Background

Previous studies suggest an association between short-term exposure to carbon monoxide and myocardial infarction. We performed a systematic review and meta-analysis to assess current evidence on this association to support the update of the World Health Organization (WHO) Global Air Quality Guidelines.

Methods

We searched Medline, Embase and Cochrane Central Register of Controlled Trials to update the evidence published in a previous systematic review up to 30th September 2018 for studies investigating the association between short-term exposure to ambient carbon monoxide (up to lag of seven days) and emergency department visits or hospital admissions and mortality due to myocardial infarction. Two reviewers assessed potentially eligible studies and performed data extraction independently. Random-effects meta-analysis was used to derive the pooled risk estimate per 1 mg/m³ increase in ambient carbon monoxide concentration. Risk of bias in individual studies was assessed using a domain-based assessment tool. The overall certainty of the body of evidence was evaluated using an adapted certainty of evidence assessment framework.

Results

We evaluated 1,038 articles from the previous review and our updated literature search, of which, 26 satisfied our inclusion criteria. Overall, myocardial infarction was associated with exposure to ambient carbon monoxide concentration (risk ratio of 1.052, 95% confidence interval 1.017–1.089 per 1 mg/m³ increase). A third of studies were assessed to be at high risk of bias (RoB) due to inadequate adjustment for confounding. Using an adaptation of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework, the overall evidence was assessed to be of moderate certainty.

Conclusions

This review demonstrated that the pooled risk ratio for myocardial infarction was 1.052 (95% CI 1.017–1.089) per 1 mg/m³ increase in ambient carbon monoxide concentration. However, very few studies originated from low- and middle-income countries.

中文翻译：

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短期接触一氧化碳和心肌梗塞：系统评价和荟萃分析。

背景

先前的研究表明，短期暴露于一氧化碳与心肌梗塞之间存在关联。我们进行了系统的回顾和荟萃分析，以评估有关该协会的当前证据，以支持世界卫生组织（WHO）全球空气质量准则的更新。

方法

我们搜索了Medline，Embase和Cochrane对照试验中央注册中心，以更新截至2018年9月30日的先前系统评价中发表的证据，以研究短期暴露于环境一氧化碳（至迟7天的时间）与急诊就诊或住院以及因心肌梗塞而导致的死亡。两名审阅者评估了可能合格的研究并独立进行了数据提取。使用随机效应荟萃分析得出每1 mg / m ³的合并风险估计值增加环境一氧化碳浓度。使用基于领域的评估工具评估了个别研究的偏倚风险。证据的整体确定性是使用经过调整的证据确定性评估框架进行评估的。

结果

我们评估了上次审查和最新文献搜索中的1,038条文章，其中26条满足我们的纳入标准。总体而言，心肌梗死与暴露于周围一氧化碳浓度有关（风险比为1.052，95％置信区间为1.017-1.089 / 1 mg / m ³升高）。三分之一的研究由于对混杂的调整不足而被评估为有偏见（RoB）的高风险。通过对“建议书评估，制定和评估等级”（GRADE）框架进行改编，对总体证据进行了中等程度的确定性评估。

结论

该评价表明，每增加1 mg / m ³的环境一氧化碳浓度，心肌梗塞的合并风险比为1.052（95％CI 1.017–1.089）。但是，很少有研究来自中低收入国家。