Chapter 2

Interventions and Services

Heart disease and stroke are chronic lifelong diseases that can be treated to relieve symptoms, improve the quality of life and reduce early death.  A myriad of interventions, such as drugs, surgical procedures and education about lifestyle adjustments, is used in ambulatory and hospital settings.  Clinical practice guidelines and care maps have been developed to improve consistency of treatment based on research evidence. 

Helping individuals, both in the immediate or acute phase and in the community with rehabilitation and support, requires a range of health services.  Community interventions are particularly important for individuals with a chronic illness such as heart disease or stroke, because they spend much of their time living in the community rather than in a hospital.

Monitoring the use of interventions and health services can provide information for planning and evaluating health services to meet the changing needs of the population.  To date, no national database of individuals with heart disease and stroke has been established to provide person-specific data on the use of interventions and health services.  Several provincial- and hospital-based databases do exist that can provide some of the information needed, but a national initiative to co-ordinate these databases would help to meet some of the need for information.

Hospitalization

Heart disease and stroke often result in health problems serious enough to require hospitalization.  The following data from the Hospital Morbidity Database of the Canadian Institute for Health Information (CIHI) provide information on the use of hospital services (acute and chronic hospitals).  The hospitalization data include individuals discharged from both acute and chronic care facilities.  However, not all chronic care facilities are included; the proportion of chronic care facilities included varies from year to year and from province to province.  Of particular note is that, as of fiscal year 1997/98, the Hospital Morbidity Database no longer included Ontario chronic care facilities.  Since the number of hospitalizations for cardiovascular diseases in the Ontario chronic care hospitals prior to this time was small, this change had minimal impact on the overall rate of cardiovascular disease hospitalization.

The data presented in this report record each separation from a hospital (including transfers) as one episode of care.  As a result, an individual will be counted more than once if he or she has more than one hospital separation.

Unfortunately, the database does not include information on visits to hospital by outpatients.

The data for most of the charts have been analyzed using the diagnosis most responsible for the length of stay.  The health care team determines this at the time of hospitalization.

The health problems studied in this chapter include cardiovascular diseases as a whole (ICD-9 390-459), and selected cardiovascular diseases: ischemic heart disease (ICD-9 410-414), acute myocardial infarction (ICD-9 410), congestive heart failure (ICD-9 428) and cerebrovascular disease (ICD-9 430-438).

Projected numbers of hospitalizations for cardiovascular diseases as a whole and for each of the four diseases listed above have been estimated assuming that annual changes in the hospitalization rates in the future will be the same as the average annual changes in age-sex rates over the last ten years.  These new annual rates were applied to Statistics Canada’s population projections to take into account the aging of the population.  Hospitalization rates have been somewhat inconsistent over the past 10 years: therefore, these projections present but one picture of a possible future.

Contribution to Hospitalizations

Cardiovascular diseases accounted for 18% of all hospitalizations among men and women in Canada in 2000/01, higher than any other health problem (Figure 2-1).

Figure 2 - 1


In 2000/01, cardiovascular diseases were the leading cause of hospitalizations for men (21% of all hospitalizations) and women (15% of all hospitalizations excluding childbirth and pregnancy) (Figures 2-2 & 2-3).

Figure 2 - 2


Figure 2 - 3


Trends over Time

Hospitalization rates for cardiovascular diseases have decreased steadily since 1985 (Figure 2-4).  The trends over time were similar for both women and men.  Hospitalizations for men for cardiovascular disease as a whole were 1.7 times higher than for women.

Figure 2 - 4


Between 1985/86 and 2000/01, hospitalization rates for ischemic heart disease decreased steadily (Figure 2-5).  The same pattern was observed for cerebrovascular disease (mostly stroke).  Rates for congestive heart failure increased to the mid-1990s then decreased.

Figure 2 - 5


Rates for acute myocardial infarction decreased to the mid-1990s, then remained steady.  This suggests that the decline in hospitalization rates has halted.

The same pattern was observed for both men and women, with the exception that the plateau in the rate of hospitalization for acute MI occurred earlier among women than men (1994 versus 1998) (Figures 2-6 and 2-7).

Figure 2 - 6


Figure 2 - 7


Cardiovascular Diseases

Hospitalization rates increased with age for all cardiovascular diseases in 2000/01, and were higher among men than women in all age groups (Figure 2-8).

Figure 2 - 8


From 1979 to the mid-1990s, the number of hospitalizations for cardiovascular diseases increased (Figure 2-9).  They then stabilized in the latter 1990s.  Based on the overall experience from 1985 onward, the number is predicted to increase among both men and women, but to a greater degree among men.

Figure 2 - 9


Where a cardiovascular disease was listed as a reason for hospital admission in 2000, it was the primary contributor to the length of stay in hospital for approximately 50% of admissions in all age groups (Figure 2-10).

Figure 2 - 10


Ischemic Heart Disease

In 2000/01, hospitalization rates for ischemic heart disease (IHD) were much higher among men than women in all age groups.  They increased steadily with age until the 90+ year age group.  Among men, the increase began in the 40-49 year age group, while among women the increase did not appear for another 10 years (Figure 2-11).

Figure 2 - 11


While the actual number of hospitalizations for ischemic heart disease is projected to increase for both men and women in the next twenty years, the increase is projected to be at a much higher rate for men (Figure 2-12).

Figure 2 - 12


Until the age of 50 years, if an individual was hospitalized for ischemic heart disease in 2000, it was usually the primary contributor to length of stay in hospital (Figure 2-13). This pattern decreased over time until the 70-79 year age group, when ischemic heart disease was more likely to be an associated factor.

Figure 2 - 13


Acute Myocardial Infarction

Hospitalization rates for acute myocardial infarction (AMI) were much higher among men than women in all age groups in 2000.  They increased steadily with age, beginning at age 40 for men and age 50 for women (Figure 2-14).

Figure 2 - 14


The actual number of hospitalizations for acute myocardial infarction (either first time or recurrent) has been increasing since 1980 and will likely continue to do so through the early part of the new century due to the aging population (Figure 2-15).

Figure 2 - 15


In all age groups, if an individual was hospitalized for acute myocardial infarction in 2000, it was usually the primary contributor to length of stay in hospital (Figure 2-16).

Figure 2 - 16


Congestive Heart Failure

Rates of hospitalization for congestive heart failure were greater for men than women in 2000/01, though the sex difference was less than for ischemic heart disease and acute myocardial infarction.  Rates increased with age, especially after the age of 70 years (Figure 2-17).

Figure 2 - 17


From 1979 to the mid-1990s, the number of hospitalizations for congestive heart failure increased, then stabilized and decreased in the latter 1990s (Figure 2-18).  The number of hospitalizations for congestive heart failure was similar for both men and women.  They are projected to increase in the future based on the experience from 1989 onward.  It will be important to monitor whether the decrease in the latter part of the 1990s continues, as this will influence the projected numbers.

Figure 2 - 18


Congestive heart failure was commonly an associated condition, rather than the most responsible condition, contributing to the length of stay in hospital in 2000/01 (Figure 2-19).  Data that track only the most responsible diagnosis will underestimate the contribution of congestive heart failure to hospitalization.

Figure 2 - 19


Cerebrovascular Disease

The rates of hospitalization for cerebrovascular disease (mostly stroke) increased over the age of 60 among both men and women (Figure 2-20).  Rates were higher among men than women, but this difference decreased over the age of 80 years.

Figure 2 - 20


Stroke is one of the most common presentations of cerebrovascular disease.  Among men and women under the age of 50 years, stroke can be due to subarachnoid hemorrhage, intracerebral hemorrhage or occlusion of cerebral arteries with cerebral infarction (Table 2-1).[1]  In 2000/01, intracerebral hemorrhage and infarction increased dramatically with age.  The hospitalization rate for intracerebral hemorrhage increased among men over the age of 60 years and for women over the age of 70 years.  The hospitalization rate for occlusion of cerebral arteries with cerebral infarction increased markedly at age 50 for both men and women, and continues to increase exponentially.

Table 2 - 1

Table 2-1        Hospitalizations* for Stroke by Age and Sex, Canada, 2000/01

Type of Stroke (ICD-9 code)

Crude Rates of Hospitalization per 100,000

(Age group)

Men

30-39

40-49

50-59

60-69

70-79

80-89

90+

All Stroke (430-432, 434, 436)

12

41

135

385

928

1,841

2,201

Subarachnoid hemorrhage (430)

4

10

14

15

14

21

14

Intracerebral hemorrhage (431)

3

7

17

53

107

166

145

Occlusion of cerebral arteries with cerebral infarction (434,436)

5

23

97

298

758

1,548

1,889

Women

 

 

 

 

 

 

 

Stroke (430-432, 434, 436)

15

36

88

239

687

1,522

1,896

Subarachnoid hemorrhage (430)

6

14

22

22

24

24

18

Intracerebral hemorrhage (431)

2

4

10

27

74

145

127

Occlusion of cerebral arteries with cerebral infarction (434,436)

6

17

54

182

568

1,311

1,703

* Acute care hospitals only, out-of-province hospitalizations excluded

Source: Hospital Morbidity Database, Canadian Institute for Health Information

 

Between 1979 and the mid-1990s, the number of hospitalizations for cerebrovascular disease increased, then decreased, then increased again, and in the last four years decreased again (Figure 2-21).  This instability makes it difficult to project the number of hospitalizations in the future.  Nevertheless, the general trend in the 1980s has shown an increase which is expected to continue because of the aging population.

Figure 2 - 21


When an individual was hospitalized with cerebrovascular disease in 2000/01, it was as likely to be the most responsible condition as it was to be an associated condition contributing to the length of stay in hospital (Figure 2-22).

Figure 2 - 22


 

Hospital Procedures

Several surgical procedures can improve the quality of life and decrease illness and death for individuals with heart disease and stroke (Figures 2-23 to 2-33). Coronary bypass grafting and angioplasty are effective treatments for ischemic heart disease.  Valve surgery can improve chances of survival.  Pacemaker implants can support the electrical functioning of the heart.  Carotid endarterectomy can improve the circulation to the brain and decrease the risk of stroke for some individuals.

The data in this report do not include procedures done on an outpatient basis since the Hospital Morbidity Database only includes inpatient admissions.

Coronary Artery Bypass Grafting

Coronary artery bypass grafting (CABG) uses arteries or veins to bypass or go around blockages in the coronary arteries.  The increased use of arteries instead of veins to bypass blocked coronary vessels has significantly improved outcomes.

In 2000, men had much higher rates of CABG than women at all ages.  The rate of CABG increased to age 70-79 years for both men and women and then decreased (Figure 2-23).

Figure 2 - 23


The number of coronary artery bypass surgeries increased among both men and women between 1994/95 and 2000/01 (Figure 2-24).

Figure 2 - 24


 

Coronary Angioplasties

Coronary angioplasty opens a blocked or narrowed coronary artery.  The merits of immediate angioplasty in acute myocardial infarctions are being studied intensively and it appears likely that angioplasty will become the intervention of choice.  By restoring blood flow to a coronary artery, balloon angioplasty preserves heart muscle function and improves outcomes.  Hospital stay is minimized with many angioplasties being done as an outpatient procedure.  The addition of a stent, particularly one that elutes an anti-thrombotic drug, has markedly improved the patency results of angioplasty.

An analysis of 1998/99 hospitalization records identified 40,680 individuals who had an acute myocardial infarction.  Of these, 24.8% underwent a revascularization procedure.  Among men under the age of 75 years, 38.8% underwent revascularization (36.0% had surgery (CABG) and 63.5% had angioplasty).  Among men aged 75+ years, 13.1% underwent revascularization (45.9% had surgery and 53.7% had angioplasty).  Among women under the age of 75 years, 33.3% were revascularized (34.7% had surgery and 63.6% had angioplasty).  Among women aged 75+ years, 9.1% underwent revascularization (34.8% had surgery and 63.4% had angioplasty).

In 2000/01, the rate of angioplasties was higher among men than women in all age groups (Figure 2-25).  The rate increased with age and more than doubled between the 40-49 and 50-59 year age groups. 

Figure 2 - 25


The number of coronary angioplasties has surpassed that of bypass operations (1.6 times higher).  Between 1994/95 and 2000/01, the number of angioplasties performed on both men and women increased by 36% (Figure 2-26).   The male:female ratio remained the same at 2.3:1.

Figure 2 - 26


 

Valve Surgery

Many diseased valves can be repaired; others are replaced either with a prosthetic tissue valve or a mechanical one.  Since the lifespan of a prosthetic valve is limited, younger patients in particular may need to undergo repeat valve surgery. The majority of operations involve one diseased valve, although some individuals require repair and/or replacement of more than one.  Older patients are typically examined for coronary artery disease, as they often require bypass surgery in addition to their valve surgery.

In 2000/01, the rate of valve surgery increased with age among men and women to age 70-79 years and decreased after the age of 80 (Figure 2-27).  The rate among men was higher than women for all age groups.

Figure 2 - 27


The number of valve surgeries increased between 1994/95 and 1998/99 (Figure 2-28).  In 2000/01, they decreased among men while they continued to increase slightly among women.

Figure 2 - 28


 

Pacemaker Implantation

Even as their size decreases, pacemakers are becoming more and more sophisticated. Consequently, their performance can be better matched to an individual patient’s needs, not only preventing catastrophic events but also improving the quality of life.  The indications for pacemaker implantation are broadening as the range of response capabilities increases.

The rate of pacemaker implantations increased steadily with age among men and women in 2000/01, and was highest in the 80-89 year age group (Figure 2-29).  The rate among men was higher than among women in all age groups.

Figure 2 - 29


Between 1994/95 and 2000/01, the number of pacemaker implants increased, mostly due to a continued increase among women (Figure 2-30).  This increase has been particularly noticeable since 1997.  The aging of the population and broadening of the indications for pacemaker use have also contributed to the increase. 

Figure 2 - 30


 

Carotid Endarterectomy

Carotid endarterectomy is a surgical treatment for the prevention of stroke.  Benefit from the procedure is greatest for symptomatic patients with at least 70% stenosis of the internal carotid artery.  Symptomatic patients with 50% to 69% stenosis experience less benefit, and those with less than 50% stenosis do not benefit from the operation.  The role of endarterectomy in the treatment of asymptomatic patients with carotid stenosis remains unclear and controversial.

In 2000/01, the rate of carotid endarterectomy peaked among adults aged 70-79 years (Figure 2-31).  The rate among men was at least twice the rate among women in all 50+ age groups.

Figure 2 - 31


The number of carotid endarterectomies has changed very little among either men or women since 1995/96 (Figure 2-32).

Figure 2 - 32


 

Heart Transplantation

Heart transplantation is a lifesaving procedure for an otherwise fatal condition.  The number of heart and combination heart and lung transplantations performed in Canada each year does not reflect the need; the limited availability of donor organs remains a major challenge. 

Mechanical devices to support or replace cardiac function offer some hope for the future and, once available, should result in dramatic growth in the number of operations.

In 2000, 171 heart transplantations and 4 heart and lung transplantations were carried out in all of Canada.  In 1995, the most common primary diagnosis for heart transplantations was coronary artery disease (46%), followed by cardiomyopathy (41%).  Congenital heart disease and valvular heart disease were the underlying health problems in 6% and 3% of heart transplantations, respectively.

The number of heart transplantations increased dramatically in the 1980s, largely due to improvements in technology and drugs (Figure 2-33).  The numbers were virtually the same in 1993 and 2001, with minor variations in intervening years.

Figure 2 - 33


Heart and lung transplantations increased to a high of 17 in 1989, then decreased to 4 in 2001.

Between 1991 and 2000, the one-year survival rate for heart transplantations was 83.7%.  For 3 years, it was 79.0%, and for 5 years, 74.7%.  The 5-year survival rate actually increased over that time period from 69.1% in 1989-1997 to 77.4% in 1995-2000.

Medication Use

In 2001, an estimated 43.5 million prescriptions were dispensed for the treatment of cardiovascular disease, an increase of 34% from the 32.5 million prescriptions in 1998, and an increase of 45% from the 30.0 million prescriptions in 1996 (Figure 2-34).  Two drug groupings showed the greatest increase: ACE inhibitors (from 7.5 million in 1996 to 8.5 million in 1998); and cholesterol reducers (from 4.8 million in 1996 to 7.3 million in 1998).  Use of these drugs increased steadily throughout the 1990s.

Figure 2 - 34


Cardiovascular disease prescriptions accounted for 13.9% of the total 312.6 million prescriptions dispensed in Canada in 2001 (Figure 2-35).  Although diuretics are analyzed separately from cardiovascular prescriptions per se, most are utilized in the treatment of hypertension and congestive heart failure.  They account for 3.7% (11.7 million) of all prescription drugs dispensed in Canada.  Pharmacists dispensed approximately 48.9 million prescriptions for anti-hyptertensive agents in 2001.

Figure 2 - 35


These tabulations do not account for homeopathic and herbal treatments, which continue to increase in popularity.

As in Canada, the greatest number of prescriptions in Japan, Germany, France, Italy and the United Kingdom are for the treatment of cardiovascular diseases.  In the United States, cardiovascular disease-related prescriptions rank second to treatment of central nervous system problems.  Unfortunately, prescriptions and sales do not indicate adherence with treatment.

Physician Visits

Using data from the Intercontinental Medical Statistics (IMS) Canada database, it has been estimated that in 2001, 29.6 million (10%) of visits made by Canadians to physicians were for cardiovascular diseases.  Of these cardiovascular disease-related visits, 59% were for the management of high blood pressure, 16% for ischemic heart disease including angina, 12% for other heart disease, and 4% for cerebrovascular disease.

Seniors made 15,182 visits to physicians in 1999 for cardiovascular diseases, twice the number for any other disease category.

There were 17.2 million visits to office-based physicians for high blood pressure in 2001, an increase of 30% since 1997.  These comprised almost 6% of all visits to community physicians in Canada.  High blood pressure was the main diagnosis from physician visits among adults aged from 38 to 57 years and those 65 years of age and over.

Discussion

Cardiovascular diseases are a major cause of hospitalization among both men and women, as either the primary or an associated health problem.  Although national data are unavailable, it is reasonable to assume that cardiovascular diseases are also a major factor in emergency department and outpatient visits.  Although hospitalization rates for cardiovascular diseases (except for congestive heart failure) are decreasing, the actual numbers of hospitalizations will increase in the future because of the aging of the population.

While hospitalization rates have been decreasing, the number of prescriptions for cardiovascular diseases has increased during the 1990s.  Improved treatment, including the introduction of new drugs, may have decreased the need for hospitalization.  Unfortunately, national data do not exist on either the health effect of this increased prescription use, the appropriateness of prescriptions, or patient compliance.

The number of several interventional procedures, including coronary artery bypass grafting, angioplasties, valve surgery, pacemaker implantation and heart transplantation, has been increasing.  This may reflect the increase in the aging population in Canada.  The actual number of procedures is actually much higher, since many procedures are being performed on an outpatient basis and are, therefore, not included in hospitalization data.  In fact, this increased use of outpatient facilities for procedures that were previously performed in hospital may, in part, account for the decrease in hospitalization rates for cardiovascular diseases.

The increase in procedures has a major impact on health care costs.  It also puts a strain on the limited availability of both human resources and equipment.

Sex differences exist in cardiovascular disease hospitalization rates and procedures.  Men have higher hospitalization rates than women for all cardiovascular diseases.  The difference is smallest for cerebrovascular disease and congestive heart failure.  All procedures are performed more often on men than women.  Whether these differences reflect gender attitudes of health professionals or biology, or both, requires further study.

Implications for Action

 


[1]  For this report, stroke is defined as ICD-9 codes 430-432, 434 and 436.  The overall cerebrovascular range includes ICD-9 codes 430-438.  The components not included in the stroke category are:

433: Occlusion and stenosis of precerebral arteries

435: Transient cerebral ischemia

437: Other and ill-defined cerebrovascular disease

438: Late effects of cerebrovascular disease