The Role Of Speckled Tracked Transthoracic Echocardiography And Global Longitudinal Strain In Heart Failure Patients With Subclinical Hypothyroid State

Background Thyroid hormone has an essential role on the functional capability of cardiac muscle with its gene modulatory and induction of vasodilatory effects. There is considerable evidence to suggest the role of thyroid hormone in acute coronary syndrome (ACS) but less is known about its prognostic role in heart failure (HF). We aimed to assess the role of global longitudinal strain (GLS) in patients hospitalized for an acute HF syndrome (AHFS) and with underlying subclinical hypothyroid state (SCHS) to predict event rates including 30-day all-cause mortality and HF readmission. Methods A retrospective chart review analysis of 161 subjects with a diagnosis of AHFS and SCHS was collected. We dichotomized the patients into HF with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF) subgroups. The SCHS was defined as thyroid stimulating hormone level >4.50 mIU/L with a normal thyroxine level. HFpEF was defined as left ventricular ejection fraction (LVEF)>40% and HFrEF was defined as having LVEF≤40%. Abnormal speckled tracked transthoracic echocardiographic (TTE) strain was defined as a LV global longitudinal strain (GLS) value of >-15%. Results Of the 161 patients admitted with AHFS and SCHS, 62 (38%) had HFpEF and 99 patients (62%) were found to have HFrEF. The mean age of the population was 62±8 years and 55% were female. The mean GLS in the HFpEF group was -9% (CI -10%,-8%) and in the HFrEF group was observed to be -14% (CI -15%,-12%). The 30-day all-cause mortality and HF readmission rates did not differ between the two subgroups (P=NS). Conclusion The SCHS is associated with abnormal GLS in HF patients (either HFpEF or HFrEF). However, its role on clinical outcomes such as mortality and readmission rates has not been determined. Further studies are warranted to validate these findings in a larger population data pool. Thyroid hormone has an essential role on the functional capability of cardiac muscle with its gene modulatory and induction of vasodilatory effects. There is considerable evidence to suggest the role of thyroid hormone in acute coronary syndrome (ACS) but less is known about its prognostic role in heart failure (HF). We aimed to assess the role of global longitudinal strain (GLS) in patients hospitalized for an acute HF syndrome (AHFS) and with underlying subclinical hypothyroid state (SCHS) to predict event rates including 30-day all-cause mortality and HF readmission. A retrospective chart review analysis of 161 subjects with a diagnosis of AHFS and SCHS was collected. We dichotomized the patients into HF with preserved ejection fraction (HFpEF) and HF with reduced ejection fraction (HFrEF) subgroups. The SCHS was defined as thyroid stimulating hormone level >4.50 mIU/L with a normal thyroxine level. HFpEF was defined as left ventricular ejection fraction (LVEF)>40% and HFrEF was defined as having LVEF≤40%. Abnormal speckled tracked transthoracic echocardiographic (TTE) strain was defined as a LV global longitudinal strain (GLS) value of >-15%. Of the 161 patients admitted with AHFS and SCHS, 62 (38%) had HFpEF and 99 patients (62%) were found to have HFrEF. The mean age of the population was 62±8 years and 55% were female. The mean GLS in the HFpEF group was -9% (CI -10%,-8%) and in the HFrEF group was observed to be -14% (CI -15%,-12%). The 30-day all-cause mortality and HF readmission rates did not differ between the two subgroups (P=NS). The SCHS is associated with abnormal GLS in HF patients (either HFpEF or HFrEF). However, its role on clinical outcomes such as mortality and readmission rates has not been determined. Further studies are warranted to validate these findings in a larger population data pool.