Left main aneurysm and what's next?

The purpose of the case report is to present a case of a 65-year-old male, referred for coronary angiography because of a typical chest pain. The coronary angiography showed an aneurysm of the left main coronary artery. Despite the absence of obvious ischemic symptoms and because of the potential complications of the aneurysm with a width of 15 mm, the patient underwent surgery.

Introduction

Coronary artery aneurysm is a rare disorder. It is diagnosed when the diameter of the vessel is at least 1.5 times that of a normal coronary artery. In the population the incidence of left main coronary artery (LMA) is approximately 0.1% of cases. The major cause of LMA in adults is atherosclerosis [1]. Other causes are inflammation, cocaine intoxication, trauma (associated with resuscitation), and iatrogenic effects (angioplasty, surgery of the ascending aorta) [2-6]. The LMA in children is often found in Kawasaki or Takayasu disease. It may also be associated with other cardiac defects such as postponement of the main arteries, or tetralogy of Fallot [7, 8]. A definitive diagnosis can rarely be made.

The LMA is associated with serious complications such as vessel dissection, rupture, or myocardial infarction, which can lead to sudden cardiac death [9, 10]. There is no officially sanctioned treatment for this disease and all existing knowledge about it can be gained from case reports mainly. The primary treatment in children and adults is a surgical procedure [11]. The first case reports about coronary artery bypass graft (CABG) in LMA can be found in the 1970s [12]. Currently, several types of treatment, such as surgical removal of the aneurysm and CABG, or isolated CABG, stent graft or coil can be applied [13-17]. A lack of surgical standards triggers the need to search for new methods such as removal of the aneurysm and replacement with a new artery or wire [18-20]. When choosing treatment one can also stick to a conservative approach [21].

Case report

The aforementioned 64-year-old male, with a past history of myocardial infarction of the inferior wall 13 years ago, hypertension, and obesity (body mass index (BMI) 37 kg/ m2), was referred to the Cardiology Clinic because of a typical chest pain. Echocardiography showed enlarged left heart (LV: 62/45 mm, LA: 44 mm), multi-segment wall motion abnormalities with decreased left ventricular ejection fraction (EF: 32%) and moderate mitral regurgitation. Coronary angiography confirmed amputation of the proximal segment of the right coronary artery (RCA) with proper filling of the circuit and the LMA with a diameter of 15 mm (Figures 1A and 1B) and turbulent blood flow. The patient was in functional class NYHA II. The surgical decision on the need for operative intervention was based on the ischemic symptoms. In order to highlight the degree of severity of the abnormal flow through the aneurysm we used the fractional flow reserve (FFR) technique which, however, showed no loss of value. After consulting another medical centre the patient was qualified for surgery. Afterwards, mitral valve plasty was performed, a venous bypass was implanted in the RCA, and the LMA was excised with uniting of the left anterior descending artery (LAD), circumflex artery (Cx) and intermediate artery (IM) with a short venous bypass. The patient underwent surgery which gave him complete revascularization, correction of mitral valve disease, and removed the risk of rupture or clotting of the aneurysm and a secondary heart attack connected with death which was, from our point of view, the most crucial.

Figure 1

Coronary angiography – left main aneurysm

Discussion

In no other field of medicine, except cardiology, have there been so many standards and guidelines of conduct. Nevertheless, there are still some disease entities with no treatment procedures formally approved. These include the rare LMA. It seems that invasive treatment may improve prognosis in this disease, but there has been no conclusive evidence for it. The question is whether cardiac surgery (involving thoracotomy and extracorporeal circulation) with its potential complications is superior to conservative treatment in a case of asymptomatic pathology [22].