5.7 million adults in the US have heart failure and exacerbation of heart failure is one of the most common causes for hospital admissions. Thyroid dysfunction can lead to heart failure and both elevated and decreased TSH levels are associated with increased mortality in patients with congestive heart failure (CHF). Hypothyroidism has not yet been investigated in the context of hospital length of stay for CHF exacerbations. The aim of our study was to evaluate hypothyroidism as a risk factor for increased mortality and increased length of stay in patients with CHF exacerbation.
The National Inpatient Survey (NIS) database from 2012 to 2014 was reviewed. Patients with primary and secondary diagnosis of Heart failure on admission were identified by ICD-9 code (428). Patients’ baseline characteristics and comorbidities were extracted and the Charlson Co-morbidity Index (CCI) was calculated for each patient. We compared baseline characteristics, comorbidities, mortality, and length of stay based on the history of hypothyroidism. Statistical analysis was done using student's t-test, chi-square test, and binary logistic regression with level of α set at 0.05.
Results : A total of 1251905 patients were admitted for heart failure and of those, 206295 (16%) had history of hypothyroidism. The mean age was 76 years in the hypothyroid group and 71 years in the euthyroid group (p<0.001). The female to male ratio was higher in the hypothyroid group compared to the euthyroid group (2.2 vs. 1, p<0.001). Length of stay was 4.09 days in patients with hypothyroidism vs. 3.69 in euthyroid patients (p<0.05). Mortality rate was 2.7% in patients admitted for HF with hypothyroidism and 2.5% in patients without hypothyroidism (p<0.05). The mean CCI was 5.3 in hypothyroid patients vs. 4.7 in the euthyroid group. When adjusted for CCI, age and sex, mortality rate remained higher in patients with hypothyroidism (p<0.05).
Our results showed that hypothyroid patients admitted for heart failure, when adjusted for comorbidities, had higher mortality compared to euthyroid patients. Thyroid hormone directly affects cardiac contractility, heart rate and cardiac output. Lower thyroid hormone levels have also been associated with higher right atrial pressures and lower ejection fractions resulting in higher incidence of CHF exacerbations and CHF exacerbation recurrences. Consequently, we demonstrated that when adjusted for comorbidities, hypothyroid patients also tend to stay in hospitals longer, compared to their euthyroid counterparts.
Hypothyroidism is a risk factor for increased mortality and increased length of stay in patients with CHF exacerbation.
Rehan Umar– Resident Physician, Rutgers University, NEWARK, New Jersey
Umar Sharif Khawaja– Resident Internal medicine, Rutgers New Jersey Medical school, Newark, New Jersey
Yasaman Motlaghzadeh– Internal Medicine Resident, Rutgers-New Jersey Medical School, West Orange, New Jersey
Jabran Umar– Internal Medicine Resident, Rutgers-New Jersey Medical School, West Orange, New Jersey
NEWARK, New Jersey
Second Year Internal Medicine resident.
Resident Internal medicine
Rutgers New Jersey Medical school
Newark, New Jersey
I completed medical school in Lahore, Pakistan and came to US for my medical residency at Rutgers New jersey medical school.
Internal Medicine Resident
Rutgers-New Jersey Medical School
West Orange, New Jersey
MD-MPH Degree: Tehran University Of Medical Sciences, Internal Medicine Residency: Rutgers- New Jersey Medical School