Publications (12)167.1 Total impact
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Article: Association Between Postoperative Troponin Levels and 30-Day Mortality Among Patients Undergoing Noncardiac Surgery
JAMA The Journal of the American Medical Association 06/2012; · 30.03 Impact Factor -
Article: Association Between Postoperative Troponin Levels and 30-Day Mortality Among Patients Undergoing Noncardiac Surgery
JAMA The Journal of the American Medical Association 06/2012; · 30.03 Impact Factor -
Article: Association between postoperative troponin levels and 30-day mortality among patients undergoing noncardiac surgery.
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ABSTRACT: Of the 200 million adults worldwide who undergo noncardiac surgery each year, more than 1 million will die within 30 days. To determine the relationship between the peak fourth-generation troponin T (TnT) measurement in the first 3 days after noncardiac surgery and 30-day mortality. A prospective, international cohort study that enrolled patients from August 6, 2007, to January 11, 2011. Eligible patients were aged 45 years and older and required at least an overnight hospital admission after having noncardiac surgery. Patients' TnT levels were measured 6 to 12 hours after surgery and on days 1, 2, and 3 after surgery. We undertook Cox regression analysis in which the dependent variable was mortality until 30 days after surgery, and the independent variables included 24 preoperative variables. We repeated this analysis, adding the peak TnT measurement during the first 3 postoperative days as an independent variable and used a minimum P value approach to determine if there were TnT thresholds that independently altered patients' risk of death. A total of 15,133 patients were included in this study. The 30-day mortality rate was 1.9% (95% CI, 1.7%-2.1%). Multivariable analysis demonstrated that peak TnT values of at least 0.02 ng/mL, occurring in 11.6% of patients, were associated with higher 30-day mortality compared with the reference group (peak TnT ≤ 0.01 ng/mL): peak TnT of 0.02 ng/mL (adjusted hazard ratio [aHR], 2.41; 95% CI, 1.33-3.77); 0.03 to 0.29 ng/mL (aHR, 5.00; 95% CI, 3.72-6.76); and 0.30 ng/mL or greater (aHR, 10.48; 95% CI, 6.25-16.62). Patients with a peak TnT value of 0.01 ng/mL or less, 0.02, 0.03-0.29, and 0.30 or greater had 30-day mortality rates of 1.0%, 4.0%, 9.3%, and 16.9%, respectively. Peak TnT measurement added incremental prognostic value to discriminate those likely to die within 30 days for the model with peak TnT measurement vs without (C index = 0.85 vs 0.81; difference, 0.4; 95% CI, 0.2-0.5; P < .001 for difference between C index values). The net reclassification improvement with TnT was 25.0% (P < .001). Among patients undergoing noncardiac surgery, the peak postoperative TnT measurement during the first 3 days after surgery was significantly associated with 30-day mortality.JAMA The Journal of the American Medical Association 06/2012; 307(21):2295-304. · 30.03 Impact Factor -
Article: High sensitivity troponin T concentrations in patients undergoing noncardiac surgery: a prospective cohort study.
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ABSTRACT: To determine the proportion of noncardiac surgery patients exceeding the published 99th percentile or change criteria with the high sensitivity Troponin T (hs-TnT) assay. We measured hs-TnT preoperatively and postoperatively on days 1, 2 and 3 in 325 adults. Postoperatively 45% (95% CI: 39-50%) of patients had hs-TnT≥14ng/L and 22% (95% CI:17-26%) had an elevation (≥14ng/L) and change (>85%) in hs-TnT. Further research is needed to inform the optimal hs-TnT threshold and change in this setting.Clinical biochemistry 05/2011; 44(12):1021-4. · 2.02 Impact Factor -
Article: Dalteparin versus unfractionated heparin in critically ill patients.
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ABSTRACT: The effects of thromboprophylaxis with low-molecular-weight heparin, as compared with unfractionated heparin, on venous thromboembolism, bleeding, and other outcomes are uncertain in critically ill patients. In this multicenter trial, we tested the superiority of dalteparin over unfractionated heparin by randomly assigning 3764 patients to receive either subcutaneous dalteparin (at a dose of 5000 IU once daily) plus placebo once daily (for parallel-group twice-daily injections) or unfractionated heparin (at a dose of 5000 IU twice daily) while they were in the intensive care unit. The primary outcome, proximal leg deep-vein thrombosis, was diagnosed on compression ultrasonography performed within 2 days after admission, twice weekly, and as clinically indicated. Additional testing for venous thromboembolism was performed as clinically indicated. Data were analyzed according to the intention-to-treat principle. There was no significant between-group difference in the rate of proximal leg deep-vein thrombosis, which occurred in 96 of 1873 patients (5.1%) receiving dalteparin versus 109 of 1873 patients (5.8%) receiving unfractionated heparin (hazard ratio in the dalteparin group, 0.92; 95% confidence interval [CI], 0.68 to 1.23; P=0.57). The proportion of patients with pulmonary emboli was significantly lower with dalteparin (24 patients, 1.3%) than with unfractionated heparin (43 patients, 2.3%) (hazard ratio, 0.51; 95% CI, 0.30 to 0.88; P=0.01). There was no significant between-group difference in the rates of major bleeding (hazard ratio, 1.00; 95% CI, 0.75 to 1.34; P=0.98) or death in the hospital (hazard ratio, 0.92; 95% CI, 0.80 to 1.05; P=0.21). In prespecified per-protocol analyses, the results were similar to those of the main analyses, but fewer patients receiving dalteparin had heparin-induced thrombocytopenia (hazard ratio, 0.27; 95% CI, 0.08 to 0.98; P=0.046). Among critically ill patients, dalteparin was not superior to unfractionated heparin in decreasing the incidence of proximal deep-vein thrombosis. (Funded by the Canadian Institutes of Health Research and others; PROTECT ClinicalTrials.gov number, NCT00182143.).New England Journal of Medicine 04/2011; 364(14):1305-14. · 53.30 Impact Factor -
Article: PROphylaxis for ThromboEmbolism in Critical Care Trial protocol and analysis plan.
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ABSTRACT: This article reports the preparatory studies as well as the design, implementation, and a priori analysis plans of PROphylaxis for ThromboEmbolism in Critical Care Trial (PROTECT) before dissemination of results. PROphylaxis for ThromboEmbolism in Critical Care Trial (NCT00182143) is a randomized, stratified, concealed international trial comparing subcutaneous injection of unfractionated heparin (UFH) 5000 IU or the low-molecular weight heparin (LMWH) dalteparin 5000 IU once daily plus once-daily placebo for the duration of the intensive care unit stay. The objective of PROTECT is to examine, among medical-surgical critically ill patients, the effect of the LMWH vs heparin on the primary outcome of proximal leg deep vein thrombosis (DVT) and the following secondary outcomes: DVT elsewhere, pulmonary embolism, any venous thromboembolism (DVT or pulmonary embolism), the composite of venous thromboembolism or death, bleeding, and heparin-induced thrombocytopenia. Patients are followed up to death or hospital discharge. Venous thromboembolism events were included after intensive care unit discharge. All patients, families, clinicians, research personnel, and the trial biostatistician are blind to allocation. We describe the pilot work, large trial methodology, implementation methods, and the analytic plan. Patient recruitment is complete, but 2 patients remain in the hospital. The rigorous design of PROTECT suggests that the risk of systematic error will be low. The sample size suggests that the risk of random error will be low. PROTECT will be the largest investigator-initiated peer-review funded thromboprophylaxis trial in critical care in the world. If PROTECT shows that LMWH is more effective than UFH, this trial will change practice in that LMWH may be the anticoagulant thromboprophylaxis of choice for this population. If the results show that UFH is as effective or more effective than LMWH, intensivists in many parts of the world may continue to use UFH, whereas those currently using LMWH may reconsider and change to use UFH. Unfavorable consequences such as major bleeding, ease of use, and the costs of complications will also factor into such decisions.Journal of critical care 04/2011; 26(2):223.e1-9. · 2.13 Impact Factor -
Article: An international prospective cohort study evaluating major vascular complications among patients undergoing noncardiac surgery: the VISION Pilot Study.
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ABSTRACT: among patients undergoing noncardiac surgery, our objectives were to: (1) determine the feasibility of undertaking a large international cohort study; (2) estimate the current incidence of major perioperative vascular events; (3) compare the observed event rates to the expected event rates according to the Revised Cardiac Risk Index (RCRI); and (4) provide an estimate of the proportion of myocardial infarctions without ischemic symptoms that may go undetected without perioperative troponin monitoring. An international prospective cohort pilot study. Patients undergoing noncardiac surgery who were >45 years of age, receiving a general or regional anesthetic, and requiring hospital admission. Patients had a Roche fourth-generation Elecsys troponin T measurement collected 6 to 12 hours postoperatively and on the first, second, and third days after surgery. Our primary outcome was major vascular events (a composite of vascular death [i.e., death from vascular causes], nonfatal myocardial infarction, nonfatal cardiac arrest, and nonfatal stroke) at 30 days after surgery. Our definition for perioperative myocardial infarction included: (1) an elevated troponin T measurement with at least one of the following defining features: ischemic symptoms, development of pathologic Q waves, ischemic electrocardiogram changes, coronary artery intervention, or cardiac imaging evidence of myocardial infarction; or (2) autopsy findings of acute or healing myocardial infarction. We recruited 432 patients across 5 hospitals in Canada, China, Italy, Colombia, and Brazil. During the first 30 days after surgery, 6.3% (99% confidence interval 3.9-10.0) of the patients suffered a major vascular event (10 vascular deaths, 16 nonfatal myocardial infarctions, and 1 nonfatal stroke). The observed event rate was increased 6-fold compared with the event rate expected from the RCRI. Of the 18 patients who suffered a myocardial infarction, 12 (66.7%) had no ischemic symptoms to suggest myocardial infarction. This study suggests that major perioperative vascular events are common, that the RCRI underestimates risk, and that monitoring troponins after surgery can assist physicians to avoid missing myocardial infarction. These results underscore the need for a large international prospective cohort study.Open Medicine 01/2011; 5(4):e193-200. -
Article: A survey evaluating surgeons' peri-operative usage of acetyl-salicylic acid (ASA) and their willingness to enroll their patients in a perioperative ASA randomized controlled trial.
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ABSTRACT: Major cardiovascular complications associated with noncardiac surgery represent a substantial population health problem for which there are no established efficacious and safe prophylactic interventions. Acetyl-salicylic acid (ASA) represents a promising intervention. The objective of this study was to determine surgeons' perioperative usage of ASA, and if they would enroll their patients in a perioperative ASA randomized controlled trial (RCT). Cross-sectional survey of all practicing Canadian general, orthopedic, and vascular surgeons. Our mailed, self-administered survey asked surgeons to consider only their patients who were at risk of a major perioperative cardiovascular complication. The response rate was 906/1854 (49%). For patients taking ASA chronically, there was marked variability regarding ASA continuation prior to surgery amongst the general and orthopedic surgeons, whereas 76% of vascular surgeons continued ASA in 81-100% of their patients. For patients not taking ASA chronically, approaches to starting ASA prior to surgery were variable amongst the vascular surgeons, whereas 70% of general and 82% of orthopaedic surgeons did not start ASA. For patients taking ASA chronically, 73% of general surgeons, 70% of orthopaedic surgeons, and 36% of vascular surgeons would allow at least 40% of their patients to participate in a perioperative RCT comparing stopping versus continuing ASA. For patients not taking ASA chronically, most general (76%), orthopaedic (67%), and vascular (51%) surgeons would allow at least 40% of their patients to participate in a perioperative RCT comparing starting ASA versus placebo. This national survey demonstrates that perioperative ASA usage as reported by surgeons is variable, identifying the need for, and community interest in, a large perioperative ASA trial.Clinical and investigative medicine. Medecine clinique et experimentale 01/2010; 33(6):E375-83. · 1.15 Impact Factor -
Article: Is a pre-operative brain natriuretic peptide or N-terminal pro-B-type natriuretic peptide measurement an independent predictor of adverse cardiovascular outcomes within 30 days of noncardiac surgery? A systematic review and meta-analysis of observational studies.
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ABSTRACT: We conducted a systematic review and meta-analysis to determine if pre-operative brain natriuretic peptide (BNP) (i.e., BNP or N-terminal pro-B-type natriuretic peptide [NT-proBNP]) is an independent predictor of 30-day adverse cardiovascular outcomes after noncardiac surgery. Pre-operative clinical cardiac risk indices have only modest predictive power. BNP predicts adverse cardiovascular outcomes in a variety of nonsurgical settings and may similarly predict these outcomes in the perioperative setting. We employed 5 search strategies (e.g., searching bibliographic databases), and we included all studies that assessed the independent prognostic value of pre-operative BNP measurement as a predictor of cardiovascular complications after noncardiac surgery. We determined study eligibility and conducted data abstraction independently and in duplicate. We calculated a pooled odds ratio using a random effects model. Nine studies met eligibility criteria, and included a total of 3,281 patients, among whom 314 experienced 1 or more perioperative cardiovascular complications. The average proportion of patients with elevated BNP was 24.8% (95% confidence interval [CI]: 20.1 to 30.4%; I(2) = 89%). All studies showed a statistically significant association between an elevated pre-operative BNP level and various cardiovascular outcomes (e.g., a composite of cardiac death and nonfatal myocardial infarction; atrial fibrillation). Data pooled from 7 studies demonstrated an odds ratio (OR) of 19.3 (95% CI: 8.5 to 43.7; I(2) = 58%). The pre-operative BNP measurement was an independent predictor of perioperative cardiovascular events among studies that only considered the outcomes of death, cardiovascular death, or myocardial infarction (OR: 44.2, 95% CI: 7.6 to 257.0, I(2) = 51.6%), and those that included other outcomes (OR: 14.7, 95% CI: 5.7 to 38.2, I(2) = 62.2%); the p value for interaction was 0.28. These results suggest that an elevated pre-operative BNP or NT-proBNP measurement is a powerful, independent predictor of cardiovascular events in the first 30 days after noncardiac surgery.Journal of the American College of Cardiology 10/2009; 54(17):1599-606. · 14.16 Impact Factor -
Article: Large randomized controlled trials in perioperative cardiovascular medicine: a proposal for the design, conduct and efficient management.
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ABSTRACT: The number of patients undergoing noncardiac surgery is growing worldwide. To optimally assist patients during the perioperative period, we must improve our knowledge of how to prevent major perioperative cardiovascular events around the time of noncardiac surgery. To achieve this goal there is a need for large randomized controlled trials that can provide reliable and conclusive results in this field. This narrative review describes a proposal for the design, conduct and management of large controlled trials in perioperative cardiovascular medicine.Arquivos brasileiros de cardiologia 06/2009; 92(5):387-91, 404-8, 419-23. · 1.32 Impact Factor -
Article: Quality of care in for-profit and not-for-profit nursing homes: systematic review and meta-analysis.
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ABSTRACT: To compare quality of care in for-profit and not-for-profit nursing homes. Systematic review and meta-analysis of observational studies and randomised controlled trials investigating quality of care in for-profit versus not-for-profit nursing homes. A comprehensive search yielded 8827 citations, of which 956 were judged appropriate for full text review. Study characteristics and results of 82 articles that met inclusion criteria were summarised, and results for the four most frequently reported quality measures were pooled. Included studies reported results dating from 1965 to 2003. In 40 studies, all statistically significant comparisons (P<0.05) favoured not-for-profit facilities; in three studies, all statistically significant comparisons favoured for-profit facilities, and the remaining studies had less consistent findings. Meta-analyses suggested that not-for-profit facilities delivered higher quality care than did for-profit facilities for two of the four most frequently reported quality measures: more or higher quality staffing (ratio of effect 1.11, 95% confidence interval 1.07 to 1.14, P<0.001) and lower pressure ulcer prevalence (odds ratio 0.91, 95% confidence interval 0.83 to 0.98, P=0.02). Non-significant results favouring not-for-profit homes were found for the two other most frequently used measures: physical restraint use (odds ratio 0.93, 0.82 to 1.05, P=0.25) and fewer deficiencies in governmental regulatory assessments (ratio of effect 0.90, 0.78 to 1.04, P=0.17). This systematic review and meta-analysis of the evidence suggests that, on average, not-for-profit nursing homes deliver higher quality care than do for-profit nursing homes. Many factors may, however, influence this relation in the case of individual institutions.BMJ (Clinical research ed.). 01/2009; 339:b2732. -
Article: The quality of reporting of trial abstracts is suboptimal: survey of major general medical journals.
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ABSTRACT: To evaluate the quality of reporting of abstracts describing randomized controlled trials (RCTs) published in four major general medical journals. Systematic survey of published RCT abstracts, with two reviewers independently extracting data. We searched MEDLINE and identified 227 RCT abstracts published in the New England Journal of Medicine (NEJM), Journal of the American Medical Association (JAMA), British Medical Journal (BMJ), and The Lancet in the year 2006. Most abstracts identified the study as a randomized trial (98.7%), reported the objectives (92.5%), described the population (90.3%), detailed the intervention (81.5%), and defined the primary outcome (71.3%). Methodological quality was poorly reported: one (0.4%) described allocation concealment; 21 (9.3%) clearly specified blinding; 51 (22.5%) described intention-to-treat analysis; and 32 (14.1%) outlined losses to follow-up. Most of the abstracts reported the effect size and the confidence intervals (62.3%), but just half of them reported side effects or harms. The quality of reporting of RCT abstracts published in main general medical journals is suboptimal. Space limitations notwithstanding, with the recent recommendations from the CONSORT for Abstracts, it is expected that the transparency of abstract reporting can and should improve.Journal of clinical epidemiology 12/2008; 62(4):387-92. · 2.96 Impact Factor
Top co-authors
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2010
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McMaster University
Hamilton, Ontario, Canada
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2009
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Hospital for the Heart
São Paulo, Estado de Sao Paulo, Brazil -
All India Institute of Medical Sciences
- Department of Cardiology
New Delhi, NCT, India
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