PURPOSE: It is well known that clinical and sub-clinical hypothyroidism (HT) leads to accelerated atherosclerosis and coronary artery disease (CAD). However, the frequency and the impact of HT in patients with acute coronary syndromes (ACS) have not been well studied and remain unclear.
METHODS: This was a retrospective cohort study of patients admitted to the coronary care unit of Creighton university medical center between January, 2003 and April, 2007. Patients with a discharge diagnosis of acute coronary syndrome and a concomitant diagnosis of clinical or sub-clinical HT were included. Demographic data, clinical features, treatment details and complications were extracted. The data was analyzed to assess the impact of thyroid stimulating hormone (TSH) on presentation and outcomes.
RESULTS: 1746 patients had a discharge diagnosis of ACS during this period of which 148 patients (8.5%) had a concomitant diagnosis of clinical or subclinical HT. Ten patients were excluded due to incomplete data leaving 138 for analysis. Fifteen (11%) of these were newly diagnosed and the others had a preexisting diagnosis of HT. Of the 138 patients, 108 (78%) had a TSH ≤ 6 and the remaining 30 (22%) had TSH>6. The upper limit of normal for our laboratory is 6. Major complications which included death, recurrent ischemia/infarction, sustained ventricular arrhythmia, bradyarrhythmia needing pacemaker placement, congestive heart failure, shock, major bleeding, stroke and respiratory failure needing mechanical ventilation were not different between the two groups. Duration of hospitalization was similar and none had > mild pericardial effusion. Initiation or dose escalation of levo-thyroxine was not associated with adverse events like recurrent ischemia, infarction or tachyarrhythmia.
CONCLUSION: HT is frequent in patients with ACS. High TSH does not portend any adverse outcomes in the short term. Initiation or escalation of levothyroxine dose appears safe in patients with ACS.
CLINICAL IMPLICATIONS: High TSH is not associated with short term adverse impact in ACS patients with HT. Further large prospective studies with longer follow up are necessary.
DISCLOSURE: Venkata Alla, No Financial Disclosure Information; No Product/Research Disclosure Information