RESUMO
BACKGROUND: 'Smoker's paradox' is a controversial phenomenon of an unexpected favourable outcome of smokers post acute myocardial infarction. There are conflicting evidences from the literature so far. We investigate for the existence of this phenomenon in our post acute myocardial infarction patients. METHODS: We analysed 12,442 active smokers and 10,666 never-smokers diagnosed with STEMI and NSTEMI from the Malaysian National Cardiovascular Database-Acute Coronary Syndrome (NCVD-ACS) year 2006-2013 from 18 hospitals across Malaysia. Comparisons in the baseline characteristics, clinical presentation, in-hospital treatment and short term clinical outcome were made between the two groups. To compare the clinical outcome, an extensive multivariate adjustment was made to estimate the allcause mortality risk ratios for both groups. RESULTS: The active smokers were younger (smokers 53.7 years vs non-smokers 62.3 years P < 0.001) and had lower cardiovascular risk burden and other co-morbidities. STEMI is more common in smokers and intravenous thrombolysis was the main reperfusion therapy in both groups. Smokers had a higher rate of in-hsopital coronary revascularisation in NSTEMI group (21.6 % smokers vs 16.7 % non-smokers P < 0.001) but similar to non-smokers in the STEMI group. Multivariate adjusted mortality risk ratios showed significantly lower mortality risks of smokers at both in-hospital (RR 0.510 [95 % CI 0.442-0.613]) and 30-day post discharge (RR 0.534 [95 % CI 0.437-0.621]). CONCLUSION: Smoking seems to be associated with a favourable outcome post myocardial infarction. The phenomenon of 'smoker's paradox' is in fact a reality in our patients population. The definitive explanation for this unexpected protective effect of smoking remains unclear.
RESUMO
BACKGROUND: The administration of evidence-based pharmacotherapy and timely primary percutaneous coronary intervention have been shown to improve outcome in ST elevation myocardial infarction (STEMI). However, implementation remains a challenge due to the limitations in facilities, expertise and funding. OBJECTIVES: To investigate adherence to guideline-based management and mortality of STEMI patients in Malaysia. DESIGN: Retrospective analysis. SETTINGS: STEMI patients from 18 participating hospital across Malaysia included in the National Cardiovascular Database-Acute Coronary Syndrome (NCVD-ACS) registry year 2006 to 2013. PATIENTS AND METHODS: Patients were categorized into four subgroups based on the year of admission (2006 to 2007, 2008 to 2009, 2010 to 2011 and 2012 to 2013). Baseline characteristics and clinical presentation, in-hospital pharmacotherapy, invasive revascularization and in-hospital/30-day mortality were analysed and compared between the subgroups. MAIN OUTCOME MEASURE(S): Rate of in-hospital catheterization/percutaneous coronary intervention. RESULTS: The registry contained data on 19483 patients. Intravenous thrombolysis was the main reperfusion therapy. Although the overall rate of in-hospital catheterisation/PCI more than doubled over the study period, while the use of primary PCI only slowly increased from 7.6% in 2006/2007 to 13.6% in 2012/2013. The use of evidence-based oral therapies increased steadily over the years except for ACe-inhibitors and angiotensin-receptor blockers. The adjusted risk ratios (RR) for in-hospital mortality for the four sub-groups have not shown any significant improvement. The 30-day adjusted risk ratios however showed a significant albeit gradual risk reduction (RR 0.773 95% CI 0.679-0.881, P < .001). CONCLUSION: Adherence to evidence-based treatment in STEMI in Malaysia is still poor especially in terms of the rate of primary PCI. Although there is a general trend toward reduced 30-day mortality, the reduction was only slight over the study period. Drastic effort is needed to improve adherence and clinical outcomes. LIMITATION: Retrospective registry data with inter-hospital variation.
