Myocardial Infarction Health care Atlas for Norway

Just under 11,900 patients were admitted with acute myocardial infarction per year in 2018-2022. Two out of three patients were men, and the men were on average younger than the women (median age 70 and 78 years, respectively).

The average annual rate for Norway was 2.8 admissions with myocardial infarction per 1,000 population. The rate decreased during the period 2018-2022, with the largest reduction in the pandemic year 2020. The decline observed over many years likely reflects a real decrease in the number of people affected by myocardial infarction (see Annual Report 2021 Norwegian Myocardial infarction Register).

There was an urban-rural gradient in the rates; the lowest rate was in areas with the largest cities. The Finnmark hospital referral area had the highest prevalence, while the Sørlandet and Diakonhjemmet hospital referral area had the lowest prevalence of acute heart attack, using patients admitted for acute myocardial infarction as an indicator of coronary morbidity.

Just over 5,200 patients, 75 years and older, were admitted with acute myocardial infarction per year in 2018-2022. There was a clear reduction in the number of elderly with acute myocardial infarction compared to 2013-2015 (6,652 patients, Elderly Health Atlas), despite an increasing number of elderly (from 359,928 elderly on average per year in 2013-2015 to 409,950 in 2018-2022). The clear reduction in acute myocardial infarction in the elderly is also shown in the Myocardial infarction Register’s annual report for 2021.

The geographical variation in 2018-2022 was moderate. As in previous analyses (Elderly Health Atlas), the Finnmark hospital referral area had the highest and the Sørlandet hospital referral area had the lowest rates. The average annual rate for Norway was 12.8 admissions for the elderly with myocardial infarction per 1,000 population. The annual rates clearly decreased in most hospital referral areas in 2018-2022.

A total of 13,038 revascularizations were performed, distributed among 12,252 patients on average per year during 2018–2022, in the age group of 18 years and older. The number includes all patients, not only those with myocardial infarction. The majority were men (77%) who underwent heart revascularization. The rate of revascularization was 3.1 per 1,000 population for Norway.

The hospital referral areas areas in Northern Norway had the highest rate of revascularization, and the Diakonhjemmet area had the clearly lowest rate. Finnmark had the highest rate of revascularization was expected since they also had the highest rate of heart attacks. There is a positive moderate correlation between the rates of admission and revascularization (r=0.57), and the correlation is statistically significant (p=0.006) for the age group 18 years and older. A positive correlation was expected because revascularization is a treatment for, among other things, heart attacks. Catchment areas with a high prevalence of infarction should have a high revascularization rate.

The geographical variation was small when excluding the highest and lowest rates for revascularization (FT2=1.6 and SCV2=1.9).

On average, 3,787 revascularizations were performed for the elderly (75 years and older) per year in 2018-2022, distributed among 3,584 patients, and 69% of the patients were men. The number of revascularizations per year was roughly unchanged from 2013-2015 (3,403, Elderly Health Atlas) despite a clear reduction in the number of heart attacks. The revascularization rate was 9.3 per 1,000 population per year for the elderly in Norway (2018-2022).

The revascularization rates were highest for the elderly from the hospital referral areas in Northern Norway. The geographical variation can be characterized as moderate (FT2=1.8 and SCV=3.8), with the highest rate for the elderly in the UNN referral area and the lowest in Inner Oslo. The rate increased significantly in the Finnmark hospital referral area from 2019, while there was a decline in 2013-2015 (Elderly Health Atlas).

In some parts of the country, the rates for both admission and revascularization were high – for example, in Finnmark. In other parts of the country, there was a high prevalence of heart attacks and a low revascularization rate – for example, in Nord-Trøndelag. The correlation between the rates of admission with myocardial infarction and revascularization was small and not statistically significant (r=0.27, p=0.2) – the same was seen for 2013-2015 (Elderly Health Atlas).

The lack of correlation between admission and revascularization rates, and the lower use of revascularization for the elderly in many hospital referral areas, may be due to different practices, service offerings, and priorities. We do not know whether the degree of morbidity among myocardial infarction patients varied more among the elderly than in the overall adult group (18 years and older) where the correlation was moderate.

14% of patients received standard rehabilitation after myocardial infarction. This is a very low percentage - for both genders and all age groups ,compared to the guidelines that recommend rehabilitation for all with coronary heart disease (Visseren et al. 2021).

There was significant geographical variation in the percentage who received standard rehabilitation after myocardial infarction based on both the extermal qutient and the systematic component of variation excluding referral areas with highest and the lowest percetage of rehabilitation (EQ2=9.3 and SCV2=45). Extermal Qutient and systematic component of variation are used to support the assessment of geographical variation. Patients from the Vestfold hospital referral area had the highest likelihood of receiving standard rehabilitation, with 41% receiving such rehabilitation ,on average per year during 2018-2022. In nine of the hospital referral areas, 5% or fewer received standard rehabilitation after an myocardial infarction.

There were regional differences in the use of standard rehabilitation, with the lowest percentage participation in Northern Norway (4%) and the highest in Southeastern Norway (16%).

Within the hospital referral areas of the health trusts in the same health region, the use of standard rehabilitation also varied. In Southeastern Norway, the Vestfold hospital referral area had the highest percentage of myocardial infarct patients receiving such rehabilitation, while the Østfold and Telemark catchment areas had the lowest in the country. Similarly, within Western Norway; high participation rates in the Bergen area, and low in the Stavanger area. In Central Norway, the percentage was systematically highest for patients from the Møre og Romsdal catchment area.

The extent of the use of standard rehabilitation varied greatly. In the OUS catchment area, an average of 15 episodes per patient was registered, and for Norway, 6.5 episodes per patient for those who received standard rehabilitation. In some catchment areas, very few rehabilitation episodes per patient were registered, which could indicate a limited service offering but also raise suspicion of inadequate coding of standard rehabilitation after an acute heart attack. The report “Rehabilitation in Specialist Health Services 2017-2021” also mentions that there may be underreporting of diagnosis codes for rehabilitation (z-codes) in day and outpatient clinics in hospitals. 

There were differences in the type of standard rehabilitation, based on how the activities were coded. For Norway as a whole, most of the activity was outpatient rehabilitation, registered with Z50.9. That cardiac rehabilitation mainly occurs on an outpatient basis corresponds with professionals’ descriptions of the field. 

The code for rehabilitation after heart disease, Z50.0, was rarely used, with a few exceptions (Fonna, Stavanger, Finnmark, and UNN areas). The reason for this has not been investigated. That the analyses in the health atlas are based on a broader set of codes than just Z50.0 seems essential when highlighting cardiac rehabilitation. 

In several areas with a low percentage of standard rehabilitation after an acute heart attack, including the Helgeland and Østfold catchment areas, much of the activity occurred as inpatient stays, coded with Z50.80 (complex rehabilitation) and Z50.89 (simple rehabilitation). 

There were more episodes coded with Z50.80 or Z50.89 in Northern Norway than in other regions. This finding indicates relatively greater use of inpatient stays in the region, which seems likely due to long travel distances for participation in outpatient or day rehabilitation. 

The number of days before the start of standard rehabilitation after an acute myocardial infarction also varied. There was a tendency for earlier start with standard rehabilitation in central areas of Eastern Norway and later start after a myocardial infarction in the north of the country. About half of the patients from the Diakonhjemmet (Oslo West) and Vestfold hospital referral areas started standard rehabilitation one month after discharge from the acute stay, while in the Stavanger and Nordland areas, about half started only after four months. For Norway (red line), half of the patients had started standard rehabilitation after 53 days. 

The analyses concerning standard rehabilitation are based on codes for rehabilitation (z-codes). There are explicit requirements for a service to be called rehabilitation and to use such a rehabilitation code. Among other things, a plan must be developed for each patient, and several professional groups must be involved (see ISF regulations 2022). Although some of the explanation for the low use of standard rehabilitation after a myocardial infarction may be due to underreporting of z-diagnosis codes, it still seems that standard rehabilitation after a myocardial infarction is a limited service offering in Norway. The impression of a limited service offering for standard cardiac rehabilitation in Norway is also supported by contact with professionals. 

The number of days before the start of standard rehabilitation after an acute myocardial infarction also varied. There was a tendency for earlier start with standard rehabilitation in central areas of Eastern Norway and later start after a myocardial infarction in the north of the country. About half of the patients from the Diakonhjemmet (Oslo West) and Vestfold hospital referral areas started standard rehabilitation one month after discharge from the acute stay, while in the Stavanger and Nordland areas, about half started only after four months. For Norway (red line), half of the patients had started standard rehabilitation after 53 days. 

The analyses concerning standard rehabilitation are based on codes for rehabilitation (z-codes). There are explicit requirements for a service to be called rehabilitation and to use such a rehabilitation code. Among other things, a plan must be developed for each patient, and several professional groups must be involved (see ISF regulations 2022). Although some of the explanation for the low use of standard rehabilitation after a myocardial infarction may be due to underreporting of z-diagnosis codes, it still seems that standard rehabilitation after a myocardial infarction is a limited service offering in Norway. The impression of a limited service offering for standard cardiac rehabilitation in Norway is also supported by contact with professionals.

68% of patients with acute myocardial infarction were men. The average age for men was 68 years and for women 74 years. 

26% of patients received rehabilitation after an acute myocardial infarction if we included both standard rehabilitation, participation in learning and mastery courses (LMC), and training in specialist health services in the analyses. In the pandemic year 2020, the percentage was lowest. In only a few catchment areas was rehabilitation back to a “pre-pandemic level” in 2021. The low level of cardiac rehabilitation in 2020 was mainly due to the shutdown associated with the pandemic (Norwegian Directorate of Health 2022). 

Participation in rehabilitation varied from 9% to 46% between the catchment areas of the health trusts, and few patients from Finnmark received rehabilitation, despite a high prevalence of myocardial infarction. The highest percentage was in the hospital referral areas with in the largest cities. The geographical variation can be characterized as systematic and large (FT2=4.5 and SCV2=23.4). 

A similar extent of participation in rehabilitation was also revealed in a study of cardiac rehabilitation after first-time PCI (Olsen et al. 2018). Of those who participated in the study (82% of all with first-time PCI in 2008-2011), 28% had participated in cardiac rehabilitation. The study found similar trends to our analyses, also in geographical variation with the lowest participation in cardiac rehabilitation in Northern Norway and the highest in Southeastern Norway. Although both the patient sample, follow-up time (3 years versus our 6 months), and use of different methods (they questionnaires, we data from NPR), their results strengthen our findings of low participation and large geographical variation in cardiac rehabilitation in Norway. 

The highest percentage of patients who received rehabilitation after a myocardial infarction was found in the hospital referral areas of OUS, Vestfold, and Diakonhjemmet. While the Vestfold area had a relatively large percentage receiving standard rehabilitation, the two areas in Oslo had little standard rehabilitation registered, but a relatively larger proportion participating in LMC courses and training. 

For patients aged 65 and older, there was a clear reduction in the percentage of patients receiving standard rehabilitation, LMC courses, and/or training after a heart attack. That myocardial infarct patients in Norway who receive rehabilitation are relatively young has also been shown previously (Olsen et al. 2018). This contrasts with recommendations for rehabilitation at all ages (Ambrosetti et al. 2020). That older people are more likely to have more complex problems and different risk profiles than younger people is an argument for specialist health services to take responsibility for rehabilitation after a myocardial infarction also for the elderly. 

The percentage of women (20%) who received rehabilitation was lower than for men (30%). This is also known from other analyses (Visseren et al. 2021). The fact that the women in our analyses were somewhat older than the men, and that the elderly are less likely to receive rehabilitation, may be one of the explanations for this finding. 

For patients who received rehabilitation, the number of rehabilitation episodes they received in the first six months after an acute myocardial infarction varied geographically. For patients from the hospital referral areas of Bergen and Østfold, patients received an average of 10 rehabilitation episodes, and for Norway, the average was 7. Included in these analyses are episodes of standard rehabilitation, LMC courses, and/or training in specialist health services. 

Most of the rehabilitation occurred in the public sector, and for Norway as a whole, 86% of rehabilitation episodes took place there. The highest percentage of private rehabilitation was in Oslo with 71% in the OUS hospital referral area, followed by 42% in the Stavanger area. 

In most catchment areas, the number of rehabilitation episodes per patient was highest in the public sector. However, there were some contrasts in the country with 7 times more episodes per patient in the private sector than in the public sector in the OUS hospital referral area, and conversely, 9 times more episodes per patient in the public sector in the Møre og Romsdal hospital referral area. By private, we mean private institutions with agreements with the regional health authority. 

The percentage distribution of types of rehabilitation measures after a heart attack; standard rehabilitation, education, and/or training, varied between different parts of the country based on the coding of activities. For Norway as a whole, only 60% of the episodes were coded as standard rehabilitation (coded with Z-codes), varying from 5% to 96% between catchment areas, and education in LMS courses accounted for 10%. 

Physical training was a central part of rehabilitation after an acute heart attack. Training was either registered as individual episodes (31% of the episodes were only training), included as part of the LMS course, or included in the standard rehabilitation episode. Although training is a core component, the guidelines are clear that the effect of a cardiac rehabilitation program depends on participation in the entire interdisciplinary program, not just the physical training (Dibben et al. 2023 and Visseren et al. 2021). 

In some catchment areas, standard rehabilitation was mainly coded as inpatient stays (Helgeland and Østfold). Otherwise, there appeared to be little rehabilitation after a heart attack. When we included LMS courses and training in the analyses, we found that patients still had a service offering after a heart attack. 

That both the type of measures and the extent of the service offering varied geographically corresponds with results from previous studies of rehabilitation and secondary preventive measures in hospitals (Peersen et al. 2017, Peersen et al. 2021, and Olsen et al. 2018). 

The number of days to the start of rehabilitation (standard rehabilitation, LMS courses, and/or training) varied greatly between hospital referral areas. The difference was nevertheless somewhat smaller than for standard rehabilitation alone. Half of the patients in several hospital referral areas in Oslo and around the Oslofjord started rehabilitation about one month after discharge from the acute stay. In the hospital referral areas in Northern Norway and Stavanger, rehabilitation started about three months after a myocardial infarction. For Norway (red line), half of the patients had started rehabilitation only after 50 days. This is despite the guidelines recommending starting as soon as possible after the myocardial infarction (Visseren et al. 2021). 

There may be several explanations for the low participation in rehabilitation after a heart attack. It is beyond the scope of the health atlas to investigate this, but we will briefly mention some points. Referral routines, availability, travel distances, capacity, how well the service is developed, patient preferences, knowledge of existing services, and knowledge of patients needing rehabilitation may vary, as we understand from contact with professionals and as highlighted in research articles ( Peersen et al. 2021, Olsen et al. 2018, and Piepoli et al. 2016). 

In the latest annual report, the Myocardial infarction Register (2022) highlights that only half of those who responded to questions from the register reported that they had been referred to cardiac rehabilitation, defined as “education on how to reduce the risk of a new myocardial infarction and the offer of physical training.” There were also large regional differences in referrals, from 37% in Western Norway to 64% in Southeastern Norway, which may affect the participation rate in cardiac rehabilitation. The guidelines recommend finding methods to increase referral and participation in cardiac rehabilitation, so that as many as possible can benefit from services that have a clear health and societal benefit (Visseren et al. 2021).

Four percent of patients trained with physiotherapists in the municipalities in the first six months after an acute myocardial infarction in 2018-2021, based on information from physiotherapists who submitted invoices to Helfo. 

There was significant geographical variation in the percentage of patients who trained with physiotherapists in the municipalities after an acute myocardial infarction in 2018-2021. The percentage varied from 13% in the Stavanger catchment area to 2% in Inner Oslo. 

In the Stavanger hospital referral area, there is a well-established collaboration between specialist health services and municipal physiotherapists in cardiac training. In this catchment area, the use of standard rehabilitation, learning and mastery courses, and training in specialist health services was very low. 

Other hospital referral areas with little use of rehabilitation in specialist health services, such as Finnmark and Helgeland, also had little use of training with physiotherapists in the municipalities after myocardial infarction. 

We are nevertheless not aware of the total service offering patients received in the municipalities; this only includes training with physiotherapists who submitted invoices to Helfo. Information about training with salaried physiotherapists in the municipalities who do not submit invoices to Helfo, training or other services at health and wellness centers, or in municipal institutions, is currently not available in the datasets from KPR on which these analyses are based. The analyses are based on small numbers and may be influenced by chance.