Mechanical Circulatory Support Devices: Role of the Endocrinologist in the Preoperative Evaluation

Mechanical circulatory support devices (MCSDs) have significantly improved survival in heart failure (HF) patients and are now considered a standard of therapy at many centers worldwide. Patients being evaluated for a MCSD often undergo laboratory and imaging studies by numerous sub-specialties without evidence supporting this testing. This study assesses the endocrinology work-up utility in the decision for MCSD placement.

Methods:

This is a retrospective chart review of 339 patients evaluated for MCSD between January 2009 and January 2019. Endocrine evaluation included 25 hydroxy vitamin D (25OHD), glycohemoglobin (A1c), TSH, FT4, FT3, AM cortisol, and computerized tomography (CT) of head, chest, abdomen, and pelvis.

Results:

245 patients received a MCSD out of 339 who were eligible. The remainder either declined a MCSD, responded to medical management, passed away during the evaluation, went directly to heart transplantation, or were found to have a social/medical history that precluded a MCSD. 51.3% were deficient in 25OHD and 25.3% were insufficient. A1c range was 3.9%-13% in 306 patients; 146 patients had Diabetes. 281 patients had thyroid studies, which resulted in thyroid therapy adjustment in 12 patients and thyroid therapy initiation in 3. 34 (11%) of the 320 patients with an AM cortisol required an ACTH stimulation and 2 had adrenal insufficiency. CT head was obtained for 298 patients, CT chest for 321, and CT abdomen/pelvis for 319. 35 (12%) patients had incidentalomas, 17 of whom required additional testing.

Discussion/Conclusion:

All patients evaluated were deemed suitable for a MCSD from an endocrine perspective. We found a high prevalence of low 25OHD levels. Endocrine incidentalomas are as common in these patients as in the general population. These patients would sure benefit from vitamin D optimization since low 25OHD levels are independently associated with increased postoperative driveline infections and higher rate of hospital readmission. 0.05% of patients who had thyroid studies required medical therapy for thyroid dysfunction. Given that symptoms of HF and hypothyroidism can overlap, and that hypothyroidism can exacerbate HF, it is reasonable to consider thyroid studies in all HF patients. HF patients may have inaccurate A1c and cortisol values in the setting of critical illness, therefore, their evaluation will not be as beneficial. CT imaging may be warranted to detect coexisting disease, which may affect patient survival. In conclusion, optimizing endocrine function may contribute to improved cardiac contractility, immune function, infection control, and rehabilitation in the setting of MCSD placement.