Efficacy of a device to narrow the coronary sinus in refractory angina.

BACKGROUND: Many patients with coronary artery disease who are not candidates for revascularization have refractory angina despite standard medical therapy. The balloon-expandable, stainless steel, hourglass-shaped, coronary-sinus reducing device creates a focal narrowing and increases pressure in the coronary sinus, thus redistributing blood into ischemic myocardium. METHODS: We randomly assigned 104 patients with Canadian Cardiovascular Society (CCS) class III or IV angina (on a scale from I to IV, with higher classes indicating greater limitations on physical activity owing to angina) and myocardial ischemia, who were not candidates for revascularization, to implantation of the device (treatment group) or to a sham procedure (control group). The primary end point was the proportion of patients with an improvement of at least two CCS angina classes at 6 months. RESULTS: A total of 35% of the patients in the treatment group (18 of 52 patients), as compared with 15% of those in the control group (8 of 52), had an improvement of at least two CCS angina classes at 6 months (P=0.02). The device was also associated with improvement of at least one CCS angina class in 71% of the patients in the treatment group (37 of 52 patients), as compared with 42% of those in the control group (22 of 52) (P=0.003). Quality of life as assessed with the use of the Seattle Angina Questionnaire was significantly improved in the treatment group, as compared with the control group (improvement on a 100-point scale, 17.6 vs. 7.6 points; P=0.03). There were no significant between-group differences in improvement in exercise time or in the mean change in the wall-motion index as assessed by means of dobutamine echocardiography. At 6 months, 1 patient in the treatment group had had a myocardial infarction; in the control group, 1 patient had died and 3 had had a myocardial infarction. CONCLUSIONS: In this small clinical trial, implantation of the coronary-sinus reducing device was associated with significant improvement in symptoms and quality of life in patients with refractory angina who were not candidates for revascularization. (Funded by Neovasc; COSIRA ClinicalTrials.gov number, NCT01205893.).

Chemical intervention in bacterial lignin degradation pathways: Development of selective inhibitors for intradiol and extradiol catechol dioxygenases.

Bacterial lignin degradation could be used to generate aromatic chemicals from the renewable resource lignin, provided that the breakdown pathways can be manipulated. In this study, selective inhibitors of enzymatic steps in bacterial degradation pathways were developed and tested for their effects upon lignin degradation. Screening of a collection of hydroxamic acid metallo-oxygenase inhibitors against two catechol dioxygenase enzymes, protocatechuate 3,4-dioxygenase (3,4-PCD) and 2,3-dihydroxyphenylpropionate 1,2-dioxygenase (MhpB), resulted in the identification of selective inhibitors D13 for 3,4-PCD (IC50 15µM) and D3 for MhpB (IC50 110µM). Application of D13 to Rhodococcus jostii RHA1 in minimal media containing ferulic acid led to the appearance of metabolic precursor protocatechuic acid at low concentration. Application of 1mM disulfiram, an inhibitor of mammalian aldehyde dehydrogenase, to R. jostii RHA1, gave rise to 4-carboxymuconolactone on the ß-ketoadipate pathway, whereas in Pseudomonas fluorescens Pf-5 disulfiram treatment gave rise to a metabolite found to be glycine betaine aldehyde.

Management of Refractory Angina Pectoris.

With improvements in survival from coronary artery disease (CAD) and an ageing population, refractory angina (RA) is becoming an increasingly common clinical problem facing clinicians in routine clinical practice. These patients experience chronic symptoms in the context of CAD, characterised by angina-type pain, which is uncontrolled despite optimal pharmacological, interventional and surgical therapy. Although mortality rates are no worse in this cohort, patients experience a significantly impaired quality of life with disproportionately high utilisation of healthcare services. It has been increasingly recognised that the needs of RA patients are multifactorial and best provided by specialist multi-disciplinary units. In this review, we consider the variety of therapies available to clinicians in the management of RA and discuss the promise of novel treatments.

The investigation and management of broad complex tachycardia and ventricular standstill presenting in pregnancy: A case report.

A 23 year old pregnant lady at 35 weeks gestation presented to accident and emergency with worsening dyspnoea, palpitations and dizziness. Twelve lead electrocardiogram, routine bloods and echocardiography were normal. Ambulatory monitoring previously had shown an episode of monomorphic broad complex tachycardia (BCT) and a short episode of ventricular standstill. She was admitted for cardiac monitoring until delivery. Several episodes of ventricular standstill and self-terminating BCT were recorded, which were not associated with symptoms. The patient's symptoms either corresponded with sinus rhythm or supraventricular tachycardia. She underwent elective caesarean section at 37 weeks with no complications. The patient's symptoms reduced considerably post delivery, and she was discharged three days later. Unfortunately she then had a presyncopal episode whilst holding her baby. Due to concern regarding the safety of her baby she had a permanent pacemaker implanted to allow safe beta-blockade. She remains asymptomatic six months later.

Breaking down lignin to high-value chemicals: the conversion of lignocellulose to vanillin in a gene deletion mutant of Rhodococcus jostii RHA1.

The aromatic polymer lignin represents a possible renewable source of aromatic chemicals, if biocatalytic routes for lignin breakdown can be developed. The availability of a genome sequence for Rhodococcus jostii RHA1, a bacterium that breaks down lignin, has allowed the application of a targeted pathway engineering strategy to lignin breakdown to produce vanillin, a valuable food/flavor chemical. A gene deletion strain of R. jostii RHA1 in which the vanillin dehydrogenase gene had been deleted, when grown on minimal medium containing 2.5% wheat straw lignocellulose and 0.05% glucose, was found to accumulate vanillin with yields of up to 96 mg/L after 144 h, together with smaller amounts of ferulic acid and 4-hydroxybenzaldehyde.