Part Three. What works: the evidence for action
Chapter Two. Review of effective interventions
Reducing the risks in established disease
For cardiovascular disease and diabetes in particular, evidence-based approaches to reducing the risk of adverse outcomes in people with the disease are very similar to the approaches used to reduce disease onset. The major difference is that the likelihood of future clinical events is much greater once disease is established. Highly effective interventions exist for reducing the risk of cardiovascular events in patients with diabetes and/or established cardiovascular disease. They include the following:
- Behavioural interventions: including those for tobacco cessation, increased physical activity and dietary change, with the promotion of weight loss if appropriate. Together, these may achieve a risk reduction of over 60% in people with established heart disease, and are also a key part of achieving good blood glucose control in people with diabetes.
- Pharmacological interventions: including aspirin, beta-blockers, angiotensin converting enzyme inhibitors and statins. A combination of all four of these is expected to reduce the risk of recurrent myocardial infarction by 75%.
People with established cardiovascular disease are at the highest risk of cardiovascular death and account for half of all cardiovascular deaths. For these people, international guidelines recommend long-term antiplatelet, blood pressure lowering and cholesterol lowering therapies. However, treatment gaps are substantial in all countries, in part because of the cost and complexity of multiple drug use.
Potential of fixed dose combination therapy
One strategy that has been proposed to reduce these barriers is a fixed dose combination pill (now commonly known as a polypill). Because each component apparently works in addition to the others, net benefits are anticipated to be substantial - risk reduction of more than two thirds within a few years of treatment - although more research is needed. Fixed dose combinations are now a core component of care for people with HIV/AIDS, tuberculosis and malaria. As well as improving clinical outcomes, they simplify distribution of multiple medications, which can be an important advantage in a resource-limited health-care setting.
The major challenge remains one of implementation - new strategies are required for the many millions of under-treated individuals with established cardiovascular disease in low and middle income countries. Ideally, these strategies should integrate with systems for other long-term medication delivery, such as those for HIV/AIDS, and complement population-wide measures to address the causes of cardiovascular disease. The components of a polypill are no longer covered by patent restrictions and could be produced at a cost of little more than US$ 1 per patient per month. For people with cardiovascular disease in low and middle income countries, access to preventive care is usually dependent upon their ability to pay, and hence it is this large, underserved group that stands to gain most from a polypill