Distribution and prevalence of cardiovascular risk factors in a aging population of thalassemia patients: looking at the heart of the problem

Abstract

Abstract Background β-thalassemia major is a hereditary genetic disease hindered by many comorbidities due to transfusion-related iron. Since the introduction of chelation therapy life expectancy of these patients has increased from the 16 years of 1964 to 50 years today, with a marked improvement in the quality of life. Iron-related heart disease is still a leading complication but diabetes mellitus and hypogonadism may impact the cardiovascular risk in these patients, with an expected change in heart involvement with this unprecedentedly seen aging of these patients. Target This study aims to evaluate the distribution and prevalence of cardiovascular risk factors in a population of thalassemia major patients, and their relationship with observed cardiovascular events and potential modifying factors. Methods and results One-hundred fifty-nine patients older than 18 years of age with clinical and molecular diagnosis of β-thalassemia major and at least 15 years of follow-up were included in this study. Mean age was 40.9±8.4 years. Low serum lipid levels with low HDL levels were noted, with 17.6% having diabetes mellitus and 62% with hypogonadism; Splenectomy was reported in 70%. During the observed period 3.8% of patients had at least one episode of heart failure, 35.9% showed early signs of heart failure, 22% received diagnosis of diastolic dysfunction, 38% had a left ventricular ejection fraction <55% and 21.4% showed supraventricular arrhythmias. Cardiovascular risk was then assessed using two algorithms (CUORE and Pooled Cohort Risk Equation - PCRE) and was generally low but despite that patients with hypogonadism (who showed lower cardiac T2* value than those without; p<0.001) showed a statistically significant correlation with the occurrence of cardiovascular events. Discussion The β-thalassemia population has a relatively low mean age, but shows a particular metabolic profile in association with numerous comorbidities: an increased prevalence of diabetes mellitus, low HDL values and frequent hypogonadism which tends to be associated with increased iron deposition in myocardium. The cardiovascular risk estimated by specific algorithms (CUORE and PCRE) was generally low, mainly due to the young age of the cohort, but the prevalence of cardiac events was not negligible. Conclusions The chronic accumulation of iron in the heart and the specific metabolic profile, particularly observed in patients with hypogonadism, allows us to define Major Thalassemia patients as a population at high cardiovascular risk from many points of view (iron-related myopathy, atherosclerosis and arrhythmias), which requires a specific follow-up program, to prevent and to identify early signs of these serious complications. Funding Acknowledgement Type of funding sources: None.