Aims Recent studies have suggested potential sex differences in treatment response to pharmacological therapies in heart failure (HF). We performed a systematic review and meta-analysis of studies comparing treatment effects between men and women with HF and reduced ejection fraction (HFrEF) using established guideline-directed medical therapy and other emerging pharmacological treatments. Methods and results Systematic search was performed on PubMed, Embase, and Cochrane Library for randomized controlled trials published in 1990-2021. Outcomes were all-cause mortality and combined outcome of all-cause mortality and/or hospitalization for HF. Of 618 articles identified, 25 articles and 100 213 patients (mean age 62 ± 1.7 years, women 23.1%, mean left ventricular ejection fraction 26.6 ± 1.3%) were included in the systematic review and meta-analysis. For the outcome of all-cause mortality, there was no evidence of treatment heterogeneity by sex for renin-angiotensin system inhibitors (RASi) [hazard ratio (HR) 0.86 (95% confidence interval 0.75-0.99) in men; HR 0.97 (0.77-1.23) in women; Pinteraction = 0.288], or for beta-blockers (BB) [HR 0.71 (0.59-0.86) in men; HR 0.87 (0.73-1.03) in women; P interaction = 0.345]. Similarly, for the composite outcome of death or HF hospitalization, there was no evidence of treatment heterogeneity by sex for RASi in men; HR 0.94 (0.81-1.08) in women; P interaction = 0.210] or BB in men; HR 0.72 (0.60-0.86) in women; P interaction = 0.650]. Results for mineralocorticoid receptor antagonists (MRA) and sodium-glucose cotransporter-2 inhibitors (SGLT2i) from previously published meta-analyses were included in the review. For the combined outcome of cardiovascular death or HF hospitalization, no significant interaction for sex was observed for MRA (P interaction = 0.78) or SGLT2i (P interaction = 0.37). Results for emerging pharmacological treatments, such as soluble guanylate cyclase stimulators and cardiac myosin activators, were included in the review and showed consistent treatment effects between men and women. Conclusions Our meta-analysis showed no differences between sex in treatment effect for BB and RASi. Review on previously published trials for MRA, SGLT2i, and emerging therapies presented consistent treatment effects between men and women.

Background Definition of temporal serum proteome profiles after out-of-hospital cardiac arrest may identify biological processes associated with severe hypoxia–ischaemia and reperfusion. It may further explore intervention effects for new mechanistic insights, identify candidate prognostic protein biomarkers and potential therapeutic targets. This pilot study aimed to investigate serum proteome profiles from unconscious patients admitted to hospital after out-of-hospital cardiac arrest according to temperature treatment and neurological outcome. Methods Serum samples at 24, 48, and 72 h after cardiac arrest at three centres included in the Target Temperature Management after out-of-hospital cardiac arrest trial underwent data-independent acquisition mass spectrometry analysis (DIA-MS) to find changes in serum protein concentrations associated with neurological outcome at 6-month follow-up and targeted temperature management (TTM) at 33 °C as compared to 36 °C. Neurological outcome was defined according to Cerebral Performance Category (CPC) scale as “good” (CPC 1–2, good cerebral performance or moderate disability) or “poor” (CPC 3–5, severe disability, unresponsive wakefulness syndrome, or death). Results Of 78 included patients [mean age 66 ± 12 years, 62 (80.0%) male], 37 (47.4%) were randomised to TTM at 36 °C. Six-month outcome was poor in 47 (60.3%) patients. The DIA-MS analysis identified and quantified 403 unique human proteins. Differential protein abundance testing comparing poor to good outcome showed 19 elevated proteins in patients with poor outcome (log2-fold change (FC) range 0.28–1.17) and 16 reduced proteins (log2(FC) between − 0.22 and − 0.68), involved in inflammatory/immune responses and apoptotic signalling pathways for poor outcome and proteolysis for good outcome. Analysis according to level of TTM showed a significant protein abundance difference for six proteins [five elevated proteins in TTM 36 °C (log2(FC) between 0.33 and 0.88), one reduced protein (log2(FC) − 0.6)] mainly involved in inflammatory/immune responses only at 48 h after cardiac arrest. Conclusions Serum proteome profiling revealed an increase in inflammatory/immune responses and apoptosis in patients with poor outcome. In patients with good outcome, an increase in proteolysis was observed, whereas TTM-level only had a modest effect on the proteome profiles. Further validation of the differentially abundant proteins in response to neurological outcome is necessary to validate novel biomarker candidates that may predict prognosis after cardiac arrest.