The Role of Ambient Temperature and Plasma Osmolarity on Clinical Outcomes of Acute Myocardial Infarction Patients during Hajj

Background: Performance of Hajj is physically very demanding, especially if performed during the summer season. The aim of this study is to evaluate the importance of ambient temperature and dehydration, indicated by plasma osmolarity on the clinical outcomes of cardiac patients during Hajj season in 2017. Methods: We included all patients referred to tertiary center with acute coronary syndrome during Hajj period of 2017. Plasma osmolarity was calculated using concentrations of sodium, plasma glucose, and blood urea nitrogen at admission. Patients were stratified by groups (G) of admission osmolarity, clinical outcome was compared. The primary endpoints were in-hospital mortality, length of stay, Cardiac complications (heart failure, re-infarction, arrhythmia, shock and thrombus formation), left ventricular function and readmission rate. Result: Total of 300 patients were identified with mean age 56.2 ±12.1, 84% males and 97(32%) were pilgrims. They were exposed to average heat index 61.9 ±10.6° C. Significantly longer admissions were found in the group of higher osmolarity (G2) (≥295 mos/L) as compared to patients with normal osmolarity in G1 [6.7 ±14.9 VS 4.0 ±4.5, P=0.045]. Total in-hospital death rate was 4.3% (13). Using Binary regression analysis; osmolarity Group [p=0.009], Pilrgrim [P=0.005], Heat index [ P=0.005], were independent predictor of inhospital mortality, while Heat index is the only independent predictor for MACE [P=0.001]. Conclusion: Plasma osmolarity and heat index significantly affect cardiac patient’s outcome. These finding underscore the importance of health awareness of protection from dehydration for pilgrims during summer season.