Exhaled Breath Analysis Using Selected Ion Flow Tube Mass Spectrometry and Disease Severity in Heart Failure

Exhaled breath volatile organic compounds (VOCs) are elevated in heart failure (HF). The ability of VOCs to predict long term cardiovascular mortality and morbidity has not been independently verified. In 55 patients admitted with acute decompensated heart failure (ADHF), we measured exhaled breath acetone and pentane levels upon admission and after 48 h of diuresis. In a separate cohort of 51 cardiac patients undergoing cardiopulmonary exercise testing (CPET), we measured exhaled breath acetone and pentane levels before and at peak exercise. In the ADHF cohort, admission acetone levels correlated with lower left ventricular ejection fraction (LVEF, r = -0.297, p = 0.035). Greater weight loss with diuretic therapy correlated with a greater reduction in both acetone levels (r = -0.398, p = 0.003) and pentane levels (r = -0.309, p = 0.021). In patients with above-median weight loss (≥4.5 kg), patients demonstrated significantly greater percentage reduction in acetone (59% reduction vs. 7% increase, p < 0.001) and pentane (23% reduction vs. 2% reduction, p = 0.008). In the CPET cohort, admission acetone and pentane levels correlated with higher VE/VCO2 (r = 0.39, p = 0.005), (r = 0.035, p = 0.014). However, there were no significant correlations between baseline or peak exercise acetone and pentane levels and peak VO2. In longitudinal follow-up with a median duration of 33 months, patients with elevated exhaled acetone and pentane levels experienced higher composite adverse events of death, ventricular assist device implantation, or orthotopic heart transplantation. In patients admitted with ADHF, higher exhaled breath acetone levels are associated with lower LVEF and poorer outcomes, and greater reductions in exhaled breath acetone and pentane tracked with greater weight loss. Exhaled acetone and pentane may be novel biomarkers in heart failure worthy of future investigation.

Heart Failure With Midrange Ejection Fraction: Prior Left Ventricular Ejection Fraction and Prognosis

Aims: Evidence-based guidelines for heart failure management depend mainly on current left ventricular ejection fraction (LVEF). However, fewer studies have examined the impact of prior LVEF. Patients may enter the heart failure with midrange ejection fraction (HFmrEF) category when heart failure with preserved ejection fraction (HFpEF) deteriorates or heart failure with reduced ejection fraction (HFrEF) improves. In this study, we examined the association between change in LVEF and adverse outcomes.

Methods: HFmrEF patients with at least two or more echocardiograms 3 months apart at the First Affiliated Hospital of Dalian Medical University between September 1, 2015 and November 30, 2019 were identified. According to the prior LVEF, the subjects were divided into improved group (prior LVEF < 40%), stable group (prior LVEF between 40 and 50%), and deteriorated group (prior LVEF ≥ 50%). The primary outcomes were cardiovascular death, all-cause mortality, hospitalization for worsening heart failure, and composite event of all-cause mortality or all-cause hospitalization.

Results: A total of 1,168 HFmrEF patients (67.04% male, mean age 63.60 ± 12.18 years) were included. The percentages of improved, stable, and deteriorated group were 310 (26.54%), 334 (28.60%), and 524 (44.86%), respectively. After a period of follow-up, 208 patients (17.81%) died and 500 patients met the composite endpoint. The rates of all-cause mortality were 35 (11.29%), 55 (16.47%), and 118 (22.52%), and the composite outcome was 102 (32.90%), 145 (43.41%), and 253 (48.28%) for the improved, stable, and deteriorated groups, respectively. Cox regression analysis showed that the deterioration group had higher risk of cardiovascular death (HR: 1.707, 95% CI: 1.064–2.739, P = 0.027), all-cause death (HR 1.948, 95% CI 1.335–2.840, P = 0.001), and composite outcome (HR 1.379, 95% CI 1.096–1.736, P = 0.006) compared to the improvement group. The association still remained significant after fully adjusted for both all-cause mortality (HR = 1.899, 95% CI 1.247–2.893, P = 0.003) and composite outcome (HR: 1.324, 95% CI: 1.020–1.718, P = 0.035).

Conclusion: HFmrEF patients are heterogeneous with three different subsets identified, each with different outcomes. Strategies for managing HFmrEF should include previously measured LVEF to allow stratification based on direction changes in LVEF to better optimize treatment.

Recovered Left Ventricular Ejection Fraction and Its Prognostic Impacts in Hospitalized Heart Failure Patients with Reduced Ejection Fraction

It has been recently recognized that recovery of left ventricular ejection fraction (EF), termed "recovered EF", occurs in a proportion of heart failure patients with reduced EF (HFrEF), and is associated with better prognosis. However, the clinical characteristics of "recovered EF" have not been fully examined.Consecutive 567 patients hospitalized due to HFrEF (EF < 40% at 1st assessment at hospital discharge) were enrolled, and EF was re-assessed within half a year in an outpatient setting (2nd assessment). Among these HFrEF patients, 235 remained EF < 40% (reduced, rEF group), 82 changed to EF 40-49% (midrange, mrEF group), and 250 recovered to EF > 50% (preserved, pEF group "recovered EF" ) at the 2nd examination. Age was lower and body mass index and systolic blood pressure were higher in pEF than in rEF. The prevalence of atrial fibrillation (AF) and usage of an implantable cardiac defibrillator and cardiac resynchronization therapy were highest in pEF. Left ventricular end diastolic dimension (LVDd) was the smallest in the pEF group. Multivariable logistic regression analysis revealed that younger age, presence of AF, and lower levels of LVDd were predictors of "recovered EF". Kaplan-Meier analysis found that pEF presented the lowest cardiac event rate (P = 0.003) and all-cause mortality (P = 0.001). In multivariable Cox proportional hazard analyses, pEF (versus rEF) was an independent predictor of both cardiac event rate (HR = 0.668, 95%CI 0.450-0.994, P = 0.046) and all-cause mortality (HR = 0.655, 95%CI 0.459-0.934, P = 0.019).Hospitalized HFrEF patients with recovered EF are associated with younger age, higher presence of AF, and better prognosis.

Prognostic Impact of Restless Legs Syndrome on Patients with Heart Failure

The restless legs syndrome (RLS) is a neurological disorder characterized by an irresistible urge to move the legs or arms for relief of uncomfortable or unpleasant sensations. Prevalence and prognostic impact of RLS on patients with heart failure (HF) remain unclear. We aimed to investigate the clinical characteristics and prognostic impact of RLS on HF patients.Consecutive 338 HF patients were evaluated for RLS and divided into two groups on the basis of presence of RLS: HF patients with RLS (RLS group, n = 29) and HF patients without RLS (non-RLS group, n = 309). We compared clinical characteristics, parameters of laboratory data and echocardiography, and rate of follow-up cardiac events including worsening HF and cardiac death between the two groups. Compared with the non-RLS group, the RLS group had higher prevalence of anemia (65.5% versus 40.8%, P = 0.010), higher usage of inotropic agents (31.0% versus 15.2%, P = 0.028), higher levels of B-type natriuretic peptide (570.8 versus 215.8 pg/mL, P = 0.018), and lower levels of left ventricular ejection fraction (40.4% versus 48.4%, P = 0.019). By contrast, age, gender, prevalence of other co-morbidities and medications were comparable between the groups. In the Kaplan-Meier analysis, the cardiac event rate was significantly higher in the RLS group than in the non-RLS group (log-rank P = 0.034). In the Cox proportional hazard analysis, RLS was a predictor for cardiac events in HF patients (hazard ratio: 1.783, 95% confidence interval: 1.038-3.063).RLS is associated with adverse prognosis in HF patients.

The effects of the ketone body β-hydroxybutyrate on isolated rat ventricular myocyte excitation-contraction coupling

β-hydroxybutyrate is the primary ketone body produced by the body during ketosis and is used to meet its metabolic demands. The healthy adult heart derives most of its energy from fatty acid oxidation. However, in certain diseases, the heart alters its substrate preference and increases its ketone body metabolism. Little is known about the effects of βOHB on ventricular myocyte excitation-contraction coupling. Therefore, we examined the effects of ketone body metabolism on single cell excitation-contraction coupling during normoxic and hypoxic conditions. Myocytes were isolated from adult rats, cultured for 18 h in RPMI 1640, RPMI 1640 no glucose, and M199, HEPES with/without various amount of βOHB added. To simulate hypoxia, myocytes were incubated at 1%O₂, 5% CO₂ for 1 h followed by incubation at atmospheric oxygen (21%O₂,5% CO₂) for 30 min before recordings. Recordings were obtained using an IonOptix system at 36±1ᵒ C. Myocytes were paced at 0.5, 1, 2, 3, and 4 Hz. We found that exposure to βOHB had no effect on excitation-contraction coupling. However, culturing cells with βOHB results in a significant increase in both contraction and calcium in RPMI 1640 media. Dose response experiments demonstrated 0.5 mM βOHB is enough to increase myocyte contraction in the absence of glucose. However, βOHB has no measurable effects on myocytes cultured in a nutrient rich media, M199, HEPES. Therefore, βOHB improves single cell excitation-contraction coupling, is protective against hypoxia, and may be a beneficial adaptation for the heart during periods of nutrient scarcity and or metabolic dysregulation.

Change of Exhaled Acetone Concentration Levels in Patients with Acute Decompensated Heart Failure

Exhaled acetone concentration is one of the expected compounds to be a breath biomarker in heart failure. However, it has not been clarified how exhaled acetone concentration changes in clinical course of heart failure.To investigate whether exhaled acetone concentration changes after treatment in acute decompensated heart failure (ADHF).This study included 19 patients with ADHF (ADHF group) and eight patients with stable heart failure (control group). Exhaled acetone was collected from these patients, and the concentration was measured with gas chromatography.The ADHF group had higher heart rates (P = 0.046), higher New York Heart Association class (P < 0.001), higher levels of brain natriuretic peptide (P = 0.026), blood total ketone bodies (P = 0.015), and exhaled acetone concentration (P < 0.001), compared with the control group. In ADHF group, exhaled acetone concentration significantly decreased after treatment (median: 2.40 versus 0.92 ppm, P < 0.001). However, in the control group, exhaled acetone concentration did not significantly change (median: 0.73 versus 0.49 ppm, P = 0.141).In these preliminary findings, exhaled acetone concentration in patients with ADHF drastically decreased by treatment. Serial exhaled acetone measurement might be useful to evaluate the course of ADHF.