The impact of public smoking ban on the incidence of myocardial infarction hospitalizations

Circulating miR-23b as a Novel Biomarker for Early Risk Stratification After ST-Elevation Myocardial Infarction

Background

miR-23b overexpression can promote cardiomyocyte apoptosis and reduce cell growth under hypoxic conditions, suggesting that miR-23b acts as a biomarker for ST-elevation myocardial infarction (STEMI). The aim of this study was to investigate the effect of miR-23b on STEMI patients.

Material/Methods

We enrolled 80 eligible patients with STEMI and 60 control subjects. Blood samples were obtained at 6 h, 12 h, 24 h, 48 h, 3 days, and 7 days after the onset of symptoms. Another blood sample was collected before and after percutaneous coronary intervention (PCI). The samples were used for real-time quantitative PCR analysis. A Siemens Immulite2000 detector (Germany) was used for cTnI detection, and the serum CK-MB content was detected by electrochemical luminescence method.

Results

The expression level of miR-23b was increased in patients with STEMI (P<0.05). No significance difference was observed among risk factors, although the clinical data was comparable (P>0.05). The level of miR-23b in STEMI patients after PCI was lower (P<0.05). The ROC curve of plasma miR-23b showed a separation, with an AUC of 0.809 (95%CI, 0.737–0.936, P<0.05), compared to CK-MB with an AUC of 0.753 (95%CI, 0.707–0.896) and cTnI with an AUC of 0.783 (95%CI, 0.723–0.917).

Conclusions

The present study reveals that miR-23b is a useful biomarker of STEMI, providing a novel insight for the diagnosis for STEMI.

Association of restaurant smoking ban and the incidence of acute myocardial infarction in Finland

OBJECTIVE

To describe the changes in nationwide acute myocardial infarction (AMI) incidence following the implementation of a law banning smoking indoors in restaurants on 1 June 2007.

METHODS

Retrospective registry study of all hospitalisations for AMI in Finland. All 34,887 hospitalisations for AMI between 1 June 2005 and 31 May 2009 were identified from the Care Register for Health Care (CRHC) and statistics for tobacco consumption were obtained from the National Institute for Health and Welfare. Comorbidities for individual hospitalisations were searched from the CRHC.

RESULTS

The incidence rate of AMI was reduced by 6.3% (95% CI 4.1% to 8.6%; p<0.0001) in the latter half of the study period following the smoking ban when adjusted for age, gender and overall population prevalence of smoking. Short-term incidence of AMI (6-month prior vs 6 months after the smoking ban) was also reduced (4.5%, 95% CI 0.2% to 9.0%; p=0.0399) and was largest in the working middle-aged group (40-50 years) but observed also in the oldest age group (>70 years). The incidence rates declined similarly for men and women.

CONCLUSIONS

Banning indoor tobacco smoking in restaurants was associated with a mild additional reduction in AMI incidence on a nationwide level in Finland.