Lars Riber

Amiodarone is a cost-neutral way of preventing atrial fibrillation after surgery for lung cancer

OBJECTIVES Our aim was to estimate the costs and health benefits of routinely administered postoperative amiodarone as a prophylactic agent in reducing the risk of atrial fibrillation in patients undergoing surgery for lung cancer. METHODS This was a cost-effectiveness study, based on the randomized, controlled, double-blinded PASCART study, using avoidance of atrial fibrillation as the measure of benefit. Two hundred and fifty-four eligible, consecutively enrolled patients, undergoing surgery for lung cancer at the department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Denmark, were included and randomized to receive either 300 mg of amiodarone or placebo (5% aqueous dextrose solution), administered intravenously over 20 min immediately after surgery, followed by 600 mg of amiodarone/placebo orally twice per day (8 a.m. and 6 p.m.) for the first five postoperative days. RESULTS In the amiodarone group there were 11 cases of atrial fibrillation, compared with 38 in the control group (P < 0.001). There were no differences in the length of hospital stay or resources used. The mean total costs per patient were equal and amounted to €7288 per patient (P = 0.23). There were no signs of adverse developments referable to amiodarone in this prophylactic regime. CONCLUSIONS For patients undergoing surgery for lung cancer, routine use of postoperative prophylactic intravenous bolus and five subsequent days of oral amiodarone therapy reduces the risk of atrial fibrillation in a cost-neutral manner.

Structural valve deterioration in the Mitroflow biological heart valve prosthesis

OBJECTIVES Concern has been raised regarding the long-term durability of the Mitroflow biological heart valve prosthesis. Our aim was to assess the incidence of structural valve degeneration (SVD) for the Mitroflow bioprosthesis in a nationwide study in Denmark including all patients alive in Denmark who had received a Mitroflow aortic bioprosthesis since 2000. METHODS Patients alive in Denmark with a Mitroflow bioprosthesis implanted since January 2000 were invited to participate in a nationwide cross-sectional study with a predefined definition of SVD. Of 1552 patients, 861 patients had died and 47 patients had been reoperated with 40 reoperations due to SVD. The remaining 644 patients were invited for evaluation; 574 patients accepted and were evaluated for SVD. The incidence of SVD was calculated using competing risk regression analysis with death as the competing event. RESULTS A total of 173 patients were diagnosed with SVD by echocardiography. Of these, 64 (11%) patients had severe SVD and 109 (19%) patients moderate SVD. Severe SVD was associated with the age of the prosthesis and small prosthesis size [Size 21: hazard ratio (95% confidence interval, CI) 2.72 (0.97-8.56), P = 0.06; Size 19: 6.26 (1.63-24.06), P = 0.008]. The cumulative incidences of reoperation or severe SVD at Year 9 were 12.5% for Size 19, 7.6% for Size 21 and 3.1 (1.2-6.4)% for Size 23. Median survival in patients with prosthesis Sizes 23-29 was 6.4 (95% CI 5.7-7.0) years, with Size 21 it was 6.5 (95% CI 5.9-7.1) years and with Size 19 it was 6.9 (95% CI 5.7-8.2) years (P = 0.78). CONCLUSIONS The incidence of undetected severe SVD was as high as the incidence of operated SVD. The overall risk for SVD is high for the Mitroflow bioprosthesis, especially if the prosthesis is small and older than 5 years.

The long-term efficacy of concomitant maze IV surgery in patients with atrial fibrillation

Background Atrial fibrillation (AF) is the most common cardiac arrhythmia, and associated with increased risk of morbidity and mortality. AF surgery is widely used for rhythm control of AF, but previous studies have shown varying results. This study sought to investigate the long-term efficacy of concomitant maze IV (CMIV) surgery in an unselected AF population and identify predictors of late AF recurrence. Methods In total 144 consecutive patients, who underwent CMIV between January 2006 and December 2010 were enrolled. By data from electronic medical records, registers, and rhythm prints, late AF recurrences and heart rhythm at latest follow-up were retrospectively registered. All patients still alive were invited to an ambulant follow-up to update rhythm status. Results During a median (IQR) follow-up of 7.39 (2.67) years, 114 (79.2%) patients had recurrence. The cumulative incidence of sinus rhythm (SR) without antiarrhythmic drugs (AADs) was 52.3% after 1 year. Long-term results after 2, 5 and 7 years were 47.9%, 32.6% and 25.1%, respectively. At latest follow-up 34.7% were in SR off AADs. No difference in 10-year event-free survival stratified by recurrence were found (p = 0.678). Contrary, time to death (5.40 vs. 3.43 years, p = 0.004) revealed death as competing risk event. The Fine-Gray model identified preoperative sustained AF (SAF) (SHR 3.54, 95%CI [2.35;5.32], p < 0.001), AF duration (1.08, [1.05;1.11], p < 0.001), and postoperative atrial tachyarrhythmia (ATA) (2.29, [1.21;4.35], p = 0.011) as predictors. Conclusion CMIV in the present cohort provided limited long-term success in obtaining SR. SAF, longer AF duration, and postoperative ATA were associated with late AF recurrence.

Relaxing Responses to Hydrogen Peroxide and Nitric Oxide in Human Pericardial Resistance Arteries Stimulated with Endothelin-1

In human pericardial resistance arteries, effects of the endothelium‐dependent vasodilator bradykinin are mediated by NO during contraction induced by K+ or the TxA2 analogue U46619 and by H2O2 during contraction by endothelin‐1 (ET‐1), respectively. We tested the hypotheses that ET‐1 reduces relaxing effects of NO and increases those of H2O2 in resistance artery smooth muscle of patients with cardiovascular disease. Arterial segments, dissected from the parietal pericardium of 39 cardiothoracic surgery patients, were studied by myography during amplitude‐matched contractions induced by K+, the TXA2 analogue U46619 or ET‐1. Effects of the NO donor Na‐nitroprusside (SNP) and of exogenous H2O2 were recorded in the absence and presence of inhibitors of cyclooxygenases, NO synthases and small and intermediate conductance calcium‐activated K+ channels. During contractions induced by either of the three stimuli, the potency of SNP did not differ and was not modified by the inhibitors. In vessels contracted with ET‐1, the potency of H2O2 was on average and in terms of interindividual variability considerably larger than in K+‐contracted vessels. Both differences were not statistically significant in the presence of inhibitors of mechanisms of endothelium‐dependent vasodilatation. In resistance arteries from patients with cardiovascular disease, ET‐1 does not selectively modify smooth muscle relaxing responses to NO or H2O2. Furthermore, the candidate endothelium‐derived relaxing factor H2O2 also acts as an endothelium‐dependent vasodilator.

Combined use of β-Blockers and Inhibitors of the Renin-Angiotensin System Decreases the Stiffness of Resistance Arteries from Cardiothoracic Surgery Patients

Introduction: Lymphatic Endothelial Cells (LECs) have been shown to express EPHB4, a receptor tyrosine kinase (TK) which signals via the ephrinB2 ligand. Previous data revealed EPHB4 as a new causative gene for Lymphatic-Related (non-immune) Hydrops Fetalis (LRHF), a form of Generalized Lymphatic Dysplasia, a subgroup of Primary Lymphoedemas. Two missense mutations in EPHB4 were reported to be associated with this phenotype and the receptor was also identified as critical regulator of lymphangiogenesis. This study aims to further investigate the role of EPHB4 in lymphangiogenesis and the mechanisms by which the two specific mutations interfere with EPHB4 signalling and dysregulate lymphangiogenesis.

Structure and Contractile Function of Pericardial Resistance Arteries from Cardiothoracic Surgery Patients; Effects of Anti‐Hypertensive Treatments

Introduction: Lymphatic Endothelial Cells (LECs) have been shown to express EPHB4, a receptor tyrosine kinase (TK) which signals via the ephrinB2 ligand. Previous data revealed EPHB4 as a new causative gene for Lymphatic-Related (non-immune) Hydrops Fetalis (LRHF), a form of Generalized Lymphatic Dysplasia, a subgroup of Primary Lymphoedemas. Two missense mutations in EPHB4 were reported to be associated with this phenotype and the receptor was also identified as critical regulator of lymphangiogenesis. This study aims to further investigate the role of EPHB4 in lymphangiogenesis and the mechanisms by which the two specific mutations interfere with EPHB4 signalling and dysregulate lymphangiogenesis.

TCT-245 Association of intraoperative transit time flow after grafting and invasive coronary flow and pressure measurements before coronary artery bypass surgery.

RESULTS 1,555 patients were included; 861 underwent PCI and 694 underwent CABG (Table 1). Patients with index PCI were more often female, African American, presented with ST-elevation MI, and had previous MI; they were less often diabetic, had congestive heart failure, proximal left anterior descending disease, or presented with stable angina. The rate of 10-year MACCE was 67.3% among PCI patients and 54.1% among CABG patients (p < 0.0001) and of RR was 24.7% vs. 12.0%. Adjusting for baseline covariates, the odds ratio of RR for patients with index CABG was 0.45 (0.28 – 0.72, pvalue < 0.0001). 57 patients with index CABG were found to have 1 occluded graft on subsequent angiography without RR; of these, 48 had inadequate targets for intervention.

Reply to Patel and Hunt.

Department of Cardiothoracic and Vascular Surgery, Institute of Clinical Medicine, Odense University Hospital, Odense, Denmark* Corresponding author. Department of Cardiothoracic and Vascular Surgery, Institute of Clinical Medicine, Odense University Hospital,Sdr. Boulevard 29, 5000 Odense C, Denmark. Tel: +45-51-920042; e-mail: larspeterriber@gmail.com (L.P. Riber).Received 19 March 2014; accepted 19 March 2014