Midterm outcomes after transcatheter aortic valve implantation.

OBJECTIVE: Transcatheter aortic valve implantation (TAVI) has become a therapeutic option for high-risk or nonoperable patients with severe symptomatic aortic valve stenosis. The best known and most frequently implanted prostheses are the CoreValve and SAPIEN prostheses. We report our experiences and analyze the results of our TAVI program. METHODS: A total of 357 patients underwent transfemoral (TF) and transapical (TA) TAVI in our center between January 2008 and October 2012. The procedure was performed in 190 patients with CoreValve, in 155 patients with SAPIEN, and in 12 patients with ACURATE TA prostheses. Transfemoral access was used in 190 patients. In 167 patients, TA access was used. The mean age was 80.2 ± 6.4 years. All patients were nonoperable or had a high risk for a conventional aortic valve replacement. The mean logistic EuroSCORE I was 25.92 ± 14.51%. The TF/CoreValve (190 patients) and TA/SAPIEN (155 patients) groups showed significant difference in the patients' mean age (81.7 ± 6.3 years vs. 79.5 ± 6.6 years, P = 0.002) and in mean logistic EuroSCORE I (22.16 ± 13.05% vs. 31.04 ± 16.40, P < 0.001). RESULTS: The overall 30-day mortality (357 patients) was 9.80% (TF, 8.42%; TA, 11.37%); overall 1-year mortality (275 patients), 21.45% (TF, 23.74%; TA, 19.12%); overall 2-year mortality (199 patients), 29.15% (TF, 35.96%; TA, 23.64%); overall 3-year mortality (133 patients), 37.59% (TF, 43.86%; TA, 32.89%); and overall 4-year mortality (38 patients), 39.47% (TF, 45%; TA, 33.33%). The rate of pacemaker implantation after TAVI was significantly higher in the CoreValve group than in the SAPIEN group: 44.74% (85/190 patients) versus 6.45% (10/155 patients), P < 0.001. Stroke rate was higher in the TF-CoreValve group than in the TA-SAPIEN group: 4.21% versus 0.64%, P = 0.045. CONCLUSIONS: Outcomes after TAVI were, in our population of nonoperable and high-risk patients, encouraging. The differences in midterm outcomes between the TF-CoreValve TAVI and the TA-SAPIEN TAVI were not significant.

Oxygenated shunting from right to left: a feasibility study of minimized atrio-atrial extracorporeal membrane oxygenation for mid-term lung assistance in an acute ovine model.

OBJECTIVES: Right ventricular failure is often the final phase in acute and chronic respiratory failure. We combined right ventricular unloading with extracorporeal oxygenation in a new atrio-atrial extracorporeal membrane oxygenation (ECMO). METHODS: Eleven sheep (65 kg) were cannulated by a 28-Fr inflow cannula to the right atrium and a 25-Fr outflow cannula through the lateral left atrial wall. Both were connected by a serial combination of a microaxial pump (Impella Elect(®), Abiomed Europe, Aachen, Germany) and a membrane oxygenator (Novalung(®)-iLA membrane oxygenator; Novalung GmbH, Hechingen, Germany). In four animals, three subsequent states were evaluated: normal circulation, apneic hypoxia and increased right atrial after load by pulmonary banding. We focused on haemodynamic stability and gas exchange. RESULTS: All animals reached the end of the study protocol. In the apnoea phase, the decrease in PaO2 (21.4 ± 3.6 mmHg) immediately recovered (179.1 ± 134.8 mmHg) on-device in continuous apnoea. Right heart failure by excessive after load decreased mean arterial pressure (59 ± 29 mmHg) and increased central venous pressure and systolic right ventricular pressure; PaO2 and SvO2 decreased significantly. On assist, mean arterial pressure (103 ± 29 mmHg), central venous pressure and right ventricular pressure normalized. The SvO2 increased to 89 ± 3% and PaO2 stabilized (129 ± 21 mmHg). CONCLUSIONS: We demonstrated the efficacy of a miniaturized atrio-atrial ECMO. Right ventricular unloading was achieved, and gas exchange was well taken over by the Novalung. This allows an effective short- to mid-term treatment of cardiopulmonary failure, successfully combining right ventricular and respiratory bridging. The parallel bypass of the right ventricle and lung circulation permits full unloading of both systems as well as gradual weaning. Further pathologies (e.g. ischaemic right heart failure and acute lung injury) will have to be evaluated.

A new approach to the interventional therapy of tricuspid regurgitation.

Currently, there are no fully developed interventional approaches for the treatment of tricuspid regurgitation (TR). The aim of this study was to evaluate the feasibility of orthotopic interventional placement of a biological prosthetic valve in the tricuspid position by inserting, with a transvenous approach, a self-expandable valve-bearing stent into the right atrium. Based on findings of computerized tomography (CT), a model of the porcine right heart was obtained. A self-expanding vascular endoprosthesis, carrying a prosthetic heart valve, was reshaped to fit the superior vena cava and the tricuspid annulus. Fenestrations were created to allow blood flow from the inferior vena cava and coronary sinus. This new device ("tricuspid endoprosthesis": TE) was implanted operatively into the superior vena cava, right atrium, and tricuspid annulus in six pigs. CT demonstrated proper fitting of the device, and echocardiography demonstrated correct positioning and function of the TE. Five animals were successfully weaned from cardiopulmonary bypass. Autopsy confirmed correct positioning of the TE without major trauma to surrounding tissues. These findings demonstrate a complete interventional approach for treating TR.

Low stroke rate and few thrombo-embolic events after HeartMate II implantation under mild anticoagulation.

OBJECTIVES: Bleeding and thrombo-embolism are two of the most threatening adverse events associated with the use of continuous flow left ventricular assist devices (LVADs) in the treatment of severe heart failure. We analysed our LVAD patients treated with the HeartMate II (HM II) device by following a low anticoagulation regimen. METHODS: Between 2008 and February 2011, we implanted 40 HM II LVADs in our institution. Intention to treat was bridge to transplant in 25, destination therapy in 9, bridge to candidacy in 5 cases and bridge to recovery in 1 case. Heparin was started only after 24 h postoperatively, and Phenprocumon (Phen) was started after removal of all chest drains. International normalized ratio (INR) target in the years 2008-2009 was 2.5, and 2.0-2.5 since 2010. Acetyl salicylic acid (ASA) was prescribed 50-100 mg/day only in patients <55 years or in case of severe atherosclerotic disease of the right coronary artery. All data were analysed consecutively concerning thrombo-embolic and bleeding events. RESULTS: Fifty-two percent of the patients were in INTERMACS level 1 or 2 at the time of implantation. The mean age was 58 ± 11 years, and the mean days under LVAD was 241 days (maximum: 1052 days). The survival rate was 87.5% after 30 years and 75% in the long term. Early postoperatively, no strokes or thrombo-embolic events occurred. In the long term, two patients suffered from ischaemic strokes, but recovered well. In both of these index events, the INR was lasting below 1.4. One of these two patients developed pump thrombosis additionally. Only three patients (ASA + Phen) developed gastrointestinal bleeding (7.5%). Two patients were withdrawn from Phen + ASA because of multiple angiodysplasia. CONCLUSIONS: Compared with the literature, even a mild anticoagulation protocol does not increase the risk of thrombotic events, but reduces bleeding events in the use of an HM II LVAD.

Feasibility and efficacy of bypassing the right ventricle and pulmonary circulation to treat right ventricular failure: an experimental study.

BACKGROUND: Right ventricular failure (RVF) and -support is associated with poor results. We aimed for a new approach of right - sided assistance bypassing the right ventricle and pulmonary circulation in order to better decompress the right ventricle and optimize left ventricular filling. METHODS: From a microaxial pump (Abiomed), a low resistance oxygenator (Maquet and Novalung) and two cannulas (28 and 27 Fr) a system was set up and evaluated in an ovine model (n = 7). Connection with the heart was the right and left atrium. One hour the system was operated without RVF and turned of again. Then a RVF was induced and the course with the system running was evaluated. Complete hemodynamic monitoring was performed as well as echocardiography, flow measurement and blood gas analysis. RESULTS: The overall performance of the system was reliable. Without RVF no relevant changes of hemodynamics occurred; blood gases were supra normal. In RVF a cardiogenic shock developed (MAP 35 ± 13 mmHg, CO 1,1 ± 0,7 l/min). Immediately after starting the system the circulation normalized (significant increase of MAP to 85 ± 13 mmHg, of CO to 4,5 ± 1,9). Echocardiography also revealed right ventricular recovery. After stopping the system, RVF returned. CONCLUSIONS: Bypassing the right ventricle and pulmonary circulation with an oxygenating assist device, which may offer the advantages of enhanced right ventricular decompression and augmented left atrial filling, is feasible and effective in the treatment of acute RVF. Long time experiments are needed.

An unusual case of pacemaker failure: complete disconnection of connector block and battery of a subpectorally implanted dual chamber pacemaker.

Local trauma to patients with implanted pacemaker devices may result in lead fracture or breakage of the lead socket with leakage of fluid into the connector system. This report describes an unusual case of complete entrance and exit block in a subpectorally implanted dual chamber pacemaker due to total disconnection and dislodgement of header block and battery part. Damage may be caused by an interaction of machine fatigue/manufacturing defective and fixation of the header with unusual movability of the battery, leading to breakage with intermittent malfunction and consecutive bradycardia and syncope.