Heart failure (HF) affects more than 10 percent of patients aged seventy and older and between 1 and 3 percent of the general population [
1,
2]. HF is a clinical condition whose prevalence is increasing, particularly in patients with type 1 diabetes (T1D) and type 2 diabetes (T2D) [
2,
3,
4]. A cascade of potentially fatal events means that while T1D and T2D increase the risk of developing HF, in turn HF also increases the risk of premature death in patients with T1D and T2D [
3,
5]. In registry studies, the prevalence of T2D among subjects with HF ranges from 25 to 40% [
4,
6,
7], while ranging between 30 and 50% in HF clinical trials [
8,
9,
10,
11,
12,
13]. Although most of these trials were conducted in subjects with T2D, even in T1D, which accounts for 10% of patients with diabetes [
14], the risk of HF is three to five times higher than in controls [
3,
15]. In a 2019 meta-analysis conducted by Ohkuma et al. involving more than twelve million subjects, the RR for HF in T1D was 5.15 in women and 3.47 in men compared with non-diabetic peers [
3]. There are currently no studies on how HF in T1D increases cardiovascular (CV) risk and overall mortality: on the other hand, the role of HF as a major contributor to CV morbidity and mortality in type 2 diabetes (T2D) has been highlighted by several clinical trials on the efficacy of sodium-glucose cotransporter-2 inhibitors (SGLT2-i) in CV prevention [
8,
9,
10,
11,
16]. Notably, although the mortality rate of patients with T1D has decreased over the past decade, it remains approximately three times higher than that of non-diabetic patients, mainly due to an increased prevalence of major CV events [
17,
18,
19]. A 2016 Swedish registry study by Petrie et al. including 27,841 T1D subjects, showed that the risk of myocardial infarction and HF remains high in T1D compared to non-diabetic subjects, resulting in a loss of life expectancy of 10-11 years in men and 11-12 years in women, respectively [
17]. A thorough understanding of the role of HF is essential to reduce CVD and all-cause mortality in patients with T1D. Measurement of left ventricular ejection fraction (LVEF) has traditionally been used to classify HF into different phenotypes: HF with reduced ejection fraction (HFrEF), where LVEF is ≤40%; HF with mildly reduced LVEF (between 40 and 50%) and HF with preserved ejection fraction (HFpEF). Notably, the prevalence of HFpEF is essentially the same as HFrEF in patients with type 1 and type 2 diabetes [
20]. Although it is commonly believed that HFpEF confers a greater chance of survival than HFrEF, most observational studies show that this difference is insignificant [
21,
22]. In a study conducted in Olmsted County, Minnesota, while the incidence of HF declined, particularly for HF with reduced ejection fraction (HFrEF), the prognosis in terms of mortality rates showed no significant difference between patients with HFrEF and those with HF with preserved ejection fraction (HFpEF), indicating similar outcomes for both subtypes despite differing trends in incidence [
21]. A study by Connie W. Tsao et al (2018) found that while the incidence of HF with reduced ejection fraction (HFrEF) decreased and HF with preserved ejection fraction (HFpEF) increased from 1990 to 2009, mortality rates remained similar for both subtypes, indicating comparable prognosis despite different incidence trends [
22]. Despite this, there are far fewer drugs to treat this condition: to date almost no treatment has been shown to convincingly reduce mortality and morbidity in patients with HFpEF [
2]: despite this, the majority of patients with HF with preserved ejection fraction have other comorbidities for which they are treated with ACE inhibitors / sartans, beta blockers or mineralocorticoid receptor antagonists [
2]. The only drugs that have been convincingly shown to be able to reduce the risk of hospitalization and mortality in HFpEF are SGLT2-i [
11,
23,
24], whose use in T1D has been severely restricted in multiple countries [
25,
26] due to their increased risk of euglycemic ketoacidosis. In a study by Bode et al, dual inhibition of sodium-glucose linked transporters type 1 and 2 (SGLT-1 and SGLT-2) with sotagliflozin improved left atrial (LA) dysfunction in a metabolic syndrome-related rat model of HF with preserved ejection fraction (HFpEF) [
23]. Treatment effectively reduced LA dilation and arrhythmogenic spontaneous calcium release events in HFpEF, while improving mitochondrial calcium buffering capacity and reducing diastolic calcium accumulation, suggesting potential benefits for the treatment of LA remodeling and arrhythmias in HFpEF [
23]. The study of empagliflozin in patients with HF with preserved ejection fraction (HFpEF) by Stefan D. Anker and colleagues showed that empagliflozin significantly reduced the combined risk of cardiovascular death or hospitalization for HF, independent of diabetes status: the study, which included 5988 patients with class II-IV HF, demonstrated the efficacy of empagliflozin in reducing hospitalizations for HF and its consistent effects across patient groups, albeit with increased reports of genital and urinary infections and hypotension [
11]. On this basis, in this manuscript, review epidemiological data on HF in T1D have been reviewed in order to provide physiopathological insights. In addition, the use of SGLT2-i has been hypothesized as the current options for prevention and treatment of HF and the risk-benefit ratio of their use in patients with T1D. Furthermore, we provide recommendations (appropriate patient education, sensors for continuous ketonemia monitoring) for the prevention of diabetic ketoacidosis (DKA) events in patients with T1D and HF, while underlying how risk of developing DKA in T1D makes the use of these drugs extremely challenging and it should be deferred to a future when continuous measurement of ketone body levels is clinically feasible to prevent DKA.