A 22-year-old male presented with central heavy chest pain, associated with radiation to the upper arm and jaw, dyspnoea and anxiety. Medical history was significant only for one-year cigarette smoking. Family history included ischaemic heart disease affecting his grandfather in old age. He had been unsuccessful conceiving with his partner for twelve months. Cardiovascular examination was unremarkable. Further clinical examination revealed normal secondary sexual characteristics, bilateral gynaecomastia and 10mL testicular volumes bilaterally. Electrocardiogram suggested ischaemia with 1mm ST-elevation in leads II,III and aVF and ST-depression in leads V2-V4 and aVL. Cardiac enzymes were significantly elevated (Table 1). Transthoracic echocardiogram showed inferior wall motion abnormalities and patent foramen ovale (PFO). Cardiac CT did not suggest coronary artery atheroma. Cardiac MRI demonstrated acute mid-inferior transmural left ventricular myocardial infarction and preserved left ventricular ejection fraction. Transoesophageal echocardiogram confirmed a PFO but two agitated saline contrast studies demonstrated no evidence of right-to-left shunting. There was no evidence of deep vein thrombosis on lower limb Doppler ultrasonography. Lipid profile, vasculitis, autoimmune and thrombophilia screening were unremarkable. A reproductive hormone profile showed primary hypogonadism with 47XXY karyotype, confirming Klinefelter’s syndrome (KS) (Table 2). The diagnosis of thromboembolic ST-elevation myocardial infarction in the setting of PFO and KS was made and the patient commenced low-dose aspirin. Fertility was discussed and the patient will be followed-up in outpatient clinics to further discuss testosterone therapy.
KS is characterised by hypergonadotropic hypogonadism, small testes, gynaecomastia and infertility. There is also significant increased risk of arterial and venous thromboembolism (VTE), the pathophysiology of which is likely multifactorial. The role of testosterone replacement therapy in thromboembolic risk in KS remains unclear. This case demonstrates the hypercoagulable state associated with KS and highlights management issues including anticoagulation and antiplatelet agents. KS warrants consideration in unusual presentations of thromboembolism in young males.