial means to publish academically.

The mixed-methods nature of the publications obtained from the literature search limited the nature of analysis. A meta-analysis was impossible, because of the inclusion of studies that were qualitative, descriptive, and non-interventional. In addition, studies were often limited in the amount of data that was publicly available: studies sometimes only published significant findings or short reports rather than exhaustive research papers. This data limitation was further complicated by the fact that the aim or research question of included studies often differed drastically from the aim of this review (Table 4). The number of publications also restricted the ability to draw conclusions about areas for improvements across the continuum of care. Studies that describe successful interventions may not apply in special population groups, but since special populations were largely not addressed, it is difficult to determine the success of interventions for them. The limited number of publications suggests that more follow-up data or research in this area is required.

The coverage of the subject matter of these publications was also restricted in regard to barriers and facilitators to primary care management of ACS, because the studies do not include patients that were prevented by some means from accessing a GP in the first place.