CVD: less well known risk factors identified

The Clinical Services Journal reports.

With three out of five of the World’s most costly diseases being cardiovascular in nature, prevention is now recognised as an urgent public health need and preventive cardiology has risen up the political as well as the clinical agenda. In 2011, for example, a UN heads-of-state meeting agreed to reduce mortality from chronic noncommunicable diseases (NCDs) by 25% by 2025. Cardiovascular disease (CVD) accounts for most non-communicable disease (NCD) deaths in the world – or 17 million people annually – followed by cancers (7.6 million), respiratory diseases (4.2 million), and diabetes (1.3 million). Together, these four groups account for around 80% of all NCD deaths. They also share four risk factors – tobacco use, physical inactivity, the harmful use of alcohol and unhealthy diets. Evidence shows that more than nine million of all deaths attributed to an NCD occurs before the age of 60, which makes all age groups vulnerable to these risk factors. This year’s EuroPRevent Congress, organised by the European Society for Cardiology (ESC), adopted as its theme the Universal Approach to Preventive Cardiology and its scientific programme sessions focused on how to achieve the UN’s target of a 25% mortality reduction by 2025. Professor Volker Adams, chairperson of the Congress Programme Committee, highlighted the fact that prevention of CVD cannot be achieved by cardiologists alone. He said: “A team approach is needed including exercise physiologists, nutritionists, psychologists and governments.” Studies presented at the event offered further insight into the risk factors for CVD. One, for example, suggested an association between mental vulnerability and an increased risk of fatal and nonfatal CVD, independent of classical risk factors. People deemed to be ‘mentally vulnerable’ are at a significantly increased risk, according to results of a large population study from Denmark.1 The study’s first author, Dr Anders Borglykke from the Research Centre for Prevention and Health at Glostrup University Hospital, Denmark, explained that psychosocial factors and personality traits have been consistently associated with cardiovascular disease and all-cause mortality, but their role in the prediction of risk was still not clear. The study investigated whether mental vulnerability (defined as ‘a tendency to experience psychosomatic symptoms or inadequate interpersonal reactions’) increases the risk of cardiovascular disease and the precision of prediction models for cardiovascular disease. It incorporated data from three prospective Danish population cohorts, from which almost 11,000 individuals free of any cardiovascular disease were followed-up for a mean period of 15.9 years (a total of 166,787 person-years). During this follow-up period all fatal and non-fatal cardiovascular events were recorded and, at the outset of the study, mental vulnerability measured on a validated 12-point scale originally constructed by the Military Psychology Services in Denmark. The results categorised subjects into three groups – nonvulnerable, latent or mentally vulnerable “The scale consists of questions on both mental and physical symptoms and generally measures a level of stress or a personality which is more receptive to stress,” said Dr Borglykke. “The scale has previously been associated with early mortality and ischaemic heart disease.”2 To assess the predictive ability of the scale, the results were added to a statistical model with classical risk factors for cardiovascular disease. During the follow-up period there were 3,045 fatal and non-fatal cardiovascular events recorded in the study population of 10,943 subjects. When the statistical analysis was performed, results showed that mental vulnerability was significantly associated with fatal and non-fatal cardiovascular events independently of the classical risk factors; the risk of events in the mentally vulnerable was 36% higher than in the non-vulnerable (hazard ratio 1.366; 1.208-1.545). “Several studies have found risk factors for cardiovascular disease which are clearly independent but within a broader context contribute little if anything to actual risk prediction,” said Dr Borglykke. “One of the reasons for this is that the impact of the well established risk factors – age, sex, smoking, blood pressure and total cholesterol – tend to dominate the risk stratification models. This means that a risk factor such as our scale of mental vulnerability clearly increases the risk significantly – by 36% – but still does not improve risk prediction in the general population.”

A new marker?