Can echocardiographically estimated pulmonary arterial elastance be a non-invasive predictor of pulmonary vascular resistance?

Role of biomarkers in evaluation, treatment and clinical studies of pulmonary arterial hypertension

Pulmonary arterial hypertension is a complex disease resulting from the interplay of myriad biological and environmental processes that lead to remodeling of the pulmonary vasculature with consequent pulmonary hypertension. Despite currently available therapies, there remains significant morbidity and mortality in this disease. There is great interest in identifying and applying biomarkers to help diagnose patients with pulmonary arterial hypertension, inform prognosis, guide therapy, and serve as surrogate endpoints. An extensive literature on potential biomarker candidates is available, but barriers to the implementation of biomarkers for clinical use in pulmonary arterial hypertension are substantial. Various omic strategies have been undertaken to identify key pathways regulated in pulmonary arterial hypertension that could serve as biomarkers including genomic, transcriptomic, proteomic, and metabolomic approaches. Other biologically relevant components such as circulating cells, microRNAs, exosomes, and cell-free DNA have recently been gaining attention. Because of the size of the datasets generated by these omic approaches and their complexity, artificial intelligence methods are being increasingly applied to decipher their meaning. There is growing interest in imaging the lung with various modalities to understand and visualize processes in the lung that lead to pulmonary vascular remodeling including high resolution computed tomography, Xenon magnetic resonance imaging, and positron emission tomography. Such imaging modalities have the potential to demonstrate disease modification resulting from therapeutic interventions. Because right ventricular function is a major determinant of prognosis, imaging of the right ventricle with echocardiography or cardiac magnetic resonance imaging plays an important role in the evaluation of patients and may also be useful in clinical studies of pulmonary arterial hypertension.

Left ventricular structural and functional changes evaluated by echocardiography and two-dimensional strain in patients with sickle cell disease

INTRODUCTION

Patients with sickle cell disease have increased left ventricular size, which is not usually accompanied by changes in systolic function indexes. We assessed echocardiographic abnormalities present in patients with sickle cell anemia (SCA) and compared echocardiographic parameters to other sickle cell diseases (OSCD).

MATERIAL AND METHODS

A blind cross-sectional study with 60 patients with SCA and 16 patients with OSCD who underwent transthoracic echocardiography was performed.

RESULTS

Echocardiographic findings were: left atrial volume index 47.7 ±11.5 ml/m² in SCA group and 31.7 ±8.42 ml/m² in OSCD group (p < 0.001); left ventricular diastolic diameter index 3.47 ±0.37 cm/m² in SCA group and 2.97 ±0.41 cm/m² in OSCD group (p < 0.001); left ventricular systolic diameter index 2.12 ±0.31 cm/m² in SCA group and 1.86 ±0.28 cm/m² in OSCD group (p < 0.001). There were no differences in the left ventricular ejection fraction: 68.2 ±6.69% in SCA group and 67.1 ±6.21% in OSCD group (p = 0.527). The ratio between mitral E wave and mean mitral annulus e' wave velocities was higher in the SCA group (7.72 ±1.54 vs. 6.70 ±1.65; p = 0.047). Mitral A wave correlated significantly with hemoglobin levels (r = -0.340; p = 0.032).

CONCLUSIONS

There was an increase of left ventricular and left atrial sizes in patients with SCA, compared to patients with OSCD, without changes in systolic or diastolic function in both groups. This could be due to the hyperkinetic state due to the more severe anemia in the SCA subjects.

The strengths and weaknesses of non-invasive parameters obtained by echocardiography and cardiopulmonary exercise testing in comparison with the hemodynamic assessment by the right heart catheterization in patients with pulmonary hypertension

PURPOSE

Pulmonary hypertension (PH) diagnosis requires invasive assessment by right heart catheterization (RHC), but screening and monitoring are performed using non-invasive methods: echocardiography and cardiopulmonary exercise testing (CPET). The aim of the study was to assess correlations between the parameters obtained in non-invasive testing and RHC in patients with PH of different etiologies.

MATERIAL/METHODS

The study included 53 medical records of PH patients (32 women) aged 29-81 years. We analyzed correlations between RHC (systolic pulmonary artery pressure (sPAP), diastolic pulmonary artery pressure (dPAP), pulmonary vascular resistance (PVR), cardiac output (CO)) and echocardiographic (tricuspid annular plane systolic excursion (TAPSE), sPAP) and CPET parameters (end-tidal oxygen and carbon dioxide pressures (PetO₂, PetCO₂), ventilation efficiency (VE/VCO₂) slope).

RESULTS

Echocardiographic estimation correlated well with RHC measurement of sPAP (r=0.65, P<0.001). TAPSE correlated with PVR assessed with thermodilution method (r=-0.5, P=0.005), dPAP (r=-0.53, P=0.002) and CO (r=0.53, P=0.002). PVR assessed with thermodilution and Fick methods showed positive correlation with PetO₂ (r=0.74, P<0.001 and r=0.72, P<0.001) and negative correlation with PetCO₂ (r=-0.59, P=0.004 and r=-0.64, P=0.002) at the anaerobic threshold. VE/VCO₂ slope correlated with dPAP (r=0.43, P=0.04) and PVR calculated with both methods (r=0.52, P=0.01 and r=0.52, P=0.02).

CONCLUSIONS

Simple cardiac function indicators obtained by commonly used non-invasive methods allow only approximate estimation of the main hemodynamic RHC-derived parameters: sPAP, CO and PVR. Obtained results suggest the relationship between RV dysfunction and ventilation abnormalities in PH patients.

Efficacy of Statin Therapy in Pulmonary Arterial Hypertension: A Systematic Review and Meta-Analysis

Since the evidence regarding statin therapy in PAH has not been conclusive, we assessed the impact of statin therapy in PAH through a systematic review and meta-analysis of available studies. We searched selected databases up to August 1, 2015 to identify the studies investigating the effect of statin administration on PAH. Meta-analysis was performed using either a fixed-effects or random-effect model according to I(2) statistic. Meta-analysis of 8 studies with 665 patients did not suggest any significant improvement in 6-min walking distance (6MWD) by statin therapy (weighed mean difference [WMD]: -6.08 m, 95% confidence interval [CI]: -25.66, 13.50, p = 0.543; Q = 8.41, I(2) = 28.64%). Likewise, none of the other indices including pulmonary arterial pressure (WMD: -0.97 mmHg, 95%CI: -4.39, 2.44, p = 0.577; Q = 14.64, I(2) = 79.51%), right atrial pressure (WMD: 1.01 mmHg, 95%CI: -0.93, 2.96, p = 0.307; Q = 44.88, I(2) = 95.54%), cardiac index (WMD: 0.05 L/min/m(2), 95%CI: -0.05, 0.15, p = 0.323; Q = 3.82, I(2) = 21.42%), and pulmonary vascular resistance (WMD: -1.42 dyn*s/cm(5), 95%CI: -72.11, 69.27, p = 0.969; Q = 0.69, I(2) = 0%) was significantly altered by statin therapy. In conclusion, the results of the meta-analysis did not show a statistically significant effect of statin therapy in the improvement of 6MWD, pulmonary arterial pressure, right atrial pressure, cardiac index and pulmonary vascular resistance.

Ear lobe crease: a marker of coronary artery disease?

The ear lobe crease (ELC) has been defined as a deep wrinkle that extends backwards from the tragus to the auricle. It has been proposed that ELC is a predictor of coronary artery disease (CAD). In this review, we consider the possible association between ELC and CAD. Our aim is to systematically address all the relevant evidence in this field. There are many studies that support an association between ELC and CAD. However, other studies did not find such an association. A recent meta-analysis supports the hypothesis that ELC could be a marker of CAD. However, several limitations raise doubts as to whether we should accept this link.