Thomas Sullivan

University of Adelaide, Tarndarnya, South Australia, Australia

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Publications (43)170.57 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Randomised controlled trials (RCT) examining the effects of fish oil supplementation on cardiac outcomes have yielded varying results over time. Although RCT are placed at the top of the evidence hierarchy, this methodology arose in the framework of pharmaceutical development. RCT with pharmaceuticals differ in important ways from RCT involving fish oil interventions. In particular, in pharmaceutical RCT, the test agent is present only in the intervention group and not in the control group, whereas in fish oil RCT, n-3 fats are present in the diet and in the tissues of both groups. Also, early phase studies with pharmaceuticals determine pharmacokinetics and pharmacodynamics to design the dose of the RCT intervention so that it is in a predicted linear dose-response range. None of this happens in fish oil RCT, and there is evidence that both baseline n-3 intake and tissue levels may be sufficiently high in the dose-response range that it is not possible to demonstrate a clinical effect with a RCT. When these issues are considered, it is possible that the changing pattern of fish consumption and fish oil use over time, especially in cardiac patients, can explain the disparity where benefit was observed in the early fish oil trials but not in the more recent trials.
    The British journal of nutrition. 06/2014;
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    ABSTRACT: BACKGROUND A recent review concluded that general health checks fail to reduce mortality in adults. AIM This review focuses on general practice-based health checks and their effects on both surrogate and final outcomes. DESIGN AND SETTING Systematic search of PubMed, Embase, and the Cochrane Central Register of Controlled Trials. METHOD Relevant data were extracted from randomised trials comparing the health outcomes of general practice-based health checks versus usual care in middle-aged populations. RESULTS Six trials were included. The end-point differences between the intervention and control arms in total cholesterol (TC), systolic and diastolic blood pressure (SBP, DBP), and body mass index (BMI) were -0.13 mmol/l (95% confidence interval [CI] = -0.19 to -0.07), -3.65 mmHg (95% CI = -6.50 to -0.81), -1.79 mmHg (95% CI = -2.93 to -0.64), and -0.45 kg/m(2) (95% CI = -0.66 to -0.24), respectively. The odds of a patient remaining at 'high risk' with elevated TC, SBP, DBP, BMI or continuing smoking were 0.63 (95% CI = 0.50 to 0.79), 0.59 (95% CI = 0.28 to 1.23), 0.63 (95% CI = 0.53 to 0.74), 0.89 (95% CI = 0.81 to 0.98), and 0.91 (95% CI = 0.82 to 1.02), respectively. There was little evidence of a difference in total mortality (OR 1.03, 95% CI = 0.90 to 1.18). Higher CVD mortality was observed in the intervention group (OR 1.30, 95% CI = 1.02 to 1.66). CONCLUSION General practice-based health checks are associated with statistically significant, albeit clinically small, improvements in surrogate outcome control, especially among high-risk patients. Most studies were not originally designed to assess mortality.
    British Journal of General Practice 01/2014; 64(618):e47-53. · 2.03 Impact Factor
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    ABSTRACT: -Surviving myocytes within scar may form channels that support ventricular tachycardia (VT) circuits. There is little data on the properties of channels that comprise VT circuits and those which are non-VT supporting channels. -In 22 patients with ischemic cardiomyopathy and VT, high-density mapping was performed with the PentaRay™ catheter and Ensite NavX™ system during sinus rhythm. A channel was defined as a series of matching pace-maps with a stimulus (S) to QRS time of ≥40ms. Sites were determined to be part of a VT channel if there were matching pace-maps to the VT morphology. This was confirmed with entrainment mapping when possible. Of the 238 channels identified, 57 channels corresponded to an inducible VT. Channels that were part of a VT circuit were more commonly located within dense scar than non-VT channels (97% vs 82%, p=0.036). VT supporting channels were of greater length (mean±SEM 53±5 vs 33±4mm), had higher longest S-QRS (130±12 vs 82±12ms), longer conduction time (103±14 vs 43±13ms) and slower conduction velocity (0.87±0.23 vs 1.39±0.21m/s) than non-VT channels (p<0.001). Of all the fractionated, late and very late potentials located in scar, only 21%, 26% and 29% respectively were recorded within VT channels. -High-density mapping shows substantial differences among channels in ventricular scar. Channels supporting VT are more commonly located in dense scar, longer than non-VT channels, and have slower conduction velocity. Only a minority of scar related potentials participate in the VT supporting channels.
    Circulation Arrhythmia and Electrophysiology 01/2014; · 5.95 Impact Factor
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    ABSTRACT: -Atrial fibrillation (AF) ablation is an established therapy; however, limited data is available on associated complications. This systematic review determines the incidence and potential predictors of acute complications. -Electronic searches were conducted in MEDLINE and EMBASE for English scientific literature up to the 18(th) June 2012. 2065-references were retrieved and evaluated for relevance. Reference lists of retrieved studies and review articles were examined to ensure all relevant studies were included. Data was extracted from 192-studies, total of 83,236-patients. The incidence of peri-procedural complications for catheter ablation of AF was 2.9% (95%CI, 2.6-3.2). There was a significant decrease in the acute complication rate in 2007-2012 compared to 2000-2006 (2.6% versus 4.0%, P=0.003). The complication rates reported were higher in prospective studies compared to those that retrospectively described complications (3.5% vs 2.7%, P= 0.03). There were no significant associations between procedure duration, ablation time, or ablation strategy, and acute complication rate. -Catheter ablation of AF has a low incidence of peri-procedural complications. The acute complication rate has decreased significantly in recent years. This may reflect improved catheter technology and experience. The use of different strategies across centers worldwide appears to be safe with no established relationship between procedural variables and complication rate.
    Circulation Arrhythmia and Electrophysiology 11/2013; · 5.95 Impact Factor
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    ABSTRACT: Background/objectives:Randomised controlled trials (RCTs) evaluating the effect of fish oil supplementation on postoperative atrial fibrillation (POAF) following cardiac surgery have produced mixed results. In this study, we examined relationships between levels of red blood cell (RBC) n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) and the incidence of POAF.Subjects/methods:We used combined data (n=355) from RCTs conducted in Australia and Iceland. The primary end point was defined as POAF lasting >10 min in the first 6 days following surgery. The odds ratios (ORs) for POAF were compared between quintiles of preoperative RBC n-3 LC-PUFA levels by multivariable logistic regression.Results:Subjects with RBC docosahexaenoic acid (DHA) in the fourth quintile, comprising a RBC DHA range of 7.0-7.9%, had the lowest incidence of POAF. Subjects in the lowest and highest quintiles had significantly higher risk of developing POAF compared with those in the fourth quintile (OR=2.36: 95% CI; 1.07-5.24 and OR=2.45: 95% CI; 1.16-5.17, respectively). There was no association between RBC eicosapentaenoic acid levels and POAF incidence.Conclusions:The results suggest a 'U-shaped' relationship between RBC DHA levels and POAF incidence. The possibility of increased risk of POAF at high levels of DHA suggests an upper limit for n-3 LC-PUFAs in certain conditions.European Journal of Clinical Nutrition advance online publication, 30 October 2013; doi:10.1038/ejcn.2013.215.
    European journal of clinical nutrition 10/2013; · 3.07 Impact Factor
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    ABSTRACT: The effects of fish oil (FO) in rheumatoid arthritis (RA) have not been examined in the context of contemporary treatment of early RA. This study examined the effects of high versus low dose FO in early RA employing a 'treat-to-target' protocol of combination disease-modifying anti-rheumatic drugs (DMARDs). Patients with RA <12 months' duration and who were DMARD-naïve were enrolled and randomised 2:1 to FO at a high dose or low dose (for masking). These groups, designated FO and control, were given 5.5 or 0.4 g/day, respectively, of the omega-3 fats, eicosapentaenoic acid + docosahexaenoic acid. All patients received methotrexate (MTX), sulphasalazine and hydroxychloroquine, and DMARD doses were adjusted according to an algorithm taking disease activity and toxicity into account. DAS28-erythrocyte sedimentation rate, modified Health Assessment Questionnaire (mHAQ) and remission were assessed three monthly. The primary outcome measure was failure of triple DMARD therapy. In the FO group, failure of triple DMARD therapy was lower (HR=0.28 (95% CI 0.12 to 0.63; p=0.002) unadjusted and 0.24 (95% CI 0.10 to 0.54; p=0.0006) following adjustment for smoking history, shared epitope and baseline anti-cyclic citrullinated peptide. The rate of first American College of Rheumatology (ACR) remission was significantly greater in the FO compared with the control group (HRs=2.17 (95% CI 1.07 to 4.42; p=0.03) unadjusted and 2.09 (95% CI 1.02 to 4.30; p=0.04) adjusted). There were no differences between groups in MTX dose, DAS28 or mHAQ scores, or adverse events. FO was associated with benefits additional to those achieved by combination 'treat-to-target' DMARDs with similar MTX use. These included reduced triple DMARD failure and a higher rate of ACR remission.
    Annals of the rheumatic diseases 09/2013; · 8.11 Impact Factor
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    ABSTRACT: QT variability (QTV) signifies repolarization lability and increased QTV is a risk predictor for sudden cardiac death. The aim of this study was to investigate the role of autonomic nervous system activity on QTV. The study was performed in 29 subjects: 10 heart failure patients with spontaneous ventricular tachycardia [HFVT(+)], 10 heart failure patients without spontaneous VT [HFVT(-)], 9 subjects with structurally normal hearts (HNorm). Beat-to-beat QT interval was measured on 3-minutes records of surface ECG at baseline and during interventions [atrial pacing, esmolol, isoprenaline and atropine infusion]. Variability in QT intervals was expressed as standard deviation of all QT intervals (SDQT). The ratio of SDQT to SDRR was calculated as an index of QTV normalized to heart rate variability. There was a trend towards higher baseline SDQT/SDRR in the HFVT(+) group compared to the HFVT(-) and HNorm groups (p=0.09). SDQT increased significantly in the HFVT(+) and HFVT(-) groups compared to HNorm patients during fixed rate atrial pacing (p=0.008). Compared to baseline, isoprenaline increased SDQT in the HNorm group (p=0.02), but not in HF patients. SDQT remained elevated in the HFVT(+) group relative to the HNorm group despite acute beta-adrenoceptor blockade with esmolol (p= 0.02). In conclusion, patients with HF and spontaneous VT have larger fluctuations in beat-to-beat QT intervals. This appears to be a genuine effect that is not solely a consequence of heart rate variation. The effect of acute autonomic nervous system modulation on QTV appears to be limited in HF patients.
    AJP Heart and Circulatory Physiology 08/2013; · 4.01 Impact Factor
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    ABSTRACT: BACKGROUND: Implantable Cardioverter Defibrillators (ICDs) have been demonstrated to reduce mortality in survivors of life-threatening arrhythmias (secondary prevention) and in patients at increased risk of sudden cardiac death (primary prevention). Other nations have reported significant increases in ICD use in recent years. We examined Australian nationwide trends of ICD procedures over a 10-year period (2000-2009). METHODS: A retrospective analysis of the Australian Institute of Health and Welfare's National Hospital Morbidity Database was performed to determine the annual number of ICD implantation and replacement procedures between 2000-2009. Rates were calculated using Australian Bureau of Statistics data on the annual estimated population. Time trends in the yearly procedure number and rate were analysed using negative binomial regression models with comparisons made by age and sex. RESULTS: The number of new ICD implantations increased from 708 to 3198 procedures between 2000-2009. Replacement procedures increased from 290 to 1378. The implantation rate (per million) increased from 37.0 to 145.6 and the replacement rate from 15.1 to 62.7. When rates were adjusted for age and sex, the implantation rate increased annually by 15.8% and the replacement rate by 16.6% (p<0.0001). Procedures occurred most commonly in men (implantations: 80.1%; replacements: 78.0%) between ages 70-79. CONCLUSIONS: ICD procedures increased significantly in Australia between 2000-2009. Despite these increases, other studies have suggested ICD devices are currently under-utilised. During the study period, males accounted for the majority of ICD procedures. While there are numerous reasons for this, it is not known if device under-use is more common in females.
    Internal Medicine Journal 06/2013; · 1.82 Impact Factor
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    ABSTRACT: Although most of the additional increases in coronary heart disease morbidity and mortality are estimated to occur outside developed regions such as North America and Europe, few nationwide studies have been published of acute myocardial infarction (MI) epidemiology from other regions. We thus sought to expand the global data regarding MI trends. Nationwide trends of incident MI, ST-segment elevation MI (STEMI), and non-ST-segment MI (non-STEMI) were analyzed during a 17-year period in Australia. We identified 714,262 hospitalizations for MI from 1993 to 2010, representing 331,871,389 person-years. During the study period, the age- and gender-adjusted incidence of all MIs increased from 215 to 251 cases per 100,000 person-years, a relative increase of 76% (p <0.0001 for trend). The adjusted incidence of STEMI decreased from 147 to 70 cases per 100,000 person-years, a relative decrease of 30% (p <0.0001 for trend). In contrast, the adjusted incidence of non-STEMI increased from 67 to 182 cases per 100,000 person-years, a relative increase of 315% (p <0.0001 for trend). Age-specific analyses suggested that statistically significant increases in MI incidence were present in those aged <50 and ≥80 years. In conclusion, although it has previously been suggested that declining trends in MI incidence in North American and European reports might be generalizable given the seemingly consistent observations thus far, the present results highlight the possibility that other global populations might have less favorable trends. The incidence of MI in Australia might not be decreasing as rapidly as that seen in other regions and requires additional exploration.
    The American journal of cardiology 04/2013; · 3.58 Impact Factor
  • Clinical Orthopaedics and Related Research 03/2013; · 2.79 Impact Factor
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    ABSTRACT: BACKGROUND: The Paprosky acetabular defect classification is widely used but has not been appropriately validated. Reliability of the Paprosky system has not been evaluated in combination with standardized techniques of measurement and scoring. QUESTIONS/PURPOSES: This study evaluated the reliability, teachability, and validity of the Paprosky acetabular defect classification. METHODS: Preoperative radiographs from a random sample of 83 patients undergoing 85 acetabular revisions were classified by four observers, and their classifications were compared with quantitative intraoperative measurements. Teachability of the classification scheme was tested by dividing the four observers into two groups. The observers in Group 1 underwent three teaching sessions; those in Group 2 underwent one session and the influence of teaching on the accuracy of their classifications was ascertained. RESULTS: Radiographic evaluation showed statistically significant relationships with intraoperative measurements of anterior, medial, and superior acetabular defect sizes. Interobserver reliability improved substantially after teaching and did not improve without it. The weighted kappa coefficient went from 0.56 at Occasion 1 to 0.79 after three teaching sessions in Group 1 observers, and from 0.49 to 0.65 after one teaching session in Group 2 observers. CONCLUSIONS: The Paprosky system is valid and shows good reliability when combined with standardized definitions of radiographic landmarks and a structured analysis. LEVEL OF EVIDENCE: Level II, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.
    Clinical Orthopaedics and Related Research 02/2013; · 2.79 Impact Factor
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    ABSTRACT: In the past decade, catheter ablation has become an established therapy for symptomatic atrial fibrillation (AF). Until very recently, few data have been available to guide the clinical community on the outcomes of AF ablation at ≥3 years of follow-up. We aimed to systematically review the medical literature to evaluate the long-term outcomes of AF ablation. A structured electronic database search (PubMed, Embase, Web of Science, Cochrane) of the scientific literature was performed for studies describing outcomes at ≥3 years after AF ablation, with a mean follow-up of ≥24 months after the index procedure. The following data were extracted: (1) single-procedure success, (2) multiple-procedure success, and (3) requirement for repeat procedures. Data were extracted from 19 studies, including 6167 patients undergoing AF ablation. Single-procedure freedom from atrial arrhythmia at long-term follow-up was 53.1% (95% CI 46.2% to 60.0%) overall, 54.1% (95% CI 44.4% to 63.4%) in paroxysmal AF, and 41.8% (95% CI 25.2% to 60.5%) in nonparoxysmal AF. Substantial heterogeneity (I(2)>50%) was noted for single-procedure outcomes. With multiple procedures, the long-term success rate was 79.8% (95% CI 75.0% to 83.8%) overall, with significant heterogeneity (I(2)>50%).The average number of procedures per patient was 1.51 (95% CI 1.36 to 1.67). Catheter ablation is an effective and durable long-term therapeutic strategy for some AF patients. Although significant heterogeneity is seen with single procedures, long-term freedom from atrial arrhythmia can be achieved in some patients, but multiple procedures may be required.
    Journal of the American Heart Association. 01/2013; 2(2):e004549.
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    ABSTRACT: AIM: To determine the effect of neonatal docosahexaenoic acid (DHA) supplementation in preterm infants on later respiratory-related hospitalisations. METHODS: We enrolled 657 infants in a multicentre, randomised, controlled trial designed to study the long-term efficacy of higher dose dietary DHA in infants born <33 weeks' gestation. Treatment was with high DHA (∼1%) compared with standard DHA (∼0.3%) in breast milk or formula, given from the first week of life to term equivalent. Parent-reported hospital admissions to 18 months corrected age were recorded. The proportion of children hospitalised for lower respiratory tract (LRT) conditions and the mean number of hospitalisations per infant were determined. RESULTS: Twenty-three per cent (154/657) of infants were hospitalised for LRT conditions. Seventy-three per cent (173/238) of admissions were for bronchiolitis. There was no significant effect of higher DHA on the proportion of infants admitted for LRT conditions (high DHA 22% vs. standard DHA 25%, adjusted relative risk 0.92, 95% confidence interval (CI) 0.68-1.24, P = 0.57) or in the mean number of admissions per infant (high DHA 0.34, standard DHA 0.38, adjusted ratio of means 0.91, 95% CI 0.63-1.32, P = 0.62). The sexes responded differently to treatment (interaction P = 0.046), with reduced admissions in boys given high DHA, but this was not statistically significant (high DHA 19%, standard DHA 28%, adjusted relative risk 0.69, 95% CI 0.46-1.04, P = 0.08). CONCLUSIONS: Hospitalisation for LRT problems in the first 18 months for preterm infants was not reduced by neonatal supplementation with 1% DHA.
    Journal of Paediatrics and Child Health 12/2012; · 1.25 Impact Factor
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    ABSTRACT: Ablation has substantial evidence base in the management of ventricular arrhythmia (VA). It can be a 'lifesaving' procedure in the acute setting of VA storm. Current reports on ablation in VA storm are in the form of small series and have relative small representation in a large observational series. The purpose of this study was to systematically synthesize the available literature to appreciate the efficacy and safety of ablation in the setting of VA storm. The medical electronic databases through 31 January 2012 were searched. Ventricular arrhythmia storm was defined as recurrent (≥3 episodes or defibrillator therapies in 24 h) or incessant (continuous >12 h) VA. Studies reporting data on VA storm patients at the individual or study level were included. A total of 471 VA storm patients from 39 publications were collated for the analysis. All VAs were successfully ablated in 72% [95% confidence interval (CI) 71-89%] and 9% (95% CI: 3-10%) had a failed procedure. Procedure-related mortality occurred in three patients (0.6%). Only 6% patients had a recurrence of VA storm. The recurrence of VA was significantly higher after ablation for arrhythmic storm of monomorphic ventricular tachycardia (VT) relative to ventricular fibrillation or polymorphic VT with underlying cardiomyopathy (odds ratio 3.76; 95% CI: 1.65-8.57; P = 0.002). During the follow-up (61 ± 37 weeks), 17% of patients died (heart failure 62%, arrhythmias 23%, and non-cardiac 15%) with 55% deaths occurring within 12 weeks of intervention. The odds of death were four times higher after a failed procedure compared with those with a successful procedure (95% CI: 2.04-8.01, P < 0.001). Ventricular arrhythmia storm ablation has high-acute success rates, with a low rate of recurrent storms. Heart failure is the dominant cause of death in the long term. Failure of the acute procedure carries a high mortality.
    European Heart Journal 12/2012; · 14.72 Impact Factor
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    ABSTRACT: Recent reports have described that hospitalizations for atrial fibrillation (AF) are continuing to increase. Given that hospitalizations are responsible for most of the economic burden associated with AF, the aim of this study was to characterize the impact of age and how changing procedural practices may be contributing to the increasing rates of AF hospitalizations. The annual age- and gender-specific incidence of hospitalizations for AF, electrical cardioversions, electrophysiologic studies, and radiofrequency ablation procedures in Australia were determined from 1993 to 2007 inclusive. Over this 15-year follow-up period spanning almost 300 million person-years, a total of 473,501 hospitalizations for AF were identified. There was a relative increase in AF hospitalizations of 203% over the study period, in contrast to an increase for all hospitalizations of only 71%. Whereas the gender-specific incidence of hospitalizations remained stable, the age-specific incidence increased significantly over the study period, particularly in older age groups. AF hospitalizations associated with electrical cardioversions decreased from 27% to 14% over the study period. Electrophysiologic studies and radiofrequency ablation procedures contributed minimally to the overall increase in AF hospitalizations observed. In conclusion, in addition to the growing prevalence of AF because of the aging population, there is an increasing age-specific incidence of hospitalizations for AF, particularly in older age groups. In contrast, changing procedural trends have contributed minimally to the increasing number of AF-associated hospitalizations. Greater attention to older patients with AF is required to develop strategies to prevent hospitalizations and contain the growing burden on health care systems.
    The American journal of cardiology 08/2012; · 3.58 Impact Factor
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    ABSTRACT: In the ovarian follicular membrana granulosa there are morphological and functional differences between cells adjacent to the follicular fluid lumen, or aligning the basal lamina. Amongst the observed functional differences are steroidogenic capacity and expression levels of a novel basal lamina, focimatrix; both of which increase in the later stages of antral follicle growth. A number of different studies have produced apparently inconsistent results as to which cell layers are more steroidogenic. To examine this systematically, individual bovine follicles, confirmed as healthy by post hoc histological examination, were used to isolate populations of apical and basal granulosa cells. Cell counts revealed that the respective groups did not differ in the numbers of cells, thus confirming the separation of these populations. We measured gene expression (quantitative RT-PCR, n=8-10, follicle diameter 14.0±0.5mm) and protein levels (Western immunoblotting, n=14, follicle diameter 11.9±0.5mm) and hormone production from granulosa cells (2.5×10(5) viable cells/well in serum-free conditions for 24h, n=15, diameter 12±0.5mm). Levels of mRNA of HSD3B1 and CYP19A1 and three focimatrix genes COL4A1, HSPG2 and LAMB2 and LHCGR were significantly lower in apical granulosa cells (P<0.05), whereas, expression of CYP11A1 and HSD17B1 were not different (P>0.05). The protein levels of steroidogenic enzymes P450scc and P450arom were significantly higher in apical cells (P<0.05), whereas those of 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase type 1 were not different (P>0.05). Progesterone production was significantly lower and oestradiol production was significantly higher in apical granulosa cells (P<0.05). These results confirm that apical and basal cells are functionally different, and the differences might be explained by the location of cells of different ages and maturity within the membrana granulosa. Discrepancies in the literature on their steroidogenic capacity may reflect differences in the steroidogenic parameters measured.
    Molecular and Cellular Endocrinology 08/2012; 363(1-2):62-73. · 4.04 Impact Factor
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    ABSTRACT: The left atrial appendage (LAA) has been suggested to be the dominant location of thrombus in atrial fibrillation (AF) and has led to the development of LAA occlusion as a therapeutic modality to reduce stroke risk. However, the patient populations that would benefit most from this therapy are not well defined. A systematic review was performed to better define subgroups amenable to appendage closure. The English scientific literature was searched using Pubmed through to March 1, 2011. Reference lists of relevant and review articles were screened to retrieve additional articles. Studies were only included if they described the location of thrombus in left atrium. Case reports and case series describing less than 10 thrombi were excluded. Two reviewers independently extracted data and assessed quality of each study. A total of 34 studies reporting on the location of atrial thrombus in patients with AF were included: 17 in valvular AF, 10 non-valvular AF and 8 in mixed valvular and non-valvular AF. Atrial thrombi were located outside the LAA in 56% (95% CI 53, 60) of valvular AF, 22% (95% CI 19, 25) in mixed cohorts and 11% (95% CI 6, 15) non-valvular AF. In non valvular AF, the studies with higher proportion of thrombi in the left atrial cavity had non-anticoagulated patients and a greater proportion of ventricular dysfunction and history of stroke. The location of atrial thrombus in patients with AF is dependent on the underlying substrate. In valvular AF, more than half the thrombi are located in the left atrial cavity. In the non-valvular AF group, a smaller proportion of thrombi were located outside the appendage. However, in certain subgroups (ie. non anti-coagulated, left ventricular dysfunction or prior stroke) the chances of left atrial cavity thrombus are higher.
    Heart (British Cardiac Society) 05/2012; 98(15):1120-6. · 5.01 Impact Factor
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    ABSTRACT: Positron emission tomography (PET) is an integral part of tumor staging for patients with esophageal cancer. Recent studies suggest a role for PET scan in predicting survival in these patients, but this relationship is unclear in the setting of neoadjuvant therapy. We examined pretreatment maximum standard uptake value (SUV(max)) of the primary tumor in patients treated with and without neoadjuvant therapy. All patients undergoing esophagectomy with a preoperative PET scan over a nine-year period (2001-2010) were identified from a prospectively maintained database. Positron emission tomography data were obtained from computers housing the original PET scans. Overall survival was correlated with SUV(max) of the primary tumor. A total of 191 patients were identified, and 103 patients met inclusion criteria. Eighty-two had an adenocarcinoma (80%), and 21 (20%) had a squamous cell carcinoma. Fifty-seven (55%) patients received neoadjuvant therapy. In the surgery alone group, a SUV(max) of > 5.0 in the primary tumor was associated with poor prognosis [Hazard Ratio (HR) 0.32; p = 0.007], but this factor did not retain its significance on multivariate analysis (HR 0.65; p = 0.43). Pretreatment SUV(max) in patients who underwent neoadjuvant therapy was not significant in predicting overall survival (p = 0.10). This study does not support the use of SUV(max) on pretreatment PET scans as a prognostic tool for patients with esophageal cancer, especially in those who have received neoadjuvant therapy. Lymph node status is a more accurate predictor of outcome, and efforts to improve pretreatment staging should focus on this factor.
    World Journal of Surgery 02/2012; 36(5):1089-95. · 2.23 Impact Factor
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    ABSTRACT: There is increasing evidence of the role direction-dependent conduction plays in the arrhythmogenic interaction between ectopic triggers and abnormal atrial substrates. We thus sought to characterize direction-dependent conduction in chronically stretched atria. Twenty-four patients with chronic atrial stretch due to mitral stenosis and 24 reference patients with left-sided accessory pathways were studied. Multipolar catheters placed at the lateral right atrium, crista terminalis, and coronary sinus (CS) characterized direction-dependent conduction along linear catheters and across the crista terminalis. Bi-atrial electroanatomic maps were created in both sinus rhythm and an alternative wavefront direction by pacing from the distal CS. This allowed an assessment of conduction velocities, electrogram, and voltage characteristics during wavefronts propagating in different directions. While differing wavefront directions caused changes in both chronic atrial stretch and reference patients (P< 0.001 for all), these direction-dependent changes were greater in chronic atrial stretch compared with reference patients, who exhibited greater slowing in conduction velocities (P= 0.09), prolongation of bi-atrial activation time (P= 0.04), increase in number (P< 0.001) and length (P< 0.001) of lines of conduction block, increase in fractionated electrograms (P< 0.001), and decrease in voltage (P= 0.08) during left-to-right compared with right-to-left atrial activation. These direction-dependent changes were associated with a greater propensity for chronically stretched atria to develop atrial fibrillation (P= 0.02). Atrial remodelling in chronic atrial stretch exacerbates physiological direction-dependent conduction characteristics. Our data suggest that the greater direction-dependent conduction seen in patients with chronic atrial stretch may promote arrhythmogenesis due to ectopic triggers from the left atrium.
    Europace 02/2012; 14(7):954-61. · 2.77 Impact Factor
  • Heart, Lung and Circulation. 01/2012; 21:S130.

Publication Stats

259 Citations
170.57 Total Impact Points

Institutions

  • 2009–2014
    • University of Adelaide
      • • Discipline of Public Health
      • • Centre for Heart Rhythm Disorders (CHRD)
      • • Research Centre for Reproductive Health
      Tarndarnya, South Australia, Australia
  • 2012
    • Royal Adelaide Hospital
      • Centre for Heart Rhythm Disorders
      Tarndarnya, South Australia, Australia