Smoking Ban Law in Chile: Impact in Newborns' Birth Weight by Women's Age Groups and by City Population Density.

Objectives: We examined the short-term impact of the Smoking Ban Law (SBL) enacted in Chile in 2013 on low birth weight (LBW) rates in cities and its differential effects by different maternal age groups and city density. Methods: We included 885,880 live births from 21 Chilean cities of ≥100,000 inhabitants. We examined the smoking and LBW prevalence distribution before and after the SBL. Through Poisson mixed effect models, we determined whether a meaningful change in LBW rate occurred after SBL implementation in the whole sample and stratified by city population density and maternal age group. Results: LBW prevalence remained stable before and after the SBL implementation (6.1% and 6.3%, respectively), while women's smoking prevalence had a relative reduction of 25.9% (p < 0.00001). No significant changes in LBW rate occurred after the implementation of SBL in the total sample or stratified by city density tertiles or maternal age groups. Conclusion: SBL implementation did not show short-term impact on LBW rate in Chile. Further studies need to examine long-term impact of SBL on low birthweight.

Varicocele at High Altitude; Venous Outflow Restriction by Hypobaric Hypoxia.

BACKGROUND: Testicular aches have been reported to occur on exposure to high altitude (HA). As a painful expression of venous congestion at the pampiniform plexus, varicocele (VC) might be a consequence of cardiovascular adjustments at HA. Chile's National Social Security Regulatory Body (SUSESO) emphasized evaluating this condition in the running follow-up study "Health effects of exposure to chronic intermittent hypoxia in Chilean mining workers." OBJECTIVES: This study aimed at investigating the prevalence of VC in a population usually shifting between sea level and HA, thereby intermittently being exposed to hypobaric hypoxia. METHODOLOGY: Miners (n=492) agreed to be examined at their working place by a physician, in the context of a general health survey, for the presence of palpable VC, either visible or not. Among them was a group exposed to low altitude (LA) <2,400 m; n=123; another one exposed to moderate high altitude (MHA) working 3,050 m; n=70, and a third one exposed to very high altitude (VHA) >3,900 m, n=165. The Chi2 test and Kruskal-Wallis test were used for the descriptive analyses, and logistic regression was applied to evaluate the association of VC with exposure to HA. The Ethics Committee for Research in Human Beings, Faculty of Medicine, University of Chile, approved this project. RESULTS: VC prevalence (grades 2 and 3) was found to be 10% at LA, 4.1% at MHA, and 16.7% at VHA (p≤0.05). Hemoglobin oxygen saturation (SaO2) was lower, and hemoglobin concentrations were higher in workers with high-grade VC at VHA compared to LA and MHA (Wilcoxon tests, p<0.001). Odds ratios (OR) for the association of VC with HA were 3.7 (95%CI: 1.26 to 12.3) and 4.06 (95%CI: 1.73 to 11.2) for MHA and VHA, respectively. CONCLUSION: Association of VC with HA, a clinically relevant finding, may be related to blood volume centralization mediated by hypobaric hypoxia.

Efecto de las temperaturas extremas en la incidencia de enfermedades cardiovasculares: revisión bibliográfica 2016-2022 / Effect of extreme temperatures on the incidence of diseases cardiovascular: bibliographic review 2016-2022

Resumen: El panel intergubernamental sobre cambio climático estima que para el año 2100 74% de la población estará expuesta a olas de calor en el peor escenario (definido como 3 días consecutivos con temperaturas igual o sobre el percentil 95 de un periodo de tiempo), abarcando en Santiago hasta 40% de los días de verano con temperaturas extremas. Producto de la crisis climática también pueden ocurrir eventos de frío extremo. Ambos fenómenos constituyen un riesgo para la salud, particularmente para las enfermedades cardiovasculares. Objetivo: Estudiar la asociación entre temperaturas extremas y enfermedades cardiovasculares (mortalidad por enfermedades cardiovasculares, infarto agudo al miocardio, accidente cerebrovascular, hipertensión y paro cardíaco extra hospitalario). Métodos: Se realizó una revisión bibliográfica en los buscadores ISI-Web of Science, Scopus y Nature utilizando los términos de búsqueda heatwave, cardiovascular disease y extreme heat entre los años 2016-2021 incluyendo trabajos que presenten medidas de asociación entre temperaturas extremas (percentil 5 para temperaturas bajas y percentil 90 para temperaturas altas) y enfermedades cardiovasculares, arrojando 130 resultados de los cuales se seleccionaron 19. Resultados: Tanto las temperaturas altas como bajas aumentaron el riesgo de muerte por infarto agudo al miocardio (IAM) (RR: 2,29 [2,18-2,40] y RR: 2,3 [1,2-4,6], respectivamente) y paro cardíaco (OR 3,34 [1,90-3,58] y OR: 1,75 [1,23-2,49], respectivamente). La mortalidad por hipertensión arterial se asoció a temperaturas altas (OR 1,91 [1,2-3,1]), mientras que la mortalidad por enfermedades cardiovasculares (ECV) en general a bajas (RR: 1,79 [1,64 - 1,95]). En hospitalizaciones por ECV el riesgo por temperaturas altas (P99) fue RR: 1,74 [IC95%: 1,30-2,32]. Se identificaron diferencias por sexo y mayor riesgo en los mayores de 75 años y quienes presentaron exposiciones prolongadas. Conclusión: Hay una fuerte asociación entre hospitalizaciones y muerte por ECV y temperaturas extremas. Las mujeres y los adultos mayores son los más afectados.

Abstract: The Inter governmental panel estimates that in a worst case scenario, by 2100 74% of people will be exposed to heat waves (3 consecutive days with temperatures at or above the 95% percentile). This might be the case in up to 40% of days in Santiago. As a consequence of climate change there will also be periods with extremely low temperatures. Both conditions increase the risk of cardiovascular disease. Aim: to study the association of extreme temperatures with the incidence of cardiovascular disease (death, myocardial infarction, stroke and out of hospital sudden death). Method: The ISI-Web of Science, Scopus and Nature databases were searched using the terms "heat wave", "cardiovascular disease" and "extreme heat" for articles published between 2016 and 2021.

High altitude exposure affects male reproductive parameters: could it also affect the prostate?†.

Living at high altitudes and living with prostatic illness are two different conditions closely related to a hypoxic environment. People at high altitudes exposed to acute, chronic or intermittent hypobaric hypoxia turn on several mechanisms at the system, cellular, and molecular level to cope with oxygen atmosphere scarcity maintaining the oxygen homeostasis. This exposure affects the whole organism and function of many systems, such as cardiovascular, respiratory, and reproductive. On the other hand, malignant prostate is related to the scarcity of oxygen in the tissue microenvironment due to its low availability and high consumption due to the swift cell proliferation rates. Based on the literature, this similarity in the oxygen scarcity suggests that hypobaric hypoxia, and other common factors between these two conditions, could be involved in the aggravation of the pathological prostatic status. However, there is still a lack of evidence in the association of this disease in males at high altitudes. This review aims to examine the possible mechanisms that hypobaric hypoxia might negatively add to the pathological prostate function in males who live and work at high altitudes. More profound investigations of hypobaric hypoxia's direct action on the prostate could help understand this exposure's effect and prevent worse prostate illness impact in males at high altitudes.

[Incidence of acute myocardial infarction in Chile between 2008 and 2016]. / Incidencia de infarto agudo de miocardio en Chile, 2008-2016.

BACKGROUND: There is no recent information on the incidence of acute myocardial infarction (AMI) in Chile. AIM: To describe and evaluate the temporal incidence trend of AMI in Chile between 2008 and 2016. MATERIAL AND METHODS: A time series study. We included all AMI cases (ICD10 = I21) that were registered in Chile between 2008 and 2016 in the national hospital discharge and death databases. Rates were stratified according to sex and age group. We calculated crude and standardized rates (direct method). Time trends were evaluated using Prais-Winsten (PW) regression models. RESULTS: There were 132,784 cases of AMI. The mean age of cases was 67 ± 14 years, 67% were men. Crude and standardized rates were 84.4 and 73.1 cases per 100,000 inhabitants, respectively. Standardized incidence increased in total population and women, whose PW coefficients were 0.43 (0.01-0.82; p = 0.045) and 0.26 (0.005-0.47; p = 0.02), respectively. Regarding age, an upward trend was observed in the younger age groups, whose coefficients were 0.20 (0.08 - 0.31; p = 0.004) for cases < 45 years, 1.31 (0.81-1.81; p < 0.01) for cases between 45 and 54 years, and 2.68 (1.31 - 4.04; p = 0.002) for cases between 55 and 64 years. CONCLUSIONS: An increase in the number of cases with AMI was observed, especially in younger age groups. This estimation could be useful for planning and evaluating public policies.

Health Effects of Chronic Intermittent Hypoxia at a High Altitude among Chilean Miners: Rationale, Design, and Baseline Results of a Longitudinal Study.

OBJECTIVES: This study aims to assess the health effects on mining workers of exposure to chronic intermittent hypoxia (CIH) at high- and very high-altitude mining compared with similar work at lower altitudes in Chile, and it also aims to constitute the baseline of a 5-year follow-up study. METHODS: We designed a cross-sectional study to assess health conditions in 483 miners working at 2 levels of altitude exposure: 336 working at a very high or high altitude (HA; 247 above 3900-4400 m, and 89 at 3000-3900 m), and 147 below 2400 m. Subjects were randomly selected in two stages. First, a selection of mines from a census of mines in each altitude stratum was made. Secondly, workers with less than 2 years of employment at each of the selected mines were recruited. The main outcomes measured at the baseline were mountain sickness, sleep alterations, hypertension, body mass index, and neurocognitive functions. RESULTS: Prevalence of acute mountain sickness (AMS) was 28.4% in the very high-altitude stratum (P = 0.0001 compared with the low stratum), and 71.7% experienced sleep disturbance (P = 0.02). The adjusted odds ratio for AMS was 9.2 (95% confidence interval: 5.2-16.3) when compared with the very high- and low-altitude groups. Motor processing speed and spatial working memory score were lower for the high-altitude group. Hypertension was lower in the highest-altitude subjects, which may be attributed to preoccupational screening even though this was not statistically significant. CONCLUSIONS: Despite longer periods of acclimatization to CIH, subjects continue to present AMS and sleep disturbance. Compromise of executive functions was detected, including working memory at HA. Further rigorous research is warranted to understand long-term health impacts of high-altitude mining, and to provide evidence-based policy recommendations.

Effects of chronic intermittent hypobaric hypoxia on prostate-specific antigen (PSA) in Chilean miners.

OBJECTIVE: The aim was to determine the effects of chronic intermittent hypobaric hypoxia (CIHH) on prostate-specific antigen (PSA) levels in Chilean miners who work at different altitudes. METHODS: A cross-sectional study was conducted between April and July 2019. Miners from five mines (N=338) at different altitudes were evaluated. We recorded sociodemographic, working and altitude information. Haemoglobin oxygen saturation (SaO2) and haemoglobin (Hb) were measured in situ, while PSA and testosterone were analysed at a low level. Linear mixed-effect models were used to evaluate the association between PSA level and two CIHH exposures: composite CIHH (with four descriptors) and ChileStd-CIHH (CIHH Chilean standard; based on the Chilean technical guide for occupational exposure to CIHH). All models were adjusted by age, body mass index and day of the work the samples were taken. RESULTS: Highest and lowest PSA levels were found in mines ≥3000 m above sea level (mine 3: median=0.75, IQR=-0.45; mine 4: median=0.46, IQR=-0.35). In the multilevel models, the wider altitude difference between mining operation and camp showed lower PSA levels (model D: ßPSA=-0.93 ng/mL, ßlogPSA=-0.07, p<0001), adjusted for other CIHH descriptors, SaO2, Hb and testosterone. The descriptors of composite CIHH explained better PSA variations than ChileStd-CIHH (model D: marginal R2=0.090 vs model A: marginal R2=0.016). CONCLUSIONS: Occupational health regulations and high altitude medicine should consider these results as initial evidence on the inclusion of new descriptors for CIHH and the possible effect of this exposure on PSA levels in this male-dominated occupational sector.

Incidencia de infarto agudo de miocardio en Chile, 2008-2016 / Incidence of acute myocardial infarction in Chile between 2008 and 2016

Background: There is no recent information on the incidence of acute myocardial infarction (AMI) in Chile. Aim: To describe and evaluate the temporal incidence trend of AMI in Chile between 2008 and 2016. Material and Methods: A time series study. We included all AMI cases (ICD10 = I21) that were registered in Chile between 2008 and 2016 in the national hospital discharge and death databases. Rates were stratified according to sex and age group. We calculated crude and standardized rates (direct method). Time trends were evaluated using Prais-Winsten (PW) regression models. Results: There were 132,784 cases of AMI. The mean age of cases was 67 ± 14 years, 67% were men. Crude and standardized rates were 84.4 and 73.1 cases per 100,000 inhabitants, respectively. Standardized incidence increased in total population and women, whose PW coefficients were 0.43 (0.01-0.82; p = 0.045) and 0.26 (0.005-0.47; p = 0.02), respectively. Regarding age, an upward trend was observed in the younger age groups, whose coefficients were 0.20 (0.08 − 0.31; p = 0.004) for cases < 45 years, 1.31 (0.81-1.81; p < 0.01) for cases between 45 and 54 years, and 2.68 (1.31 − 4.04; p = 0.002) for cases between 55 and 64 years. Conclusions: An increase in the number of cases with AMI was observed, especially in younger age groups. This estimation could be useful for planning and evaluating public policies.

[Balloon pulmonary angioplasty for the treatment of chronic thromboembolic pulmonary hypertension]. / Angioplastía con balón para el tratamiento de la hipertensión arterial pulmonar por enfermedad tromboembólica crónica. Resultados hemodinámicos y clínicos inmediatos.

BACKGROUND: Balloon pulmonary angioplasty (BPA) is a therapeutic alternative for patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). AIM: To report the initial experience with the "refined BPA technique" with the use of intravascular images. PATIENTS AND METHODS: Between June 2015 and June 2016 we selected fourteen patients with CTEPH who were considered candidates for BPA. Lesions targeted for treatment were further analyzed using intravascular imaging with optical frequency domain imaging (OFDI). We report the immediate hemodynamic results and four weeks of follow-up of the first eight patients of this series. RESULTS: We performed 16 BPA in eight patients aged 61 ± 14 years (88% women). Mean pulmonary artery pressure (PAPm) was 48.6 ± 5.8 mmHg. Success was achieved in seven patients (88%). A mean of 2.3 segments per patient were intervened in 11 sessions (1.6 sessions/ patient). Only one patient developed lung reperfusion injury. No mortality was associated with the procedure. After the last BPA session, PAPm decreased to 37.4 ± 8.6 mmHg (p=0.02). Pulmonary vascular resistance (RVP) decreased from 858,6 ± 377,0 at baseline to 516,6 ± 323,3 Dynes/sec/cm-5 (p<0.01) and the cardiac index increased from 2.4±0.6 at baseline to 2.8±0.3 L/min/m2 (p=0.01). At 4 weeks after the last BPA, WHO functional class improved from 3.3±0.5 to 2.5±0.5 (p<0,01) and six minutes walking distance from 331±92 to 451±149 m (p=0.01). CONCLUSIONS: BPA guided by OFDI for the treatment of inoperable CTEPH patients is a safe alternative with excellent immediate hemodynamic and clinical results.

Angioplastía con balón para el tratamiento de la hipertensión arterial pulmonar por enfermedad tromboembólica crónica. Resultados hemodinámicos y clínicos inmediatos / Balloon pulmonary angioplasty for the treatment of chronic thromboembolic pulmonary hypertension

Background: Balloon pulmonary angioplasty (BPA) is a therapeutic alternative for patients with inoperable chronic thromboembolic pulmonary hypertension (CTEPH). Aim: To report the initial experience with the "refined BPA technique" with the use of intravascular images. Patients and Methods: Between June 2015 and June 2016 we selected fourteen patients with CTEPH who were considered candidates for BPA. Lesions targeted for treatment were further analyzed using intravascular imaging with optical frequency domain imaging (OFDI). We report the immediate hemodynamic results and four weeks of follow-up of the first eight patients of this series. Results: We performed 16 BPA in eight patients aged 61 ± 14 years (88% women). Mean pulmonary artery pressure (PAPm) was 48.6 ± 5.8 mmHg. Success was achieved in seven patients (88%). A mean of 2.3 segments per patient were intervened in 11 sessions (1.6 sessions/ patient). Only one patient developed lung reperfusion injury. No mortality was associated with the procedure. After the last BPA session, PAPm decreased to 37.4 ± 8.6 mmHg (p=0.02). Pulmonary vascular resistance (RVP) decreased from 858,6 ± 377,0 at baseline to 516,6 ± 323,3 Dynes/sec/cm−5 (p<0.01) and the cardiac index increased from 2.4±0.6 at baseline to 2.8±0.3 L/min/m2 (p=0.01). At 4 weeks after the last BPA, WHO functional class improved from 3.3±0.5 to 2.5±0.5 (p<0,01) and six minutes walking distance from 331±92 to 451±149 m (p=0.01). Conclusions: BPA guided by OFDI for the treatment of inoperable CTEPH patients is a safe alternative with excellent immediate hemodynamic and clinical results.

Reducing Health Inequalities: Comparison of Survival After Acute Myocardial Infarction According to Health Provider in Chile.

Health inequalities are marked in Chile. To address this situation, a health reform was implemented in 2005 that guarantees acute myocardial infarction (AMI) health care for the entire population. We evaluated if the health reform changed AMI early and long-term survival rates by hospital provider (public/private) using a longitudinal population-based study of patients ≥15 years with a first AMI in Chile between 2002 and 2011. Time trends and early (within 28 days) and long-term (29-365 days) survival by age were assessed. We identified 59,557 patients: median age of 64 years; 68.9% men; 83.2% treated at public hospitals; 74.4% with public insurance. Early and long-term case-fatality was higher at public hospitals (14.6% vs 9.3%; P < .001 and 5.8% vs 3.3%; P < .001, respectively). There was a higher annual increase for early and long-term survival in public hospitals, 0.008 percentage points (95% CI: 0.006, 0.009; P < .0001) and 0.03 (0.002, 0.003; P < .0001), than in private hospitals, 0.0002 (95% CI: -0.0001, 0.005; P = .10) and 0.002 (95% CI: 0.0007, 0.003; P = .004), respectively. Being served at public hospitals affected early and long-term survival, especially in patients <70 years: hazard ratio was 2.01 (95% CI: 1.77, 2.28) and 3.11 (2.41, 4.01), respectively. Therefore, even if inequalities persist, there was a higher increase in early and long-term survival in public versus private hospitals.

Variación estacional de las hospitalizaciones por infarto agudo de miocardio según sexo y edad en Chile / Seasonal variation in hospital admissions due to acute myocardial infarction according to sex and age in Chile

Background: The incidence of acute myocardial infarction (AMI) varies according to seasonality, being higher in winter. The effect of sex on this phenomenon is not clear. Aim: To evaluate the effect of seasonality in men and women hospitalized for AMI at different ages. Material and Methods: We included all patients with a primary diagnosis of AMI admitted in public and private hospitals in Chile during 2002-2011 (codes I21-I22, of the tenth international classification of diseases). We obtained data from the National Discharge databases available at the Ministry of Health website. We estimated the number of discharges per month and per seasonality (cold /template), and the Standardized Incidence Ratio (SIR) with the formula: number of observed cases/expected cases (average annual hospitalizations), stratified by sex and age (< 50 years, 50-64 years, 6574 years, ≥ 75 years). We evaluated the effect of sex with binomial regressions for the different age strata. Results: We assessed 59,557 AMI hospitalizations (69% men, with and without ST elevation segment). May, June and July (austral winter) had a SIR of 1.10; 1.12 and 1.10, respectively. Women had a 20% excess of hospitalizations during cold seasons at any age. In men, the excess of hospitalizations increased from 9% in those aged < 50 years to 21% in those ≥ 75 years (p = 0.043). When comparing women and men, women aged < 50 years showed the higher risk of being hospitalized during cold seasons (adjusted risk ratio = 1.06; 95% confidence intervals 1.01-1.13). Conclusions: Women have a stronger seasonal pattern in AMI hospitalizations than men. While this effect increases with age in men, in women it remains constant at all ages.

Clinical, Socioeconomic, and Psychosocial Factors Associated with Blood Pressure Control and Adherence: Results from a Multidisciplinary Cardiovascular National Program Providing Universal Coverage in a Developing Country.

BACKGROUND: Limited information exists on blood pressure (BP) control factors and adherence to antihypertensive drug therapy (Rx) in developing countries. METHODS: Cross-sectional study in randomly selected 992 hypertensive patients under a Chilean national comprehensive Cardiovascular Health Program (CVHP). Association of education, income, diabetes, obesity, physical activity, psychosocial characteristics, smoking, and alcohol abuse with BP control and adherence were evaluated by multivariate logistic regression. RESULTS: BP control (<140/90 mmHg) was achieved in 63.1% of patients, with 38.4% adherent to Rx. Uncontrolled BP significantly associated with male sex (OR: 1.73 [95% CI 1.35-2.22]), low family income, high emotional-stress-depression score, body mass index, no adherence (OR: 1.83 [95% CI 1.44 - 2.32]), multiple Rx, baseline systolic BP value, and sedentary life style. Males (OR: 1.54 [95% CI 1.23 - 1.93]), low family income, high emotional stress-depression score (OR: 2.15 [95% CI 1.68 - 2.76]), low social support, and uncontrolled BP (OR: 1.52 [95% CI 1.22-1.90]) associated with no adherence. CONCLUSIONS: Comparable BP control (63.1%) to higher-income societies was observed. Uncontrolled BP associated significantly to no adherence and both to male sex, socioeconomic, and psychosocial factors. Global low adherence (38.4%) and improved BP control and adherence in diabetics were noted.

Educational Inequalities in Cardiovascular Risk Factor and Blood Pressure Control in the Elderly: Comparison of MESA Cohort and Chilean NHS Survey Outcome Measures.

BACKGROUND: Social determinants differ between countries, which is not always considered when adapting health policies and interventions to face inequalities in noncommunicable diseases and their risk factors. OBJECTIVES: The study sought to analyze educational inequalities in controlled blood pressure (CBP), obesity, and smoking in study populations from Chile and the United States in 2 periods, both countries with large social inequalities. METHODS: The study used data from the first and fifth waves of the MESA (Multiethnic Study of Atherosclerosis) cohort, and the 2003 and 2009 to 2010 Chilean National Health Survey (CNHS) survey outcome measures. The study compared cardiovascular risk factors prevalence as well as relative index of inequality (RII) and slope index of inequality (SII) between the 2 samples. RESULTS: In the CNHS 67.9% and 52.6% of participants had below primary education in 2003 and 2009 to 2010, respectively, compared with 12.3% and 8.1% in the first and fifth waves of the MESA study, respectively. Smoking prevalence was higher and increased in the CNHS compared with the MESA study, concentrated in better-educated women in both years (RII: 0.34; 95% confidence interval [CI]: 0.17 to 0.68; and RII: 0.55; 95% CI: 0.34 to 0.89, respectively). In contrast, smoking decreased over time in the MESA study in all socioeconomic strata, although relative inequalities increased in both sexes (for women, RII: 2.32; 95% CI 1.36 to 3.97; for men, RII: 3.34; 95% CI 2.04 to 5.47). CBP prevalence in both periods was higher in the first and fifth waves of the MESA study (69.7% and 80.2%) compared with the 2003 and 2009 to 2010 CNHS samples (34.2% and 52.3%), but only for the MESA study RII, favoring the better educated, was it significant in both periods and sexes. Obesity inequalities for Chilean women decreased slightly between 2003 and 2009 as prevalence grew in the most educated (RII: 2.21 to 1.68; SII: 0.29 to 0.22, respectively); conversely, they increased for both sexes in the MESA study. CONCLUSIONS: The study findings confirm that patterns and trends in prevalence, and absolute and relative inequalities vary by country, suggesting that context and cultural issues matters.

[Seasonal variation in hospital admissions due to acute myocardial infarction according to sex and age in Chile]. / Variación estacional de las hospitalizaciones por infarto agudo de miocardio según sexo y edad en Chile.

BACKGROUND: The incidence of acute myocardial infarction (AMI) varies according to seasonality, being higher in winter. The effect of sex on this phenomenon is not clear. AIM: To evaluate the effect of seasonality in men and women hospitalized for AMI at different ages. MATERIAL AND METHODS: We included all patients with a primary diagnosis of AMI admitted in public and private hospitals in Chile during 2002-2011 (codes I21-I22, of the tenth international classification of diseases). We obtained data from the National Discharge databases available at the Ministry of Health website. We estimated the number of discharges per month and per seasonality (cold /template), and the Standardized Incidence Ratio (SIR) with the formula: number of observed cases/expected cases (average annual hospitalizations), stratified by sex and age (< 50 years, 50-64 years, 6574 years, ≥ 75 years). We evaluated the effect of sex with binomial regressions for the different age strata. RESULTS: We assessed 59,557 AMI hospitalizations (69% men, with and without ST elevation segment). May, June and July (austral winter) had a SIR of 1.10; 1.12 and 1.10, respectively. Women had a 20% excess of hospitalizations during cold seasons at any age. In men, the excess of hospitalizations increased from 9% in those aged < 50 years to 21% in those ≥ 75 years (p = 0.043). When comparing women and men, women aged < 50 years showed the higher risk of being hospitalized during cold seasons (adjusted risk ratio = 1.06; 95% confidence intervals 1.01-1.13). CONCLUSIONS: Women have a stronger seasonal pattern in AMI hospitalizations than men. While this effect increases with age in men, in women it remains constant at all ages.

[Association between socioeconomic status and survival after a first episode of myocardial infarction]. / Tendencia en la sobrevida de pacientes hospitalizados por infarto agudo de miocardio según nivel socioeconómico: Chile, 2002-2012.

BACKGROUND: A low socioeconomic status is associated with higher overall mortality rates. AIM: To assess the effect of socioeconomic inequalities on survival of patients hospitalized with a first myocardial infarction. MATERIAL AND METHODS: Analysis of hospital discharge and mortality databases of the Ministry of Health. Patients aged over 15 years discharged between 2002 and 2011 with a first myocardial infarction (code I-21, ICD-10) were identified. Their survival was verified with the mortality registry. Survival from 0 to 28 and from 29 to 365 days was analyzed. Socioeconomic status was determined using the type of health insurance, stratified as public insurance (low and medium status) and private insurance (high status). Prais-Winsten trend (P-W) and Cox survival analyses were done. RESULTS: We analyzed 59,557 patients (69% males). Sixty three percent were of low socioeconomic status, 19% medium and 18% high. Between 2002 and 2011 the increase in survival was higher among patients of low socioeconomic status, mainly in women (P-W coefficients 0.58:0.31-0.86 in men and 1.12:0.84-1.41 in women for 0-28 days survival and 0.24:0.09-0.39 in men and 0.48:0.37-0.60 in women for 29-365 days survival, respectively). However, age and year of hospitalization adjusted analysis showed a higher mortality risk among patients of low socioeconomic status at 0-28 days (HR 1.67:1.53-1.83 for men and 1.49:1.34-1.66 for women) and at 29-365 days (HR 2.30:1.75-2.71 for men and 1.90:1.56-1.85 for women). CONCLUSIONS: Survival after a myocardial infarction improved in the last decade especially in patients of low socioeconomic status. However, subjects of this stratum continue to have a higher mortality.

Lower incidence of myocardial infarction after smoke-free legislation enforcement in Chile.

OBJECTIVE: To evaluate the impact of a complete smoking ban in enclosed spaces on the incidence of acute myocardial infarction in Chile. METHODS: The population-based study involved residents of urban areas, where 80% of the Chilean population live, aged 20 years or older who had a myocardial infarction. Monthly myocardial infarction incidence and mortality rates at health-care facilities between January 2011 and December 2014 were derived from admission and mortality databases. Regression discontinuity methods were used to estimate the near-immediate impact on disease incidence of enforcing smoke-free legislation in March 2013. The same analysis was performed for ischaemic stroke, degenerative disc disease and colon cancer. Data on the concentration of fine respirable particulates were included in an additional analysis of myocardial infarction incidence in the Santiago metropolitan area. RESULTS: The enforcement of smoke-free legislation was associated with an abrupt, near-immediate decline of 0.639 cases of myocardial infarction per 100 000 adults per month (95% confidence interval, CI: 0.242 to 1.036; relative decline: 7.8%). Similar declines were observed in men and women and in people aged over and under 70 years. However, enforcement of the legislation was not associated with a significant change in the rate of ischaemic stroke, degenerative disc disease or colon cancer. The abrupt decline in myocardial infarction incidence was also observed when data on fine respirable particulates were included in an analysis for Santiago. CONCLUSION: The enforcement of extensive smoke-free legislation in Chile was associated with an abrupt, near-immediate decline in the incidence of myocardial infarction.

Safety and Efficacy of the Intravenous Infusion of Umbilical Cord Mesenchymal Stem Cells in Patients With Heart Failure: A Phase 1/2 Randomized Controlled Trial (RIMECARD Trial [Randomized Clinical Trial of Intravenous Infusion Umbilical Cord Mesenchymal Stem Cells on Cardiopathy]).

RATIONALE: Umbilical cord-derived mesenchymal stem cells (UC-MSC) are easily accessible and expanded in vitro, possess distinct properties, and improve myocardial remodeling and function in experimental models of cardiovascular disease. Although bone marrow-derived mesenchymal stem cells have been previously assessed for their therapeutic potential in individuals with heart failure and reduced ejection fraction, no clinical trial has evaluated intravenous infusion of UC-MSCs in these patients. OBJECTIVE: Evaluate the safety and efficacy of the intravenous infusion of UC-MSC in patients with chronic stable heart failure and reduced ejection fraction. METHODS AND RESULTS: Patients with heart failure and reduced ejection fraction under optimal medical treatment were randomized to intravenous infusion of allogenic UC-MSCs (Cellistem, Cells for Cells S.A., Santiago, Chile; 1×106 cells/kg) or placebo (n=15 per group). UC-MSCs in vitro, compared with bone marrow-derived mesenchymal stem cells, displayed a 55-fold increase in the expression of hepatocyte growth factor, known to be involved in myogenesis, cell migration, and immunoregulation. UC-MSC-treated patients presented no adverse events related to the cell infusion, and none of the patients tested at 0, 15, and 90 days presented alloantibodies to the UC-MSCs (n=7). Only the UC-MSC-treated group exhibited significant improvements in left ventricular ejection fraction at 3, 6, and 12 months of follow-up assessed both through transthoracic echocardiography (P=0.0167 versus baseline) and cardiac MRI (P=0.025 versus baseline). Echocardiographic left ventricular ejection fraction change from baseline to month 12 differed significantly between groups (+7.07±6.22% versus +1.85±5.60%; P=0.028). In addition, at all follow-up time points, UC-MSC-treated patients displayed improvements of New York Heart Association functional class (P=0.0167 versus baseline) and Minnesota Living with Heart Failure Questionnaire (P<0.05 versus baseline). At study completion, groups did not differ in mortality, heart failure admissions, arrhythmias, or incident malignancy. CONCLUSIONS: Intravenous infusion of UC-MSC was safe in this group of patients with stable heart failure and reduced ejection fraction under optimal medical treatment. Improvements in left ventricular function, functional status, and quality of life were observed in patients treated with UC-MSCs. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov/ct2/show/NCT01739777. Unique identifier: NCT01739777.