Exertional Cardiac and Pulmonary Vascular Hemodynamics in Patients With Heart Failure With Reduced Ejection Fraction

Left atrial shunting devices: why, what, how, and… when?

Left atrial (LA) hypertension is central in the pathophysiology of heart failure (HF) in general and of HF with preserved ejection fraction (HFpEF) in particular. Despite approved treatments, a number of HF patients continue experiencing disabling symptoms due to LA hypertension, causing pulmonary congestion, pulmonary hypertension, and right heart dysfunction, at rest and/or during exercise. LA decompression therapies, i.e., left atrial shunting through a specifically designed device (either implant-based or implant-free), are being studied in various forms of HF to alleviate LA hypertension and patients' symptoms. Despite a solid background and favorable signals from initial non-randomized clinical trials, the quest for the optimal HF candidate for interatrial shunt devices is still an area of active research that at the same time is helping to better elucidate the intricate pathophysiology of HF(pEF).

Determinants of cardiac output in health and heart failure

Sustained physical exercise depends on delivery of oxygenated blood to exercising muscle. At least among healthy individuals, bulk transport of blood is tightly matched to metabolic demand, such that cardiac output increases by ∼6 L/min for every 1 L/min increase in oxygen uptake. Multiple factors contribute to the regulation of cardiac output, including central command, the exercise pressor reflex (EPR) and arterial baroreceptors. Pulmonary arterial and left ventricular pressures increase in proportion to the rise in cardiac output and exercise intensity. The right ventricle augments contractility to maintain ventricular-arterial (VA) coupling and lusitropy to facilitate venous return. Among patients with heart failure (HF), however, the ability to deliver blood to exercising muscle is compromised as a result of multiple abnormalities impacting EPR, ventricular contractility, haemodynamics and VA coupling. The purpose of this review is to provide an overview of the factors limiting exercise capacity and cardiac output among patients with HF compared to what is known about normal physiology among healthy individuals.

The relation between socioeconomic status and invasive haemodynamics at evaluation for advanced heart failure

AIMS

Socioeconomic deprivation is a risk marker for worse prognosis in patients with heart failure (HF), and a potential barrier to referral for advanced HF evaluation. The relationship between socioeconomic status (SES) and invasive haemodynamics in patients undergoing evaluation for advanced HF therapies is unknown.

METHODS

We combined a consecutive clinical registry of patients evaluated for advanced HF with patient-level data on SES (household income, education, workforce status, cohabitant status and distance from home to tertiary HF centre) derived from nationwide registries. Using this information, the cohort was divided into groups of low-, medium- and high degree of socioeconomic deprivation. The associations between SES and invasive haemodynamics were explored with multiple linear regression adjusted for age and sex.

RESULTS

A total of 631 patients were included. The median age was 53 years, and 23% were women. Patients in the highest income quartile versus the lowest (Q4 vs. Q1) were older (median age 57 vs. 50 years) and more often male (83% vs. 67%), both P < 0.001. Increasing household income (per 100 000 Danish kroner,1 EUR = 7.4 DKK) was associated with lower pulmonary capillary wedge pressure (PCWP) [-0.18 mmHg, 95% confidence interval (CI) -0.36 to -0.01, P = 0.036] but not significantly associated with central venous pressure (CVP) (-0.07 mmHg, 95% CI -0.21 to 0.06, P = 0.27), cardiac index (-0.004 L/min/m2, 95% CI -0.02 to 0.01, P = 0.60), or pulmonary vascular resistance (PVR) (-0.003 Wood units, 95% CI -0.37 to 0.16, P = 0.84). Comparing the most deprived with the least deprived group, adjusted mean PVR was higher (0.35 Wood units, 95% CI 0.02 to 0.68, P = 0.04), but PCWP (0.66 mmHg, 95% CI -1.49 to 2.82, P = 0.55), CVP (-0.26 mmHg, 95% CI -1.76 to 1.24, P = 0.73) and cardiac index (-0.03 L/min/m2, 95% CI -0.22 to 0.17, P = 0.78) were similar.

CONCLUSIONS

Most haemodynamic measurements were similar across layers of SES. Nevertheless, there were some indications of worse haemodynamics in patients with lower household income or a high accumulated burden of socioeconomic deprivation. Particular attention may be warranted in socioeconomically deprived patients to ensure timely referral for advanced HF evaluation.

Influence of socioeconomic status on rates of advanced heart failure therapies

BACKGROUND

Socioeconomic deprivation is associated with a lower likelihood of referral for advanced heart failure (HF) evaluation, but it is not known whether it influences rates of advanced HF therapies independently of key hemodynamic measures and comorbidity following advanced HF evaluation in a universal healthcare system.

METHODS

We linked data from a single-center Danish clinical registry of consecutive patients evaluated for advanced HF with patient-level information on socioeconomic status. Patients were divided into groups based on the level of education (low, medium, and high), combined degree of socioeconomic deprivation (low, medium, and high), and household income quartiles. Rates of the combined outcome of left ventricular assist device implantation or heart transplantation (advanced HF therapy) with death as a competing risk were estimated with cumulative incidence functions, and Cox proportional hazards models adjusted for age, sex, central venous pressure, cardiac index, and comorbidities.

RESULTS

We included 629 patients, median age 53 years, of whom 77% were men. During a median follow-up of 5 years, 179 (28%) underwent advanced HF therapy. The highest level of education was associated with higher rates (high vs low, adjusted HR 1.81 95% CI 1.14-2.89, p = 0.01), whereas household income quartile groups (Q4 vs Q1, adjusted HR 1.37 95% CI 0.76-2.47, p = 0.30) or groups of combined socioeconomic deprivation (high vs low degree of deprivation, adjusted HR 0.86 95% CI 0.50-1.46, p = 0.56) were not significantly associated with rates of advanced HF therapy.

CONCLUSIONS

Patients with a lower level of education might be disfavored for advanced HF therapies and could require specific attention in the advanced HF care center.