Prognostic impact of elevated fatty acid-binding protein 1 in patients with heart failure

Adiposity and clinical outcomes in East Asian patients with heart failure and preserved ejection fraction

Background

Despite the obesity paradox, visceral adiposity is associated with poor clinical outcomes in patients with heart failure with preserved ejection fraction (HFpEF). However, it remains unclear whether a relationship between visceral fat and clinical outcomes exists in Asian patients with HFpEF, in whom obesity is rare.

Methods

Visceral and subcutaneous adipose tissue (VAT and SAT) volume and area were measured using computed tomography (CT) in 196 HFpEF patients. The primary endpoint was a composite of all-cause mortality or HF hospitalization.

Results

Participants had a normal body mass index (BMI) (22.5 ± 4.4 kg/m²), and obesity (BMI > 30 kg/m²) was rare (4.6 %). The primary outcome was observed in 64 patients during a median follow-up of 11.6 months. Lower VAT and SAT volumes were associated with underweight and malnutrition. Composite outcomes increased as body weight, BMI, and height-indexed SAT volume and area decreased. Lower height-indexed VAT volume and area were also associated with the outcomes. The height-indexed SAT area provided independent and incremental prognostic value over age, BMI, blood pressure, and creatinine and albumin levels.

Conclusions

In lean East Asian patients with HFpEF, a lower VAT volume was associated with poorer clinical outcomes. CT-based assessments of adiposity may provide incremental prognostic value over simple anthropometric indices in lean HFpEF patients.

Right atrial pressure represents cumulative cardiac burden in heart failure with preserved ejection fraction

AIMS

Right-sided filling pressure is elevated in some patients with heart failure (HF) and preserved ejection fraction (HFpEF). We hypothesized that right atrial pressure (RAP) would represent the cumulative burden of abnormalities in the left heart, pulmonary vasculature, and the right heart.

METHODS AND RESULTS

Echocardiography was performed in 399 patients with HFpEF. RAP was estimated from inferior vena cava morphology and its respiratory change [estimated right atrial pressure (eRAP)], and patients were divided according to eRAP (3 or ≥8 mmHg). Patients with higher eRAP displayed more severe abnormalities in LV diastolic function as well as right heart structure and function than those with normal eRAP. Cardiac deaths or HF hospitalization occurred in 84 patients over a median follow-up of 19.0 months (interquartile range 6.7-36.9). The presence of higher eRAP was independently associated with an increased risk of the composite outcome (adjusted hazard ratio 2.20 vs. normal eRAP group, 95% confidence interval 1.34-3.62, P = 0.002). Kaplan-Meier curves separating the patients into four groups based on eRAP and E/e' ratio showed that event-free survival varied among the groups, providing an incremental prognostic value of eRAP over E/e' ratio. The classification and regression tree analysis demonstrated that eRAP was the strongest predictor of the outcome followed by right ventricular dimension, E/e' ratio, and estimated right ventricular systolic pressure, stratifying the patients into four risk groups (incident rate 8.8-72.2%).

CONCLUSIONS

These data may provide new insights into the prognostic role of RAP in the complex pathophysiology of HFpEF and suggest the utility of eRAP for the risk stratification in patients with HFpEF.

Cardiac Power Output Is Independently and Incrementally Associated With Adverse Outcomes in Heart Failure With Preserved Ejection Fraction

BACKGROUND

Cardiac power output is a measure of cardiac performance, and its prognostic significance has been shown in heart failure (HF) with reduced ejection fraction. Patients with HF with preserved ejection fraction may have altered cardiac performance, but the prognostic relevance of cardiac power output is unknown. This study sought to determine the association between cardiac power output and clinical outcomes in HF with preserved ejection fraction and to compare its prognostic effect to other measures of cardiac performance including ventricular-arterial coupling and mechanical efficiency.

METHODS

Cardiac power output normalized to left ventricular mass was assessed by echocardiography in 408 patients with HF with preserved ejection fraction. Load-independent contractility (end-systolic elastance), arterial elastance, its coupling (arterial elastance/end-systolic elastance), left ventricular global longitudinal strain, and mechanical efficiency (stroke work/pressure-volume area) were also estimated noninvasively. The primary end point was a composite of cardiovascular mortality or HF hospitalization.

RESULTS

The primary composite outcome occurred in 84 patients during a median follow-up of 19.4 months. There was a dose-dependent association between cardiac power output and the composite outcomes, in which patients with the lowest tertile of cardiac power output had >3-fold risk than those with the highest tertile (hazard ratio, 3.04 [95% CI, 1.66-5.57]; P=0.0003). In a multivariable model, lower cardiac power output was independently associated with adverse outcomes (hazard ratio, 0.70 per 1 SD [95% CI, 0.49-0.97]; P=0.03). In contrast, left ventricular size, end-systolic elastance, arterial elastance, arterial elastance/end-systolic elastance ratio, and left ventricular mechanical efficiency were not associated with outcomes. Cardiac power output provided an incremental prognostic effect over the model based on clinical (age, gender, diastolic blood pressure, and atrial fibrillation) and echocardiographic markers (left atrial size, pulmonary pressures, global longitudinal strain, and the ratio of early diastolic mitral inflow velocity to early diastolic mitral annular tissue velocity; P=0.03).

CONCLUSIONS

In patients with HF with preserved ejection fraction, cardiac power output was independently and incrementally associated with adverse outcomes whereas other markers of cardiac performance were not.

Pathophysiological and diagnostic importance of fatty acid-binding protein 1 in heart failure with preserved ejection fraction

Elevated intracardiac pressure at rest and/or exercise is a fundamental abnormality in heart failure with preserved ejection fraction (HFpEF). Fatty acid-binding protein 1 (FABP1) is proposed to be a sensitive biomarker for liver injury. We sought to determine whether FABP1 at rest would be elevated in HFpEF and would correlate with echocardiographic markers of intracardiac pressures at rest and during exercise. In this prospective study, subjects with HFpEF (n = 22) and control subjects without HF (n = 23) underwent resting FABP1 measurements and supine bicycle exercise echocardiography. Although levels of conventional hepatic enzymes were similar between groups, FABP1 levels were elevated in HFpEF compared to controls (45 [25–68] vs. 18 [14–24] ng/mL, p = 0.0008). FABP1 levels were correlated with radiographic and blood-based markers of congestion, hemodynamic derangements during peak exercise (E/e’, r = 0.50; right atrial pressure, r = 0.35; pulmonary artery systolic pressure, r = 0.46), reduced exercise cardiac output (r = − 0.49), and poor exercise workload achieved (r = − 0.40, all p < 0.05). FABP1 distinguished HFpEF from controls with an area under the curve of 0.79 (p = 0.003) and had an incremental diagnostic value over the H₂FPEF score (p = 0.007). In conclusion, FABP1 could be a novel hepatic biomarker that associates with hemodynamic derangements, reduced cardiac output, and poor exercise capacity in HFpEF.

Prognostic impact of elevated fatty acid-binding protein 1 in patients with heart failure

Aims

Few biomarkers to evaluate pathophysiological changes in extra‐cardiac tissues have been identified in patients with heart failure (HF). Fatty acid‐binding protein 1 (FABP), also known as liver FABP, is predominantly expressed in the liver. Circulating FABP1 has been proposed to be a sensitive biomarker for liver injury. However, little is known about the potential role of FABP1 as a biomarker for HF.

Methods and results

Measurements of serum FABP1 and echocardiography were performed in subjects with compensated HF (n = 162) and control subjects without HF (n = 20). Patients were prospectively followed‐up for a composite outcome of all‐cause mortality or HF hospitalization. Compared with control subjects, levels of FABP1 were elevated in HF patients [7.9 (6.4–11.7) vs. 17.6 (10.4–28.9) ng/mL, P < 0.0001]. There were significant correlations between FABP1 levels and estimated right ventricular systolic pressure and right atrial pressure. During a median follow‐up of 12.0 months, there were 55 primary composite endpoints in the HF cohort. The highest FABP1 tertile was associated with a three‐fold increased risk of the composite outcome compared with the lowest tertile [95% confidence interval (1.46–6.68), P = 0.003], but other conventional hepatobiliary markers did not predict the outcome. After adjusting for age, sex, atrial fibrillation, and N‐terminal pro‐B‐type natriuretic peptide levels, serum FABP1 remained independently associated with the outcome. Adding FABP1 to the model based on clinical factors and N‐terminal pro‐B‐type natriuretic peptide significantly improved the prognostic value (global χ² 20.8 vs. 15.5, P = 0.01).

Conclusion

Serum FABP1 levels are elevated in compensated HF patients, and the magnitude of elevation is independently associated with pulmonary hypertension, right atrial hypertension, and worse clinical outcomes. FABP1 may serve as a new potential biomarker for the assessment of hitherto unrecognized derangement of cardio‐hepatic interaction in HF.