What is the risk of having another heart attack?
Unfortunately, anyone who has a past history of having a heart attack is at high risk of having another one, as is anyone who has other significant vascular disease, including any of the following:
- A heart attack
- Heart pain (angina) (Many people suffer from heart pain without having a heart attack. They are, however, a greatly increased risk of having a heart attack.)
- A thromboembolic stroke (one not due to a haemorrhage (bleed) into the brain)
- A transient ischaemic attack (This is a short stroke-like event that completely resolves within 24 hours.)
- Pain in the legs due to poor blood supply (a blocked artery) - usually called peripheral vascular disease or 'claudication'.
- Tests showing evidence of a significantly blocked artery supplying the heart, brain, legs or kidney.
'High risk' means a risk of 15% or more of having another cardiovascular event within the next 5 years. It is important to emphasise that the actual risk in this group can be much higher than 15%, especially if the person does not reduce their risk by aggressively minimizing their cardiovascular disease risk factors. Below is an outline of the overall 'risk reduction' plan recommended for people who have had a heart attack.
Attending a Cardiac rehabilitation program. A great idea.
All people who have had a heart attack should participate in a recognised cardiac rehabilitation program so that 'best practice' management can be initiated and maintained. Cardiac rehabilitation (CR) programs are also very important for people who have had coronary artery surgery, including bypass surgery or stent insertion. This program should include on-going communication with the person's other treating doctors (including their GP) so that they remain informed of the overall management plan and its progress.
Cardiac rehabilitation programs that include promoting physical activity have been shown to:
- reduce cardiac related deaths by about 25 per cent
- decrease the incidence of future heart attacks and the need for stents and by-pass surgery
- reduce symptoms such as chest pain and shortness of breath
- reduce the incidence of depression that occurs following heart attacks
Cardiac rehabilitation programs are under-utilized in Australia
Unfortunately, many people who would benefit greatly from a rehabilitation program do not attend one. For example, a study published in June 2008 of 174 patients who had bypass surgery at Royal Melbourne Hospital (between 2001 and 2004) showed that despite all being encouraged as much as possible to participate in a cardiac rehabilitation program, only about 72 per cent actually attended. More worrying still is the fact that the study mentioned that this was the best result ever reported either within Australia or overseas. It is thought that, overall in Australia, over two thirds of eligible patients do not use CR programs. And unfortunately, those who do not attend CR programs are often the patients who would benefit most. Factors identified as contributing to patients not attending CR programs include:
- Distance from the rehabilitation centre
- Lack of referral by doctors
- Patient disinterest in or lack of knowledge about the benefits of CR
- Depression
- Lack of flexibility of available programs
CR programs in Australia
At present (2009) there are about 370 CR programs operating in Australia. Most of these CR programs are conducted in groups (about 75%) and include both educational and exercise components (also about 75%). The average program duration is seven weeks. About 50% are conducted in hospital and 50% in community-based facilities.
Over the past 10 years there has been a movement away from standardized group CR programs to more individualised programs that often also last much longer; up to four years.
People who suffer from angina or who have had a heart attack or coronary artery surgery (by pass or stent insertion) and never attended a rehabilitation program can consult their GP or their local hospital regarding find one. It is never too late. Involving partners in rehabilitation programs is often very helpful. A list of the locations of CR programs in Australia is also available by ringing the National Heart Foundation or from the Australian Cardiovascular Health and Rehabilitation Association website: http://www.acra.net.au
What should a cardiac rehabilitation program include?
Every person's rehabilitation plan is unique and will depend on many variables including:
- the person's age
- other illnesses
- the person's previous fitness level
- the patient’s degree of heart failure following the heart attack (Heart attacks damage the heart muscle and this can impede the heart’s ability to pump adequately. The main symptoms that heart failure causes are shortness of breath and fatigue.)
- whether there are on-going heart symptoms, especially chest pain and shortness of breath
- the person's cardiac risk factors
- the person's response to medication
- the persn's level of education
- the person's motivation (depression can be a big problem)
Each cardiac rehabilitation program should include addressing the following eight topics. It may seem like a lot to cover but it can make a huge difference to the patient’s life expectancy (and general well being) following a heart attack or the diagnosis of angina.
1. Encouraging physical activity
Encouraging physical activity is the most important component of the rehabilitation program. An exercise program that optimally should see each patient doing moderate physical activity for 30 minutes a day for most days (at least 5 days) each week; a total of at least 150 minutes of moderate exercise per week. Moderate activity is that which causes a noticeable increase in the rate and depth of breathing, whilst still being able to talk (e.g. purposeful walking or cycling for pleasure).
This should commence at a level that is comfortable and then increase (in a step-by-step manner) in duration and intensity of activity as the person gains fitness until this level is reached. Generally it is best to increase the duration of exercise first and then increase the intensity.
While exercise will benefit most people with cardiovascular disease, specialist assessment BEFORE initiating physical activity is always recommended in people with a past history of cardiovascular disease, especially in the following cases.
- People who have recently had their heart attack
- People who have continuing chest pain or unstable angina
- People with aortic stenosis (a narrowing of the aortic valve in the heart)
- People with uncontrolled diabetes
- People with uncontrolled heart failure (Most people with stable heart failure benefit significantly from increasing physical activity.)
- People with uncontrolled or severe high blood pressure
- People with low blood pressure
- People with an arrhythmia (heart rhythm abnormality) that is present at rest
It is also best to avoid doing exercise when sufferingfrom an acute infection or a fever.
Not all patients will be able to achieve this level of physical activity. Some people who suffered significant damage to their heart muscle as a result of their heart attack are left with hearts that cannot pump blood normally and this will limit the exercise level that they can achieve. Further information on this topic can be gained by reading the National Heart Foundation's position statement on physical activity in people with cardiovascular disease;
http://www.mja.com.au/public/issues/184_02_160106/bri10727_fm.html
2. Education regarding the following
- The cause of heart attacks
- Risk factors for heart attacks and how to reduce them
- Resuming normal activities. It is important that the person is reassured that most people can resume a relatively normal life after having a heart attack and that a program for the resumption of normal asctivities is devised and implemented as soon as possible. Activities to consider include:
- Work (This will depend on the nature of the work and the severity of the heart attack.)
- Household activities
- Sexual activity (This is usually allowed after about four weeks in people who have had an uncomplicated recovery from their heart attack.) Medication to to treat erectile dysfunction should NOT be used without a doctors permission as it may interact with other medication.)
- Driving
- Air travel (This is usually allowed after three to four weeks in people who have had an uncomplicated heart attack.)
- Psychological issues that often arise following a heart attack. These include:
- Fear of future heart attacks and death
- Depression
3. Risk factor assessment to identify conditions that increase the risk of a future heart attack
- Smoking
- High blood pressure
- High cholesterol
- Heart failure. Heart attacks are one of the most common causes of heart failure. Special programs are available for the assessment and treatment of patients with heart failure but these are also poorly utilized, with only about 10% of heart failure patients using such programs. Ask your doctor about them. All patients who have had a heart attack should:
- be assessed for heart failure (usually this includes an easily done, non-invasive test called echocardiogram)
- have optimum treatment for the condition.
- Diabetes. All people who have had a heart attack need to be screened for diabetes. A diagnosis of diabetes should not be made on tests taken immediately after a heart attack as these tests can be misleading. (Abnormal results suggesting a diagnosis of diabetes at this time should be reconfirmed two months after the heart attack.)
- Kidney (renal) failure. All people who have had a heart attack need to be screened for renal failure.
- Depression and anxiety. All people who have had a heart attack need to be screened for depression and anxiety as these conditions are common after heart attacks and are a risk factor for future heart attacks. Counselling will usually help as will increasing physical activity. Medication can also be helpful but selection of which medications to use requires care. Selective serotonin reuptake inhibitor (SSRI) medications are generally safe to use in people who have had heart attacks. Tricyclic antidepressants are NOT safe as they can cause abnormal heart rhythms. Social isolation can aggravate these problems and initiating a program of social activities can be very beneficial in socially isolated people.
4. Initiate and maintain risk-reducing lifestyle initiatives
- Quitting smoking. (See section on smoking.)
- Weight loss. Ideal waist circumference in men is less than 94cm and in women is less than 80cm. (See section on weigh loss.)
- Exercise as stated above.
- Improved diet: The advice of a dietitian should be sought. Dietary advice will usually include recommending:
- Modification of fat intake so that (See section on dietary fats.):
- total fat intake provides about 25% of total energy intake
- saturated fat intake provides less than 7% of total energy intake and trans fat intake provides less that 1% of total energy intake.
- the consumption of omega-3 fats, mostly from seafood sources, is increased. (At least two to three serves a week.) (Fish oil capsules can also be used as a source of omega-3s.)
- consume mainly plant based foods that includes five servings of vegetables and two servings of fruit per day
- appropriate energy intake to maintain a healthy weight (see above).
- limiting alcohol intake to no more than two standard drinks per day for men and one standard drink per day for women, with at least two alcohol free days per week.
- There is NO evidence that shows any benefit from the consumption of antioxidant or vitamin supplements and they are not recommended.
5. Initiating treatment with appropriate medications
A recent Australian study (2009) found that 47% of people at high risk of cardiovascular disease due to a past / present history of cardiovascular disease (which includes all people who have had a previous heart attack) were undertreated regarding appropriate medication therapy. This was a significantly greater problem with regard to the use of cholesterol lowering medication than it was with the use of blood pressure lowering medication.
All people who have had a heart attack should be offered the following medications (as long as there are no contraindications to their use).
- ACE (angiotensin-converting enzyme) inhibitor. This medication helps lower blood pressure and reduces heart failure symptoms by reducing the heart's muscle's workload, thus helping to reduce the risk of further heart attacks. Patients who can not tolerate ACE inhibitors should be considered for treatment with a Angiotensin-II-receptor antagonist medication.
- A statin drug. Statin drugs help lower LDL cholesterol levels and in doing so can reduce the risk of future heart attacks by as much as 25%.
- A beta-blocker. This medication has been shown to reduce the risk of recurrent heart attacks and helps in the treatment of people with stable heart failure. It also helps lower blood pressure. It should be commenced by all patients who have had a heart attack (unless contraindicated) and continued indefinitely, especially in high-risk patients (i.e. those who have continuing chest pain, those who had a large heart attack, those who have heart failure and those who have ventricular arrhythmias.)
- Aspirin / other drugs to reduce blood clotting. Aspirin reduces the clotting ability of the blood and this helps prevent future heart attacks. The drug clopidogrel is given in addition to aspirin in some patients to help reduce clotting further; mainly to those who have had stents inserted and those who have had recurrent heart attacks. This combination is also commonly given in the period immediately after a heart attack, especially if the heart attack was more serious.
Please note that aspirin has serious side effects (mainly bleeding) and is only of benefit in high risk males to reduce heart attack and high risk females to reduce strokes. Also, some people are allergic to aspirin. People should only use long-term aspirin if advised to do so by their doctor as serious side effects can occur.
6. Annual immunisation against influenza and a five-yearly pneumococcal immunisation.
These vaccinations have been shown to significantly reduce death rates, especially in people over the age of 65 years.
7. Assessment by cardiologist (heart specialist) regarding the possibility of surgical intervention:
All patients should be offered an assessment by a cardiologist to decide whether surgical treatments, such as by-pass surgery or 'stent' insertion, would be of benefit. Assessment needs to take into account the person's overall medical condition. Most patients who have suffered a heart attack will have been treated by a cardiologist in hospital and should have received such an assessment. Patients suffering from angina who have not required hospital admission should be also be reviewed by a cardiologist.
8. A program for monitoring future cardiovascular health
Many patients are not adequately followed up once the leave the CR program. The type of follow up available will vary from area to area but minimum follow up should include:
- contacting the patient’s GP and encouraging him or her to become actively involved
- long term review by appropriate specialists.
- regular review and telephone follow up by the CR unit.
Treatment target levels
Target levels are detailed in the table below. These target blood pressure and lipid levels may not be able to be achieved in some people, either because the required doses of medications can not be tolerated or because maximum doses do not achieve the target levels.
Target levels for risk factors in people who have had a heart attack |
|
Risk factor |
Target level |
Systolic blood pressure (the higher reading) |
130mmHg (Benefit occurs to levels as low as 115mmHg) |
Diastolic blood pressure (the lower reading) |
85mmHg |
Smoking |
Nil |
Weight |
Waist circumference in males: 94cm Waist circumference in females: 80cm BMI of 20 to 25 |
Physical activity |
20 to 30 minutes per day of moderate activity |
Total cholesterol |
Less than 4.0mmol/L |
LDL cholesterol |
Less than 2.0mmol/L |
HDL cholesterol |
Greater than 1.0mmol/L |
Triglycerides |
Less than 1.5mmol/L |