Circulating levels and prognostic cut-offs of sST2, hs-cTnT, and NT-proBNP in women vs. men with chronic heart failure.

AIMS: To define plasma concentrations, determinants, and optimal prognostic cut-offs of soluble suppression of tumorigenesis-2 (sST2), high-sensitivity cardiac troponin T (hs-cTnT), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in women and men with chronic heart failure (HF). METHODS AND RESULTS: Individual data of patients from the Biomarkers In Heart Failure Outpatient Study (BIOS) Consortium with sST2, hs-cTnT, and NT-proBNP measured were analysed. The primary endpoint was a composite of 1 year cardiovascular death and HF hospitalization. The secondary endpoints were 5 year cardiovascular and all-cause death. The cohort included 4540 patients (age 67 ± 12 years, left ventricular ejection fraction 33 ± 13%, 1111 women, 25%). Women showed lower sST2 (24 vs. 27 ng/mL, P < 0.001) and hs-cTnT level (15 vs. 20 ng/L, P < 0.001), and similar concentrations of NT-proBNP (1540 vs. 1505 ng/L, P = 0.408). Although the three biomarkers were confirmed as independent predictors of outcome in both sexes, the optimal prognostic cut-off was lower in women for sST2 (28 vs. 31 ng/mL) and hs-cTnT (22 vs. 25 ng/L), while NT-proBNP cut-off was higher in women (2339 ng/L vs. 2145 ng/L). The use of sex-specific cut-offs improved risk prediction compared with the use of previously standardized prognostic cut-offs and allowed to reclassify the risk of many patients, to a greater extent in women than men, and for hs-cTnT than sST2 or NT-proBNP. Specifically, up to 18% men and up to 57% women were reclassified, by using the sex-specific cut-off of hs-cTnT for the endpoint of 5 year cardiovascular death. CONCLUSIONS: In patients with chronic HF, concentrations of sST2 and hs-cTnT, but not of NT-proBNP, are lower in women. Lower sST2 and hs-cTnT and higher NT-proBNP cut-offs for risk stratification could be used in women.

Cardiac biomarkers retain prognostic significance in patients with heart failure and chronic obstructive pulmonary disease.

AIMS: Chronic obstructive pulmonary disease (COPD) is a frequent comorbidity in patients with heart failure (HF). We assessed the influence of COPD on circulating levels and prognostic value of three HF biomarkers: N-terminal pro-B-type natriuretic peptide (NT-proBNP), high-sensitivity troponin T (hs-TnT), and soluble suppression of tumorigenesis-2 (sST2). METHODS: Individual data from patients with chronic HF, known COPD status, NT-proBNP and hs-TnT values (n = 8088) were analysed. A subgroup (n = 3414) had also sST2 values. RESULTS: Patients had a median age of 66 years (interquartile interval 57-74), 77% were men and 82% had HF with reduced ejection fraction. NT-proBNP, hs-TnT and sST2 were 1207 ng/l (487-2725), 17 ng/l (9-31) and 30 ng/ml (22-44), respectively. Patients with COPD (n = 1249, 15%) had higher NT-proBNP (P = 0.042) and hs-TnT (P < 0.001), but not sST2 (P = 0.165). Over a median 2.0-year follow-up (1.5-2.5), 1717 patients (21%) died, and 1298 (16%) died from cardiovascular causes; 2255 patients (28%) were hospitalized for HF over 1.8 years (0.9-2.1). NT-proBNP, hs-TnT and sST2 predicted the three end points regardless of COPD status. The best cut-offs from receiver-operating characteristics analysis were higher in patients with COPD than in those without. Patients with all three biomarkers higher than or equal to end-point- and COPD-status-specific cut-offs were also those with the worst prognosis. CONCLUSIONS: Among patients with HF, those with COPD have higher NT-proBNP and hs-TnT, but not sST2. All these biomarkers yield prognostic significance regardless of the COPD status.

Impact of change in iron status over time on clinical outcomes in heart failure according to ejection fraction phenotype.

AIMS: The importance of iron deficiency (ID) in heart failure with preserved ejection fraction (HFpEF) is unknown. In HF with reduced ejection fraction (HFrEF), ID is reported as an independent predictor of mortality in HF although not all published studies agree. Different definitions of ID have been assessed, and the natural history of untreated ID not established, which may explain the conflicting results. This study aimed to assess the relationship between ID and mortality in HFpEF, clarify which definition of ID correlates best with outcomes in HFrEF, and determine the prognostic importance of change in ID status over time. METHODS AND RESULTS: Analyses were conducted on data from 1563 patients participating in a prospective international cohort study comparing HFpEF with HFrEF. Plasma samples from baseline and 6 month visits were analysed for the presence of ID. Two ID definitions were evaluated: IDFerritin  = 'ferritin < 100 mcg/L or ferritin 100-300 mcg/L + transferrin saturation < 20%' and IDTsat  = 'transferrin saturation < 20%'. The risk of all-cause mortality and death/HF hospitalization associated with baseline ID (IDFerritin or IDTsat ) and change in ID status at 6 months (persistent, resolving, developing, or never present) was estimated in multivariable Cox proportional hazards models. Of 1563 patients, 1115 (71%) had HFrEF and 448 (29%) HFpEF. Prevalence of ID was similar in HFpEF and HFrEF (58%). Patients with ID were more likely to be female, diabetic, and have a higher co-morbid burden than patients without ID. ID by either definition did not confer independent risk for either all-cause mortality or death/HF hospitalization for patients with HFpEF [IDFerritin hazard ratio (HR) 0.65 (95% confidence interval 0.40-1.05), P = 0.08; IDTsat HR 1.16 (0.72-1.87), P = 0.55]. In the overall study cohort (HFrEF + HFpEF) and HFrEF subgroup, IDFerritin was inferior to IDTsat in prediction of all-cause mortality [overall cohort: HR 1.21 (0.95-1.53), P = 0.12 vs. HR 1.95 (1.52-2.51), P < 0.01; HFrEF: HR 1.12 (0.85-1.48), P = 0.43 vs. HR 1.57 (1.15-2.14), P < 0.01]. Persistence of IDTsat at 6 months was strongly associated with poor outcomes compared with never having IDTsat [HR 2.22 (1.42-3.46), P < 0.01] or having IDTsat at baseline self-resolve by 6 months [HR 1.40 (1.06-1.86), P = 0.02]. CONCLUSIONS: Iron deficiency is equally prevalent in HFpEF and HFrEF but is negatively prognostic only in HFrEF. The natural history of ID is important; persistent ID is strongly associated with mortality whereas resolution is not. IDTsat is the superior definition of ID and should inform future trials investigating the efficacy of intravenous iron replacement in patients with HFrEF.

Iron deficiency in a multi-ethnic Asian population with and without heart failure: prevalence, clinical correlates, functional significance and prognosis.

AIMS: Current heart failure (HF) guidelines highlight the importance of iron deficiency (ID) in HF. Whether HF itself or age-related comorbidities contribute to ID is uncertain, and previous data were limited to Western populations. We aimed to study the prevalence, clinical correlates, functional significance and prognosis of ID in HF patients, compared with community-based controls in a multi-ethnic Southeast Asian population. METHODS AND RESULTS: Iron status was assessed in 751 HF patients (age 62.0 ± 12.2 years, 75.5% men, 64.7% Chinese, 23.9% Malay, 10.2% Indian) and 601 controls (age 56.9 ± 10.4 years, 49.8% men, 70.9% Chinese, 21.5% Malay, 7.2% Indian). ID, defined as ferritin <100 µg/L or ferritin 100-300 µg/L and transferrin saturation (Tsat) <20%, was present in 39.3% of controls and 61.4% of HF [odds ratio (OR) 3.5, 95% confidence interval (CI) 2.5-4.9, adjusting for clinical covariates]. Independent correlates of ID in HF were Indian ethnicity (OR 2.4 vs. Chinese, 95% CI 1.2-5.0), female gender (OR 2.8, 95% CI 1.7-4.8), larger body mass index (OR 1.05/unit increase, 95% CI 1.01-1.1) and decreased left ventricular ejection fraction (OR 1.03/unit decrease, 95% CI 1.01-1.04). In a subset of 48 HF patients undergoing cardiopulmonary exercise testing, Tsat correlated with peak oxygen consumption (ρ = 0.53, P < 0.01), independent of baseline characteristics. The HF patients with Tsat <20% as well as anaemia showed the poorest event-free survival after adjusting for clinical covariates. CONCLUSIONS: ID was highly prevalent and independently related to functional capacity and outcomes in our cohort. These findings suggest a pathophysiological role of ID in HF and support its importance as a therapeutic target in Southeast Asian patients with HF.

Renal sympathetic denervation for the treatment of refractory hypertension.

Resistant hypertension poses significant health concerns. There are strong demands for new and safe therapies to control resistant hypertension while addressing its common causes, specifically poor compliance to lifelong polypharmacy, lifestyle modifications, and physician inertia. The sympathetic nervous system plays a significant pathophysiological role in hypertension. Surgical sympathectomy for blood pressure reduction is an old but extremely efficacious therapeutic concept, now abandoned with the dawn of a safer contemporary pharmacology era. Recently, clinical studies have revealed promising results for safe and sustained blood pressure reduction with percutaneous renal sympathetic denervation. This is a novel, minimally invasive, device-based therapy, specifically targeting and ablating the renal artery nerves with radiofrequency waves without permanent implantation. There are also reported additional benefits in related comorbidities, such as impaired glucose metabolism, renal impairment, left ventricular hypertrophy, heart failure, and others. This review focuses on how selective renal sympathetic denervation works, its present and potential therapeutic indications, and its future directions.

How does renal denervation lower blood pressure and when should this technique be considered for the treatment of hypertension?

Resistant hypertension poses significant health concerns. There are strong demands for new safe therapeutics to control resistant hypertension, while addressing its common causes, specifically poor compliance to lifelong polypharmacy, lifestyle modification and physician inertia. The sympathetic nervous system plays a significant pathophysiological role in hypertension. Surgical sympathectomy for blood pressure reduction is an old but extremely efficacious therapeutic concept, since abandoned, with the dawn of safer contemporary pharmacology era. Recently, clinical studies have revealed promising results for safe and sustained blood pressure reduction with percutaneous renal sympathetic denervation. This is a novel, minimally-invasive, device-based therapy, specifically targeting and ablating the renal artery nerves with radiofrequency waves, without permanent implantation. There are also reported additional benefits in related comorbidities, such as impaired glucose metabolism, renal impairment, left ventricular hypertrophy, heart failure, and others. This review will focus on how selective renal sympathetic denervation works, as well as its present and potential therapeutic indications.