# Update: Heart Failure in Systemic Lupus Erythermatosus
## 2 Epidemiology of Heart Failure in Systemic Lupus Eryhematosus  
Regardless of the long-standing and widespread awareness of the increased cardiovascular risk in patients with SLE, more detailed epidemiological data on heart failure in this group are beginning to appear. Autopsies of SLE patients have demonstrated that almost half of them presented signs of myocardial involvement, whereas the disease had been diagnosed premortem in solely about 1/10 patients, which indicates the scale of the diagnostic problem in the coexistence of these diseases [18]. Despite medical advances, cardiovascular disease mortality has remained unchanged for 30 years [19], whereas the incidence of HF in SLE patients is estimated to be 5 times higher than in the general population [3; 4]. Importantly, SLE may predispose to HF more strongly than diabetes (DM) or dyslipidemia [3]. However, some studies indicate that the incidence of HF in patients with SLE is 2.7 times higher than in the general population, which is comparable to the risk associated with DM. Other studies have also observed a 3.2-3.8 times higher risk compared to the general population. The hazard ratio decreases with age, reaching a value of about 1.25 for patients over 65 years of age [3; 20; 21]. Patients with SLE are characterized by a higher frequency of hospitalization due to HF, and this risk decreases with age, conversely to the general population [19; 21]. Nevertheless, age remains an independent risk factor for HF [22].  
Considering gender, women remain the dominant group of patients with SLE, but younger men have a higher (up to 3.5-fold) risk of developing HF [3; 21; 23]. Similarly, the Black race significantly increases the risk of developing HF, even 1.5-fold [8; 24; 25; 26]. In the multivariable model proposed by [PERSON] et al., inclusion ethnicity indicates a 4.2-fold increase in the risk of HF in SLE patients with SLE [20].  
Available data indicate that most acute cardiac symptoms occur within the first 6 months of SLE diagnosis. Therefore, HF is more likely to be related to SLE than to atherosclerosis, which develops in the later decades of life [8; 27; 28]. The prevalence of subclinical left ventricular systolic as well as left ventricular diastolic dysfunction is estimated to be about 11-16% and 4-8%, respectively. However, data from studies using magnetic resonance imaging suggest a higher percentage [29; 30; 31; 32].  
Despite the widespread recognition of the increased cardiovascular risk in SLE patients, the first epidemiological data on heart failure are emerging, underlining the difficulty of its early detection. Analysis of autopsies in SL patients exhibits that myocardial involvement occurs much more frequently than previously thought and consequently how often cases of HF are undiagnosed or diagnosed with delay. Therefore, not only the identification but also the effective treatment of heart failure in this group is an urgent problem. Moreover, the comparison of the risk of HF in SLE with other metabolic diseases, such as diabetes or dyslipidemia, indicates a preeminent predisposition of patients with lupus to the development of heart failure.  
In addition, the higher risk of HF in younger men and Black patients, as well as other demographic characteristics, may be crucial in identifying groups at increased risk. It is worth emphasizing that the subclinical changes in the heart, such as left ventricular systolic and diastolic dysfunction, may go unnoticed, which impedes the introduction of early treatment. Further studies are necessary to better understand the mechanisms leading to heart failure in SLE and to develop appropriate diagnostic and therapeutic strategies.