A novel echocardiographic estimate of pulmonary vascular resistance employing the hydraulic analogy to Ohm's law.

Background: Assessment of pulmonary vascular resistance (PVR) is critical for accurate diagnosis and optimal pharmacotherapy in pulmonary hypertension. We aimed to test the diagnostic performance of a novel, Doppler-based method to evaluate PVR based on Ohm's law (PVRecho) using pragmatic estimates of pulmonary capillary wedge pressure (PCWP). Methods and results: Simultaneous right heart catheterization (RHC) and echocardiography was performed in a derivation cohort of 111 patients in sinus rhythm referred for PH evaluation and PVRecho independently validated in 238 patients. PVRecho was calculated using pulmonary artery mean pressure estimates (PAMPecho) obtained from peak tricuspid gradient employing a fixed right atrial pressure estimate, PCWPecho was estimated as 10 or 20 mmHg using age-related mitral E/A cut-offs and cardiac output from left ventricular outflow. In the derivation cohort, both PAMPecho and PCWPecho estimates demonstrated excellent agreement with catheterization measurements. PVRecho was highly feasible, demonstrated negligible bias and excellent agreement with PVRRHC (Bias = -0.58, SD 2.2 mmHg) and outperformed the Abbas method to identify PVRRHC > 3WU (AUC = 0.85 vs. 0.70; p = 0.02). In the validation cohort, PVRecho preserved good invasive agreement with negligible bias, displayed strong diagnostic performance (AUC = 0.84) and significant ability to distinguish isolated post-capillary from combined post- and pre-capillary pulmonary hypertension (PH) subgroups (AUC = 0.77). Conclusion: PVRecho based on Ohm's law employing pragmatic estimates of PCWPecho demonstrates excellent agreement with invasive reference standard measurements and strong diagnostic ability to identify elevated PVRRHC. This novel approach may be useful during therapy selection to distinguish PH hemodynamic subgroups.

Elevated serum gamma-glutamyltransferase levels in patients with dilated ascending aorta.

OBJECTIVE: This study aimed to evaluate the serum gamma-glutamyltransferase (GGT) levels as an indirect marker of elevated oxidative stress in patients with dilated ascending aorta. METHODS: The study was designed as an observational cross-sectional controlled study. One hundred consecutive patients with dilated ascending aorta and 50 consecutive controls with normal ascending aorta diameter were selected for the study by comprehensive transthoracic echocardiography (TTE). The aortic dilatation group was divided into two subgroups, according to the literature as the ectasia group (3.8-4.3 cm, 53 patients, 24 male and 29 female, mean age: 62.9±10.9 years) and the aneurysm group (≥4.4 cm, 47 patients, 18 male and 29 female, mean age: 65.5±11.1 years). The control group consisted of patients demonstrating no ascending aorta dilatation (≤3.7 cm, 50 patients, 24 male and 26 female, mean age: 62.7±9.2 years). ANOVA, Mann-Whitney U test, Pearson's correlation analysis, multivariate logistic regression analysis, and receiver-operator curve analysis were used for statistical analysis. RESULTS: Regarding the comparison of laboratory parameters between the patient and control groups, serum gamma-glutamyltransferase (GGT) levels were found to be statistically significantly higher in both of the aortic dilatation subgroups than in the control group (p<0.001). In the correlation analysis between the ascending aorta diameter and GGT, a statistically significant positive correlation was found (r=0.282, p<0.001). The multivariate regression analysis revealed a significant relationship between GGT and the proximal ascending aorta diameter (ß=0.131, odds ratio: 1.140, 95% CI: 1.060-1.225, p<0.001). CONCLUSION: GGT as a marker of oxidative stress may play a role in the pathogenesis of aneurysm of the ascending aorta.

Risk of cerebral embolism after interventional closure of symptomatic patent foramen ovale or atrial septal defect: a diffusion-weighted MRI and neuron-specific enolase-based study.

OBJECTIVES: The aim of this single-center prospective study is to investigate the silent and clinically apparent cerebral embolic events after transcatheter closure of atrial septal defect (ASD) and patent foramen ovale (PFO). BACKGROUND: Although transcatheter closure of ASD and PFO is a widely accepted technique and has been proven to be safe and effective with different kinds of devices, there are few studies in the literature that report the peri-interventional cerebral embolism risk and neurological complications. In this study, we investigated the peri-interventional cerebral embolism incidence with diffusion-weighted magnetic resonance imaging (DW-MRI) and its relation to patients' clinical neurologic examination findings and plasma neuron-specific enolase (NSE) levels. METHODS: Sixteen patients with hemodynamically significant ASD and 14 symptomatic PFO patients underwent transcatheter closure procedures with new-generation PFO or ASD occluder devices. All cases were examined with DW-MRI before and after the transcatheter closure procedure. Patients were clinically examined for any signs of neurologic deficit at the time of MRI studies. Blood samples for NSE, a marker of brain tissue damage involved in an ischemic event, were taken before the procedure and at 12 and 24 hours after the procedure. RESULTS: Successful transcatheter closure of PFO or ASD was achieved in all patients. In the DW-MRI exam following the procedure, a new microembolic lesion was found in only 1 of 30 patients (3.3%). None of the patients had positive clinical neurological exam findings. NSE levels after the procedure were found to be not correlated with presence of DWMRI lesion and intervention times. CONCLUSION: With the new-generation ASD and PFO occluder devices, the incidence of clinically silent peri-interventional cerebral embolic lesions after transcatheter closure of ASD and PFO is low. Plasma NSE levels offered no additional benefit for monitoring ischemic events after ASD and PFO transcatheter closure procedures.