PARIS — Periodic cardiac evaluations should be a routine part of the management of all patients with systemic sclerosis, beginning “from the first day of the disease.”
Cardiac problems in patients with systemic sclerosis (Ssc) were thought to occur mainly in those with the diffuse subtype of disease, not the limited cutaneous subtype. But with the use of contemporary cardiac evaluation tools, including tissue Doppler echocardiography, myocardial scintigraphy, and cardiac MRI, it has become apparent that coronary lesions occur early in the course of both subtypes—and are far more prevalent than previously realized, Dr. André Kahan said at the annual European Congress of Rheumatology. “I'd say they are present in close to 100% of patients,” said Dr. Kahan, professor of rheumatology at René Descartes University, Paris.
Subclinical myocardial perfusion abnormalities, diminished coronary reserve, and reduced left and/or right ventricular contractility are common in patients with Ssc. The good news is that numerous studies by Dr. Kahan and others have demonstrated that these abnormalities are reversible with high-dose vasodilator therapy using calcium channel blockers or angiotensin-converting enzyme inhibitors. In addition, bosentan in standard doses has been shown to reverse the early abnormalities.
However, if these cardiovascular abnormalities aren't treated early, then fibroblasts become activated, collagen is deposited, and irreversible myocardial fibrosis occurs.
When clinical cardiac disease is present, as in 15%–25% of Ssc patients, all-cause mortality is sharply increased. The coronary disease in Ssc patients is completely different both in site and mechanism from that encountered in rheumatoid arthritis, systemic lupus erythematosus, or atherosclerotic heart disease in the general population. In those cohorts, the large coronary arteries are involved, whereas in Ssc, it is the small coronary vessels.
Vascular lesions in Ssc patients are vasospasm-induced ischemic reperfusion injuries. Not just the small coronary arteries are affected, but small arteries everywhere else in the body, too, including the digits, pulmonary circulation, and the kidneys. These vascular injuries and the resultant fibrotic changes lead to the major complications of Ssc.
Tissue-Doppler echo is now widely available in routine cardiology practice; it provides an excellent noninvasive means of assessing left and right ventricular function. It is far more sensitive than standard echocardiography and should be applied routinely in all Ssc patients undergoing periodic cardiac assessment, in Dr. Kahan's view.
Cardiac MRI is probably the method of choice for evaluating myocardial perfusion in these patients. Scintigraphy has excellent sensitivity, too, but the need to inject radioisotopes is a significant disadvantage over the course of years of repeated testing, he continued.
Diffuse myocardial perfusion abnormalities are common in Ssc patients. They can be detected at rest and induced by cold, high altitude, or exercise.
An audience member asked whether the aggressive exercise program he and his colleagues prescribe for their Ssc patients is a good idea. Dr. Kahan replied that his research in the mid-1980s showed that coronary reserve in Ssc patients is only half that of normal subjects, so he counsels his patients to stick to limited exercise relieved by liberal rest periods. “They must not exercise at too high a level because they may induce ischemia.”
If these cardiac abnormalities aren't treated early on, irreversible myocardial fibrosis can occur. DR. KAHAN