Seasonal changes in proportion of cardiac surgeries associated with diabetes, smoking and elderly age

Abstract

Background Seasonal variations in the ambient temperature may affect the exacerbation of cardiovascular diseases. Our primary objective was to evaluate the seasonality of the monthly proportion of cardiac surgeries associated with diabetes, smoking and/or elderly age at a tertiary-care university hospital in East-Central Europe with a temperate climate zone. As a secondary objective, we also assessed whether additional factors affecting small blood vessels (smoking, aging, obesity) modulate the seasonal variability of diabetes. Methods Medical records were analyzed for 9838 consecutive adult patients who underwent cardiac surgery in 2007–2018. Individual seasonal variations of diabetes, smoking, and elderly patients were analyzed monthly, along with the potential risk factors for cardiovascular complication. We also characterized whether pairwise coexistence of diabetes, smoking, and elderly age augments or blunts the seasonal variations. Results Seasonal variations in the monthly proportion of cardiac surgeries associated with diabetes, smoking and/or elderly age were observed. The proportion of cardiac surgeries of non-elderly and smoking patients with diabetes peaked in winter (amplitude of change as [peak-nadir]/nadir: 19.2%, p<0.02), which was associated with increases in systolic (6.1%, p<0.001) and diastolic blood pressures (4.4%, p<0.05) and serum triglyceride levels (27.1%, p<0.005). However, heart surgery in elderly patients without diabetes and smoking was most frequently required in summer (52.1%, p<0.001). Concomitant occurrence of diabetes and smoking had an additive effect on the requirement for cardiac surgery (107%, p<0.001), while the simultaneous presence of older age and diabetes or smoking eliminated seasonal variations. Conclusions Scheduling regular cardiovascular control in accordance with periodicities in diabetes, elderly, and smoking patients more than once a year may improve patient health and social consequences. Trial registration NCT03967639.

The Role of Cold Exposure on Ischemic Heart Disease: A Systematic Review

“…Furthermore, recent findings indicate that myocardial infarction and sudden cardiac death are more likely in regions of extreme cold. Two potential explanations for the decrease in ischemia threshold when exposed to low temperatures include an increase in peripheral vascular resistance, which raises myocardial oxygen demand, and disruptions in coronary artery vasomotion [11,12]. There are data on how more extreme environmental cold exposure affects the ischemia threshold in the general population and CAD patients, including how extreme cold exposure affects the ischemic threshold even in people who do not have coldinduced angina.…”