Risk factors for chronic thromboembolic pulmonary hypertension – Importance of thyroid disease and function

Abstract

Introduction: Although a number of risk factors for chronic thromboembolic pulmonary hypertension (CTEPH) have been reported, the exact prevalence is controversial and varies between published cohorts. The aim of the present study was to investigate the prevalence of risk factors in operable CTEPH patients with special emphasis on thyroid disease and function. Material and methods: Overall, 228 CTEPH patients (47.7% female; median age 63 [IQR 52-72] years) scheduled for pulmonary endarterectomy between 01/2014 and 12/2015 were studied. Prevalence of risk factors was assessed, and patients were classified according to their thyroid function based on laboratory measurements. Results: As many as 86.0% of patients reported a history of pulmonary embolism (PE; of those, 24.5% were diagnosed with "acute" PE less than six months before the diagnosis of CTEPH), 80.7% of patients had a blood group non-0 and 24.1% of patients had known thyroid disease (of those, 78.2% hypothyroidism). Laboratory measurements revealed thyroid dysfunction in 10.5% of patients (of those, 54.8% had no known thyroid disease). Patients with hypothyroid function had higher WHO functional classes, NT-proBNP levels and a lower cardiac index compared to patients with euthyroid function. Conclusions: The prevalence of a history of PE and blood group non-0 was higher than previously reported. However, a relevant proportion of patients might have suffered from pre-existing CTEPH rather than acute PE. Thyroid disease and dysfunction were frequent and hypothyroid function associated with more severe disease.

Characteristics and outcomes of patients with chronic thromboembolic pulmonary hypertension in the era of modern therapeutic approaches: data from the Polish multicenter registry (BNP-PL)

“…This may result from the fact that Polish adults are generally burdened with a higher incidence of CVD risk factors and a higher risk of CVD mortality than their counterparts in western European countries. 47,48 Thyroid disorders, especially hypothyroidism and treatment with levothyroxine, have previously been linked to CTEPH, 49,50 and our results complement the previous findings. Our new observation is that hyperthyroidism was over two times more prevalent in non-operable patients as compared to operable patients.…”

Association between thyroid dysfunction and venous thromboembolism: A systematic review and meta-analysis

“…In contrast, in long-term follow-up, both hyperthyroidism and hypothyroidism were associated with an increased risk of long-term mortality. In a chronic thromboembolic pulmonary hypertension (CTEPH) study, thyroid hormone replacement therapy in hypothyroid patients appeared to lead to an increased proportion of CTEPH, [37] and hypothyroid patients with CTEPH have more severe clinical symptoms, higher NT-proBNP and lower cardiac index than those without CTEPH, [38] of which the mechanism is still unclear, and further studies are needed to elucidate their association. Nevertheless, current observational evidence suggests that early diagnosis and treatment of thyroid dysfunction are important in clinical VTE prevention and prognosis.…”

The Role of Thyroid Disorders, Obesity, Diabetes Mellitus and Estrogen Exposure as Potential Modifiers for Pulmonary Hypertension

“…Thyroid dysfunction and thyroid replacement therapy have also been identified as risk factors for the development of Group 4 PH, i.e., CTEPH [17,18]. Hypothyroidism was found as the predominant thyroid condition and was associated with more severe cases of CTEPH [19].…”