(10.04) Look what we found…:Utility of CAC score in a high risk patient with overt hyperthyroidism and “normal” lipid profile.

Patients with hyperthyroidism have increased risks of an array of cardiovascular problems, such as: atrial fibrillation, coronary artery disease, stroke and heart failure. Thyroid disease are common with cardiac disease patient, reaching 11%. Coronary artery calcium (CAC) on computed tomography (CT) is a well validated measure of subclinical atherosclerosis. It has been shown to be useful way of improving cardiovascular risk assessment in asymptomatic individuals with risk factors for atherosclerotic cardiovascular disease (ASCVD).  Hereby, we describe the case of a patient presented with overt hyperthyroidism with substernal goiter and high risk for ASCVD  above 20% but with normal levels of LDL on which a coronary artery calcium score served as a predictive tool for risk stratification.


Case(s) Description : A case of a 61-year-old male with past medical history of arterial hypertension, and active smoker referred for further evaluation of altered thyroid function tests (TFTs). Over the last 2 months he had being dealing with: palpitations, tremors and neck enlargement. Physical exam was remarkable for tachycardia, a palpable goiter, presence of Pemberton’s sign and increased deep tendon reflexes. Thyroid ultrasound revealed a diffuse goiter with possible extension to substernal area. Laboratory results showed a suppressed TSH level (< 0.008 uIu/ml), elevated free T4 level (1.98 ng/dl), Thyroid stimulating immunoglobulin (80.5 IU/L) and total T3 uptake of 52% consistent with an overt hyperthyroid state secondary to Grave’s disease. Patient was started on methimazole 30 mg daily in order to control hyperthyroidism. Also noted a normal LDL (46 mg/dl) and Non-HDL levels (38 mg/dl) but patient with High risk for ASCVD ( > 20%),reluctant to start statin therapy. Chest CT scan was done due to possible goiter with substernal extension and based on his reluctant to start statin therapy a coronary Calcium was order to look for subclinical ASCVD. Substernal Goiter extension was confirmed on chest CT and coronary calcium score was reported elevated at 680 AU, leading to ASCVD risk of more than 30%. Cardiology evaluation was recommended before total thyroidectomy surgery. 2D-echocardiography was done revealing a Grade 2 diastolic dysfunction and ejection fraction between 45-50% with pulmonary hypertension (pulmonary artery pressure of 26 mmHg). Cardiologist recommended patient stratificaction due to suspected asymptomatic coronary heart disease. Planning perform an heart catheterization before decide final treatment.

Discussion : CAC score as a non invasive tool gives us a summary measure of ASCVD, reflecting the cumulative lifetime effect of both measurable and unmeasurable risk. CAC score has emerged as the single most predictive cardiovascular risk marker in asymptomatic individuals as in our patient with multiple risk factor and normal lipid profile. In patients as ours with extensive CAC, the likelihood of significant coronary artery stenosis is more than 90% reported. The use for Calcium score  was helpful tool to convince this patient about the need of use statins but also to guide our clinical decision before establishing definitive management.