Whether they are paid public servants or members of a volunteer force, all firefighters face external risks. Yet the greatest risk might be internal; 44% of firefighters who die on the job die from heart attacks, making it the leading cause of death. What's more, according to a 10-year study of sudden cardiac deaths of American firefighters by the National Fire Protection Association, about half of the firefighters who died of heart attacks had known heart conditions, and about 75% had heart conditions that simple medical testing could have detected.
Firefighters weigh more, smoke more and exercise less than their male counterparts of the same age. Their cholesterol levels are higher and aerobic capacity is lower than middle-aged men, and both measures tend to get worse over their careers. A study of retired Massachusetts firefighters found that the risk of heart attack and other heart problems was the principal reason for leaving the force. It also found that cholesterol, blood pressure, smoking and obesity levels were higher than firefighters currently working.
“Fire departments should consider mandatory annual fitness exams for firefighters,” says Marilyn Ridenour, co-author of the report and an epidemic intelligence officer with the Centers for Disease Control and Prevention's National Institute for Occupational Safety and Health. “That should help reduce these risks.”
The study shows that progress has been made. While heart attacks consistently cause the most deaths among firefighters, the absolute number of deaths have decline by one-third over the past 25 years, through 2006.
“We do have standards, but we need implementation and adherence to the standards,” says Rita Fahy, the study's other co-author who is the with the NFPA.
As with improvements in the detection and treatment of heart disease and related conditions over the past decades, advances in medicines have reduced heart attacks and strokes. It's likely that reducing the risk of heart disease will take the latest insights in cardiovascular medicine and tailor it to the unique work and environmental conditions that firefighters face on a daily basis.
Screening isn't enough to get the job done. A more comprehensive and personalized approach is needed that takes into account the unique needs of firefighters and states the goal of reducing the rate of death from stroke and heart attack. And there should be an obligation to apply the best science to the problem in ways that provide firefighters with a personalized approach to disease prevention and wellness.
First, reducing the risk of stroke and heart attack can't be started soon enough. Take the issue of high blood pressure. An accumulation of data on lifetime risk, which showed that blood-pressure levels previously considered normal or high-normal are associated with substantial risks of cardiovascular complications and that these lifestyle factors are directly linked with high blood pressure: obesity, lack of physical activity, smoking, excessive sodium intake and over-consumption of alcohol. For these reasons, assessing and potentially treating patients with pre-hypertension can reduce the risk of stroke.
Pre-hypertension is systolic pressure of 120 to 139 mmHg or untreated diastolic pressure of 80 to 89 mmHg. Even a relatively young patient with no current evidence of any major target organ damage can eventually reach that category. It's best to protect against advancing vascular disease and changes in the blood pressure early.
As for treatment, too much of what passes for medical practice is influenced by what is read in the media, which boils down to an either/or choice. People get caught up in debates about if a calcium channel blocker is better than a diuretic is better than an angio receptor blocker or an ACE inhibitor. Instead, the prevention and treatment of high blood pressure will vary by many factors including vascular properties, body weight, metabolic features (and community trends in these features) ethnicity, age and renin profile.
For instance, there is a big difference between skinny and obese hypertension. Skinny hypertension is driven by increased activity of the angiotensin renin and sympathetic systems, particularly when patients become physically stressed — an issue of considerable importance to firefighters. Underweight hypertensive patients actually are more challenging to treat then obese hypertensives, because the latter have a tendency to respond well to diuretics and, consequently, often have better outcomes.
Ethnicity imposes different clinical endpoints that required distinct drug strategies. Evidence suggests that combination therapy works equally well across various ethnic subgroups and should be taken into account as fire departments become increasingly diverse. For instance, a recent study found that 52% of black participants required combination therapy to achieve blood pressure control, compared with only 39% of white patients.
Nevertheless, black patients continue to have poorer outcomes and higher mortality rates than white patients. One study showed an overall 15% stroke event rate in those getting the ACE inhibitor compared to a diuretic. However, there is no difference in stroke outcomes for non-black patients. This is explained by a 40% excess stroke rate in black patients, almost certainly a reflection of poorer blood-pressure control because of treatment with inappropriate drugs. This is a dramatic example of where phenotype and drug selection make a very important difference.
Another concern is age. Despite blood-pressure values, most patients over the age of 65 will become hypertensive and have increased coronary risk. There is clear reasoning for clinicians to treat an aging population more aggressively than younger patients.
Phenotypes can help clinicians decide how and when to treat. Most importantly, when it comes to therapy, one size doesn't fit all, and great deal of thinking about optimal strategies is still needed.
Low-density lipoprotein often is referred to as bad cholesterol because it carries cholesterol into the blood, where it can do harm. LDL plays the lead role in causing fatty buildup in the arteries, increasing the risk of heart disease.
High-density lipoprotein, the good cholesterol, carries blood cholesterol back to the liver where it can be disposed of. HDL also aids in producing hormones, building cell walls and digesting dietary fats.
High LDL levels greatly increase risk while normal HDL levels can decrease risk. This is where statins have come into play in a big way, but not just because of their direct impact on cholesterol levels.
Although some have tried to claim that statins should not be used by anyone other than those with a high risk of heart disease, the evidence of early intervention is compelling. Large-scale intervention trials have shown a clear relationship between reduction of cholesterol and reduction in mortality. This kind of data has driven guideline bodies to recommend more aggressive treatment.
Data has shown that a 1% decrease in LDL cholesterol reduces heart disease risk by 1%. In addition, epidemiology studies have shown that HDL-cholesterol levels can influence cardiovascular risk alongside LDL-cholesterol levels; a 1% change in HDL has been shown to be associated with a 1% to 3% reduction in heart-disease risk.
Lipid-management guideline treatment goals have become more aggressive and are likely to become even more so with the availability of more effective therapies. The evidence has driven this evolution, which also has been seen in other national and international guidelines, from the statin trials (together with epidemiological evidence) that confirm that effective lowering of LDL is the key driver for reducing cardiovascular events. Achieving the goals set out in evidence-based guidelines is therefore important in saving lives and reducing cardiovascular events.
The remaining question is at what point should doctors begin statin therapy and which statin to use for which purpose? Here too, a one-size fits all approach should be avoided. For instance, studies have found that certain drugs such as rosuvastatin seem to be better metabolized by people of Asian and Latin American origin than Caucasians. Variations in response also occur in patients by age, weight, smoking habits and sex, though all of these are likely to be representative of individual genetic variations that have yet to be clearly identified.
Finally, recent studies and new markers for heart attacks such as the C-reactive protein test show that the relative benefit of statins to be greater among those with increased CRP and that achieved CRP levels after statin therapy and that an increase in CRP levels predict reduced rates of heart attacks as much as achieved levels of LDL cholesterol.
The best approach to reducing cardiovascular disease among firefighters is a personalized and prospective one. Departments, in cooperation with health plans, university medical centers and other health providers, should create personalized strategic health plans for each member of their force:
-
Develop a one-page form that collects all necessary personal clinical data that have predictive power for cardiovascular diseases and metabolic diseases. Using published research, develop a computer-based algorithm that uses the historical, demographic and clinical data to make specific health protective recommendations (diagnostic, lifestyle or therapeutic) for each person.
-
Assign each department a health advocate to help implement the strategy for every firefighter.
-
Provide each firefighter who completes an annual health report form a cash bonus that could be increased based on how healthy he or she is.
The NFPA and CDC could collect the data and conduct evaluations on changes in health measures. And while the payment to stay healthy may seem out of the ordinary, consider that firefighters are paid to save others. It would be both cost-effective and appropriate to invest a small amount of money to reward them if they took steps to help save themselves.
Michael Weber, M.D., is associate dean and professor of medicine at the State University of New York Health Science Center at Brooklyn. He also is a fellow of the Council for High Blood Pressure Research of the American Heart Association, the American College of Cardiology, and the American College of Clinical Pharmacology. Weber currently serves as a consultant to the Center for Drug Evaluation and Research of the FDA.
