Relationship between temperature change and the requirement for a permanent pacemaker implantation in bradyarrhythmias

Association of onset-season with characteristics and long-term outcomes in acute myocardial infarction patients: results from the Japanese registry of acute myocardial infarction diagnosed by universal definition (J-MINUET) substudy

It is known that incidence and short-term mortality rate of acute myocardial infarction (AMI) tend to be higher in the cold season. The aim of our study was to investigate the association of onset-season with patient characteristics and long-term prognosis of AMI. This was a prospective, multicenter, Japanese investigation of 3,283 patients with AMI who were hospitalized within 48 h of symptom onset between July 2012 and March 2014. Patients were divided into 3 seasonal groups according to admission date: cold season group (December-March), hot season group (June-September), and moderate season group (April, May, October, and November). We identified 1356 patients (41.3%) admitted during the cold season, 901 (27.4%) during the hot season, and 1026 (31.3%) during the moderate season. We investigated the seasonal effect on patient characteristics and clinical outcomes. Baseline characteristics of each seasonal group were comparable, with the exception of age, Killip class, and conduction disturbances. The rates of higher Killip class and complete atrioventricular block were significantly higher in the cold season group. The 3-year cumulative survival free from major adverse cardiac events (MACE) rate was the lowest in the cold season (67.1%), showing a significant difference, followed by the moderate (70.0%) and hot seasons (72.9%) (p < 0.01). Initial severity and long-term prognoses were worse in patients admitted during the cold season. Our findings highlight the importance of optimal prevention and follow-up of AMI patients with cold season onset.

Seasonal variation in the risk of ischemic stroke in patients with atrial fibrillation: A nationwide cohort study

BACKGROUND

Several cardiovascular diseases exhibit seasonal variations, but data about cold temperature and risk of ischemic stroke in patients with atrial fibrillation (AF) are limited.

OBJECTIVE

The purpose of this study was to investigate the risk of ischemic stroke in different seasons, testing the hypothesis that the cold weather season would increase the risk of stroke in AF.

METHODS

This study used the National Health Insurance Research Database in Taiwan. From 2000 to 2012, a total of 289,559 AF patients were enrolled, and 34,991 experienced ischemic stroke after mean follow-up of 3 years. The relationship between risk of ischemic stroke and temperatures was analyzed.

RESULTS

The highest incidence of ischemic stroke was observed in winter, which was the coldest season, with an incidence rate of 0.33 per 100 person-months. Compared with the summer period, the risk of ischemic stroke increased by 10% in spring (incidence rate ratio [IRR] 1.10; 95% confidence interval [CI] 1.07-1.13) and by 19% in winter (IRR 1.19; 95% CI 1.15-1.22) but did not differ significantly between summer and autumn (IRR 1.00; 95% CI 0.97-1.03). Compared with the days with an average temperature of 30°C, the risk of ischemic stroke for days with an average temperature <20°C significantly increased. Lower 7-, 10-, or 14-day average temperatures were significantly associated with an increased risk of ischemic stroke in the case-crossover analysis.

CONCLUSION

In this nationwide study, a seasonal variation of incidence of ischemic stroke in AF patients was observed, with an increased risk of stroke on days with an average temperature <20°C. AF-related stroke may be influenced by environmental interactions.

Past, present and future of the climate and human health commission

The following paper presents the history of the Climate and Human Health Commission at the International Society of Biometeorology after more than one decade since its creation. A brief history of the origins of the human biometeorology is revealed through some of the main research topics and publications of the founders of the society in this field. Secondly, it is presented as a brief review of the activities of the commission in the last 10 years, based on the reports that have periodically been submitted by members of the commission to the Bulletin of the society. A summary of the topics of interest on human biometeorology and the most frequent research topics are also described. Thirdly, the need of adapting human biometeorology contents, methods and techniques to a changing world is articulated according to some of the new environmental threats in the XXI century. Finally, a list of future actions and research lines collected through a form from members of the commission is presented. The paper concludes with the existence of great challenge for human biometeorology in order to transform biometeorological knowledge into specific services to improve the wellbeing of human beings.

Nature's wrath-The effect of weather on pain following orthopaedic trauma

BACKGROUND

Despite frequent complaints by orthopaedic trauma patients, to our knowledge there is no data regarding weather's effect on pain and function following acute and chronic fracture. The aim of our study was to investigate the influence of daily weather conditions on patient reported pain and functional status.

METHODS

We retrospectively examined prospectively collected data from 2369 separate outpatient visits of patients recovering from operative management of acute tibial plateau fractures, acute distal radius fractures, and chronic fracture nonunions. Pain and functional status were assessed using a visual analogue scale (VAS) and the DASH and SMFA functional indexes. For each visit date, the mean temperature, difference between mean temperature and expected temperature, dew point, mean humidity, amount of rain, amount of snow, and barometric pressure were recorded. Statistical analysis was run to search for associations between weather data and patient reported pain and function.

RESULTS

Low barometric pressure was associated with increased pain across all patient visits (p=0.007) and for patients at 1-year follow-up only (p=0.005). At 1-year follow-up, high temperature (p=0.021) and high humidity (p=0.030) were also associated with increased pain. No significant association was noted between weather data and patient reported functional status at any follow-up interval.

CONCLUSIONS

Patient complaints of weather influencing pain after orthopaedic trauma are valid. While pain in the immediate postoperative period is most likely dominated by incisional and soft tissue injuries, as time progresses barometric pressure, temperature, and humidity impact patient pain levels. Affirming and counseling that pain may vary based on changing weather conditions can help manage patient expectations and improve satisfaction.

Relationships of physiologically equivalent temperature and hospital admissions due to I30-I51 other forms of heart disease in Germany in 2009-2011

We aimed to understand relationships of the weather as biometeorological and hospital admissions due to other forms of heart disease by subtypes, which have been paid less attention, in a national setting in recent years. This is an ecological study. Ten percent of daily hospital admissions of the included hospitals (n = 1618) across Germany that were available between 1 January 2009 and 31 December 2011 (n = 5,235,600) were extracted from Statistisches Bundesamt, Germany. We identified I30-I51 other forms of heart disease by the International Classification of Diseases version 10 as the study outcomes. Daily weather data from 64 weather stations that have covered 13 German states, including air temperature, humidity, wind speed, cloud cover, radiation flux and vapour pressure, were obtained and generated into physiologically equivalent temperature (PET). Admissions due to other diseases of pericardium, nonrheumatic mitral valve disorders, nonrheumatic aortic valve disorders, cardiomyopathy, atrioventricular and left bundle-branch block, other conduction disorders, atrial fibrillation and flutter, and other cardiac arrhythmias peaked when PET was between 0 and 10 °C. Complications and ill-defined descriptions of heart disease admissions peaked at PET 0 °C. Cardiac arrest and heart failure admissions peaked when PET was between 0 and -10 °C while the rest did not vary significantly. A common drop of admissions was found when PET was above 10 °C. More medical resources could have been needed for heart health on days when PETs were <10 °C than on other days. Adaptation to such weather change for medical professionals and the general public would seem to be imperative.

Relationship between seasonal weather changes, risk of dehydration, and incidence of severe bradyarrhythmias requiring urgent temporary transvenous cardiac pacing in an elderly population

There is little information on any seasonal variations or meteorological factors associated with symptomatic bradyarrhythmias requiring cardiac pacing. The aim of this single-center study was to investigate the seasonal distribution of the incidence of severe, life-threatening bradyarrhythmias requiring urgent temporary transvenous cardiac pacing in an elderly population. Consecutive patients who underwent urgent temporary transvenous cardiac pacing between 2007 and 2012 were enrolled. The baseline characteristics of the patients and some meteorological parameters, including the calculation the daily heat index (HI), were recorded. During the study period, 79 consecutive patients (mean age 82 ± 8 years, 41% male) underwent urgent temporary transvenous cardiac pacing, mainly for third-degree atrioventricular block (79%). The incidence of bradyarrhythmias was significantly higher in summer than in the other seasons (P < 0.001). Moreover, the highest incidence was observed in months with HI > 90 °F for >3 h per day for at least 10 days (P < 0.001). A direct correlation was found between the average monthly temperature and the monthly number of patients undergoing temporary cardiac pacing (r = 0.54, P < 0.001). Compared with other patients, those observed during the hottest months were significantly older and more frequently affected by chronic disabling neurological diseases (all P < 0.05). In addition, they more frequently showed biochemical indices of dehydration, renal function impairment and hyperkalemia (all P < 0.05). This study showed an increased incidence of severe bradyarrhythmias in an elderly population during the hottest months of the year. In these months, in subjects characterized by increased susceptibility to dehydration, the risk of developing bradyarrhythmias was increased significantly.