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Dive into the research topics where Robert Lew is active.

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Featured researches published by Robert Lew.


Catheterization and Cardiovascular Interventions | 2007

An evaluation of octogenarians undergoing percutaneous coronary intervention from the Melbourne Interventional Group registry

Bryan P. Yan; Ronen Gurvitch; S. Duffy; David J. Clark; M. Sebastian; G. New; R. Warren; J. Lefkovits; Robert Lew; A. Brennan; Christopher M. Reid; Nick Andrianopoulos; Andrew E. Ajani

The objective of this study was to evaluate the clinical characteristics and outcomes of octogenarians (≥80 years of age) in a contemporary, multi‐centre percutaneous coronary intervention (PCI) registry.


American Journal of Cardiology | 2008

Rates of Stent Thrombosis in Bare-Metal Versus Drug-Eluting Stents (from a Large Australian Multicenter Registry)

Bryan P. Yan; S. Duffy; David J. Clark; J. Lefkovits; Roderic Warren; Ronen Gurvitch; Robert Lew; M. Sebastian; A. Brennan; Nick Andrianopoulos; Christopher M. Reid; Andrew E. Ajani

Recent reports suggest that drug-eluting stents (DESs) may increase the risk of stent thrombosis (ST) relative to bare-metal stents (BMSs). Therefore, the aim of this study was to compare DES and BMS outcomes with a specific focus on ST. We analyzed 30-day and 1-year outcomes of 2,919 patients who underwent percutaneous coronary intervention with stent implantation from the Melbourne Interventional Group registry. Academic Research Consortium definitions of ST were used: (1) definite ST (confirmed using angiography in patients with an acute coronary syndrome), (2) probable ST (unexplained death <30 days or target-vessel myocardial infarction without angiographic confirmation), and (3) possible ST (unexplained death >30 days). Multivariate analysis was performed to identify predictors of ST. The incidence of ST (early or late) was similar between BMSs and DESs (1.6% vs 1.4%; p=0.66), and DES use was not predictive of ST. Independent predictors of ST included the absence of clopidogrel therapy at 30 days (odds ratio [OR] 2.58, 95% confidence interval [CI] 1.29 to 5.29, p<0.01), renal failure (OR 3.30, 95% CI 1.43 to 7.59, p<0.01), index procedure presentation with an acute coronary syndrome (OR 2.59, 95% CI 1.14 to 5.87, p=0.02), diabetes mellitus (OR 2.25, 95% CI 1.19 to 4.23, p=0.01), and total stent length >or=20 mm (OR 1.85, 95% CI 1.00 to 3.42, p=0.04). In conclusion, DESs were not associated with increased risk of ST compared with BMSs at 12 months in this large Australian registry that selectively used DESs for patients at high risk of restenosis.


Cardiovascular Revascularization Medicine | 2008

Renal impairment is an independent predictor of adverse events post coronary intervention in patients with and without drug-eluting stents.

James Shaw; Nick Andrianopoulos; S. Duffy; Anthony Walton; David J. Clark; Robert Lew; M. Sebastian; G. New; A. Brennan; Christopher M. Reid; Andrew E. Ajani

Renal impairment (RI) is known to be an independent risk factor for the progression of cardiovascular disease. Its impact, however, on the outcomes in patients undergoing percutaneous coronary intervention (PCI) especially in the era of drug-eluting stents (DES) is not well known. We analysed data from patients undergoing PCI from April 1, 2004, to September 30, 2006, who were part of the Melbourne Interventional Group registry. RI was defined as an estimated glomerular filtration rate (eGFR), calculated using Cockcroft-Gault formula, of <60 ml/min. We compared outcomes at 30 days and 12 months in patients with and without RI. Four thousand one hundred ninety-five patients (3043 male) with an average age 65+/-12 years (mean+/-S.D.) underwent PCI. Twelve-month follow-up was available in 3963 (95%) patients, and these were included in the analysis. One thousand twelve patients (26%) had RI; of these, 608 (60%) presented with an acute coronary syndrome. Both 30-day major adverse cardiac events (MACE), 9.1% vs. 4.6% (P<.01), and all-cause mortality, 4.5% vs. 0.7% (P<.01), were significantly higher in those with RI compared to those without RI. Twelve-month mortality (8.8% vs. 1.7%, P<.01) and MACE (19.7% vs. 10.3%, P<.01) were also significantly higher in those with RI. In multiple regression analysis, RI was an independent predictor of 12-month MACE [OR 2.0 (CI 1.6-2.6), P<.01]. RI is an independent predictor of 30-day and 12-month MACE and death after PCI in patients with stable and unstable coronary syndromes, even with widespread use of DES. eGFR should be used to help risk-stratify patients undergoing PCI.


Circulation | 2003

Repeat Intracoronary Radiation for Recurrent In-Stent Restenosis in Patients Who Failed Intracoronary Radiation

Ron Waksman; Robert Lew; Andrew E. Ajani; Augusto D. Pichard; Lowell F. Satler; Kenneth M. Kent; Rosanna Chan; R.Larry White; William O. Suddath; Ellen Pinnow; Rebecca Torguson; Christian Dilcher; Roswitha Wolfram; Joseph Lindsay

Background—Intracoronary radiation therapy (IRT) is the only proven treatment for in-stent restenosis (ISR). It is, however, associated with a significant failure rate. The present study evaluated the outcomes of patients who underwent repeat intracoronary radiation for recurrent ISR. Methods and Results—Fifty-one consecutive patients who failed a previous radiation treatment, presented with angina and angiographic evidence of ISR, and were treated with percutaneous coronary intervention (PCI) and repeat radiation to the same segment were studied. Twenty-five patients were treated with gamma radiation in a dose of 15 Gy, and 26 were treated with beta radiation doses of 18.3 to 23 Gy. The mean cumulative dose for this cohort was 39.5±11.9 Gy (range, 29 to 75.6 Gy). The outcomes of those patients were compared with outcomes of 299 patients who also failed initial radiation but were treated with repeat conventional PCI to a previously irradiated segment without repeat radiation. At 9 months after treatment, the repeat-IRT group had lower rates of target lesion revascularization (23.5% versus 54.6%; P <0.001) and major adverse cardiac events, including target vessel revascularization (29.4% versus 61.3%; P <0.001). At 9 months, patients with repeat IRT were free of angiographic and clinical events related to the radiation therapy. Conclusions—Repeat gamma or beta radiation to treat failed IRT for ISR after conventional PCI is safe and effective at 9 months and should be considered as a therapeutic option for this difficult patient subset.


International Journal of Cardiology | 2008

Are drug-eluting stents indicated in large coronary arteries? Insights from a multi-centre percutaneous coronary intervention registry

Bryan P. Yan; Andrew E. Ajani; G. New; S. Duffy; Omar Farouque; James Shaw; M. Sebastian; Robert Lew; A. Brennan; Nick Andrianopoulos; Christopher M. Reid; David J. Clark

BACKGROUND Restenosis rates are low in large coronary vessels >/=3.5 mm after bare-metal stent (BMS) implantation. The benefit of drug-eluting stents (DES) in large vessels is not established. OBJECTIVE We aim to assess clinical outcomes after deployment of BMS compared to DES in patients with large coronary vessels >/=3.5 mm. METHODS We analysed 672 consecutive patients undergoing percutaneous coronary interventions with >/=3.5 mm stent implantation in native coronary artery de-novo lesions from the Melbourne Interventional Group (MIG) registry. Baseline characteristics, 30-day and 12-month outcomes of patients receiving BMS were compared to DES. Multivariate analysis was performed to identify predictors of major adverse cardiac events [MACE, consisting of death, myocardial infarction (MI) and target vessel revascularisation (TVR)]. RESULTS Of the 672 PCIs performed in 844 lesions, DES was implanted in 39.5% (n=333) and BMS in 60.5% (n=511) of lesions. Patients who received DES compared to BMS were older, more likely to be diabetic, had left ventricular dysfunction <45% or complex lesions. Significantly fewer patients who presented with ST-elevation MI received DES compared to BMS. There were no significant differences in 12-month mortality (0.5 vs. 2.9%, p=0.07), TVR (3.6 vs. 4.8%, p=0.54), MI (6.3 vs. 3.4%, p=0.15), stent thrombosis (0.9 vs. 1.0%, p=0.88), or MACE (9.4 vs. 9.4%, p=0.90) in patients who received DES vs. BMS. Stent length >/=20 mm was the only independent predictor of 12-month MACE (Odds Ratio 2.07, 95% CI 1.14-3.76, p=0.02). CONCLUSION In this registry, BMS implantation in large native coronary vessels >/=3.5 mm was associated with a low risk of MACE and repeat revascularization at 12 months that was comparable to DES.


Cardiovascular Radiation Medicine | 2003

Acute procedural complications and in-hospital events after percutaneous coronary interventions: eptifibatide versus abciximab.

Andrew E. Ajani; Ron Waksman; Luis Gruberg; Arvind K. Sharma; Robert Lew; Ellen Pinnow; Daniel Canos; Edouard Cheneau; Marco T. Castagna; Lowell F. Satler; Augusto D. Pichard; Kenneth M. Kent

BACKGROUND Glycoprotein IIb/IIIa antagonists reduce peri-angioplasty ischemic complications and improve in-hospital outcome in patients undergoing percutaneous coronary interventions (PCI). Prior studies have demonstrated favorable results with both eptifibatide and abciximab. The purpose of this study was to assess whether there are any differences in rates of acute procedural complications and in-hospital events with the use of these two agents. METHODS A retrospective review of 359 elective PCIs from June 1998 to August 2000 identified 152 PCIs treated with eptifibatide (bolus 180 microg/kg, infusion 2 microg/kg/min for 12-48 h) and 205 PCIs treated with abciximab (bolus 0.25 mg/kg, infusion 10 microg/min for 12 h). All patients received IIb/IIIa antagonists at the initiation of the intervention. RESULTS The clinical demographics, the angiographic morphology, the indications, and the procedural details were similar in both groups. In the eptifibatide group, the maximum ACT was lower (235+/-45 vs. 253+/-40, P<.0001). The incidence of major procedural and in-hospital events was compared. Eptifibatide and abciximab had similar rates of major complications (death or myocardial infarction) (1.4% vs. 2.9%), repeat PTCA (3.4% vs. 1.9%), and major bleeding (3.3% vs. 4.3%). CONCLUSIONS Eptifibatide is comparable to abciximab in regards to acute procedural complications and in-hospital events after PCI.


Catheterization and Cardiovascular Interventions | 2004

Effects of gamma radiation on the noninjured and unprotected left main.

Roswitha Wolfram; Edouard Cheneau; Robert Lew; Rosanna Chan; Augusto D. Pichard; Lowell F. Satler; Kenneth M. Kent; Christian Dilcher; Ellen Pinnow; Anh B. Bui; Ron Waksman

The aim of this study was to evaluate the effect of gamma radiation on the noninjured, unprotected left main coronary artery. Noninjured vessel segments are often radiated during treatment of in‐stent restenosis with PCI and gamma radiation. Angiographic analysis using QCA methods was performed on 55 left main arteries of patients (32 with radiation of the left main compared to 23 controls) who participated in the Washington Radiation for In‐Stent Restenosis Trials (WRIST). Baseline demographics and follow‐up were comparable between the two groups, concluding that gamma radiation with long radiation safety margins is feasible and safe. Gamma radiation of noninjured irradiated left main vessels when used to facilitate wide radiation margins for proximal irradiated injured LAD and LCx is safe and does not compromise the vessel integrity and its lumen. Catheter Cardiovasc Interv 2004;61:477–481.


Heart Lung and Circulation | 2006

The foundation and launch of the Melbourne Interventional Group: a collaborative interventional cardiology project.

Andrew E. Ajani; G. Szto; S. Duffy; David Eccleston; David J. Clark; J. Lefkovits; Derek P. Chew; R. Warren; Alexander Black; G. New; A. Walton; Robert Lew; Jonathan E. Shaw; M. Horrigan; M. Sebastian; Bernard Yan; A. Brennan; Adam Meehan; Christopher M. Reid; Henry Krum


The Medical Journal of Australia | 2008

Outcomes after percutaneous coronary intervention in contemporary Australian practice: insights from a large multicentre registry.

Andrew E. Ajani; Christopher M. Reid; S. Duffy; Nick Andrianopoulos; Jeffrey Lefkovits; Alexander Black; G. New; Robert Lew; James Shaw; Bryan P. Yan; Ronen Gurvitch; A. Al-Fiadh; A. Brennan; David J. Clark


American Journal of Cardiology | 2004

Usefulness of periprocedural creatinine phosphokinase-MB release to predict adverse outcomes after intracoronary radiation therapy for in-stent restenosis

Andrew E. Ajani; Ron Waksman; Arvind K. Sharma; Robert Lew; Ellen Pinnow; Daniel Canos; Edouard Cheneau; Marco T. Castagna; Dong-Hun Cha; Laurent Leborgne; Lowell F. Satler; Augusto D. Pichard; Kenneth M. Kent; Joseph Lindsay

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Ron Waksman

MedStar Washington Hospital Center

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Lowell F. Satler

MedStar Washington Hospital Center

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Kenneth M. Kent

MedStar Washington Hospital Center

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