Association between Air Temperature and Acute Myocardial Infarction Hospitalizations in Tehran, Iran: A Time-Stratified Case-Crossover

Weather Impact on Acute Myocardial Infarction Hospital Admissions With a New Model for Prediction: A Nationwide Study

Introduction: Cardiovascular disease is one of the leading causes of mortality worldwide. Acute myocardial infarction (AMI) is associated with weather change. The study aimed to investigate if weather change was among the risk factors of coronary artery disease to influence AMI occurrence in Taiwan and to generate a model to predict the probabilities of AMI in specific weather and clinical conditions.

Method: This observational study utilized the National Health Insurance Research Database and daily weather reports from Taiwan Central Weather Bureau to evaluate the discharge records of patients diagnosed with AMI from various hospitals in Taiwan between January 1, 2008 and December 31, 2011. Generalized additive models (GAMs) were used to estimate the effective parameters on the trend of the AMI incidence rate with respect to the weather and health factors in the time-series data and to build a model for predicting AMI probabilities.

Results: A total of 40,328 discharges were listed. The minimum temperature, maximum wind speed, and antiplatelet therapy were negatively related to the daily AMI incidence; however, a drop of 1° when the air temperature was below 15°C was associated with an increase of 1.6% of AMI incidence. By using the meaningful parameters including medical and weather factors, an estimated GAM was built. The model showed an adequate correlation in both internal and external validation.

Conclusion: An increase in AMI occurrence in colder weather has been evidenced in the study, but the influence of wind speed remains uncertain. Our analysis demonstrated that the novel GAM model can predict daily onset rates of AMI in specific weather conditions.

The application of Gensini score and IL-1ra in assessing the condition and prognosis of patients with coronary artery disease

OBJECTIVE

This study aimed to investigate the value of Gensini score and interleukin-1 receptor antagonist (IL-1ra) in assessing the condition and prognosis of patients with coronary heart disease (CHD).

METHODS

According to their condition, 175 patients were divided into stable angina group (SA, 60 cases), unstable angina group (UA, 60 cases) and acute myocardial infarction group (AMI, 55 cases). The Gensini score, GRACE score, IL-1ra and troponin (Tn) were compared in the three groups. The correlation between Gensini score and GRACE score, IL-1ra and Tn, were explored. The patients were divided into death group (21 cases), adverse cardiovascular events group (MACE, 50 cases) and good prognosis group (104 cases) according to clinical outcomes. The ROC curve with regard to Gensini score, IL-1ra and the clinical outcome was plotted.

RESULTS

With the exacerbation of the disease, the Gensini score, GRACE score, IL-1ra and Tn were significantly higher in patients with CHD (P<0.05). Correlation analysis showed a positive association between Gensini score and GRACE score (r=0.9751, P<0.05). IL-1ra showed a positive association with Tn level (r=0.9731, P<0.05); Gensini score and IL-1ra had an area under the curve (AUC) of 0.9350 and 0.9499 for adverse CHD outcome, respectively (P<0.001).

CONCLUSION

Gensini score and IL-1ra reflect better the severity of CHD in patients with CHD, and also the AUC of 0.9350 and 0.9499 (P<0.001). It can be used in the prognostic evaluation of patients with CHD.

Investigation of the value of carotid-femoral pulse wave velocity and coronary artery lesions in prognosis of percutaneous coronary intervention patients

OBJECTIVE

To investigate the value of carotid-femoral pulse wave velocity (CFPWV) and coronary artery lesions in assessing prognosis of percutaneous coronary intervention (PCI) patients.

METHODS

A total of 300 PCI patients admitted to our hospital were selected as study subjects, and were divided into Group A (0-13 m/s, n=180) and Group B (> 13 m/s, n=120) in accordance with different carotid-femoral pulse wave velocities (CFPWVs). Coronary artery lesions, incidence rates of major adverse cardiac events (MACE) at different stages, and differences in the indexes of cardiac function were compared between the two groups.

RESULTS

Compared to Group A, Group B had more severe coronary artery lesions and higher incidence rates of postoperative complications and MACE during hospital stay and 2-year follow-up (P < 0.05). At 1 month after surgery, the left ventricular stroke volume, left ventricular end-diastolic volume and left ventricular ejection fraction in Group A were higher than those of Group B. CFPWV was significantly correlated with Gensini score (GS) and incidence rate of MACE (P < 0.05), and the differences in the area under curve (AUC) of CFPWV for predicting the incidence rate of MACE were significant (P < 0.05).

CONCLUSION

CFPEV, exhibits value in assessing the prognosis of PCI patients, and can effectively predict the postoperative incidence of MACE, which is conducive to the establishment of subsequent regimens. Therefore, CFPEV is worthy of clinical promotion and implementation.

The feasibility of using Hcy, CRP, and Cys-C to analyze AMI patients' disease conditions and prognoses

OBJECTIVE

This study was conducted to investigate the feasibility of using the serum homocysteine (Hcy), C-reactive protein (CRP), and cystatin C (Cys-C) levels to evaluate the conditions and prognoses of acute myocardial infarction (AMI) patients.

METHODS

One hundred and twenty patients with AMI were enrolled as an observation group (the AMI group). Eighty patients with stable angina pectoris were included in a control group (the SA group). Eighty healthy volunteers were enrolled as a healthy control group (the NCHD group). The AMI patients were divided into groups of >20 (n = 32), 10-20 (n = 45) and <10 (n = 43) according to their APACHE-II scores. The groups were divided into a death group (n = 23) and a survival group (n = 97) according to the patients' 1-year follow-up outcomes. The differences in the serum Hcy, CRP, and Cys-C levels among the different groups, and the correlations between the serum levels were calculated.

RESULTS

The serum Hcy, CRP, and Cys-C levels in the AMI group were significantly higher than they were in the SA and NCHD groups (P<0.05), and the serum levels in the APACHE-II score >20 group were significantly higher than the serum levels in the 10-20 group. The dead group exhibited higher serum Hcy, CRP, and Cys-C levels than the survival group (P<0.05), and our Spearman's correlation analysis showed that the serum Hcy, CRP and Cys-C levels were positively correlated with the APACHE II scores (r = 0.9157, r = 0.8519, r = 0.8598, P<0.001). The area under curve of Hcy, CRP, and Cys-C for the AMI diagnoses were 0.9638 (95% CI: 0.9183-1.000), 0.8125 (95% CI: 0.6652-0.9598), and 0.7515 (95% CI: 0.5847-0.9184), respectively.

CONCLUSION

Serum Hcy, CRP, and Cys-C levels can reflect the severity of the patients' conditions.

Impact of ambient temperature on hospital admissions for cardiovascular disease in Hefei City, China

Many studies have quantified the hospitalization risk for cardiovascular disease (CVD) caused by temperature, but the results of most studies are not consistent. In this study, we evaluate the effect of temperature on CVD hospitalizations. We use a quasi-Poisson regression with a distributed-lag nonlinear model (DLNM) to evaluate the effect of temperature on CVD hospitalizations between July 1, 2015, and October 31, 2017, in Hefei City, China. We found that the cold effect and heat effect of temperature can impact CVD hospital admissions. Compared with the 25th percentile of temperature (10.3 °C), the cumulative relative risk (RR) of extremely low temperature (first percentile of temperature, 0.075 °C) over lags 0-27 days was 0.616 (95% CI 0.423-0.891), and the cumulative RR of moderate low temperature (10th percentile of temperature, 5.16 °C) was 1.081 (95% CI 1.019-1.147) over lags 0-7 days. Compared with the 75th percentile of temperature (25.6 °C), the cumulative RR of extremely high temperature (99th percentile of temperature, 33.7 °C) was 1.078 (95% CI 0.752-1.547) over lags 0-27 days, and the cumulative RR of moderate-high temperature (90th percentile of temperature, 29.0 °C) was 1.015 (95% CI 0.988-1.043) over lag 0 day. In the subgroup, the < 65-year group and male were more susceptible to low temperature; however, the ≥ 65-year group and female were more vulnerable to high temperature. The high temperature's impact on CVD hospital admissions was found to be more obvious in female and the ≥ 65-year group compared to male and the < 65-year group. However, the < 65-year group and men are more sensitive to low temperature.

Effects of ambient temperature on myocardial infarction: A systematic review and meta-analysis

Previous studies have suggested that ambient temperature is associated with the mortality and morbidity of myocardial infarction (MI) although consistency among these investigations is lacking. We performed a meta-analysis to investigate the relationship between ambient temperature and MI. The PubMed, Web of Science, and China National Knowledge Infrastructure databases were searched back to August 31, 2017. The pooled estimates for different temperature exposures were calculated using a random-effects model. The Cochran's Q test and coefficient of inconsistency (I²) were used to evaluate heterogeneity, and the Egger's test was used to assess publication bias. The exposure-response relationship of temperature-MI mortality or hospitalization was modeled using random-effects meta-regression. A total of 30 papers were included in the review, and 23 studies were included in the meta-analysis. The pooled estimates for the relationship between temperature and the relative risk of MI hospitalization was 1.016 (95% confidence interval [CI]: 1.004-1.028) for a 1 °C increase and 1.014 (95% CI: 1.004-1.024) for a 1 °C decrease. The pooled estimate of MI mortality was 1.639 (95% CI: 1.087-2.470) for a heat wave. The heterogeneity was significant for heat exposure, cold exposure, and heat wave exposure. The Egger's test revealed potential publication bias for cold exposure and heat exposure, whereas there was no publication bias for heat wave exposure. An increase in latitude was associated with a decreased risk of MI hospitalization due to cold exposure. The association of heat exposure and heat wave were immediate, and the association of cold exposure were delayed. Consequently, cold exposure, heat exposure, and exposure to heat waves were associated with an increased risk of MI. Further research studies are required to understand the relationship between temperature and MI in different climate areas and extreme weather conditions.