SNOWMASS, COLO. – Cardiac abnormalities were detected by magnetic resonance imaging in three-quarters of an unselected consecutive series of systemic sclerosis patients, underscoring the impressive frequency of heart involvement in this collagen vascular disease.
"The heart is something we often forget in scleroderma. The heart disease is underestimated," Dr. Fredrick M. Wigley said at the symposium sponsored by the American College of Rheumatology.
The hallmark of cardiac involvement in systemic sclerosis (SSc) is fibrosis and inflammation. Cardiac MRI is unequalled at visualizing these features, he said.
"You can see fibrosis of the myocardium, pericardium, coronary circulation, and conduction system. Arrhythmias are common. Coronary vasospasm is thought to occur, particularly with cold conduction – the so-called Raynaud’s of the heart – leading to ischemic reperfusion injury and fibrosis of the heart," said Dr. Wigley, professor of medicine and director of the scleroderma center at Johns Hopkins University, Baltimore.
A resting tachycardia in patients with systemic sclerosis is a common clinical manifestation of cardiac involvement. Clinically evident heart disease carries an unfavorable prognosis, as do cardiac abnormalities detected via right heart catheterization or other invasive methods. The prognostic significance of asymptomatic abnormalities that are detected only on cardiac MRI and that are not evident at the bedside remains to be established. The noninvasive imaging technique has only recently been applied in systemic sclerosis.
Scleroderma patients at greatest risk for clinically severe cardiac involvement are those with myopathy and rapidly progressing skin disease, according to the rheumatologist.
Dr. Wigley highlighted a recent study by investigators at Lille 2 (France) University that effectively demonstrated the power of cardiac MRI in detecting heart involvement in SSc. The French investigators examined 52 consecutive unselected scleroderma patients with both Doppler echocardiography and cardiac MRI. One or more cardiac abnormalities were found on cardiac MRI in 75% of the patients, while Doppler detected the abnormalities in only 48% of the patients.
Moreover, only cardiac MRI permitted precise analysis of the patterns of cardiac involvement in SSc, as it was able to distinguish between the fibrotic, inflammatory, and microvascular components. Interestingly, patients with limited cutaneous SSc had cardiac MRI abnormalities that were similar to those with diffuse cutaneous disease.
Seven of the 40 patients without pulmonary arterial hypertension were found to have right ventricular dilation on cardiac MRI, underscoring the point that right ventricular dilation is not specific for this common respiratory manifestation of SSc.
Study participants had a mean 11.2-year disease history since developing Raynaud’s phenomenon. The longer a patient’s disease duration, the greater the number of cardiac segments with kinetic abnormalities and delayed contrast enhancement on MRI (Ann. Rheum. Dis. 2009;68:1878-84).
Dr. Wigley said that while to date no therapy has been shown to alter the natural course of cardiac disease in patients with scleroderma, French investigators strongly believe calcium channel blockers are cardioprotective, and they have documented increased myocardial perfusion in nifedipine-treated SSc patients.
He said that he receives consulting fees and/or research grants from Actelion, Amira, Kinemed, Medimmune, Novartis, Orion, Pfizer, and United Therapeutics.