Most individuals with recognized CVD are able to work effectively and productively in most of the jobs found in the modern workplace. Just a few decades ago, individuals surviving an acute myocardial infarction were cosseted and pampered for weeks and months with close supervision and enforced inactivity. Laboratory confirmation of the diagnosis was enough to justify labelling the individual as “permanently and totally disabled”. New diagnostic technology that provides more accurate evaluation of cardiac status and the favourable experiences of those who could not or would not accept such a label, soon demonstrated that an early return to work and an optimal level of activity was not only possible but desirable (Edwards, McCallum and Taylor 1988; Theorell et al. 1991; Theorell 1993). Today, patients commence supervised physical activity as soon as the acute effects of the infarction subside, are often out of the hospital in a few days instead of the mandatory 6 to 8 weeks of yore, and are often back on the job within a few weeks. When desirable and feasible, surgical procedures such as angioplasty, by-pass operations and even cardiac transplantation can improve the coronary blood flow, while a regimen featuring diet, exercise and control of the risk factors for CHD can minimize (or even reverse) the progression of coronary atherosclerosis.
Once the acute, often life-threatening phases of the CVD have been overcome, passive movement followed by active exercise should be initiated early during the stay in the hospital or clinic. With heart attacks, this phase is completed when the individual can climb stairs without great difficulty. At the same time, the individual is schooled in a risk-prevention regimen that includes proper diet, cardiovascular conditioning exercises, adequate rest and relaxation, and stress management. During these phases of rehabilitation, support from family members, friends and co-workers can be particularly helpful (Brusis and Weber-Falkensammer 1986). The programme can be carried out in rehabilitation facilities or in ambulatory “heart groups” under the supervision of a trained physician (Halhubar and Traencker 1986). The focus on controlling lifestyle and behavioural risk factors and controlling stress has been shown to result in a measurable reduction in the risk of re-infarction and other cardiovascular problems.
Throughout the programme the attending physician should maintain contact with the employer (and particularly with the company doctor, if there is one) to discuss the prospects for recovery and the probable duration of the period of disability, and to explore the feasibility of any special arrangements that may be needed to permit an early return to the job. The worker’s knowledge that the job is waiting and that he or she is expected to be able to return to it is a potent motivating factor for the enhancement of recovery. Experience has amply demonstrated that the success of the rehabilitation effort diminishes as the absence from work lengthens.
In instances where desirable adjustments in the job and/or the workplace are not possible or feasible, retraining and appropriate job placement can obviate unnecessary invalidism. Specially protected workshops are often helpful in reintegrating into the workplace people who have been absent from the job for long periods while receiving treatment for the serious effects of stroke, congestive heart failure or disabling angina pectoris.
Following the return to work, continued surveillance by both the attending physician and the occupational physician is eminently desirable. Periodic medical evaluations, at intervals that are frequent initially but lengthen as recovery is assured, are helpful in assessing the worker’s cardiovascular status, adjusting medications and other elements in the maintenance regimen and monitoring the adherence to the lifestyle and behavioural recommendations. Satisfactory findings in these examinations may allow the gradual easing of any work limitations or restrictions until the worker is fully integrated into the workplace.
Workplace Health Promotion and Prevention Programmes
The prevention of occupational diseases and injuries is a prime responsibility of the organization’s occupational health and safety programme. This includes primary prevention (i.e., the identifica- tion and elimination or control of potential hazards and strains by changing the work environment or the job). It is supplemented by secondary prevention measures which protect the workers from the effects of existing hazards and strains that cannot be elim- inated (i.e., personal protective equipment and periodic medical surveillance examinations). Workplace health promotion and pre- vention (HPP) programmes go beyond these goals. They place their emphasis on health-conscious behaviour as it relates to life- style, behavioural risk factors, eliminating or coping with stress and so on. They are of great significance, particularly in pre- venting CVD. The goals of HPP, as formulated by the WHO Committee on Environmental and Health Monitoring in Occupational Health, extend beyond the mere absence of disease and injury to include well-being and functional capacity (WHO 1973).
The design and operation of HPP programmes are discussed in more detail elsewhere in the chapter. In most countries, they have a particular focus on the prevention of CVDs. For example, in Germany, the “Have a heart for your heart” programme supplements the heart health circles organized by the health insurance companies (Murza and Laaser 1990, 1992), while the “Take Heart” movement in Britain and Australia has similar goals (Glasgow et al. 1995).
That such programmes are effective was verified in the 1980s by the WHO Collaborative Trial in Prevention of Heart Disease, which was carried out in 40 pairs of factories in four European countries and involved approximately 61,000 men aged 40 to 59. The preventive measures largely comprised health education activities, carried out primarily by the organization’s employee health service, focused on cholesterol-lowering diets, giving up cigarette smoking, weight control, increased physical activity and controlling hypertension. A randomized screening of 10% of the eligible workers in the factories designated as controls demonstrated that during the 4 to 7 years of the study, overall risk of CVDs could be reduced by 11.1% (19.4% among those initially at high risk). In the study factories, mortality from CHDs fell by 7.4%, while overall mortality fell by 2.7%. The best results were achieved in Belgium, where the intervention was carried out continuously during the entire study period, while the poorest results were seen in Britain, where the prevention activities were sharply curtailed prior to the last follow-up examination. This disparity emphasizes the relationship of success to the duration of the health education effort; it takes time to inculcate the desired lifestyle changes. The intensity of the educational effort was also a factor: in Italy, where six full-time health educators were involved, a 28% reduction in overall risk-factor profile was achieved, whereas in Britain, where only two full-time educators served three times the number of workers, a risk factor reduction of only 4% was achieved.
While the time required to detect reductions in CHD mortality and morbidity is a formidable limiting factor in epidemiological studies aimed at evaluating the results of company health programmes (Mannebach 1989), reductions in risk factors have been demonstrated (Janssen 1991; Gomel et al. 1993; Glasgow et al. 1995). Temporary decreases in the number of lost workdays and a decline in hospitalization rates have been reported (Harris 1994). There seems to be general agreement that HPP activities in the community and particularly in the workplace have significantly contributed to the reduction in cardiovascular mortality in the United States and other western industrialized countries.
CVDs loom large in the workplace, not so much because the cardiovascular system is particularly vulnerable to environmental and job hazards, but because they are so common in the popu- lation of working age. The workplace offers a singularly advant- ageous arena for the detection of unrecognized, asymptomatic CVDs, for the circumvention of workplace factors that might accelerate or aggravate them and for the identification of factors that increase the risk of CVDs and the mounting of programmes to eliminate or control them. When CVDs do occur, prompt attention to control of job-related circumstances that may prolong or increase their severity can minimize the extent and duration of disability, while early, professionally supervised rehabilitation efforts will facilitate the restoration of working capacity and reduce the risk of recurrences.
Physical, Chemcial and Biological Hazards
The intact cardiovascular system is remarkably resistant to the harmful effects of physical, chemical and biological hazards encountered on the job or in the workplace. With a very few exceptions, such hazards are rarely a direct cause of CVDs. On the other hand, once the integrity of the cardiovascular system is compromised—and this may be entirely silent and unrecognized—exposure to these hazards may contribute to the ongoing development of a disease process or precipitate symptoms reflecting functional impairment. This dictates early identification of workers with incipient CVD and modification of their jobs and/or the work environment to reduce the risk of harmful effects. The following segments will include brief discussions of some of the more commonly encountered occupational hazards that may affect the cardiovascular system. Each of the hazards presented below is discussed more fully elsewhere in the Encyclopaedia.