Luis Maroto

Nitric oxide inhibits Kv4.3 and human cardiac transient outward potassium current (Ito1).

AIMS Chronic atrial fibrillation (CAF) is characterized by a shortening of the plateau phase of the action potentials (AP) and a decrease in the bioavailability of nitric oxide (NO). In this study, we analysed the effects of NO on Kv4.3 (I(Kv4.3)) and on human transient outward K(+) (I(to1)) currents as well as the signalling pathways responsible for them. We also analysed the expression of NO synthase 3 (NOS3) in patients with CAF. METHODS AND RESULTS I(Kv4.3) and I(to1) currents were recorded in Chinese hamster ovary cells and in human atrial and mouse ventricular dissociated myocytes using the whole-cell patch clamp. The expression of NOS3 was analysed by western blotting. AP were recorded using conventional microelectrode techniques in mouse atrial preparations. NO and NO donors inhibited I(Kv4.3) and human I(to1) in a concentration- and voltage-dependent manner (IC(50) for NO: 375.0 +/- 48 nM) as a consequence of the activation of adenylate cyclase and the subsequent activation of the cAMP-dependent protein kinase and the serine-threonine phosphatase 2A. The density of the I(to1) recorded in ventricular myocytes from wild-type (WT) and NOS3-deficient mice (NOS3(-/-)) was not significantly different. Furthermore, the duration of atrial AP repolarization in WT and NOS3(-/-) mice was not different. The increase in NO levels to 200 nM prolonged the plateau phase of the mouse atrial AP and lengthened the AP duration measured at 20 and 50% of repolarization of the human atrial CAF-remodelled AP as determined using a mathematical model. However, the expression of NOS3 was not modified in left atrial appendages from CAF patients. CONCLUSION Our results suggested that the increase in the atrial NO bioavailability could partially restore the duration of the plateau phase of CAF-remodelled AP by inhibiting the I(to1) as a result of the activation of non-canonical enzymatic pathways.

In-hospital and Mid-term Predictors of Mortality After Transcatheter Aortic Valve Implantation: Data From the TAVI National Registry 2010-2011 §

INTRODUCTION AND OBJECTIVES The treatment of severe symptomatic aortic stenosis has been revolutionized by the technique of transcatheter valve replacement. The purpose of this study was to present the outcomes and predictors of mortality in patients enrolled between 2010 and 2011 in the Transcatheter Aortic Valve Replacement National Registry. METHODS We collected 131 preprocedural, 31 periprocedural, and 76 follow-up variables, and analyzed the immediate implant success rate, the 30-day safety endpoint, and all-cause 30-day and mid-term (mean follow-up, 244 days) mortality. RESULTS From January 2010 to December 2011, a total of 1416 patients were included: 806 with Edwards valves and 610 with CoreValves. The implant success and 30-day mortality rates were 94% and 8%, respectively, without differences between types of valves and approaches. The 30-day safety endpoint and mid-term mortality rates were 14% and 16%, respectively, which were also similar between groups. The presence of comorbidities (renal failure, peripheral vascular disease, ejection fraction, and atrial fibrillation), the need for conversion to surgery, and at least moderate aortic regurgitation after transcatheter aortic valve implantation were identified as independent predictors of in-hospital and mid-term mortality. CONCLUSIONS The prognosis of valve implant patients could be improved by including comorbidities in patient selection and by minimizing the degree of residual aortic regurgitation to optimize the results of the procedure.

Quality of life improvement at midterm follow-up after transcatheter aortic valve implantation.

BACKGROUND Transcatheter aortic valve implantation (TAVI) techniques have been presenting good procedural success and favorable clinical outcomes. However, optimal management of aortic valve disease in elderly patients depends on quality of life (QoL) improvement. In this study we aimed to evaluate changes in QoL in patients referred for TAVI. METHODS AND RESULTS Prospective analysis of 74 consecutive patients (34 male), aged 81.6 ± 8 years with symptomatic severe aortic valve stenosis (AS) ineligible for conventional aortic valve replacement, referred to TAVI in one tertiary center. For the assessment of QoL, the Minnesota Living with Heart Failure Questionnaire (MLHFQ) was used before the procedure and at 6.5 months. The mortality was 9.5% at 30 days and 20.2% at 6.5 months follow-up. Fifty three (71.6%) patients completed MLHFQ at baseline and at follow-up. All patients showed good hemodynamic results and no signs of prosthesis dysfunction were observed on transthoracic echocardiography. The New York Heart Association (NYHA) class (2.9 ± 0.4 to 1.4 ± 0.7; p<0.001), and the MLHFQ scores [overall (37.0 ± 14.7 vs. 14.4 ± 10.1; p<0.001), physical dimension (23.2 ± 9.5 vs. 8.6 ± 5.9; p<0.001) and emotional dimension (5.4 ± 4.2 vs. 2.6 ± 3.0; p<0.001)] were significantly improved 6.5 months after TAVI. Patients with peripheral vascular disease (PVD) had an inferior improvement in QoL caused by a lower enhancement in physical dimension MLHFQ score (mean difference: -17.0 ± 10.2 vs. -10.1 ± 11.5; p=0.036). CONCLUSION TAVI significantly improves symptoms and QoL in patients with severe AS and high surgical risk. Patients with PVD might be expected to have a less impressive improvement in QoL after TAVI.

Transapical off-pump aortic valve-in-a-valve implantation in two elderly patients with a degenerated porcine bioprosthesis.

Re-operative heart-valve replacement is a high-risk procedure and even more so in elderly patients. Another option in high-risk patients with a degenerated aortic xenograft is the implant of a second aortic bioprosthesis using a transcatheter approach. We report two cases of patients with a severely degenerated porcine aortic bioprosthesis who were successfully treated by a transapical valve-in-a-valve implantation.

Hydatid cyst of the interventricular septum in a 3.5-year-old child

An asymptomatic cardiac cyst located in the interventricular septum was diagnosed in a 3.5-year-old child by echocardiographic findings. Surgical ablation was done and histopathologic analysis confirmed a hydatid cyst. The patient was discharged without symptoms.

Comparative Expression of Proteins in Left and Right Atrial Appendages From Patients With Mitral Valve Disease at Sinus Rhythm and Atrial Fibrillation

Proteomics and Atrial Appendages. Introduction: The objective was to compare by proteomics the expression of proteins associated with the cytoskeleton, energetic metabolism, and cardiac cytoprotection between left atrial appendages (LAA) and right atrial appendages (RAA) obtained from patients with mitral valve disease both in sinus rhythm (SR, n = 6) and in permanent atrial fibrillation (AF, n = 11).

Case-control study of risk factors for mediastinitis after cardiovascular surgery

We report results of a case-control study in which we evaluated 41 risk factors potentially associated with the development of postsurgical mediastinitis. There were 163 case patients and 326 control patients. Independent risk factors kept in the final multivariate logistic regression model were obesity (defined as a body mass index of greater than 30), diabetes mellitus, chronic obstructive pulmonary disease, preoperative stay longer than 1 week, pulmonary hypertension, perioperative myocardial infarction, and reoperation.

Delayed dislocation of a transapically implanted aortic bioprosthesis

Trans-apical aortic bioprosthesis implantation is currently evaluated as an alternative technique in high-risk patients. We report the case of a delayed upward displacement of a prosthesis after this procedure. It is hypothesised that the asymmetric calcification of the native valve and the presence of a mitral prosthesis caused the dislocation.

Intracardiac thrombus trapped in a patent foramen ovale.

We describe a case of impending paradoxical embolism due to a thrombus trapped in a patent foramen ovale in a 22-year-old woman. Transthoracic and transesophageal echocardiography detected the thrombus. She was operated on and discharged asymptomatic.

Supervisión con ecocardiografía 3D en tiempo real intraoperatoria de la implantación de prótesis valvular aórtica por vía transapical

La estenosis aortica degenerativa es la valvulopatia mas frecuente en Europa. En pacientes sintomaticos, la sustitucion valvular aortica por una protesis mejora su pronostico. Un elevado porcentaje de candidatos a cirugia de reemplazo valvular son desestimados por elevado riesgo de complicaciones graves. En los ultimos anos, se han desarrollado tecnicas percutaneas o quirurgicas minimamente invasivas de implantacion de protesis valvular aortica transcateter (PATC), que persiguen elevar la tasa de intervencion en pacientes de alto riesgo manteniendo los beneficios en el pronostico y disminuyendo las complicaciones. Describimos el protocolo de supervision intraoperatoria con ecocardiografia transesofagica (ETE), hallazgos morfologicos, resultados hemodinamicos y complicaciones detectadas en 21 pacientes sometidos a la implantacion de PATC por abordaje transapical. Proponemos una estandarizacion de la exploracion, en la que la ETE tridimensional en tiempo real aportaria informacion adicional en la supervision intraoperatoria de implantacion por via transapical de la PATC.