Appropriateness of Levothyroxine Prescription: A Multicenter Retrospective Study.

CONTEXT: Levothyroxine is one of the most prescribed medications in the United States. OBJECTIVE: This study explores the appropriateness of levothyroxine prescriptions. METHODS: A retrospective multicenter study was conducted on adult patients who were prescribed levothyroxine for the first time between 2017 and 2020 at three academic centers in the United States. We classified each case of levothyroxine initiation into one of three mutually exclusive categories: appropriate (clinically supported), indeterminate (clinically unclear), or nonevidence based (NEB, not clinically supported). RESULTS: A total of 977 participants were included. The mean age was 55 years (SD 19), there was female (69%) and White race predominance (84%), and 44% had possible hypothyroid symptoms. Nearly half of the levothyroxine prescriptions were considered NEB (528, 54%), followed by appropriate (307, 31%) and indeterminate (118, 12%). The most common reason for NEB prescription was an index thyrotropin (TSH) value of less than 10 mIU/L without previous TSH or thyroxine values (131/528, 25%), for appropriate prescription, was overt hypothyroidism (163/307, 53%), and for an indeterminate prescription was a nonconfirmed subclinical hypothyroidism with TSH greater than or equal to 10 mIU/L (no confirmatory testing) (51/118, 43%). In multivariable analysis, being female (odds ratio [OR]: 1.3; 95% CI, 1.0-1.7) and prescription by a primary care provider (OR: 1.5; 95% CI, 1.2-2.0) were associated with NEB prescriptions. CONCLUSION: There is a considerable proportion of NEB levothyroxine prescriptions. These results call for additional research to replicate these findings and to explore the perspective of those prescribing and receiving levothyroxine.

The Right Ventricular Function After Left Ventricular Assist Device (RVF-LVAD) study: rationale and preliminary results.

AIMS: Despite improved outcomes and lower right ventricular failure (RVF) rates with continuous-flow left ventricular assist devices (LVADs), RVF still occurs in 20-40% of LVAD recipients and leads to worse clinical and patient-centred outcomes and higher utilization of healthcare resources. Preoperative quantification of RV function with echocardiography has only recently been considered for RVF prediction, and RV mechanics have not been prospectively evaluated. METHODS AND RESULTS: In this single-centre prospective cohort study, we plan to enroll a total of 120 LVAD candidates to evaluate standard and mechanics-based echocardiographic measures of RV function, obtained within 7 days of planned LVAD surgery, for prediction of (i) RVF within 90 days; (ii) quality of life (QoL) at 90 days; and (iii) RV function recovery at 90 days post-LVAD. Our primary hypothesis is that an RV echocardiographic score will predict RVF with clinically relevant discrimination (C >0.85) and positive and negative predictive values (>80%). Our secondary hypothesis is that the RV score will predict QoL and RV recovery by 90 days. We expect that RV mechanics will provide incremental prognostic information for these outcomes. The preliminary results of an interim analysis are encouraging. CONCLUSION: The results of this study may help improve LVAD outcomes and reduce resource utilization by facilitating shared decision-making and selection for LVAD implantation, provide insights into RV function recovery, and potentially inform reassessment of LVAD timing in patients at high risk for RVF.