Exercise capacity reflects ventricular function in patients having the Fontan circulation.

BACKGROUND: In this study we sought to determine, first, whether maximal exercise capacity reflects ventricular function, and second, whether the age of the patient, and the age of completion of the Fontan circulation, influence ventricular function and exercise performance. METHODS AND RESULTS: Cardiac magnetic resonance imaging and cardiopulmonary exercise testing were performed in 29 patients at a median time of 6.9 years after completion of the Fontan circulation. We divided the patients into 2 groups, the first 19 having their operation below the age of 18 years, and the second group, of 10 patients, having completion of the Fontan circulation when they were older than 18 years. Parameters for ventricular function and exercise were compared for both groups with controls. Compared to controls, the younger patients had normal end-diastolic ventricular volumes, but significantly impaired ventricular function, lower maximal work load and consumption of oxygen. The older patients had greater end-diastolic ventricular volumes, and significantly poorer ventricular function than both the younger patients and the controls. Maximal work load and consumption of oxygen were significantly lower in the older patients than in the younger ones and the controls. CONCLUSION: Patients with the Fontan circulation have an impaired systolic ventricular function, which correlates with maximal exercise capacity and uptake of oxygen. Those having completion of the Fontan circulation when younger than 18 years had significantly better ventricular function and exercise performance than those who had completion of the Fontan circulation at an older age. An early creation of the Fontan circulation may preserve cardiac function and exercise capacity.

Oral everolimus inhibits neointimal proliferation in prosthetic pulmonary valved stents in pigs.

BACKGROUND AND AIM OF THE STUDY: Growth factor-dependent cell proliferation can cause in-stent neointimal hyperplasia. The study aim was to evaluate whether oral everolimus inhibits the intimal proliferation associated with the implantation of prosthetic pulmonary valved stents. METHODS: Prosthetic pulmonary valves were implanted in 12 pigs (mean bodyweight 25 kg) using a transcatheter technique. Tricuspid valves were prepared from a titanium-coated polymer and sewn into a self-expanding nitinol stent (diameter 20 mm). Valved stents were implanted in the pulmonary position, where they remained for three months. In six animals, treatment with 2 mg/kg everolimus (Certican; Novartis) per day was started three days before implantation and continued throughout the course of the experiment. The other six pigs acted as controls. Adjuvant anticoagulation treatment consisted of acetylsalicylic acid and oral clopidogrel. After three months, hemodynamic valve function was investigated at catheterization and with MRI. At postmortem investigation the valved stents were explanted and subjected to macroscopic, histological and electron microscopic examination. RESULTS: There were no adverse side effects due to everolimus treatment. The overall mean everolimus plasma level during the study was 4.2 +/- 2.4 ng/ml. MRI revealed intact valve function with a regurgitation fraction of 7.3 +/- 4.2% in controls and 4.3 +/- 3.1% in the everolimus group (p <0.01). On macroscopic inspection and histological examination, the everolimus group showed only a thin tissue coverage of the stent struts. The valve cusps were free from intimal thickening, and electron microscopy showed a thin continuous cellular coating. In contrast, substantial neointimal formation was noted in controls. Tissue neogenesis was pronounced at the base of the valve, extended to the valve cusps, and caused valve thickening and foreshortening. CONCLUSION: The oral administration of everolimus effectively inhibits tissue neogenesis in pulmonary valved stents in pigs.

Adult patent ductus arteriosus : An unusual cause of heart failure in an octogenarian female.

Patent ductus arteriosus (PDA) is the third most common congenital abnormality in which the arterial duct, which normally closes spontaneously after birth within 24-48 h in full-term infants, remains permanently open. Breathlessness is very common in elderly patients and can be caused by several comorbidities, mostly cardiac and pulmonary diseases. PDA as a cause of heart failure in this patient population is very rare and diagnosis depends on high clinical awareness. Here we present a case diagnosed with multimodality imaging including 3­dimensional (3D) transthoracic and transesophageal echocardiography and 3D-volume rendering technique (VRT) computed tomography.

A prospective, randomized, double-blind, placebo controlled trial of beta-blockade in patients who have undergone surgical correction of tetralogy of Fallot.

AIMS: Our purpose was to evaluate the effect of a treatment over six months with bisoprolol on the surrogate parameters of N-Terminal-pro brain natriuretic peptide, subsequently to be described as brain natriuretic peptide, peak uptake of oxygen, and ventricular function assessed by magnetic resonance imaging in grown ups and adults who had undergone surgical correction of tetralogy of Fallot. METHODS AND RESULTS: We designed a prospective, randomized, double-blind, placebo controlled trial. We enrolled 33 patients, aged 30.9 plus or minus 9.5 years in either class 1 or 2 of the grading of the New York Heart Association class with both levels of brain natriuretic peptide greater than 100 pg/ml and a reduced peak uptake of oxygen less than 25 ml/kg/min. During treatment with Bisoprolol, the levels of brain natriuretic peptide increased significantly from 206 plus or minus 95 to 341 plus or minus 250 pg/ml (p< 0.05), and those of atrial natriuretic peptide from 4117 plus or minus 1837 to 5340 plus or minus 2102 fmol/ml (p = 0.0005). These measures remained unchanged in the group of patients receiving the placebo. Peak uptake of oxygen did not differ significantly in either group, nor did treatment have any significant effect on right and left ventricular volumes and ejection fractions as determined by magnetic resonance imaging. The clinical state as judged within the grading system of the New York Heart Association was also unchanged by beta-blockade. CONCLUSION: Beta blockade with Bisoprolol seems to have no beneficial effect on asymptomatic or mildly symptomatic patients with right ventricular dysfunction secondary to repaired tetralogy of Fallot with residual pulmonary regurgitation and/or stenosis.