The effect of door-to-balloon delay in primary percutaneous coronary intervention on clinical outcomes of STEMI: a systematic review and meta-analysis protocol

BACKGROUND: Acute myocardial infarction (AMI) is a medical emergency in which sudden occlusion of coronary artery(ies) results in ischemia and necrosis of the cardiac tissues. Reperfusion therapies that aim at reopening the occluded artery remain the mainstay of treatment for AMI. Primary percutaneous coronary intervention (PCI), which enables the restoration of blood flow by reopening the occluded artery(ies) via a catheter with an inflatable balloon, is currently the preferred treatment for AMI with ST segment elevation (STEMI). The door-to-balloon (D2B) delay refers to the time interval counting from the arrival of a patient with STEMI at a hospital to the time of the balloon inflation (or stent deployment) that reopens the occluded artery(ies). Reducing this delay in primary PCI is thought to be an important strategy toward achieving better patient outcomes. Unfortunately, significant reduction of D2B delay in the USA over the last decade has not been shown to be associated with improved STEMI mortality. It has been suggested that the lack of impact could be due to the expanding use of primary PCI in STEMI as well as the survival cohort effect, leading to a shift toward a higher risk population receiving the procedure. Others have suggested that reduction in D2B delay may not be as impactful as expected, given that it only represents a small fraction of the total ischemic time. Although most existing evidence have pointed to the presence of a beneficial effect of shorter D2B delay, some inconsistencies however exist. This study aims to synthesize available evidence in order to answer the following questions: (1) what is the overall effect of D2B delay on clinical outcomes in patients with STEMI treated with primary PCI? (2) What factors explain the differences of the effect estimates among the studies? (3) What are the important strength and limitation of the existing body of evidence? METHOD: We will search PubMed/MEDLINE, EMBASE, ClinicalTrials.gov, WHO International Clinical Trials Registry, CINAHL Database, and the Cochrane Library using a predefined search strategy. Other sources of literature will include proceedings from the European Society of Cardiology, the American College of Cardiology, the American Heart Association, the EUROPCR, and the ProQuest Dissertations and Theses Database. We will include data from observational studies (case-control and cohort study design) and randomized control trials (that have investigated the relationship of D2B time and clinical outcome(s) in an adult (older than 18) STEMI population). Mortality (cardiac related and all-cause) and incidence heart failure (HF) have been prioritized as the primary outcomes. All eligible studies will be assessed for risk of bias using the Risk Of Bias in Non-randomized Studies - of Interventions tool. The Grading of Recommendations, Assessment, and Evaluation (GRADE) framework will be used to report the quality of evidence and strength of recommendations. We will proceed to analyze the data quantitatively if the pre-specified conditions are satisfied. DISCUSSION: Recent discussion on the negative findings of improved D2B delay over time being unrelated to better STEMI outcomes at the population level has reminded us of an important knowledge gap we have on this domain. This systematic review will serve to address some of these key questions not previously examined. Answers to these questions could clarify the controversies and offer empirical support for or against the suggested hypotheses. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42015026069 ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s13643-016-0304-7) contains supplementary material, which is available to authorized users

The effect of door-to-balloon delay in primary percutaneous coronary intervention on clinical outcomes of STEMI: a systematic review and meta-analysis protocol

Daniel Reidpath - ORCID: 0000-0002-8796-0420 https://orcid.org/0000-0002-8796-0420Background Acute myocardial infarction (AMI) is a medical emergency in which sudden occlusion of coronary artery(ies) results in ischemia and necrosis of the cardiac tissues. Reperfusion therapies that aim at reopening the occluded artery remain the mainstay of treatment for AMI. Primary percutaneous coronary intervention (PCI), which enables the restoration of blood flow by reopening the occluded artery(ies) via a catheter with an inflatable balloon, is currently the preferred treatment for AMI with ST segment elevation (STEMI). The door-to-balloon (D2B) delay refers to the time interval counting from the arrival of a patient with STEMI at a hospital to the time of the balloon inflation (or stent deployment) that reopens the occluded artery(ies). Reducing this delay in primary PCI is thought to be an important strategy toward achieving better patient outcomes. Unfortunately, significant reduction of D2B delay in the USA over the last decade has not been shown to be associated with improved STEMI mortality. It has been suggested that the lack of impact could be due to the expanding use of primary PCI in STEMI as well as the survival cohort effect, leading to a shift toward a higher risk population receiving the procedure. Others have suggested that reduction in D2B delay may not be as impactful as expected, given that it only represents a small fraction of the total ischemic time. Although most existing evidence have pointed to the presence of a beneficial effect of shorter D2B delay, some inconsistencies however exist. This study aims to synthesize available evidence in order to answer the following questions: (1) what is the overall effect of D2B delay on clinical outcomes in patients with STEMI treated with primary PCI? (2) What factors explain the differences of the effect estimates among the studies? (3) What are the important strength and limitation of the existing body of evidence? Method We will search PubMed/MEDLINE, EMBASE, ClinicalTrials.gov, WHO International Clinical Trials Registry, CINAHL Database, and the Cochrane Library using a predefined search strategy. Other sources of literature will include proceedings from the European Society of Cardiology, the American College of Cardiology, the American Heart Association, the EUROPCR, and the ProQuest Dissertations and Theses Database. We will include data from observational studies (case-control and cohort study design) and randomized control trials (that have investigated the relationship of D2B time and clinical outcome(s) in an adult (older than 18) STEMI population). Mortality (cardiac related and all-cause) and incidence heart failure (HF) have been prioritized as the primary outcomes. All eligible studies will be assessed for risk of bias using the Risk Of Bias in Non-randomized Studies - of Interventions tool. The Grading of Recommendations, Assessment, and Evaluation (GRADE) framework will be used to report the quality of evidence and strength of recommendations. We will proceed to analyze the data quantitatively if the pre-specified conditions are satisfied. Discussion Recent discussion on the negative findings of improved D2B delay over time being unrelated to better STEMI outcomes at the population level has reminded us of an important knowledge gap we have on this domain. This systematic review will serve to address some of these key questions not previously examined. Answers to these questions could clarify the controversies and offer empirical support for or against the suggested hypotheses.https://doi.org/10.1186/s13643-016-0304-75pubpub1

Re-examining the effect of door-to-balloon delay on STEMI outcomes in the context of unmeasured confounders: a retrospective cohort study

Daniel Reidpath - ORCID: 0000-0002-8796-0420 https://orcid.org/0000-0002-8796-0420Literature studying the door-to-balloon time-outcome relation in coronary intervention is limited by the potential of residual biases from unobserved confounders. This study re-examines the time-outcome relation with further consideration of the unobserved factors and reports the population average effect. Adults with ST-elevation myocardial infarction admitted to one of the six registry participating hospitals in Australia were included in this study. The exposure variable was patient-level door-to-balloon time. Primary outcomes assessed included in-hospital and 30 days mortality. 4343 patients fulfilled the study criteria. 38.0% (1651) experienced a door-to-balloon delay of >90 minutes. The absolute risk differences for in-hospital and 30-day deaths between the two exposure subgroups with balanced covariates were 2.81 (95% CI 1.04, 4.58) and 3.37 (95% CI 1.49, 5.26) per 100 population. When unmeasured factors were taken into consideration, the risk difference were 20.7 (95% CI −2.6, 44.0) and 22.6 (95% CI −1.7, 47.0) per 100 population. Despite further adjustment of the observed and unobserved factors, this study suggests a directionally consistent linkage between longer door-to-balloon delay and higher risk of adverse outcomes at the population level. Greater uncertainties were observed when unmeasured factors were taken into consideration.https://doi.org/10.1038/s41598-019-56353-79pubpub

The Association Between Hospital Characteristics and Nonresponse in an Organization Survey: An Analysis of the National Healthcare Establishment and Workforce Survey in Malaysia

Daniel Reidpath - ORCID: 0000-0002-8796-0420 https://orcid.org/0000-0002-8796-0420Item is not available in this repository.In any survey where some of the invited participants fail to respond estimates may be biased. The literature on survey nonresponse is substantial, and the intellectual focus has typically been on the nonresponse of individuals. An important yet less scrutinized area in the analysis of nonresponse is in organizational surveys, particularly surveys of health-care organizations. This study used data from the 2010 National Healthcare Establishment and Workforce Survey in Malaysia to examine the relationship between a set of measurable hospital attributes and their probability of survey response and the relationship between this probability and the differences in survey estimates. We found that readily measurable hospital characteristics such as size and geographical location are useful predictors of survey response likelihood. Larger hospitals and hospitals located in less developed geographical regions responded more favorably than their counterparts. We have also illustrated that the resulting response pattern affected some key survey estimates. These findings have the potential to extend our understanding of nonresponse to organization surveys in the health-care sector, potentially allow for the prediction of nonresponse, and help researchers to identify profiles of “reluctant responders” before a survey commences, so that additional engagement strategies may be used.https://doi.org/10.1177/016327871771356942pubpub

Estimating the population health and economic impacts of introducing a pneumococcal conjugate vaccine in Malaysia- an economic evaluation

Pneumococcal disease is a potentially fatal bacterial infection that is vaccine-preventable. Malaysia has yet to adopt a pneumococcal conjugate vaccine (PCV) into its national immunization program (NIP). In 2016, pneumonia was the 3rd leading cause of death in children under five in Malaysia, accounting for 3.8% of under-five deaths. Introducing a pneumococcal conjugate vaccine (PCV) is an effective strategy to reduce the disease burden. This study used a decision-analytic model to assess the potential impacts of introducing the available PCVs (13-valent and 10-valent) in Malaysia. Epidemiological and costs inputs were sourced from published literature. For each vaccination program, health outcomes and associated healthcare costs were estimated. The scenarios of initiating PCV13 vs. PCV10 and the status quo (no pneumococcal vaccine) were compared. Serotype trends of Finland and the U.K. were used to model the clinical impacts of PCV10 and PCV13 respectively. The base-case analysis used a societal perspective over a 5-year time horizon. Compared with PCV10, PCV13 was projected to avert an additional 190,628 cases of pneumococcal disease and 1126 cases of death. The acquisition of PCV13 was estimated to cost an incremental US$89,904,777, offset by a cost reduction of -US$250,219,914 on pneumococcal disease-related medical care and lost productivity. PCV13 demonstrated a higher cost-saving potential over PCV10. Compared with no vaccination, PCV13 was estimated as cost-saving. Results were robust across a series of sensitivity analyses. The introduction of PCV13 in a NIP was estimated to reduce a significant burden of disease and to be a cost-saving for the Malaysian health system

Coronary intervention door-to-balloon time and outcomes in ST-elevation myocardial infarction: a meta-analysis

Daniel Reidpath - ORCID: 0000-0002-8796-0420 https://orcid.org/0000-0002-8796-0420Item is not available in this repository.Objective This study aims to determine the relationship between door-to-balloon delay in primary percutaneous coronary intervention and ST-elevation myocardial infarction (MI) outcomes and examine for potential effect modifiers. Methods We conducted a systematic review and meta-analysis of prospective observational studies that have investigated the relationship of door-to-balloon delay and clinical outcomes. The main outcomes include mortality and heart failure. Results 32 studies involving 299 320 patients contained adequate data for quantitative reporting. Patients with ST-elevation MI who experienced longer (>90 min) door-to-balloon delay had a higher risk of short-term mortality (pooled OR 1.52, 95% CI 1.40 to 1.65) and medium-term to long-term mortality (pooled OR 1.53, 95% CI 1.13 to 2.06). A non-linear time–risk relation was observed (P=0.004 for non-linearity). The association between longer door-to-balloon delay and short-term mortality differed between those presented early and late after symptom onset (Cochran’s Q 3.88, P value 0.049) with a stronger relationship among those with shorter prehospital delays. Conclusion Longer door-to-balloon delay in primary percutaneous coronary intervention for ST-elevation MI is related to higher risk of adverse outcomes. Prehospital delays modified this effect. The non-linearity of the time–risk relation might explain the lack of population effect despite an improved door-to-balloon time in the USA.https://doi.org/10.1136/heartjnl-2017-312517104pubpub1

Large-Scale Whole-Genome Sequencing of Three Diverse Asian Populations in Singapore

Because of Singapore's unique history of immigration, whole-genome sequence analysis of 4,810 Singaporeans provides a snapshot of the genetic diversity across East, Southeast, and South Asia.</p