Cardiac involvement in small and medium-sized vasculitides

Necrotizing vasculitides are classified according to the predominant type of affected vessels.

1. Polyarteritis nodosa (PAN) and Kawasaki disease (KD) involve medium sized vessels.
2. Microscopic polyangiitis (MPA), Wegener’s granulomatosis (WG) and Churg-Strauss syndrome (CSS) involve preferentially small vessels.

(1). They share several clinical and pathologic features, as well as the association with the presence of serum antineutrophil cytoplasmic antibodies (ANCA) (1, 2), whereas it is unusual in PAN (2).  Classification of systemic necrotizing vasculitides was established at the Chapel Hill Consensus Conference (3).

I - Symptomatology

ANCA-associated vasculitides are characterised by the involvement of small vessels in various organs, including lungs, kidneys, skin and peripheral nervous system (1-2).  Systemic symptoms are present in at least 50% of all patients in MPA and PAN.

A) Polyarteritis nodosa (PAN) typically includes

• deep skin inflammation or progresses to infarction and gangrene (30-50%)
• neuropathy (mononeuritis multiplex in 20-50%)
• mesenteric vasculitis
• hypertension due to renal arteritis and cardiac disease in 10-30% of cases
• new onset hypertension in a patient with systemic symptoms such as fever, weight loss and joint pain is a clue of PAN

B) Microscopic polyangiitis (MPA)
The coexistence of all these findings with

• glomerulonephritis
• palpable purpura
• pulmonary infiltrates or hemorrhag is supportive of MPA

C) Churg-Strauss syndrome (CSS)
In CSS the diagnosis requires

• a past or present history of asthma
• systemic symptoms are present in 70% of cases.
• congestive heart failure occurs in 15-30% of cases.
• gastrointestinal ischemia (5% of cases) contributes to mortality
• peripheral neurological abnormalities affect more than 2/3 of patients
• musculoskeletal symptoms and rashes may be found in 1/2
  and renal disease in 1/3 of cases

D) Wegener’s granulomatosis (WG)

• WG is characterised by its predilection to affect upper respiratory tract in 70-90% of cases in form of nasal disease and sinusitis
• lower respiratory tract is also involved in 45-87% of cases, presenting as pulmonary infiltrates, nodules or pleuritis
• in most cases kidney disease coexists (11-85%) in form of glomerulonephritis, resulting in end-stage renal failure
• the frequency of cardiac involvement in WG varies from 6-30% presenting as pericarditis, myocardial ischemia, myocarditis, endocarditis, valvulitis or conduction defects
• definite proof of the diagnosis depends on visualising vasculitic lesions in affected tissues and the greatest success in achieving diagnosis comes from biopsy of abnormal sites giving positive results in more than 65% of cases (1, 2)

II  - Cardiac involvement

Clinically significant cardiac involvement is a rare complication in systemic vasculitides, but it can be life-threatening (2). As many cardiac manifestations are clinically silent at least during their early stages, heart function should be systematically evaluated by ECG and echocardiography. If symptoms appear and the basic investigation is normal, further evaluation using cardiovascular magnetic resonance is of great value, because it is the ideal technique to reveal the presence of myocardial inflammation.

Every cardiac tissue from myocardium to epicardium, endocardium, conduction system and coronary arteries may be affected by vasculitides. However cardiovascular manifestations due to vasculitides must be distinguished from those that can arise as a consequence of treatment with corticosteroids and immunosuppresants.

Myocarditis due to vasculitis varies widely from 25 to 70% of cases. It is due to necrotizing vasculitis, presence of granulomas or fibrosis. In CSS, infiltration by  eosinophils is considered as a possible cause and cardiac magnetic resonance (CMR) is of value for early detection of myocardial inflammation, especially in patients with atypical presentation (4). In KD it can be identified in almost half of patients.

Coronary artery involvement can be detected, due to coronary arteritis that causes thromboses, dissections, stenosis and possible myocardial infarction. Coronary involvement was documented in 50% of PAN. It is also very common in KD (20% of untreated cases) and can be easily diagnosed by both echocardiography and CMR (5). CMR is also of value for myocardial infarction detection and coronary arteries evaluation (6).

Pericardial involvement was documented in 22% of CSS, 8% of WG and 0-27% of PAN and it can contribute to constrictive pericarditis, if left untreated. Endocardium involvement is rather unusual, but it can promote valve distortion in some cases. Arrhythmias (mainly supraventricular), AV or bundle branch block can also be found due to myocarditis, ischemia or heart failure (2). Pulmonary hypertension is a rare complication in vasculitides.

III - Treatment

The treatment is mainly immunosuppressive, cardiac medication including b-blocker, ACE-inhibitors, diuretics, antithrombotic, antiarrhythmic drugs and even pacemaker implantation should also be considered accordingly. Cardiologists in close collaboration with rheumatologists should be on alert about the importance of cardiac involvement in vasculitides, in order to early identify and treat these patients before severe complications take place.

The content of this article reflects the personal opinion of the author/s and is not necessarily the official position of the European Society of Cardiology.