Hwee Bee Wong

Duke-NUS Graduate Medical School Singapore, Singapore, Singapore

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Publications (26)86.03 Total impact

  • Article: Severe obstructive sleep apnea and outcomes following myocardial infarction.
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    ABSTRACT: We sought to determine the effect of severe obstructive sleep apnea (OSA) on long-term outcomes after myocardial infarction. We hypothesized that severe OSA was associated with lower event-free survival rate after ST-segment elevation myocardial infarction (STEMI). A total of 120 patients underwent an overnight sleep study during index admission for STEMI. Severe OSA was defined as apnea hypopnea index (AHI) ≥ 30, and non-severe OSA defined as AHI < 30. Among the 105 patients who completed the study, 44 (42%) had severe OSA and 61 (58%) non-severe OSA. The median creatine kinase level and mean left ventricular systolic function were similar between the 2 groups. None of the 105 study patients had received treatments for OSA. Between 1- and 18-month follow-up, the severe OSA group incurred 1 death, 2 reinfarctions, 1 stroke, 6 unplanned target vessel revascularizations, and 1 heart failure hospitalization. In contrast, there were only 2 unplanned target vessel revascularizations in the non-severe OSA group. The incidence of major adverse events was significantly higher in the severe OSA group (15.9% versus 3.3%, adjusted hazard ratios: 5.36, 95% CI: 1.01 to 28.53, p = 0.049). Kaplan-Meier event-free survival curves showed the event-free survival rates in the severe OSA group was significantly worse than that in the non-severe OSA group (p = 0.021, log-rank test). 42% of the patients admitted with STEMI have undiagnosed severe OSA. Severe OSA carries a negative prognostic impact for this group of patients. It is associated with a lower event-free survival rate at 18-month follow-up.
    Journal of clinical sleep medicine: JCSM: official publication of the American Academy of Sleep Medicine 12/2011; 7(6):616-21. · 3.23 Impact Factor
  • Article: Quality-of-life-adjusted survival analysis of concurrent chemo radiotherapy for locally advanced (nonmetastatic) nasopharyngeal cancer.
    Fei Gao, Joseph Wee, Hwee Bee Wong, David Machin
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    ABSTRACT: To assess whether the benefits of adding cisplatin (CDDP) concurrent with radiotherapy, followed by adjuvant CDDP and fluorouracil, justifies the toxicity cost for nasopharyngeal cancer (NPC) using the quality-adjusted time without symptoms or toxicity (Q-TWiST) approach. One hundred seven patients treated with radiotherapy (RT) and 111 with concurrent chemotherapy and radiotherapy (CRT) were analyzed. The overall survival was divided into three health states: time on active treatment only, during which any subjective nonhematologic toxic event of grade > = 3 was reported; time without symptoms of disease relapse; or treatment and time following first disease RELapse. The relative advantage of CRT and RT was examined by conducting the analysis cumulatively at restriction times 3, 6, 24, 36, 48 months. At 48 months, the improvement in disease-free survival was 14.4% for CRT, whereas that for overall survival was 18.9%. The differences in Q-TWiST were -0.4, -0.7, 0.1, 1.6, and 3.6 months at 3, 6, 24, 36, and 48 months, respectively, with positive differences favoring CRT. At 24 months, the difference in Q-TWiST began to favor CRT. At 36 months, CRT may be the preferred option from the patient's viewpoint if the time spent in the REL state is valued to be <0.83, with the value of perfect health being 1. Finally, Q-TWiST accumulated within 48 months indicated a significant advantage in quality-adjusted survival time for CRT (p = 0.020). Irrespective of how patients valued periods of toxicity and delayed disease progression, concurrent chemotherapy and radiotherapy offered NPC patients significantly more quality-adjusted survival than radiotherapy alone in the long term.
    International journal of radiation oncology, biology, physics 10/2010; 78(2):454-60. · 4.59 Impact Factor
  • Article: The effect of body mass on health-related quality of life among Singaporean adolescents: results from the SCORM study.
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    ABSTRACT: To investigate the relationship between body mass and health-related quality of life (HRQOL) among Singaporean adolescents. Variation in this relationship by age, gender and ethnicity, and association of HRQOL with change in body mass over time and with demographic, socioeconomic and health variables were also assessed. HRQOL was assessed for Singaporean adolescents aged 11-18 from their own (N=1,249) and their parent’s (N=948) perspective using PedsQLTM 4.0 generic core scales. Body mass, measured as body mass index z-score based on the WHO Reference 2007, was categorized as thin, healthy weight, overweight and obese. Multiple linear regression models assessed the relationship between current body mass and HRQOL, adjusting for demographic, socioeconomic and health variables. Differences between adolescent and parent-proxy reported HRQOL were also investigated. Obese adolescents (and their parents) reported significantly lower HRQOL, overall and in most domains, compared to healthy weight adolescents. Parents tended to report lower HRQOL for their adolescents than the adolescents did themselves; however, this difference was much larger and statistically significant for obese adolescents. Obesity is associated with reduced HRQOL among adolescents. The effect in these Singaporean adolescents is similar to that in populations with higher rates of obesity. Awareness of this relationship can make it easier for health professionals, teachers, parents and peers to be supportive of obese adolescents.
    Quality of Life Research 03/2010; 19(2):167-76. · 2.30 Impact Factor
  • Article: Ocular component growth curves among Singaporean children with different refractive error status.
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    ABSTRACT: To describe and compare ocular component growth curves among different refractive error groups in Singaporean children. Data collected yearly in 1775 Asian children aged 6 to 10 years with at least three visits were analyzed. Cycloplegic refractive error and biometry variables were measured by autorefractor and A-scan ultrasound machine. Growth curves were compared between five groups: persistent hyperopia of spherical equivalent (SE) > +1.00 D, emmetropizing hyperopia of SE > +1.00 D on the first visit and between -0.50 D and +1.00 D subsequently, persistent emmetropia of SE between -0.50 D and +1.00 D, incident myopia of SE <or= -0.50 D at subsequent visits, and persistent myopia of SE <or= -0.50 D. The axial length and vitreous chamber elongated faster in the children younger than 10 years, but elongation slowed with age. Growth patterns of axial length and vitreous chamber in the children with newly developed or persistent myopia (P < 0.01) showed faster elongation than in the emmetropic children. The anterior chamber deepened until approximately 9 or 10 years of age but became shallower as the myopic and emmetropic children grew older. Conversely, the lens thinned at younger ages and thickened at older ages for all except the persistently hyperopic children. In young Asian children, the axial length and vitreous chamber depth increased, but the elongation slowed with age. There was a U-shaped growth curve for lens thickness and an inverted U-shaped curve for anterior chamber depth. The findings of early lens thinning followed by thickening suggest a two-phase growth of the lens.
    Investigative ophthalmology & visual science 10/2009; 51(3):1341-7. · 3.43 Impact Factor
  • Article: Visual impairment and its impact on health-related quality of life in adolescents.
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    ABSTRACT: To determine the impact of visual impairment on health-related quality of life (QoL) measures in adolescents. School-based, cross-sectional study. Adolescents aged 11 to 18 years from the Singapore Cohort Study of the Risk Factors for Myopia were analyzed. QoL scores were determined using parallel child-self and parent proxy-report of PedsQL 4.0 Generic Core Scales. Refractive error was measured using the table-mounted autorefractor (model RK5 Canon Inc, Ltd, Tochigiken, Japan) and habitual distance logarithm of the minimal angle of resolution (logMAR) visual acuity charts were used. Data on 1,249 adolescents and 948 parents were analyzed. The prevalence of better eye presenting visual impairment > 0.3 logMAR was 5.7%. The mean (standard deviation) total, physical, and psychosocial health scores of all adolescents were 83.6 (11.8), 89.9 (11.8), and 80.3 (13.7). Healthy adolescents with visual impairment reported statistically but not clinically lower total (-3.8; 95% confidence interval [CI], -7.1 to -0.5; P = .03), psychosocial (-4.2; 95% CI, -8.1 to -0.3; P = .03), and school functioning scores (-5.5, 95% CI, -10.2 to -0.9; P = .02) than those with normal vision. However, no significant difference was observed in the parent proxy-reported scores between the two groups. Differences in total scores between high (1.9; 95% CI, -0.6 to 4.4) and low-myopes (0.2; 95% CI, -1.3 to 1.6) compared with nonmyopes were not significant. Comparable scores were also reported by hyperopes, astigmatism, and their counterparts, as well as their parents. Concordance between child and parent proxy-report was < 0.07. Healthy adolescents with visual impairment experienced statistically though not clinically impaired health related QoL, but refractive errors did not appear to have an impact on QoL.
    American journal of ophthalmology 01/2009; 147(3):505-511.e1. · 3.83 Impact Factor
  • Article: Evaluation of the linearity of soft- to hard-tissue movement after orthognathic surgery.
    Ming Tak Chew, Andrew Sandham, Hwee Bee Wong
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    ABSTRACT: Our aim in this study was to investigate whether a linear relationship exists between soft- to hard-tissue changes for both maxillary and mandibular landmarks over a wide range of skeletal changes. The sample consisted of 30 Chinese patients with Class III malocclusion treated with bilateral sagittal split osteotomy and LeFort I advancement. Lateral cephalograms were taken within 2 months before surgery and at least 6 months after surgery. Soft- and hard-tissue changes were recorded by computer-supported measurements of presurgical and postsurgical lateral cephalograms. To evaluate the linear association between soft- and hard-tissue movement, a quadratic function of hard-tissue movement adjusted for sex was initially fitted to the data. The residual plots were used to examine the appropriateness of the fitted quadratic function, and the lack of fit was examined by the F test. A linear function was fitted to the data when the quadratic term was not significant. Visual inspection of the scatter plots of the 5 pairs of corresponding soft- and hard-tissue landmarks showed that relationships between the soft and hard tissues were reasonably linear for both male and female subjects, except for the Sn-ANS pair that showed a curvilinear relationship. Statistical tests confirmed that the association for the Sn-ANS pair was quadratic. The results of this study provide evidence of a linear relationship between soft- to hard-tissue changes for mandibular landmarks over a wide range of skeletal changes. The nonlinear response of maxillary soft tissues to underlying hard-tissue change in the Sn-ANS pair supports the use of nonlinear ratios for selected maxillary soft- to hard-tissue movements in simulation software.
    American journal of orthodontics and dentofacial orthopedics: official publication of the American Association of Orthodontists, its constituent societies, and the American Board of Orthodontics 12/2008; 134(5):665-70. · 1.33 Impact Factor
  • Article: Can external and subjective information ever be used to reduce the size of randomised controlled trials?
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    ABSTRACT: In the design of randomised trials in rare cancers, a Bayesian approach has been advocated, which allows for external and subjective information to be formally incorporated. We explore whether this can be extended more generally to allow for smaller trials to be conducted using a case study involving a trial of nasopharyngeal carcinoma. The external information available at various points during the trial is first summarised in the form of 'prior distributions'. Each of these is then combined with the accumulated data from the trial at that point in time to form 'posterior distributions', from which conclusions are drawn. We have argued that such a framework for the design, analysis and interpretation of a randomised trial in the light of external evidence is particularly useful in situations such as trials in rare cancers. But more generally, it may potentially also allow for smaller trials to be conducted. Although, at this point in time, we are hesitant to recommend the full implementation of the Bayesian methodology to modify the (conventionally) planned trial size we submit that a formal synthesis of the external evidence bearing on the question of concern is a valuable exercise in itself.
    Contemporary Clinical Trials 04/2008; 29(2):211-9. · 1.81 Impact Factor
  • Article: Prognostic value of left atrial size in chronic kidney disease.
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    ABSTRACT: Patients with chronic kidney disease (CKD) have high cardiovascular risk. Although stress imaging provides accurate risk estimation in this population, it is unknown if combinatorial cardiac imaging adds incremental value. We performed transthoracic echocardiography and stress single photon emission computed tomography (SPECT) to assess their value in predicting late cardiovascular disease (CVD) mortality in 200 patients with creatinine clearance <60 mL/min without a history of coronary heart disease. During a median follow-up duration of 3.7 (3.5-4.0) years, there were 25 deaths because of CVD. Older age, abnormal SPECT, and increased indexed left atrial (LA) diameter were associated with CVD mortality on univariate analysis with P = 0.007, 0.01, and 0.004, respectively. In multivariable analysis, indexed LA diameter >24 mm/m(2) was independently predictive of CVD mortality [hazard ratio (HR) 2.75, confidence interval (CI) 1.14-6.59], but abnormal SPECT was not. Each mm/m(2) increase in indexed atrial diameter was associated with an HR 1.20 (95% CI 1.06-1.37). In patients with CKD, the indexed LA diameter predicts CVD mortality independent of an abnormal SPECT result. Consideration should be given to this simple measurement as a prognostic tool in this population.
    European Heart Journal – Cardiovascular Imaging 03/2008; 9(6):736-40. · 2.32 Impact Factor
  • Article: Subjective evaluation of the accuracy of video imaging prediction following orthognathic surgery in Chinese patients.
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    ABSTRACT: The aims of this retrospective study were to assess the subjective accuracy of predictions generated by a computer imaging software in Chinese patients who had undergone orthognathic surgery and to determine the influence of initial dysgnathia and complexity of the surgical procedure on prediction accuracy. The sample consisted of 40 Chinese patients who had completed treatment involving orthodontics and orthognathic surgery. All the patients had lateral cephalometric radiographs and profile photographs taken within 3 months before surgery and at least 6 months after surgery. The computer-generated predicted images and the actual post-treatment images were displayed simultaneously to a panel of orthodontists, oral maxillofacial surgeons and laypersons to allow side-by-side comparison. The panel was asked to determine which image was more esthetic and to rate the likeness between the actual and predicted images using a 10 cm visual analog scale. The results showed that the actual image was judged to be more esthetic in 82% of the cases, with the orthodontists more likely to select the actual profile compared to laypersons (P = .005). Orthodontists and surgeons rated the likeness of the images similarly while laypersons rated the likeness significantly lower than the clinicians (P = .012 and P = .015, respectively). Skeletal III cases were judged to be less accurately predicted than skeletal II cases by laypersons (P = .006) and orthodontists (P = .036). Cases treated by single-jaw osteotomy were given better ratings compared to cases with bimaxillary osteotomy by all panel groups but the differences did not reach significant level. Skeletal III cases managed by bimaxillary osteotomy were least accurately predicted by the computer program. As there exists a possibility that the predicted image may be judged to be more esthetic than the actual image, clinicians must make extra effort to manage patient expectations when using computer simulations for patient education.
    Journal of oral and maxillofacial surgery: official journal of the American Association of Oral and Maxillofacial Surgeons 03/2008; 66(2):291-6. · 1.58 Impact Factor
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    Article: Effect of a milk formula containing probiotics on the fecal microbiota of asian infants at risk of atopic diseases.
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    ABSTRACT: The fecal microbiota of 37 infants with (n = 20) or without (n = 17) probiotic administration was evaluated on D 3, and at 1, 3, and 12 mo by fluorescence in situ hybridization-flow cytometry (FISH-FC), PCR, and bacteriological culture methods. They represent consecutive subjects of an ongoing double-blind, placebo-controlled trial on a probiotic formula (LGG and Bifidobacterium longum) administered during the first 6 mo of life. Despite varying composition in each baby, there was a general bacterial colonization pattern in the first year. Bifidobacteria increased markedly (p = 0.0003) with a parallel decrease in Enterobacteriaceae (p < 0.001) and Bacteroides-Prevotella (p = 0.005) populations. Eubacterium rectale-Clostridium coccoides (p < 0.001) and Atopobium (p = 0.039) groups also gradually increased. This overall pattern was unaffected by probiotic administration (p > 0.05). B. longum (p = 0.005) and Lactobacillus rhamnosus (p < 0.001) were detected more frequently in probiotic group during supplementation, but no difference after supplementation had ceased (p > 0.05). Cultured lactic acid bacteria were also more numerous in the probiotic-administered babies during treatment period (log CFU/g 8.4 versus 7.4; p = 0.035). Our results indicate that supplemented strains could be detected but did not persist in the bowel once probiotic administration had ceased.
    Pediatric Research 12/2007; 62(6):674-9. · 2.70 Impact Factor
  • Article: Impact of different Asian ethnic groups on correlation between heparin dose, activated clotting time and complications in percutaneous coronary intervention.
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    ABSTRACT: The current recommended weight-adjusted dosing regimen of unfractionated heparin and target activated clotting time (ACT) in percutaneous coronary intervention (PCI) is based on limited data from the western population, and the applicability in the various Asian ethnic groups remains unknown. This is a retrospective study in an Asian university teaching hospital. Among the 1287 patients who have undergone PCI, Chinese constituted 70.4% (n=906), Malay 15.5% (n=199) and Indian 14.1% (n=182). Overall, the mean total heparin dose was 6224+/-1548 U, mean weight-adjusted heparin dose was 95+/-30 U/kg, and mean ACT was 325+/-95 s. There was no significant difference in the 3 ethnic groups. Both the incidences of in-hospital ischemic complications (Chinese 2.4%, Malay 3.5%, Indian 2.2%, p=0.641) as well as in-hospital bleeding complications (Chinese 4.5%, Malay 3.5%, Indian 6.0%, p=0.490) were similar in the 3 ethnic groups. When the patients were divided based on ACT into 3 groups:<250, 250-350 and>350 seconds, the incidence of ischemic complication (2.5%, 2.5%, 2.7%) was similar (p=819), while that of bleeding complications (4.1%, 3.5%, 6.8%) showed a strong trend (p=0.057) of increased risk in patients with ACT>350 s. In conclusion, the recommended weight-adjusted heparin-dosing regimen in PCI derived from the western population is equally applicable to the Asian patients. ACT does not correlate with in-hospital ischemic complications, but increased bleeding complications were observed with ACT>350 s.
    International journal of cardiology 09/2007; 130(3):500-2. · 7.08 Impact Factor
  • Article: Outcome of orthognathic surgery in Chinese patients. A subjective and objective evaluation.
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    ABSTRACT: To evaluate the outcome of orthognathic surgery by objective cephalometric measurement of posttreatment soft-tissue profile and by subjective evaluation of profile esthetics by laypersons and clinicians. The sample consisted of 30 Chinese patients who had completed combined orthodontic and orthognathic surgical treatment. The posttreatment cephalograms of these patients were analyzed with respect to profile convexity, facial height, and lip contours and these were compared to the previously established esthetic norms. Line drawings of the soft-tissue profile were displayed to a panel comprising six laypersons and six clinicians who scored the esthetics of each profile using a 7-point scale. Complete normalization of cephalometric soft-tissue variables was not achieved with orthognathic surgery in most patients, with four of the six soft-tissue cephalometric measurements showing significant differences compared to the esthetic norms. There were good correlations in the esthetic scores between laypersons and clinicians, even though clinicians tend to rate the profiles more favorably. Facial convexity and facial height did not significantly influence the subjective scores of both the laypersons and clinicians. Lower lip protrusion was the only cephalometric variable that significantly influenced clinicians' assessment of profile esthetics (P<.01). Profile convexity and lower facial height proportion had little influence on both lay and professional perception of profile esthetics. Lower lip position is the only cephalometric variable that significantly influenced clinicians' assessment of profile esthetics.
    The Angle Orthodontist 09/2007; 77(5):845-50. · 1.21 Impact Factor
  • Article: CYPHER versus TAXUS stent for bifurcation lesions beyond 30 days-long-term follow-up results.
    International journal of cardiology 06/2007; 117(3):422-4. · 7.08 Impact Factor
  • Article: Sirolimus-eluting, bioabsorbable polymer-coated constant stent (Cura) in acute ST-elevation myocardial infarction: a clinical and angiographic study (CURAMI Registry).
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    ABSTRACT: There are safety concerns over the current polymer-based drug-eluting stents (DES) on the possible delayed healing process and adverse reactions to the polymer when drug elution is completed. Cura (Orbus Neich) is a sirolimus-eluting, bioabsorbable, polymer-coated constant stent. From March 1 to June 30, 2005, Cura stent implantation was instituted as the default strategy for percutaneous coronary intervention in 49 consecutive ST-Elevation Myocardial Infarction (STEMI) patients (male 86%; average age 55 +/- 10 years; diabetes 31%). The angiographic success rate was 100%. In-hospital adverse events consisted of 1 in-hospital death (2% heart failure). A total of 27 patients (56%) underwent 8-month angiographic follow up. Binary restenosis occurred in 6 patients (22%), and late loss was 0.74 +/- 0.89 mm. At 9-month follow up, a total of 5 patients had 6 major adverse events (1 death, 1 reinfarction, and 4 target lesion revascularizations). There was no incidence of stent thrombosis. Cura stent implantation appears to be feasible and safe in the treatment of STEMI. However, the binary restenosis rate and late loss at angiographic follow up were similar to that of bare-metal stents, and therefore compare unfavorably with other proven benchmark DES.
    The Journal of invasive cardiology 04/2007; 19(4):182-5. · 1.84 Impact Factor
  • Article: An Asian community's perspective on facial profile attractiveness.
    Jen Soh, Ming Tak Chew, Hwee Bee Wong
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    ABSTRACT: To assess the facial profile preferences of laypersons in an Asian community and the influence of age, ethnic and gender on profile selection. A sample of 149 laypersons (65.1% Chinese, 21.5% Malays and 13.4% Indians), comprising of 112 females (75.2%) participated in the study. The mean age was 24.6 years (SD 4.4). A facial profile photograph and a lateral cephalometric radiograph of a Chinese male and female adult with a normal profile and a class I incisor and skeletal relationship were digitized to create a baseline template. Computerized digital photographic image modification was carried out on the template to obtain seven facial profiles [bimaxillary protrusion, protrusive mandible, retrusive mandible, normal profile (incisor and skeletal class I pattern), retrusive maxilla, protrusive maxilla and bimaxillary retrusion] for each gender. The laypersons were asked to rank the profiles of each gender on a scale of 1 (very attractive) to 7 (least attractive). Orthognathic Chinese male and female profiles were perceived to be the most attractive. A male orthognathic profile with normative Chinese cephalometric values was perceived to be more attractive than a 'flatter' bimaxillary retrusive profile. Bimaxillary retrusion and normal Chinese female profiles were perceived to be the most attractive. A male or female profile with a protrusive mandible was judged to be the least attractive. Age, gender and ethnicity were nonsignificant predictors for the most attractive female profile. Orthognathic Chinese male and female profiles were judged to be the most attractive by Asian adult laypersons. Male and female profiles with mandibular protrusion were judged to be the least attractive.
    Community Dentistry And Oral Epidemiology 03/2007; 35(1):18-24. · 1.89 Impact Factor
  • Article: Incidence, predictors, and outcomes of device failure of X-sizer thrombectomy: real-world experience of 200 cases in 5 years.
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    ABSTRACT: Clinical studies have evaluated the safety and efficacy of adjunctive X-sizer (EndiCOR Inc, San Clemente, CA) in percutaneous coronary intervention (PCI). However, patient and lesion subsets were highly selected, and extrapolation of the results to daily practice is problematic. X-sizer thrombectomy was performed in 200 procedures from August 2000 to July 2005. The indications for the procedures were primary PCI in 71%. Device failure was defined as the occurrence of 1 or more of the following conditions: (a) failure of the X-sizer to reach the target segment, (b) failure to achieve final thrombolysis in myocardial infarction 3 flow, (c) slow flow or no-reflow, (d) distal embolization, and (e) coronary perforation. Device failure occurred in 48 procedures, giving a device failure rate of 24%. Logistic regression analysis showed that ostial lesion was the only independent predictor of device failure (OR 4.89, 95% CI 1.23-19.51, P = .024). A total of 19 patients had developed 22 adverse events, giving a 30-day adverse event rate of 9.5%. Among these, there were 13 deaths, 4 strokes, 2 reinfarctions, 2 repeat PCIs, and 1 coronary artery bypass grafting. Logistic regression analysis showed that X-sizer device failure was independently associated with 30-day adverse events (OR 3.42, 95% CI 1.04-11.25, P = .043). The incidence of device failure of X-sizer thrombectomy was 24%. Ostial lesion was an independent predictor of device failure. Notably, X-sizer device failure was independently associated with 30-day adverse event. These highlight the importance of case selection and the problem with its use in ostial lesions.
    American heart journal 02/2007; 153(1):14.e13-9. · 4.65 Impact Factor
  • Article: Randomised clinical trials in plastic surgery: survey of output and quality of reporting.
    Journal of Plastic Reconstructive & Aesthetic Surgery 02/2007; 60(8):965-6. · 1.49 Impact Factor
  • Article: Inverse relation between diastolic blood pressure and long-term outcomes in patients undergoing pharmacoinvasive therapy for myocardial infarction: the J-shaped relation in the contemporary era of revascularisation.
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    ABSTRACT: In the thrombolytic era, it was reported that in the presence of significant coronary stenosis, lowering diastolic blood pressure (DBP) below a critical threshold would result in a paradoxical increase in the occurrence of myocardial infarction (MI). We sought to re-evaluate this J-shaped relation in the era of pharmacoinvasive therapy. A total of 182 patients who underwent early (<1 week, mean 2.3 days) coronary angioplasty after thrombolysis were analysed. Thrombolytic agents (streptokinase in 60%, tissue plasminogen activator in 40%) were administered in an average door-to-needle time of 66 min (<=30 min in 43 [24%] patients). A thrombolysis in myocardial infarction (TIMI) 3 flow was achieved in 56% of patients after thrombolysis, and it was enhanced to 92% after angioplasty. During an average follow-up period of 26 +/-13 months, the adverse event (death, re-MI, target vessel revascularisation or stroke) rate was 21%. Older age, low systolic blood pressure and DBP, fast heart rate, high creatine kinase, hypercholesterolaemia, thrombus-laden lesion, baseline TIMI 0-2 flow were associated with higher occurrence of adverse events. After adjusting for the differing clinical and procedural factors, low DBP (odds ratio 1.10, 95% confidence interval 1.01-1.20, P = 0.041), fast heart rate (odds ratio 1.08, 95% confidence interval 1.02-1.14, P = 0.008) and anterior MI (odds ratio 18.98, 95% confidence interval 2.13-169.19, P = 0.008) were all independent predictors of long-term adverse rate occurrence. A low DBP is an independent predictor of long-term adverse event rates in patients undergoing routine early coronary angioplasty after thrombolysis. This suggests that excessive lowering of DBP may not be desirable before complete revascularisation.
    Journal of Cardiovascular Medicine 11/2006; 7(11):806-11. · 1.51 Impact Factor
  • Article: Randomized trial of radiotherapy versus concurrent chemoradiotherapy followed by adjuvant chemotherapy in patients with American Joint Committee on Cancer/International Union against cancer stage III and IV nasopharyngeal cancer of the endemic variety.
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    ABSTRACT: The Intergroup 00-99 Trial for nasopharyngeal cancer (NPC) showed a benefit of adding chemotherapy to radiotherapy. However, there were controversies regarding the applicability of the results to patients in endemic regions. This study aims to confirm the findings of the 00-99 Trial and its applicability to patients with endemic NPC. Between September 1997 and May 2003, 221 patients were randomly assigned to receive radiotherapy (RT) alone (n = 110) or chemoradiotherapy (CRT; n = 111). Patients in both arms received 70 Gy in 7 weeks using standard RT portals and techniques. Patients on CRT received concurrent cisplatin (25 mg/m2 on days 1 to 4) on weeks 1, 4, and 7 of RT and adjuvant cisplatin (20 mg/m2 on days 1 to 4) and fluorouracil (1,000 mg/m2 on days 1 to 4) every 4 weeks (weeks 11, 15, and 19) for three cycles after completion of RT. All patients were analyzed by intent-to-treat analysis. The median follow-up time was 3.2 years. Distant metastasis occurred in 38 patients on RT alone and 18 patients on CRT. The difference in 2-year cumulative incidence was 17% (95% CI, 14% to 20%; P = .0029). The hazard ratio (HR) for disease-free survival was 0.57 (95% CI, 0.38 to 0.87; P = .0093). The 2- and 3-year overall survival (OS) rates were 78% and 85% and 65% and 80% for RT alone and CRT, respectively. The HR for OS was 0.51 (95% CI, 0.31 to 0.81; P = .0061). This report confirms the findings of the Intergroup 00-99 Trial and demonstrates its applicability to endemic NPC. This study also confirms that chemotherapy improves the distant metastasis control rate in NPC.
    Journal of Clinical Oncology 10/2005; 23(27):6730-8. · 18.37 Impact Factor
  • Article: Impact of glycemic control on occurrence of no-reflow and 30-day outcomes in diabetic patients undergoing primary angioplasty for myocardial infarction.
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    ABSTRACT: Diabetes mellitus is associated with endothelial dysfunction and platelet activation that may contribute to the occurrence of no-reflow. We postulate that optimal glycemic control is associated with the lower risk of no-reflow and better outcomes. Diabetic patients who underwent primary angioplasty for myocardial infarction from January 2001 to June 2004 were analyzed. No-reflow was defined as TIMI flow < 3 in the absence of mechanical obstruction. Patients were divided into 2 glycemic control groups according to the HbA1c value: optimal (less than or equal to 7%), and suboptimal (> 7%). A total of 183 diabetic patients (93% noninsulin-requiring) were included for analysis. The median HbA1c of the optimal (n = 37) and suboptimal (n = 146) glycemic control groups were 6.5% and 8.5%, respectively. Compared to the suboptimal glycemic control group, the optimal glycemic control group was older, likely to have hypertension, previously suffered a stroke, have renal failure and a higher baseline creatinine. No-reflow occurred in 16% of the optimal and 18% of the suboptimal glycemic control groups. Multivariate analysis showed that optimal glycemic control was not associated with a lesser occurrence of no-reflow (OR 1.27, 95% CI 0.19-8.29; p = 0.807). The optimal glycemic control group had 30-day survival (90% versus 93%; p = 0.698) and 30-day event-free survival (84% versus 86%; p = 0.695) rates similar to the suboptimal glycemic control group. Among diabetic patients undergoing primary angioplasty, optimal glycemic control was not associated with a lesser occurrence of no-reflow or better 30-day outcomes.
    The Journal of invasive cardiology 09/2005; 17(8):422-6. · 1.84 Impact Factor

Institutions

  • 2010
    • Duke-NUS Graduate Medical School Singapore
      Singapore, Singapore
  • 2005–2010
    • National Cancer Centre Singapore
      • Division of Clinical Trials and Epidemiological Sciences
      Singapore
  • 2009
    • Ministry of Health, Singapore
      Singapore, Singapore
  • 2008
    • National Dental Centre of Singapore
      Singapore, Singapore
  • 2005–2007
    • National University of Singapore
      • Faculty of Dentistry
      Singapore, Singapore
  • 2004
    • National Skin Centre
      Singapore, Singapore
    • National Neuroscience Institute
      Singapore, Singapore