Nicholas Bett

Lack of effect of coenzyme Q on left ventricular function in patients with congestive heart failure.

OBJECTIVES This study evaluated the effects of oral therapy with coenzyme Q on echocardiographic and hemodynamic indexes of left ventricular function and on quality of life in patients with chronic left ventricular dysfunction. BACKGROUND Coenzyme Q a coenzyme for oxidative phosphorylation and an antioxidant and free radical scavenger. It has been claimed to improve symptoms, quality of life, left ventricular ejection fraction and prognosis in patients with cardiac failure. METHODS Thirty patients with ischemic or idiopathic dilated cardiomyopathy and chronic left ventricular dysfunction (ejection fraction 26 +/- 6%) were randomized to a double-blind crossover trial of oral coenzyme Q versus placebo each for 3 months. Right heart pressures, cardiac output and echocardiographic left ventricular volumes were measured at baseline and after each treatment phase, and quality of life was assessed using the Minnesota Living With Heart Failure questionnaire. It was calculated that to demonstrate an increase in left ventricular ejection fraction from 25% to 30% with a standard deviation of 5% using 95% confidence intervals with a power of 80% we would require 17 patients. RESULTS Twenty-seven completed both treatment phases. There was no significant difference in left ventricular ejection fraction, cardiac volumes or hemodynamic and quality of life indices after treatment with coenzyme Q placebo, although plasma coenzyme Q levels increased from 903 +/- 345 nmol/l(-1) to 2,029 +/- 856 nmol/l(-1). CONCLUSIONS Inpatients with left ventricular dysfunction, treatment for three months with oral coenzyme Q failed to improve resting left ventricular systolic function or quality of life despite an increase in plasma levels of coenzyme Q to more than twice basal values

The value of dual-source 64-slice CT coronary angiography in the assessment of patients presenting to an acute chest pain service.

BACKGROUND The absence of radiological evidence of plaque on computed tomographic coronary angiography (CTCA) reliably excludes obstructive coronary artery disease. METHODS We studied patients who presented to our emergency department with chest pain and were admitted to our chest pain assessment service. If they were free of pain and without high-risk features of myocardial ischaemia including elevation of serum biomarkers they underwent CTCA and performed a standard treadmill exercise test. RESULTS Eighty-nine patients aged 56.3+/-8.6 years were admitted. Eleven of them had selective angiography; CTCA identified all who had obstructive disease. More than half of the 85 patients who had normal values of cardiac troponin and of the 75 with a negative exercise test had radiological evidence of disease. During follow-up for 355+/-72 days none died, suffered myocardial infarction or required coronary artery surgery: two with obstructive disease underwent percutaneous coronary intervention 1 and 7 days after the index study. CONCLUSIONS The CTCA findings were significantly correlated with those of selective angiography and with troponin status and increased the ascertainment of coronary artery disease in a cohort of patients at low risk for clinically significant ischaemic heart disease.

Outcome five years after percutaneous transluminal coronary angioplasty or coronary artery bypass grafting for significant narrowing limited to the left anterior descending coronary artery

Percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG) are both used widely for angina but information about their comparative efficacy is limited. This study compared the outcome of 358 consecutive patients undergoing initial revascularization for significant narrowing of the left anterior descending artery (LAD) by PTCA (n = 254) or CABG (n = 104) from 1987 to 1989. PTCA was successful in 93% but complicated by urgent CABG in 3%. A left internal mammary graft was used in 88% of those having elective CABG. There was 1 perioperative death. Follow-up data were obtained after a median interval of 5.5 years (maximum 7.1). Rates for freedom from death (97% PTCA vs 93% CABG, p = 0.06) were similar, but CABG patients had greater rates for freedom from chest pain recurrence (74% CABG vs 48% PTCA, p < 0.0001), myocardial infarction (98% vs 92%, p = 0.04), and from need for further revascularization (99% vs 67%, p < 0.0001). Both groups achieved similar status, with 81% of PTCA and 90% of CABG patients having angina no worse than functional class I. Quality-of-life index was high for both groups (0.983 +/- 0.034/1.000 vs 0.987 +/- 0.032/1.000, p = 0.3). Both PTCA and CABG result in excellent survival, functional ability, and quality of life, but patients undergoing PTCA require more procedures to achieve this.

Takotsubo cardiomyopathy: an Australian single centre experience with medium term follow up.

Background:  Takotsubo cardiomyopathy (TC) is increasingly recognised in patients presenting with features of acute coronary syndrome. We present a single centre experience of TC with medium term follow up.

Massive Left Atrial Thrombus in a Patient With Rheumatic Mitral Stenosis and Atrial Fibrillation While Anticoagulated With Dabigatran

Dabigatran is an oral direct thrombin inhibitor licensed for use by the Food and Drug Administration.1,2 This novel anticoagulant is effective and approved for prevention of stroke and systemic embolism in nonvalvular atrial fibrillation (AF) and prevention of venous thromboembolism in adults receiving elective total hip or knee replacement surgery.1,2 These images present a cautionary account of failed dabigatran anticoagulation in a patient with valvular AF: an indication for which its use has not been approved. A 50-year-old female with severe rheumatic mitral stenosis underwent open mitral valvotomy under cardiopulmonary bypass 25 years prior. On subsequent annual surveillance, she remained asymptomatic and her mitral stenosis remained moderate on echocardiography with a mean transmitral gradient of 8 mm Hg. Permanent AF was previously diagnosed 12 months earlier, and she was commenced on warfarin and metoprolol. She had stable anticoagulation monitoring, no bleeding complications, and normal renal function, but was needle-phobic with psychological …

Transcatheter valve-in-valve replacement of degenerated bioprosthetic aortic valves: a single Australian Centre experience.

BACKGROUND Patients with degenerated surgical bioprosthetic valves may be at high risk for further surgery because of age, comorbidities and the difficulties of repeat procedures. Percutaneous valve-in-valve implantation offers what may be a simpler and safer procedure. METHODS From May 2009 to March 2014 at the Prince Charles Hospital 1625 patients underwent surgical aortic valve replacement while 262 underwent transcatheter aortic valve implantation. Twelve patients had valve-in-valve implants for degenerated bioprosthetic aortic valves. RESULTS These implants were deployed successfully without major valvular or paravalvular regurgitation. There were no periprocedural deaths, myocardial infarcts, neurological events or major vascular complications. Two patients died after 1624 and 1319days. Median survival for the remainder is 581days; they are stable with New York Heart Association class I/II functional status although 4 have a degree of patient-prosthesis mismatch, one has moderate aortic regurgitation and one required surgery for a late aortic dissection. CONCLUSION Transcatheter valve-in-valve implantation is safe and effective treatment for patients with failed bioprosthetic aortic valves for whom reoperation is considered to be hazardous.

Factors Contributing to Acute Kidney Injury and the Impact on Mortality in Patients Undergoing Transcatheter Aortic Valve Replacement

BACKGROUND Transcatheter aortic valve replacement (TAVR) patients are at a high risk of acute kidney injury (AKI). This study aimed to investigate AKI and the relationship with iodinated contrast media (ICM), whether there are significant pre- or peri- procedural variables predicting AKI, and whether AKI impacts on hospital length of stay and mortality. METHODS Serum creatinine (SC) levels pre- and post- (peak) TAVR were recorded in 209 consecutive TAVR patients. AKI was defined by the Valve Academic Research Consortium 2 (VARC2) criteria. Baseline characteristics, procedural variables, hospital length of stay (LOS) and mortality at 72hours, 30 days and one year were analysed. RESULTS Eighty-two of 209 (39%) patients suffered AKI. Mean ICM volume was 228cc, with no difference between patients with AKI and those with no AKI (227cc (213-240(95%CI)) vs 231cc (212-250) p=0.700)). Univariate and multivariate analysis demonstrated that chronic kidney disease, respiratory failure, previous stroke, the need for blood transfusion and valve repositioning were all predictors of AKI. Acute kidney injury increased LOS (5.6 days (3.8 - 7.5) vs 3.2 days (2.6 - 3.9) no AKI (P=0.004)) but was not linked to increased mortality. Mortality rates did increase with AKI severity. CONCLUSION Acute kidney injury is a common complication of TAVR. The severity of AKI is important in determining mortality. Acute kidney injury appears to be independent of ICM use but pre-existing renal impairment and respiratory failure were predictors for AKI. Transcatheter aortic valve replacement device repositioning or retrieval was identified as a new risk factor impacting on AKI.

A comparison of anticoagulation with bivalirudin and provisional GPIIb/IIIa inhibition with unfractionated heparin and mandatory GPIIb/IIIa inhibition during percutaneous coronary intervention in relation to platelet activation and the inhibition of coagulation

AIMS Our study sought to evaluate mechanisms of the current strategies for optimal anticoagulation during percutaneous coronary intervention (PCI). METHODS AND RESULTS Thirty-two high risk acute coronary syndrome patients were randomised to bivalirudin and provisional GPIIb/IIIa inhibition (GPIIb/IIIa) or unfractionated heparin (UFH) and mandatory GPIIb/IIIa. Flow cytometric measurements immediately after anticoagulation showed that, unlike UFH, bivalirudin did not activate platelets as indicated by P-selectin expression and fibrinogen binding while decreasing platelet-monocyte aggregates and monocyte expression of tissue factor. UFH released tissue factor pathway inhibitor (TFPI) during and immediately after PCI while bivalirudin (irrespective of GP IIb/IIIa) did not. Lower levels of TFPI with bivalirudin were seen during and immediately after PCI (P<0.01). Thrombin generation as indicated by prothrombin fragment F 1+2 levels was reduced during PCI in the UFH group (P<0.01) but not with bivalirudin. Soluble CD40 ligand is associated with thrombosis and levels were higher in the bivalirudin group irrespective of GPIIb/IIIa at the same stages (P<0.05). CONCLUSIONS Bivalirudin has some early advantages on platelet activation when compared to UFH. However, there are significant limitations in its mechanism of action, particularly a lack of release of tissue factor pathway inhibitor.

Fistula From Aneurysmal Saphenous Vein Graft to Right Atrium Treated with Covered Stents

Rarely aneurysmal dilatation of saphenous vein grafts following coronary artery bypass surgery may be complicated by fistulae which communicate with cardiac chambers. We describe our attempt to close a fistula which entered the right atrium by deploying covered stents within the graft.

Outcomes of transcatheter aortic valve implantation in high surgical risk and inoperable patients with aortic stenosis: a single Australian Centre experience

Degenerative aortic stenosis is the most common valvular heart disease in the elderly, and many patients are not suitable for aortic valve replacement surgery. Transcatheter aortic valve implantation (TAVI) is a new therapeutic option for selected patients at high risk for surgery.