Hemodynamic and Functional Impact of Epicardial Adipose Tissue in Heart Failure With Preserved Ejection Fraction

Current Limitations of Invasive Exercise Hemodynamics for the Diagnosis of Heart Failure With Preserved Ejection Fraction

BACKGROUND

Exercise hemodynamics can differentiate heart failure with preserved ejection fraction (HFpEF) from noncardiac dyspnea. However, respiratory pressure swings may impact hemodynamic measurements, potentially leading to misdiagnosis of HFpEF. Moreover, threshold values for abnormal hemodynamic response indicative of HFpEF are not universally accepted. Thus, we sought to evaluate the impact of respiratory pressure swings on hemodynamic data interpretation as well as the concordance among 3 proposed exercise hemodynamic criteria for HFpEF: (1) end-expiratory pulmonary artery wedge pressure (PAWP_exp) ≥25 mm Hg; (2) PAWP_exp/cardiac output slope >2 mm Hg/L per minute; and (3) respiratory-averaged (avg) mean pulmonary artery pressure >30 mm Hg, total pulmonary resistance_avg >3 WU, PAWP_avg ≥20 mm Hg.

METHODS

Fifty-seven patients with unexplained dyspnea (70% women, 70±9 years) underwent exercise cardiac catheterization. The difference between end-expiratory and averaged hemodynamic values, as well as the concordance among the 3 hemodynamic definitions of HFpEF, were assessed.

RESULTS

End-expiratory hemodynamics measurements were higher than values averaged across the respiratory cycle. During exercise, a larger proportion of patients exceeded the threshold of 25 mm Hg for PAWP_exp rather than for PAWP_avg (70% versus 53%, P<0.01). The concordance of 3/3 HFpEF exercise hemodynamic criteria was recorded in 70% of patients. PAWP_exp/cardiac output slope identified HFpEF more frequently than the other 2 criteria (81% versus 64% to 69%), incorporating over 97% of abnormal responses to the latter. Patients with 3/3 positive criteria had worse clinical, gas-exchange, and hemodynamic profiles.

CONCLUSIONS

Respiratory pressure swings impact on the exercise hemodynamic definitions of HFpEF that provide discordant results in 30% of patients. Equivocal diagnoses of HFpEF might be limited by adopting the most sensitive and inclusive criterion alone (ie, PAWP_exp/cardiac output slope).

Current gaps in HFpEF trials: Time to reconsider patients' selection and to target phenotypes

Heart Failure with preserved Ejection Fraction (HFpEF) is an increasingly prevalent clinical condition associated with cardiovascular aging, characterized by different pathophysiological mechanisms and poor outcomes. In this manuscript, we analysed the main differences in terms of updated diagnostic criteria and patients' selection in the most recent HFpEF trials. Recent algorithm purposed for HFpEF diagnosis, does not reflect common criteria adopted in clinical trials. Patients included in the larger studies experienced different characteristics in terms of clinical presentation and echocardiographic features. Current concerns complicate results interpretation and could hypothesize different stages of disease progression, rather than different cardiac phenotypes. Both the lack of diagnostic standardization and the population heterogeneity, might explain why trials investigating the effects of different therapeutic interventions failed to show improved outcomes for patients with HFpEF. Accordingly, we propose to exceed current view mainly based on the morphological adaptations evaluating patients' characterisation, their cardiovascular risk, associated diseases, and structural features consistent with disease progression. Detailed clinical, imaging and biological characterisation of this population, along with the identification of mechanisms linked with disease progression and prognosis, would allow for tailored treatments and provide important mechanistic insights into the complex HFpEF pathophysiology.

Association of pericardial adipose tissue with left ventricular structure and function: a region-specific effect?

BACKGROUND

The independent role of pericardial adipose tissue (PAT) as an ectopic fat associated with cardiovascular disease (CVD) remains controversial. This study aimed to determine whether PAT is associated with left ventricular (LV) structure and function independent of other markers of general obesity.

METHODS

We studied 2471 participants (50.9 % women) without known CVD from the Korean Genome Epidemiology Study, who underwent 2D-echocardiography with tissue Doppler imaging (TDI) and computed tomography measurement for PAT.

RESULTS

Study participants with more PAT were more likely to be men and had higher cardiometabolic indices, including blood pressure, glucose, and cholesterol levels (all P < 0.001). Greater pericardial fat levels across quartiles of PAT were associated with increased LV mass index and left atrial volume index (all P < 0.001) and decreased systolic (P = 0.015) and early diastolic (P < 0.001) TDI velocities, except for LV ejection fraction. These associations remained after a multivariable-adjusted model for traditional CV risk factors and persisted even after additional adjustment for general adiposity measures, such as waist circumference and body mass index. PAT was also the only obesity index independently associated with systolic TDI velocity (P < 0.001).

CONCLUSIONS

PAT was associated with subclinical LV structural and functional deterioration, and these associations were independent of and stronger than with general and abdominal obesity measures.

Sustained Improvement in Diastolic Reserve Following Percutaneous Pericardiotomy in a Porcine Model of Heart Failure With Preserved Ejection Fraction

BACKGROUND

Heart failure with preserved ejection fraction is increasing in prevalence, but few effective treatments are available. Elevated left ventricular (LV) diastolic filling pressures represent a key therapeutic target. Pericardial restraint contributes to elevated LV end-diastolic pressure, and acute studies have shown that pericardiotomy attenuates the rise in LV end-diastolic pressure with volume loading. However, whether these acute effects are sustained chronically remains unknown.

METHODS

Minimally invasive pericardiotomy was performed percutaneously using a novel device in a porcine model of heart failure with preserved ejection fraction. Hemodynamics were assessed at baseline and following volume loading with pericardium intact, acutely following pericardiotomy, and then again chronically after 4 weeks. Cardiac structure was assessed by magnetic resonance imaging.

RESULTS

The increase in LV end-diastolic pressure with volume loading was mitigated by 41% (95% CI, 27%-45%, P<0.0001; ΔLV end-diastolic pressure reduced from +9±3 mm Hg to +5±3 mm Hg, P=0.0003, 95% CI, -2.2 to -5.5). The effect was sustained at 4 weeks (+5±2 mm Hg, P=0.28 versus acute). There was no statistically significant effect of pericardiotomy on ventricular remodeling compared with age-matched controls. None of the animals developed hemodynamic or pathological indicators of pericardial constriction or frank systolic dysfunction.

CONCLUSIONS

The acute hemodynamic benefits of pericardiotomy are sustained for at least 4 weeks in a swine model of heart failure with preserved ejection fraction, without excessive chamber remodeling, pericarditis, or clinically significant systolic dysfunction. These data support trials evaluating minimally invasive pericardiotomy as a novel treatment for heart failure with preserved ejection fraction in humans.