Interview with Dr. David R. Schlessel, M.D.
Dr. David R. Schlessel defines preventive cardiology as improving cardiovascular health and quality of life through the treatment of disease, the prevention of clinical events, and the detection, prevention and treatment of risk factors.
Preventive cardiology may be divided into two categories, primary and secondary, secondary being the treatment of patients who have had problems or who have had clinical events. "The primary category involves prevention of disease status or problems to begin with," Dr. Schlessel said.
"The two categories have become blurred because the tools to detect potential problems have improved." Dr. Schlessel continued. As an example, he cited the use of CAT scans and carotid ultrasound to detect subclinical atherosclerosis. "This is an exciting time because we have an increasing number of effective interventions," Dr. Schlessel said.
"Aspirin and ACE inhibitors have been shown to be effective interventions to prevent heart attack or stroke," he said. Based on evidence supported by two recent trials, ACE inhibitors can now be added to the standard interventions along with beta blockers, blood pressure control and "old-fashioned things such as tobacco cessation, weight loss, aerobic exercise, salt restriction and sugar (glycemic) control."
Risk factors for heart disease include both unmodifiable factors - age, maleness, heredity - and modifiable factors - tobacco use, diabetes, high blood pressure, cholesterol levels and obesity. To these, a newer risk factor - inflammation - has been added. According to Dr. Schlessel, inflammation elevates the level of Hs-CRP (high-sensitivity c-reactive protein), a marker for increased risk of cardiovascular disease. This is evidenced, for example, in people with rheumatoid arthritis or gum disease who, Dr. Schlessel explained, "have revved-up immune systems that may contribute to coronary problems. We can intervene with aspirin and statins to lower Hs-CRP."
New studies have also shown that statins may be effective in reducing the incidence of heart attacks in high-risk patients. Specifically, the Heart Protection Study, conducted by Oxford University and involving more than 20,000 patients, found that simvastatin, when added to existing treatments, produces substantial additional benefits for high-risk patients no matter their initial cholesterol levels. "Statins have pleiotropic effects that influence vascular events above and beyond cholesterol lowering. They effect the stability of plaques and reduce the risk of rupture by reducing inflammation," Dr. Schlessel said.
Other risk factors for heart disease and atherosclerois have been identified, but they should not be the focus for most doctors, according to Dr. Schlessel. He cited both Lp(a) levels and homocysteine levels as modifiable factors that are the subjects of continuing study, but he said that for now both should remain secondary to the primary risk factors.
Coronary disease equivalents
Coronary disease equivalents are now being more closely monitored because they indicate a high risk of heart attack, according to Dr. Schlessel. For example, patients who evidence three of the five factors comprising metabolic syndrome - high triglycerides, low HDL, high blood pressure, central obesity and impaired fasting glucose - qualify for aggressive therapy.
Other coronary disease equivalents that qualify for aggressive therapy are diabetes, aortic aneurysm, carotid blockages and peripheral vascular disease.
For patients with atrial fibrillation who are 65 or older, who have hypertension, diabetes or heart disease or who have had strokes or mini-strokes, Coumadin remains the best measure to prevent stroke, although a new drug still in trials may be shown to have some advantages, Dr. Schlessel said.
Finally, Dr. Schlessel noted that vigilance is needed to diagnose and treat women because of the high prevalence of heart disease among them, particularly in older women.
- The tools available to physicians to detect potential heart problems have improved, thus increasing the options for effective interventions.
- Statins have been shown to influence vascular events beyond the lowering of cholesterol levels. By reducing inflammation they stabilize plaques and reduce the risk of rupture.
- Coronary disease equivalents such as metabolic syndrome must be closely monitored because they indicate a high risk of heart attack.