Background Smoking restriction laws have spread worldwide during the last decade. Previous studies have shown a decline in the community rates of myocardial infarction after enactment of these laws. However, data are scarce about the Latin American population. In the first phase of this study, we reported the successful implementation of the law in São Paulo city, with a decrease in carbon monoxide rates in hospitality venues.

Objective To evaluate whether the 2009 implementation of a comprehensive smoking ban law in São Paulo city was associated with a reduction in rates of mortality and hospital admissions for myocardial infarction.

Methods We performed a time-series study of monthly rates of mortality and hospital admissions for acute myocardial infarction from January 2005 to December 2010. The data were derived from DATASUS, the primary public health information system available in Brazil and from Mortality Information System (SIM). Adjustments and analyses were performed using the Autoregressive Integrated Moving Average with exogenous variables (ARIMAX) method modelled by environmental variables and atmospheric pollutants to evaluate the effect of smoking ban law in mortality and hospital admission rate. We also used Interrupted Time Series Analysis (ITSA) to make a comparison between the period pre and post smoking ban law.

Results We observed a reduction in mortality rate (−11.9% in the first 17 months after the law) and in hospital admission rate (−5.4% in the first 3 months after the law) for myocardial infarction after the implementation of the smoking ban law.

Conclusions Hospital admissions and mortality rate for myocardial infarction were reduced in the first months after the comprehensive smoking ban law was implemented.