During the European Society of Cardiology 2011 in Paris, France, Professor Salim Yusuf from McMaster University, Hamilton, Ontario, Canada presented results from the Prospective Urban Rural Epidemiological (PURE) trial, and the results made for very somber reading.
Sparked by the global rise in obesity, diabetes and CVD, this large-scale, prospective epidemiological study examined the use of secondary prevention of cardiovascular disease (CVD) in 154,000 people with a history of heart disease or stroke, across 17 countries. “We aimed to document rates of use of proven secondary preventative medicine in the community,” says Professor Yusuf. “We examined societal and individual factors,” he adds, which included age, gender, weight, social and economic status, geography (rural or urban), smokers, non-smokers, diet and exercise.
The initial results show severe worldwide gaps – across both high- and low-income countries (as defined by the World Bank Group) – in the use of simple, cheap drugs for secondary CVD prevention. Even the use of aspirin was woefully underused, and the use of statins in secondary prevention of CVD in middle- to low-income countries was almost non-existent. The most shocking data reveals that 85% of those in low- to middle-income countries do not receive any secondary CVD prevention therapy at all.
Epidemiological Transitions and CVD
Approximately 80% of the world’s population live in developing countries, where communicable infectious disease are generally more likely to cause death than lifestyle-related conditions such as CVD. However, since the Industrial Revolution cardiovascular disease has emerged as one of the leading global causes of morbidity and mortality – first in the West, and more recently in countries experiencing modernisation. In fact it has been estimated that by 2020, CVD will account for 25 million deaths every year.
The fact that countries experience changes in health and disease patterns as they modernise is well-established. The Omran epidemiological model developed by Dr Omran AR in 1971 describes five stages: the ‘Age of Pestilence and Famine’, the ‘Age of Receding Pandemics’, the ‘Age of Degenerative and Man-Made Diseases’, the ‘Age of Delayed Degenerative Diseases’ and most recently the ‘Age of Emergent and Re-Emergent Infections’. Many developing counties undergoing significant economic development are currently existing in the third stage of development.
But what is unique about the current global CVD epidemic is the unprecedented timescale, which has contributed towards a rapid and lethal rise of chronic diseases in countries, where often there are inadequate health infrastructures unable to cope with these illnesses on a wide scale. As Dr Samuel Agyei-Mensah from the University of Ghana, Legon, Ghana writes in the Journal of Urban Health: “A protracted double burden of infections and chronic disease contributes major causes of morbidity and mortality.” That is, the CVD burden has not replaced the dominance of communicable diseases, it has added to it.
New drugs, new technology, so why the rise in CVD?
Since the early 1990s, the emergence of new lipid-lowering therapies – most notably statins – have made significant in-roads into the management of CVD. In the UK alone, approximately 7 million people take prescribed statins daily, which in turn has prevented around 7000 deaths every year. So the question remains, with all the therapies and technology that we have at our fingertips – much of which are inexpensive, relatively safe and readily available – why are we falling short in managing CVD?
All the figures in PURE point to systemic failure at all levels, says Professor Yusif. “The system failures are preventing the effective distribution of drugs,” he adds, pointing out that governments must implement logistical systems of drug delivery that address the needs of the local population.
“This data is a tragedy,” he concludes. “We have the knowledge, and we have the therapy. What we now need to the delivery. We need the will and we need the way.”