Phrenic nerve stimulation improves physical performance and hypoxemia in heart failure patients with central sleep apnea

Background: Central sleep apnea (CSA) is a common comorbidity in patients with heart failure (HF) and has been linked to increased morbidity and mortality risk. In addition, CSA is associated with impaired quality of life, reduced physical performance capacity, and hypoxemia. Phrenic nerve stimulation (PNS) is a novel approach to the treatment of CSA and has been shown to be safe and effective in this indication. However, there are currently no data on the effects of PNS on physical performance and hypoxia in CSA HF patients, both of which have been shown to be linked to mortality in HF. Methods: This prospective study enrolled patients with HF and CSA diagnosed using polysomnography. All were implanted with a PNS system (remedē® system, Respicardia Inc., Minnetonka, MN, USA) for the treatment of CSA. Examinations included polysomnography (to determine hypoxemic burden), echocardiography and a standardized 6-min walk test prior to device implantation (baseline) and after 6 months of follow-up. Results: A total of 24 patients were enrolled (mean age 67.1 $\pm$ 11.2 years, 88% male). The 6-min walk distance was 369.5 $\pm$ 163.5 m at baseline and significantly improved during follow-up (to 410 $\pm$ 169.7 m; $\it p$ = 0.035). Hypoxemic burden, determined based on time with oxygen saturation < 90% improved from 81 $\pm$ 55.8 min at baseline to 27.9 $\pm$ 42.8 min during PNS therapy ($\it p$ < 0.01). Conclusion: In addition to safely and effectively treating CSA, PNS is also associated with improved physical performance capacity and reduced hypoxemic burden in patients with HF

Infective endocarditis after isolated aortic valve replacement

$\textbf {Background and aims}$ Prosthetic valve endocarditis (PVE) is the prognostically most unfavourable complication after aortic valve replacement. This study aims to contribute to a better understanding of the different pathological and therapeutical aspects between PVE following surgical (SAVR) and transcatheter aortic valve replacement (TAVI). $\bf Methods$ All patients who had undergone primary isolated SAVR ($\it n$ = 3447) or TAVI ($\it n$ = 2269) at our Centre between 01/2012 and 12/2018 were analysed. Diagnosis of PVE was based on Duke criteria modified in 2015. Incidence, risk factors, pathogens, impact of complications or therapy on mortality were analysed and compared between SAVR- and TAVI-PVE. $\bf Results$ PVE incidence did not differ significantly after SAVR with 4.9/100 patient-years and TAVI with 2.4/100 patient-years ($\it p$ = 0.49), although TAVI patients were older (mean 80 vs. 67 years) and had more comorbidities (STS score mean 5.9 vs. 1.6) ($\it p$  0.05). Propensity-score matching analysis showed that the type of aortic valve replacement had no effect on the development of post-procedural PVE ($\it p$ = 0.997). One-year survival was higher in TAVI-PVE patients treated with antibiotics only compared to additional surgical therapy (90.9% vs. 33.3%; $\it p$ = 0.005). In SAVR-PVE patients, both therapies were comparable in terms of survival ($\it p$ = 0.861). However, SAVR-PVE patients who were not operated, despite ESC-guideline recommendation, had significantly poorer one-year survival ($\it p$ = 0.004). $\bf Conclusion$ TAVI patients did not have a significantly higher risk to develop PVE. Our data suggest that TAVI-PVE patients in contrast to SAVR-PVE patients can more often be treated with antibiotics only, presumably due to the lack of a polymeric suture ring

Non-invasive assessment of central venous pressure in heart failure

Assessing hemodynamics, especially central venous pressure (CVP), is essential in heart failure (HF). Right heart catheterization (RHC) is the gold-standard, but non-invasive methods are also needed. However, the role of 2-dimensional echocardiography (2DE) remains uncertain, and 3-dimensional echocardiography (3DE) is not always available. This study investigated standardized and breathing-corrected assessment of inferior vena cava (IVC) volume using echocardiography (2DE and 3DE) versus CVP determined invasively using RHC. Sixty consecutive HF patients were included (82% male, age 54 $\pm$ 11 years, New York Heart Association class 2.23 $\pm$ 0.8, ejection fraction 46 $\pm$ 18.4%, brain natriuretic peptide 696.93 $\pm$ 773.53 pg/mL). All patients underwent Swan-Ganz RHC followed by 2DE and 3DE, and IVC volume assessment. On 2DE, mean IVC size was 18.3 $\pm$ 5.5 mm and 13.8 $\pm$ 6 mm in the largest deflection and shortest distention, respectively. Mean CVP from RHC was 9.3 $\pm$ 5.3 mmHg. Neither 2DE nor 3DE showed acceptable correlation with invasively measured CVP; IVC volume acquisition showed optimal correlation with RHC CVP (0.64; 95% confidence interval 0.46–0.77), with better correlation when mitral valve early diastole E wave and right ventricular end-diastolic diameter were added. Using a CVP cut-point of 10 mmHg, receiver operating characteristic curve showed true positivity (specificity) of 0.90 and sensitivity of 62% for predicting CVP. A validation study confirmed these findings and verified the high predictive value of IVC volume assessment. Neither 2DE nor 3DE alone can reliably mirror CVP, but IVC volume acquisition using echocardiography allows non-invasive and adequate approximation of CVP. Correlation with invasively measured pressure was strongest when CVP is > 10 mmHg

Hemodynamic performance of two current-generation transcatheter heart valve prostheses in severely calcified aortic valve stenosis

Background: Treatment of severely calcified aortic valve stenosis is associated with a higher rate of paravalvular leakage (PVL) and permanent pacemaker implantation (PPI). We hypothesized that the self-expanding transcatheter heart valve (THV) prostheses Evolut Pro (EPro) is comparable to the balloon-expandable Sapien 3 (S3) regarding hemodynamics, PPI, and clinical outcome in these patients. Methods: From 2014 to 2019, all patients with very severe calcification of the aortic valve who received an EPro or an S3 THV were included. Propensity score matching was utilized to create two groups of 170 patients. Results: At discharge, there was significant difference in transvalvular gradients (EPro vs. S3) (dPmean 8.1 vs. 11.1 mmHg, $\it p$ $\leq$ 0.001) and indexed effective orifice area (EOAi) (1.1 vs. 0.9, $\it p$ $\leq$ 0.001), as well as predicted EOAi (1 vs. 0.9, $\it p$ $\leq$ 0.001). Moderate patient prosthesis mismatch (PPM) was significantly lower in the EPro group (17.7% vs. 38%, $\it p$ $\leq$ 0.001), as well as severe PPM (2.9% vs. 8.8%, $\it p$ = 0.03). PPI and the PVL rate as well as stroke, bleeding, vascular complication, and 30-day mortality were comparable. Conclusions: In patients with severely calcified aortic valves, both THVs performed similarly in terms of 30-day mortality, PPI rate, and PVL occurrence. However, patient prothesis mismatch was observed more often in the S3 group, which might be due to the intra-annular design