Ahmed El-Gamel

Transcatheter aortic valve implantation for severe aortic stenosis—a new paradigm for multidisciplinary intervention: A prospective cohort study

BACKGROUND Transcatheter aortic valve implantation (TAVI) is an alternative treatment option for patients with aortic stenosis deemed high risk or unsuitable for aortic valve replacement. The aim of this study was to assess the feasibility of TAVI in elderly patients, the delivery of this technology with a multidisciplinary approach, and the use of traditional surgical scoring systems. METHODS One hundred fifty-one consecutive patients (mean age 82.6 +/- 7.3 years) with severe aortic stenosis underwent TAVI with the Edwards Lifesciences (Irvine, CA) Sapien bioprosthesis using the transapical (n = 84; 56%) or transfemoral (n = 67; 44%) approach from August 2007 to September 2009 at Kings Health Partners, London, United Kingdom. We analyzed procedural outcome, complications, functional status, and midterm outcome of patients. RESULTS The multidisciplinary team comprised interventional cardiologists, cardiothoracic surgeons, imaging specialists, cardiac anesthetists, and specialist nurses. Seventy percent of patients were in New York Heart Association class III/IV, and logistic EuroSCORE was 21.6 +/- 11.9. Procedural success was achieved in 98%. Postoperative complications included stroke (6%), complete atrioventricular block (5.3%), renal failure requiring hemofiltration (9.3%), and vascular injury (8.6%). Overall 30-day mortality was 9.9% (n = 15). The logistic EuroSCORE was a predictor of short-term mortality (logistic regression model, P < .05). Thirty-day mortality post-TAVI for patients with logistic EuroSCORE <20, 20 to 40, and >40 was 5.4%, 13.2%, and 22.2%, respectively. CONCLUSIONS Transcatheter aortic valve implantation is a feasible treatment option in this patient group with promising short/medium-term results. Renal failure is the commonest short-term complication, and the incidence of vascular complications remains high. Risk prediction/case selection remains challenging, and a multidisciplinary team approach appears to be helpful in appropriate patient selection.

Reduced Nicotinamide Adenine Dinucleotide Phosphate Oxidase-Derived Superoxide and Vascular Endothelial Dysfunction in Human Heart Failure

OBJECTIVES We investigated the role of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in endothelial dysfunction in human heart failure. BACKGROUND Vascular endothelial dysfunction in human heart failure contributes to increased tone, exercise limitation, and dysregulation of venous capacitance and vascular volume. The NADPH oxidases (Nox) are an important source of oxidative stress, but their role in the endothelial dysfunction of human heart failure remains unknown. METHODS Endothelium-dependent and -independent vasorelaxation were assessed in saphenous vein segments obtained from consecutive patients with heart failure (n = 19) or normal left ventricular function (control; n = 35) undergoing coronary artery bypass graft. Saphenous vein superoxide production was measured by lucigenin-enhanced chemiluminescence and messenger ribonucleic acid expression of relevant transcripts quantified by real-time polymerase chain reaction. RESULTS Heart failure patients had significantly worse endothelial function than control subjects (15.2 +/- 3% vs. 40.5 +/- 8.4% relative relaxation; p < 0.05), elevated C-reactive protein (CRP) levels (8.6 +/- 2.7 mg/l vs. 2.6 +/- 0.4 mg/l; p < 0.05), over 2-fold higher NADPH-dependent superoxide generation (p < 0.05), and significantly higher expression of the Nox4 isoform and regulatory subunit p67phox. Superoxide levels were positively correlated with New York Heart Association functional class (r = 0.684; p < 0.05) and CRP (r = 0.501; p < 0.005; n = 32). CONCLUSIONS Venous endothelial dysfunction in human heart failure is associated with increased Nox-derived superoxide generation. Inflammatory mechanisms may be involved in the increased reactive oxygen species generation.

Does Stopping Amiodarone after Successfully Treating Atrial Fibrillation Occurring after Cardiac Surgery Increase the Risk of Recurrence

OBJECTIVES Atrial fibrillation (AF) following cardiac surgery is common and can complicate postoperative recovery. Amiodarone is a drug frequently used for cardioversion. Some clinicians advocate only in-hospital use of amiodarone until cardioversion, whereas others continue its use for several weeks following cardiac surgery. Inadvertent long-term administration of the drug could be harmful. This study assessed the risk of AF recurrence under 2 different regimens of amiodarone treatment. METHODS From January 2005 to July 2007, we reviewed 296 patients who developed postoperative AF. Group A consisted of 198 patients who were discharged on amiodarone treatment, and group B consisted of 98 patients who were discharged without amiodarone treatment. The patients were followed for 8 weeks after cardiac surgery and were observed for the development of symptoms such as palpitations, transient ischemic attack (TIA), stroke, and recurrence of or readmission for AF. In addition, we evaluated a control group of 145 patients with similar characteristics and no postoperative AF for the incidence of stroke and AF and compared the results with their rates in the study groups. RESULTS Patients discharged on amiodarone therapy were more likely to experience episodes of palpitations than those not on amiodarone (13% versus 10%); however, the rates of AF recurrence were almost the same for the 2 groups (8% and 9%, respectively). The 2 groups also showed no difference in the incidence of TIA and stroke (5% versus 4%). A low incidence of stroke and AF (1%-2%) was observed in patients with no perioperative AF. CONCLUSIONS Long-term treatment of patients with amiodarone should be reconsidered, because it may not be as effective as previously thought in preventing symptoms and AF recurrence. The surprising incidence of neurologic events requires further investigation.