Association of Weather With Day-to-Day Incidence of Myocardial Infarction: A SWEDEHEART Nationwide Observational Study

Impact of Foehn Wind and Related Environmental Variables on the Incidence of Cardiac Events

In Poland there is no data related to the impact of halny wind and the related environmental variables on the incidence of cardiac events. We decided to investigate the relationship between this weather phenomenon, as well as the related environmental variables, and the incidence of cardiac events in the population of southern Poland, a region affected by this type of wind. We also decided to determine whether the environmental changes coincide with or predate the event examined. We analysed data related to 465 patients admitted to the cardiology ward in a large regional hospital during twelve months of 2011 due to acute myocardial infarction. All the patients in the study group lived in areas affected by halny wind and at the time of the event were staying in those areas. The frequency of admissions on halny days did not differ significantly from the admissions on the remaining days of the year (p = 0.496). No statistically significant differences were found between the number of admissions on halny days and on the remaining days during halny months (p = 0.084). We have identified a difference in the number of admissions between days with no halny and days immediately preceding onset of halny (p = 0.001). However, no effects of the related environmental variables have been observed in the incidence of cardiac events (p = 0.866, F = 0.37). On the days with halny wind, incidence of cardiac events is similar to that on the remaining days of the year.

Acute and short-term efficacy of sauna treatment on cardiovascular function: A meta-analysis

OBJECTIVE

The role of sauna bathing in cardiovascular function treatment has been increasingly explored, but insufficient attention has been paid to its efficacy. We performed a meta-analysis to provide more evidence for the efficacy of sauna treatment in cardiovascular nursing.

METHODS

Sixteen peer-reviewed journal articles were screened to summarize the efficacy of the sauna on cardiovascular function. Both acute (0-30 min after the sauna) and short-term (2-4 weeks following the sauna treatment) efficacies were investigated.

RESULTS

For pooled acute efficacy, body temperature and heart rate significantly (p<0.001) grew by 0.94℃ and 17.86 beats/min, respectively; reductions of 5.55 mmHg (p<0.001) and 6.50 mmHg (p<0.001) were also observed in systolic blood pressure and diastole blood pressure, respectively. For combined short-term efficacy, left ventricular ejection fraction (LVEF), 6-min walk distance, and flow-mediated dilation (p<0.001) increased by 3.27%, 48.11 m, and 1.71%, respectively; greater amelioration in LVEF was observed in participants with lower LVEF. The proportion of patients with New York Heart Association class III and IV decreased by 10.9% and 12.2%, respectively. Systolic blood pressure, diastolic blood pressure, brain natriuretic peptide concentration, left ventricular end-diastolic dimension, cardiothoracic ratio, and left atrial dimension reduced by 5.26 mmHg (p<0.001), 4.14 mmHg (p<0.001), 116.66 pg/mL (p<0.001), 2.79 mm (p<0.001), 2.628% (p<0.05), and 1.88 mm (p<0.05), respectively, while the concentration of norepinephrine in the plasma remained unchanged.

CONCLUSION

Sauna treatment was found to play a positive role in improving cardiovascular function and physical activity levels, especially in patients with low cardiovascular function. These findings reveal that thermal intervention may be a promising means for cardiovascular nursing.

Climate changes and ST-elevation myocardial infarction treated with primary percutaneous coronary angioplasty

BACKGROUND

The impact of seasonal changes on the incidence of acute myocardial infarction has been incompletely appraised, especially in the modern era of primary percutaneous coronary intervention (PPCI). We aimed to appraise the overall and season-specific impact of climate changes on the daily rate of PCCI.

METHODS

Details on PPCI and climate changes were retrospectively collected in three high-volume Italian institutions with different geographical features. The association between rate of PPCI and temperature, atmospheric pressure (ATM), humidity and rainfall was appraised with Poisson models, with overall analyses and according to season of the year.

RESULTS

Details on 6880 days with a total of 4132 PPCI were collected. Overall adjusted analysis showed that higher minimum atmospheric pressure 3 days before PPCI were associated with lower risk (regression coefficient = 0.999 [95% confidence interval 0.998-1.000], p = 0.030). Focusing on season, in Winter PPCI rates were increased by lower same day mean temperature (0.973 [0.956-0.990], p = 0.002) and lower rainfall (0.980 [0.960-1.000], p = 0.049). Conversely, in Spring greater changes in atmospheric pressure 3 days before PPCI were associated with increased risk (1.023 [1.002-1.045], p = 0.032), with similar effects in Summer for minimum temperature on the same day (1.022 [1.001-1.044], p = 0.040).

CONCLUSIONS

Climate has a significant impact on the risk of PPCI in the current era, with a complex interplay according to season. Higher risk risk is expected with lower minimum atmospheric pressure in the preceding days, lower rainfall in Winter, greater changes in atmospheric pressure in Spring, and higher temperatures in Summer. These findings have important implications for prevention strategies.

Heat waves, ambient temperature, and risk of myocardial infarction: an ecological study in the Community of Madrid

INTRODUCTION AND OBJECTIVES

Episodes of extreme heat are associated with increased morbidity and mortality in chronically-ill patients but there is a need to clearly establish the relationship between extreme heat and myocardial infarction. The aim of this study was to analyze the relationship between the incidence of ST-segment elevation myocardial infarction (STEMI) and maximum temperature, in particular during heat wave alert periods (HWAP).

METHODS

The population studied consisted of confirmed STEMI cases registered in the Infarction Code of the Community of Madrid between June 2013 and June 2017. Incidence rate ratios (IRR) adjusted for trend and seasonality and 95%CI were estimated using time series regression models.

RESULTS

A total of 6465 cases of STEMI were included; 212 cases occurred during the 66-day period of HWAP and 1816 cases during the nonalert summer period (IRR, 1.14; 95%CI, 0.96-1.35). The minimum incidence rate was observed at the maximum temperature of 18°C. Warmer temperatures were not associated with a higher incidence (IRR,1.03; 95%CI, 0.76-1.41), whereas colder temperatures were significantly associated with an increased risk (IRR, 1.25; 95%CI, 1.02-1.54). No effect modification was observed by age or sex.

CONCLUSIONS

We did not find an increased risk of STEMI during the 66 days of HWAP in the Community of Madrid between June 2013 and June 2017. However, an increased risk was found during colder temperatures. No extra health resources for STEMI management are required during periods of extreme heat, but should be considered during periods of cold weather.

Impact of Temperature Variation on Acute Myocardial Infarction in Karachi, Pakistan

Introduction

Environmental triggers of acute myocardial infarction (AMI) have gained mounting evidence from various geographies of the world. However, due to geographic variations in seasonal temperature and other metrological parameters, it is difficult to generalize the findings in one population to another population with different climatic conditions. Therefore, the aim of this study was to assess the relationship between meteorological parameters and the number of primary percutaneous coronary intervention (PCI) procedures for AMI at a tertiary care cardiac hospital in Karachi, Pakistan.

Methods

For this cross-sectional study, data was obtained on the number of primary PCI procedures conducted at the National Institute of Cardiovascular Diseases (NICVD) Karachi, Pakistan during 1^st June 2016 to 31^st May 2018. Daily meteorological data of the Karachi region for the same period was obtained from the Pakistan Meteorological Department. It consists of temperature, atmospheric pressure, and relative humidity. Based on the weather conditions of Karachi, the data was divided into two seasons; summer (April to October) and winter (November to March). Multiple linear regression analysis was performed taken the number of primary PCI performed as regressand and time trend, average temperature, temperature variation, and relative humidity as regressors.

Results

A total of 115,494 hospital admissions were recorded during the study period out of which rate of primary PCI was 10.5% (12,107). A negative relationship between average temperature and number of primary PCI was observed with standardized regression coefficients of -0.13 (p < 0.001) on the overall regression model. A similar significant negative relationship of average temperature was observed on the regression model for the cold season with standardized regression coefficients of -0.17 (p < 0.001). While no such relationship was observed for the warm season.

Conclusion

The average daily temperature was found to be negatively related to the number of primary PCI. Subgroup analysis revealed that the average daily temperature had a significant negative relationship with the number of primary PCI in the cold season; however, no such impact was observed in the warm season.

Mortality Related to Cold Temperatures in Two Capitals of the Baltics: Tallinn and Riga

Background and objectives: Despite global warming, the climate in Northern Europe is generally cold, and the large number of deaths due to non-optimal temperatures is likely due to cold temperatures. The aim of the current study is to investigate the association between cold temperatures and all-cause mortality, as well as cause-specific mortality, in Tallinn and Riga in North-Eastern Europe. Materials and Methods: We used daily information on deaths from state death registries and minimum temperatures from November to March over the period 1997-2015 in Tallinn and 2009-2015 in Riga. The relationship between the daily minimum temperature and mortality was investigated using the Poisson regression, combined with a distributed lag non-linear model considering lag times of up to 21 days. Results: We found significantly higher all-cause mortality owing to cold temperatures both in Tallinn (Relative Risk (RR) = 1.28, 95% Confidence Interval (CI) 1.01-1.62) and in Riga (RR = 1.41, 95% CI 1.11-1.79). In addition, significantly increased mortality due to cold temperatures was observed in the 75+ age group (RR = 1.64, 95% CI 1.17-2.31) and in cardiovascular mortality (RR = 1.83, 95% CI 1.31-2.55) in Tallinn and in the under 75 age group in Riga (RR = 1.58, 95% CI 1.12-2.22). In this study, we found no statistically significant relationship between mortality due to respiratory or external causes and cold days. The cold-related attributable fraction (AF) was 7.4% (95% CI -3.7-17.5) in Tallinn and 8.3% (95% CI -0.5-16.3) in Riga. This indicates that a relatively large proportion of deaths in cold periods can be related to cold in North-Eastern Europe, where winters are relatively harsh.

Circadian onset and prognosis of myocardial infarction with non-obstructive coronary arteries (MINOCA)

Background

Many acute cardiovascular events such as myocardial infarction (MI) follow circadian rhythms. Myocardial infarction with non-obstructive coronary arteries (MINOCA) is a newly noticed entity with limited data on onset pattern and its impact on prognosis.

Material and methods

In this observational study of Swedish MINOCA patients registered in the SWEDEHEART registry between 2003–2013 and followed until December 2013 we identified 9,092 unique patients with MINOCA out of 199,163 MI admissions in total. Incidence rate ratios (IRR) were calculated for whole hours, parts of the day, weekdays, months, seasons and major holidays.

Results

The mean age was 65.5 years, 62.0% were women and 16.6% presented with STEMI. The risk for MINOCA proved to be most common in the morning (IRR = 1.70, 95% CI [1.63–1.84]) with a peak at 08.00 AM (IRR = 2.25, 95% CI [1.96–2.59]) and on Mondays (IRR = 1.28, 95% CI [1.18–1.38]). No altered risk was detected during the different seasons, the Christmas and New Year holidays or the Swedish Midsummer festivities. There was no association between time of onset of MINOCA and short- or long-term prognosis.

Conclusion

The onset of MINOCA shows a circadian and circaseptan variation with increased risk at early mornings and Mondays, similar to previous studies on all MI, suggesting stress related triggering. However, during holidays were traditional MI increase, we did not see any increase for MINOCA. No association was detected between time of onset and prognosis, indicating that the underlying pathological mechanisms of MINOCA and the quality of care are similar at different times of onset but triggering mechanism may be more active early mornings and Mondays.

Sex-specific differences regarding seasonal variations of incidence and mortality in patients with myocardial infarction in Germany

BACKGROUND

Seasonal variation regarding the incidence and the short-term mortality of acute myocardial infarction (MI) was frequently reported, but data about sex-specific differences are sparse.

METHODS

We analysed the impact of seasons and temperature on incidence and in-hospital mortality of patients with acute MI in Germany between 2005 and 2015.

RESULTS

The nationwide sample comprised 3,008,188 hospitalizations of MI patients (2005-2015). The incidence was 334.7/100,000 citizens/year. Incidence inclined from 316.3 to 341.6/100,000 citizens/year (β 0.17 [0.10 to 0.24], P < 0.001), while in-hospital mortality rate decreased from 14.1% to 11.3% (β -0.29 [-0.30 to -0.28], P < 0.001). Overall, 377,028 (12.5%) patients died in-hospital. Seasonal variation of both incidence and in-hospital mortality was of substantial magnitude. Seasonal incidence (86.1 vs. 79.0/100,000 citizens/year, P < 0.001) and in-hospital mortality (13.2% vs. 12.1%, P < 0.001) were higher in winter than in summer. Risk to die in winter was elevated (OR 1.080 (95% CI 1.069-1.091), P < 0.001) compared to summer season independently of sex, age and comorbidities. Reperfusion treatment with drug eluting stents and coronary artery bypass graft were more often used in summer. We observed sex-specific differences regarding the seasonal variation of in-hospital mortality: males showed lowest mortality in summer, while females during fall. Low temperature dependency of mortality seems more pronounced in males.

CONCLUSION

Incidence of acute MI increased 2005-2015, while in-hospital mortality rate decreased. Seasonal variation of incidence and in-hospital mortality were of substantial magnitude with lowest incidence and lowest mortality in the summer season. Additionally, we observed sex-specific differences regarding the seasonal variation of the in-hospital mortality.