Hypothyroidism is a risk factor for increased length of hospital stay and mortality in patients with congestive heart failure (CHF), according to study results presented at the American Association of Clinical Endocrinologists 28th Annual Congress, held April 24 to 28 in Los Angeles, California.
Researchers at Rutgers University in New Jersey used information from the National Inpatient Survey database from 2012 to 2014 to identify 1,251,905 patients with a diagnosis of primary or secondary heart failure, 206,295 of whom also had a history of hypothyroidism based on International Classification of Diseases, Ninth Edition (ICD-9) coding. The researchers compared baseline characteristics, comorbidities, mortality, and length of hospital stay in patients based on their history of hypothyroidism. Baseline and comorbidity data were used to calculate the Charlson Comorbidity Index (CCI) score for each patient.
The mean age in the hypothyroidism group was 76 years compared with 71 years in the euthyroid group. The hypothyroidism group also showed a higher female-to-male ratio compared with the euthyroid group (2.2 vs 1.0; P <.001).
The results showed that length of hospital stay was 4.09 days in patients with hypothyroidism and CHF compared with 3.69 days in euthyroid patients with CHF (P <.05). Mortality rate was 2.7% in patients with CHF with hypothyroidism vs 2.5% in patients with CHF without hypothyroidism (P <.05), and remained significantly higher even after adjustment for CCI score, age, and sex. Mean CCI was 5.3 in the hypothyroid group vs 4.7 in the euthyroid group.
The researchers noted that lower thyroid hormone levels have been associated with higher right atrial pressures and lower ejection fractions, leading to higher risk for CHF exacerbations.
“[W]e demonstrated that when adjusted for comorbidities, [patients with hypothyroidism and CHF] also tend to stay in hospitals longer, compared with their euthyroid counterparts,” wrote the researchers.
Umar R, Khawaja US, Motlaghzadeh Y, Umar J. Mortality and length of hospital stay for hypothyroid patients in heart failure exacerbation. Presented at: American Association of Clinical Endocrinologists 28th Annual Scientific & Clinical Congress; April 24-28, 2019; Los Angeles, CA.