Background Cardiac involvement is a significant cause of the death and disability in systemic vasculitis. The comprehensive analysis of histopathologic findings in polyarteritis nodosa (PN) can help better understand mechanisms of excessive cardiovascular risk in patients with systemic vasculitis.
Objectives To investigate the variation of cardiac pathological findings in autopsy cases of PN.
Methods A retrospective analysis of cardiac pathological changes was performed in 37 autopsy cases of PN over period of 15 years. There were 28 males and 9 females, ranging from 23 to 85 years. The median age at disease onset was 35, 7 years; the median duration of disease was 2.1 years with a range of 2 month to 7 years.
Results The destructive-productive vasculitis of the coronary arteries have been found in 30 cases (81.1%) of PN. The vessels most affected were myocardial, and epicardial medium and small-sized arteries. Histologically, the remodelling of coronary artery tree in PN had a wide range of acute and chronic changes that likely were depended on the duration of the disease. There were three types of pathological findings: (1) arteritis with predominantly destructive changes; (2) arteritis with predominantly proliferative changes; (3) destructive-productive arteritis. The early phase of PN has been characterized by abnormalities of vessels wall from mucoid swelling to fibrinoid necrosis. The most common was panarteritis with involvement of all layers of the arterial wall, and inflammatory responses with intramural, and perivascular infiltrates, mainly composed of lymphocytes, and neutrophils. However, endo-, meso-, and periarteritis also were observed in some cases. The most remarkable lesions in coronary arteries were the nodules visible to the naked eye along coronary arteries. They were present in 9 cases (30%), and can be described as well-demarcated nodular thickening of the artery walls with size from 0.1 to 0.4 cm. The pathological basis of nodules are areas of focal inflammation, destruction and aneurysmal dilatations of artery wall. In cases of chronic course of PN, the intimal hyperplasia due to proliferation of endothelial cells have been observed. Interestingly, that this productive endarteritis with luminal narrowing of coronary arteries was common in patients who were exposed to different types of occupational xenobiotic (silica dust, pesticides, insecticides, solvents, heavy metals). In 5 (16.7%) cases, luminal occlusion due to intimal proliferation, fibrosis and thrombus formation led to the myocardial infarction, and death. Pathological manifestation of cardiac involvement in PN included the left ventricular hypertrophy due to renovascular arterial hypertension in 26 cases (70.3%). In addition, interstitial myocarditis was observed in 4 cases (10.8%).
Conclusions Our date suggest that cardiac involvement is common in polyarteritis nodosa (81.1%), and coronary vasculitis affecting medium and small-sized arteries with wide range of acute and chronic changes can be the life-threatening condition.
Disclosure of Interest None declared