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Featured researches published by Andrew Newcomb.


Eurointervention | 2014

Transfemoral aortic valve replacement with the repositionable Lotus Valve System in high surgical risk patients: the REPRISE I study.

Ian T. Meredith; Stephen G. Worthley; Robert Whitbourn; Paul Antonis; Joseph Montarello; Andrew Newcomb; Siohban Lockwood; Nicole Haratani; Dominic J. Allocco; Keith D. Dawkins

AIMS To assess outcomes with a new fully repositionable and retrievable valve for transcatheter aortic valve replacement (TAVR). METHODS AND RESULTS The Lotus Aortic Valve System is designed to facilitate precise positioning and minimise paravalvular regurgitation. REPRISE I enrolled symptomatic, high-surgical-risk patients with severe aortic stenosis. The primary endpoint (clinical procedural success) included successful implantation without major adverse cardiovascular or cerebrovascular events (MACCE). In all patients (N=11) the first Lotus Valve was successfully deployed. Partial resheathing to facilitate accurate placement was attempted and successfully performed in four patients; none required full retrieval. The primary endpoint was achieved in 9/11 with no in-hospital MACCE in 10/11. There was one major stroke; in another patient, discharge mean aortic gradient was 22 mmHg (above the primary endpoint threshold of 20 mmHg), but improved to 15 mmHg at 30 days. The cohorts mean aortic gradient decreased from 53.9±20.9 mmHg at baseline to 15.4±4.6 mmHg (p<0.001) at one year; valve area increased from 0.7±0.2 cm2 to 1.5±0.2 cm2 (p<0.001). Discharge paravalvular aortic regurgitation, adjudicated by an independent core laboratory, was mild (n=2), trivial (n=1), or absent (n=8). Four patients required a permanent pacemaker post-procedure. There were no deaths, myocardial infarctions or new strokes through one year. CONCLUSIONS Initial results support proof-of-concept with the Lotus Valve for TAVR.


American Journal of Cardiology | 2012

Usefulness of postoperative atrial fibrillation as an independent predictor for worse early and late outcomes after isolated coronary artery bypass grafting (multicenter Australian study of 19,497 patients).

Akshat Saxena; D. Dinh; Julian Smith; Gilbert Shardey; Christopher M. Reid; Andrew Newcomb

Several studies have shown that postoperative atrial fibrillation (POAF) is associated with poorer short- and long-term outcomes after isolated coronary artery bypass grafting surgery. Nevertheless, there is considerable debate as to whether this reflects an independent association of POAF with poorer outcomes or confounding by other factors. We sought to investigate this issue. Data obtained from June 2001 through December 2009 by the Australasian Society of Cardiac and Thoracic Surgeons National Cardiac Surgery Database Program were retrospectively analyzed. Demographic and operative data were compared between patients who developed POAF and those who did not using chi-square and t tests. The independent impact of POAF on 14 short-term complications and long-term mortality was determined using binary logistic and Cox regression, respectively. Excluding patients with preoperative arrhythmia, isolated coronary artery bypass grafting surgery was performed in 19,497 patients. Of these, 5,547 (28.5%) developed POAF. Patients with POAF were generally older (mean age 69 vs 65 years, p <0.001) and presented more often with co-morbidities including congestive heart failure (p <0.001), hypertension (p <0.001), cerebrovascular disease (p <0.001), and renal failure (p = 0.046). Patients with POAF demonstrated a greater 30-day mortality on univariate analysis but not on multivariate analysis (p = 0.376). Patients with POAF were, however, at an independently increased risk of perioperative complications including permanent stroke (p <0.001), new renal failure (p <0.001), infective complications (p <0.001), gastrointestinal complications (p <0.001), and return to the theater (p <0.001). POAF was also independently associated with shorter long-term survival (p = 0.002). In conclusion, POAF is a risk factor for short-term morbidity and decreased long-term survival. Rigorous evaluation of various therapies that prevent or decrease the impact of POAF is imperative. Moreover, patients who develop POAF should undergo strict surveillance and be routinely screened for complications after discharge.


European Journal of Cardio-Thoracic Surgery | 2012

Sex differences in outcomes following isolated coronary artery bypass graft surgery in Australian patients: analysis of the Australasian Society of Cardiac and Thoracic Surgeons cardiac surgery database

Akshat Saxena; D. Dinh; Julian Smith; Gilbert Shardey; Christopher M. Reid; Andrew Newcomb

OBJECTIVES Women undergoing isolated coronary artery bypass graft (CABG) surgery have been previously shown to be at an independently increased risk for post-operative morbidity and mortality. The current study evaluates the impact of sex as an independent risk factor for early and late morbidity and mortality following isolated CABG surgery. METHODS Data obtained between June 2001 and December 2009 by the Australasian Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database Program was retrospectively analysed. Demographic, operative data and post-operative complications were compared between male and female patients using chi-square and t-tests. Long-term survival analysis was performed using Kaplan-Meier survival curves and the log-rank test. Independent risk factors for short- and long-term mortality were identified using binary logistic and Cox regression, respectively. RESULTS CABG surgery was undertaken in 21 534 patients at 18 Australian institutions; 22.2% were female. Female patients were generally older (mean age, 68 vs. 65 years, P < 0.001) and presented more often with congestive heart failure (P < 0.001), hypertension (P < 0.001), diabetes mellitus (P < 0.001) and cerebrovascular disease (P < 0.001). Women demonstrated a greater 30-day mortality (2.2% vs. 1.5%, P < 0.001) on univariate analysis but not on multivariate analysis (P = 0.638). Similarly, women demonstrated a greater late mortality than men on univariate analysis (P = 0.006) but not on multivariate analysis (P = 0.093). Women had a decreased risk of early complications including new renal failure (P = 0.001) and deep sternal wound infection (P = 0.017) but were more likely to require red blood cell transfusion (P < 0.001). CONCLUSIONS Female patients undergoing isolated CABG surgery have a greater 30-day mortality which may be accounted for by a poorer pre-operative risk factor profile. Further investigation is required into the reasons for differential outcome after CABG based on sex.


Transfusion | 2013

The association of blood transfusion with mortality after cardiac surgery: cause or confounding? (CME)

Barry Dixon; John D. Santamaria; David A Reid; Marnie Collins; Thomas Rechnitzer; Andrew Newcomb; Ian Nixon; Michael Yii; Alexander Rosalion; Duncan J. Campbell

BACKGROUND: Bleeding into the chest is a life‐threatening complication of cardiac surgery. Blood transfusion has been implicated as an important cause of harm associated with bleeding, based largely on studies demonstrating an independent association between transfusion and mortality. These studies did not, however, consider the possibility that bleeding may in itself be harmful, inasmuch as drains are inefficient at clearing blood from the chest and retained blood may compromise cardiac and lung function.


The Journal of Thoracic and Cardiovascular Surgery | 2013

A systematic review on the quality of life benefits after aortic valve replacement in the elderly.

Leonard Shan; Akshat Saxena; Ross McMahon; A. Wilson; Andrew Newcomb

BACKGROUND Surgical aortic valve replacement is being increasingly performed in elderly patients with good perioperative outcomes and long-term survival. Evidence is limited on health-related quality of life after aortic valve replacement, which is an important measure of operative success in the elderly. METHODS A systematic review of clinical studies after January 2000 was performed to identify health-related quality of life in the elderly after aortic valve replacement. Strict inclusion and exclusion criteria were applied. Quality appraisal of each study also was performed using predefined criteria. Health-related quality of life results were synthesized through a narrative review with full tabulation of the results of all included studies. RESULTS Health-related quality of life improvements were shown across most or all domains in different health-related quality of life instruments. Elderly patients experienced marked symptomatic improvement. Health-related quality of life was equivalent or superior to both an age-matched population and younger patients undergoing identical procedures. There were excellent functional gains after surgery, but elderly patients remain susceptible to geriatric issues and mood problems. Concomitant coronary artery bypass did not affect health-related quality of life. There was a diverse range of study designs, methods, and follow-up times that limited direct comparison between studies. CONCLUSIONS Aortic valve replacement results in significant health-related quality of life benefits across a broad range of health domains in elderly patients. Age alone should not be a precluding factor for surgery. Data are heterogeneous and mostly retrospective. We recommend future studies based on consistent guidelines provided in this systematic review.


The Annals of Thoracic Surgery | 2011

Critical analysis of early and late outcomes after isolated coronary artery bypass surgery in elderly patients.

Akshat Saxena; D. Dinh; Cheng-Hon Yap; Christopher M. Reid; Baki Billah; Julian Smith; Gilbert Shardey; Andrew Newcomb

BACKGROUND The proportion of elderly (≥80 years) patients undergoing coronary artery bypass surgery (CABG) is increasing. METHODS A retrospective analysis of data, collected by the Australasian Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database Program between June 2001 and December 2009 was performed. Isolated CABG was performed in 21,534 patients; of these, 1,664 (7.7%) were at least 80 years old (group 1). Patient characteristics, morbidity, and short-term mortality of these patients were compared with those aged less than 80 years (group 2). The long-term outcome of group 1 patients after CABG surgery was compared with an age and sex-matched Australian population. RESULTS Patients over 80 years old were more likely to be female (36.6% vs 17.3%, p < 0.001) and presented significantly more often with heart failure, hypertension, and triple-vessel disease (all p < 0.05). The 30-day mortality was higher in group 1 patients (4.2% vs 1.5%, p < 0.001). Group 1 patients also had an increased risk of complications, including prolonged (>24 hours) ventilation (14.2% vs 8.2%, p < 0.001), renal failure (7.3% vs 3.4%, p < 0.001), and mean intensive care unit stay (60.7 vs 42.5 hours, p < 0.001). The 5-year survival of elderly patients (73%) was comparable with the age-matched Australian population. Independent risk factors for 30-day mortality in group 1 patients included preoperative renal failure (p = 0.010), congestive heart failure (p = 0.014), and a nonelective procedure (p = 0.016). CONCLUSIONS Elderly patients who undergo isolated CABG have significantly lower perioperative risks than have been previously reported. The long-term survival of these patients is comparable with an age-adjusted population.


Hypertension | 2011

Differences in Myocardial Structure and Coronary Microvasculature Between Men and Women With Coronary Artery Disease

Duncan J. Campbell; J. Somaratne; Alicia J. Jenkins; David L. Prior; Michael Yii; James F. Kenny; Andrew Newcomb; Darren J. Kelly; Mary Jane Black

Women younger than 75 years with stable angina or acute coronary syndrome have higher cardiac mortality than similarly aged men, despite less obstructive coronary artery disease. To determine whether the myocardial structure and coronary microvasculature of women differs from that of men, we performed histological analysis of biopsies from nonischemic left ventricular myocardium from 46 men and 11 women undergoing coronary artery bypass graft surgery who did not have previous cardiac surgery, myocardial infarction, heart failure, atrial fibrillation, or furosemide therapy. The 2 patient groups had similar clinical characteristics, apart from a lower body surface area (BSA) in women (P=0.0015). Women had less interstitial fibrosis than men (P=0.019) but similar perivascular fibrosis. Arteriolar wall area/circumference ratio, a measure of arteriolar wall thickness, was 47% greater in women than men (P=0.012). Cardiomyocyte width and diffusion radius were positively correlated, and capillary length density was negatively correlated with BSA (P<0.05). Whereas cardiomyocyte width, capillary length density, diffusion radius, and cardiomyocyte width/BSA ratio were similar for men and women, women had a greater diffusion radius/BSA ratio (P=0.0038) and a greater diffusion radius/cardiomyocyte width ratio (P=0.027). Women also had lower vascular endothelial growth factor (VEGF) receptor-1 levels (P=0.048) and VEGF receptor-1/VEGF-A ratio (P=0.024) in plasma. We conclude that women with extensive coronary artery disease have greater arteriolar wall thickness and diffusion radius relative to BSA and to cardiomyocyte width than men, which may predispose to myocardial ischemia. Additional studies of larger numbers of women with less extensive coronary artery disease are required to confirm these findings.


Jacc-cardiovascular Interventions | 2009

Does Prior Percutaneous Coronary Intervention Adversely Affect Early and Mid-Term Survival After Coronary Artery Surgery?

Cheng-Hon Yap; Bryan P. Yan; Enoch Akowuah; D. Dinh; Julian Smith; Gilbert Shardey; James Tatoulis; Peter D. Skillington; Andrew Newcomb; Morteza Mohajeri; Adrian Pick; Siven Seevanayagam; Christopher M. Reid

OBJECTIVES To determine the association between previous percutaneous coronary intervention (PCI) and results after coronary artery bypass graft surgery (CABG). BACKGROUND Increasing numbers of patients undergoing CABG have previously undergone PCI. METHODS We analyzed consecutive first-time isolated CABG procedures within the Australasian Society of Cardiac and Thoracic Surgeons Database from June 2001 to May 2008. Logistic regression and propensity score analyses were used to assess the risk-adjusted impact of prior PCI on in-hospital mortality and major adverse cardiac events. Cox regression model was used to assess the effect of prior PCI on mid-term survival. RESULTS Of 13,184 patients who underwent CABG, 11,727 had no prior PCI and 1,457 had prior PCI. Mean follow-up was 3.3 +/- 2.1 years. Patients without prior PCI had a higher EuroSCORE value (4.4 +/- 3.3 vs. 3.6 +/- 3.0, p < 0.001), were older, and more likely to have left main stem stenosis and recent myocardial infarction. There was no difference in unadjusted in-hospital mortality (1.65% vs. 1.55%, p = 0.78) or major adverse cardiac events (3.0% vs. 3.0%, p = 0.99) between patients with or without prior PCI. After adjustment, prior PCI was not a predictor of in-hospital (odds ratio: 1.22, 95% confidence interval [CI]: 0.76 to 2.0, p = 0.41) or mid-term mortality at 6-year follow-up (hazard ratio: 0.94, 95% CI: 0.75 to 1.18, p = 0.62). CONCLUSIONS In this large registry study, prior PCI was not associated with increased short- or mid-term mortality after CABG. Good outcomes can be obtained in the group of patients undergoing CABG who have had previous PCI.


Circulation | 2013

Coronary Artery Bypass Graft Surgery in the Elderly A Review of Postoperative Quality of Life

Leonard Shan; Akshat Saxena; Ross McMahon; Andrew Newcomb

As a result of a rapidly ageing population and increasing incidence of coronary artery disease (CAD), the demand for coronary artery bypass graft surgery (CABG) in the elderly is growing. Almost 25% of all patients undergoing CABG are >70 years of age.1 Contemporary studies focus on health-related quality of life (HRQOL) following CABG, which is a key measure of operative success in the elderly. However, HRQOL outcomes remain unclear. This review provides an evidence-based overview of the HRQOL data from the literature in elderly patients undergoing CABG. To identify HRQOL outcomes, a literature search was conducted in August 2012 on PubMed by using the medical subject headings terms (MeSH) “Cardiac Surgical Procedures” and “Coronary Artery Bypass” and “Quality of Life” and “Elderly,” not “Angioplasty, Transluminal, Percutaneous Coronary” not “Heart Defects, Congenital” not “Heart Transplantation.” A manual search of EMBASE, DISCOVERY, and MEDLINE, and bibliographies of included studies, as well, was also conducted to identify any other studies not retrieved by the initial search. We identified 18 studies published in English since the year 2000 (Figure).2–19 Figure. Search algorithm.2–19 HRQOL indicates health-related quality of life. According to the United Nations Population Division, the world’s population is ageing at a rapid and unprecedented rate. Within developed countries, the proportion of people >60 years of age is projected to double from 11% to 22% by 2050, constituting 2 billion people.20 In this time period, the number of very elderly people >80 years of age is projected to increase by a factor of 26 in comparison with a factor of 3.7 for overall world population.20 Recent data from the American Heart Association’s Heart Disease and Stroke 2012 Update shows >16 million American adults have CAD with a prevalence exceeding 80% in those >80 years of …


European Journal of Cardio-Thoracic Surgery | 2011

Early and late outcomes after isolated aortic valve replacement in octogenarians: an Australasian Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database Study

Akshat Saxena; Chin-Leng Poh; D. Dinh; Christopher M. Reid; Julian Smith; Gilbert Shardey; Andrew Newcomb

OBJECTIVE The advent of percutaneous aortic valve implantation has increased interest in the outcomes of conventional aortic valve replacement in elderly patients. The current study critically evaluates the short-term and long-term outcomes of elderly (≥80 years) Australian patients undergoing isolated aortic valve replacement. METHODS Data obtained prospectively between June 2001 and December 2009 by the Australasian Society of Cardiac and Thoracic Surgeons National Cardiac Surgery Database Program were retrospectively analysed. Isolated aortic valve replacement was performed in 2791 patients; of these, 531 (19%) were at least 80 years old (group 1). The patient characteristics, morbidity and short-term mortality of these patients were compared with those of patients who were <80 years old (group 2). The long-term outcomes in elderly patients were compared with the age-adjusted Australian population. RESULTS Group 1 patients were more likely to be female (58.6% vs 38.0%, p<0.001) and presented more often with co-morbidities including hypertension, cerebrovascular disease and peripheral vascular disease (all p<0.05). The 30-day mortality rate was not independently higher in group 1 patients (4.0% vs 2.0%, p=0.144). Group 1 patients had an independently increased risk of complications including new renal failure (11.7% vs 4.2%, p<0.001), prolonged (≥24 h) ventilation (12.4% vs 7.2%, p=0.003), gastrointestinal complications (3.0% vs 1.3%, p=0.012) and had a longer mean length of intensive care unit stay (64 h vs 47 h, p<0.001). The 5-year survival post-aortic valve replacement was 72%, which is comparable to that of the age-matched Australian population. CONCLUSION Conventional aortic valve replacement in elderly patients achieves excellent outcomes with long-term survival comparable to that of an age-adjusted Australian population. In an era of percutaneous aortic valve implantation, it should still be regarded as the gold standard in the management of aortic stenosis.

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Akshat Saxena

Royal Prince Alfred Hospital

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Michael Yii

St. Vincent's Health System

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Philip Davis

St. Vincent's Health System

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Alexander Rosalion

St. Vincent's Health System

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A. Wilson

St. Vincent's Health System

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Ian Nixon

St. Vincent's Health System

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