Long-term durability and haemodynamic performance of a self-expanding transcatheter heart valve beyond five years after implantation: a prospective observational study applying the standardised definitions of structural deterioration and valve failure.

AIMS: Long-term results of transcatheter aortic valve implantation (TAVI), in particular the incidence of bioprosthetic valve failure (BVF), are uncertain. This study presents data derived from a long-term, structured follow-up programme of the self-expanding CoreValve device utilising standardised definitions and core lab adjudication of valve performance. METHODS AND RESULTS: The study prospectively included all 152 patients who had undergone TAVI with the self-expanding CoreValve up to December 2011 at the Heart Center, Bad Segeberg, Germany. Late BVF (>30 days) was defined as either: 1) severe structural valve deterioration (transprosthetic mean pressure gradient ≥40 mmHg and/or ≥20 mmHg rise from baseline OR severe intraprosthetic aortic regurgitation), OR 2) bioprosthetic valve dysfunction leading to death or reintervention. Echocardiographic follow-up at 6.3±1.0 years (range: 5.0-8.9 years) was 88% complete (60 out of 68 survivors beyond five years) and all echocardiograms were analysed by an independent core laboratory. The all-cause mortality rate at 1, 2, 5, 6, 7 and 8 years was 14%, 20%, 50%, 60%, 65%, and 73%, respectively. Among survivors beyond five years, effective orifice area was 1.60±0.46 cm2, and transvalvular mean pressure gradient was 6.7±3.1 mmHg; no cases showed evidence of structural valve deterioration. Five patients (3.3%) had undergone redo TAVI (n=4) or surgery (n=1) 0.6 to 5.2 years after the index procedure, all due to paravalvular leakage. The estimated rate of BVF at eight years was 7.9% for the actuarial and 4.5% for the actual analysis. CONCLUSIONS: Long-term follow-up up to 8.9 years after TAVI documents favourable performance of the self-expanding CoreValve with low rates of BVF.

The subtype-specific effects of droperidol on action potential duration in cellular and computational models of long QT syndrome.

BACKGROUND: Droperidol is a highly potent butyrophenone used for the therapy of postoperative nausea and vomiting. Its cardiac safety in cardiovascular-healthy patients and those with long QT (LQT) syndrome is a matter of debate. In this study, we investigated whether droperidol has subtype-specific effects in cellular and computational models of LQT syndrome. METHODS: Left ventricular cardiac myocytes were isolated from adult guinea pig hearts. LQT1-like behavior was pharmacologically induced by chromanol 293B (10 micromol/L) and LQT2-like states by E4031 (10 micromol/L). Computational analysis was performed using the Luo-Rudy dynamic model. Data are given as mean + or - SEM. RESULTS: In control myocytes, droperidol lengthened action potentials in a concentration-dependent manner with a maximal prolongation of 37% + or - 13% (n = 4) at a concentration of 0.6 micromol/L. In LQT1-like myocytes, droperidol (0.6 micromol/L) further prolonged action potentials by 31% + or - 6% (n = 6) but shortened action potentials of LQT2-like myocytes by 11% + or - 2% (n = 8). Computational modeling supported the concept that droperidol, in addition to the rapid component of the delayed K(+) current, blocks depolarizing targets, such as the L-type Ca(2+) current, the Na(+)-Ca(2+) exchanger, and the Na(+)-K(+) adenosine triphosphatase. CONCLUSIONS: Droperidol has more detrimental effects on cardiac repolarization of LQT1-like than of LQT2-like myocytes suggesting subtype-specific cardiotoxic effects in patients with LQT syndrome. The subtype specificity of droperidol seems to be caused by a complex interaction of droperidol with several different molecular targets. This interaction deserves further investigation to establish the feasibility of a subtype-directed approach in the perioperative management of patients with LQT syndrome.