Research On The Relationship Between Early Hypokalemia And Prognosis In Patients With Acute Myocardial Infarction

Acute myocardial infarction(AMI)are the leading cause of death in China.During the acute phase of myocardial infarction,the vital signs of patients with will change in varying degrees,especially the electrolytes,Previous studies have shown that different degrees of hypokalemia,hyponatremia,hypocalcemia,hypomagnesaemia during the acute phase of myocardial infarction,there was a significant correlation between potassium homeostasis and cardiovascular events and mortality.Potassium plays a key role in normal myocardial function,which widely distributed in intracellular fluid,only 2.00% in extracellular fluid.Previous studies have suggested that hypokalemia is associated with arrhythmias and sudden cardiac death,so we put forward the appropriate threshold of serum potassium in patients with acute myocardial infarction,but the incidence of arrhythmia after infarction was significantly decreased with the wide application of beta blockers,reperfusion therapy and early invasive treatment.Therefore,the current management of blood potassium in patients with myocardial infarction is a controversial task,and it is necessary to further explore the relationship between different serum potassium levels and prognosis.Through retrospective analysis,Grouping according to different serum potassium gradient,To investigate the difference of adverse events in patients with different serum potassium levels,than explore the risk factors of adverse events in hospital.This study is divided into the following two parts:Part I Analysis of short-term prognosis in patients with acute myocardial infarction with different blood potassium levelsObjective: To investigate the difference of short-term prognosis in patients with acute myocardial infarction(AMI)with different serum potassium levels.Methods: A retrospective analysis of 232 cases consecutive hospitalized patients with acute myocardial infarction from May 2013 to May 2016,Baseline clinical characteristics(gender,age,smoking history,past medical history),vital signs on admission,serum potassium,all blood potassium during hospitalization,blood tests,reperfusion therapy,observed during hospitalization of malignant arrhythmia,cardiogenic shock and death,blood biochemistry index,reperfusion Therapy,observed the adverse events during hospitalization(malignant arrhythmia,cardiogenic shock,death).Ptatients were categorized into hypokalemia group(K <3.50 mmol/L),normal potassium group A(3.50 mmol/L?K<4.50 mmol/L),and normal potassium group B(4.50 mmol/L?K<5.50 mmol/L)according to the serum potassium levels on admission.To observe hypokalemia and study its incidence,and compare the incidence of malignant arrhythmia,cardiogenic shock and death in each group.Results: 232 patients were eligible for the inclusion,there were 164 males(70.70%)and 68females(29.30%),the mean value of serum potassium was 3.95 mmol/l,hypokalemia was found in 37 cases(15.90%),and the mean value was 3.23 mmol/l.There was no significant difference in gender,age,past medical history and PCI treatment between the hypokalemia group and group A or B.There were significant differences between the three groups in leukocyte,neutrophil,urea nitrogen,creatinine,GFR,CK and CK-MB.The incidence of ventricular arrhythmia in three groups : a total of 15 cases of ventricular fibrillation,the incidence was 6.47%,hypokalemia group,A,B group,there was statistical difference between hypokalemia,group A and B.A total of 13 persons were recorded with nonsustained ventricular tachycardia.The incidence of each component was [11.10%(4)vs.5.20%(8)vs2.60%(1),P=0.249].Between the three groups of,There was no statistical difference between three groups in frequent premature ventricular contractions,bradycardia and atrial fibrillation.There were 23 deaths in the hospital,the mortality rate was 9.91%,there was not statistically significant difference between three groups.Conclusion: The incidence of ventricular fibrillation in AMI patients with hypokalemia was significantly higher than that in normal patients,had no obvious effects on premature ventricular arrhythmia,bradycardia and atrial fibrillation.Blood potassium in patients admitted between 3.50 mmol/L and 4.50 mmol/L has lower incidence of ventricular fibrillation and died in hospital.Part II Prediction of cardiovascular adverse events in patients with acute myocardial infarction by different levels of serum potassiumObjective: To investigate the predictive value of serum potassium in the risk factors of cardiovascular adverse events in patients with acute myocardial infarctionMethods: According to the occurrence of ventricular arrhythmia(ventricular fibrillation and ventricular tachycardia)during hospitalization,the patients were divided into arrhythmia group and non arrhythmia group.The characteristics of pations,the vital signs,biochemical indexes,and treatment were compared between the two groups.To explore the risk factors of arrhythmia and the predictive value of different serum potassium levels in arrhythmia by Logistics regression analysis.The patients were divided into death group and survival group according to the occurrence of death during hospitalization,to analyze the risk factors of in-hospital mortality and the predictive value of serum potassium in in-hospital mortality.Results: According to the occurrence of ventricular arrhythmia during hospitalization,the patients were divided into arrhythmia group and non arrhythmia group.gender,age,comorbidity,and treatment showe no statistically significant differences between two groups.systolic pressure was significantly lower in arrhythmia group than non arrhythmia group,there is no statistically in diastolic pressure or heart rate.The Killip score of arrhythmia group was lower than that non arrhythmia group.Arrhythmia group has higher leukocyte and lower serum potassium than non arrhythmia group.There was no significant difference in blood glucose,blood lipid,CK and CK-MB between the two groups.Malignant arrhythmia multi factor Logistic regression analysis showed that the risk factors of hospital related ventricular arrhythmia including abnormal potassium(<3.50 mmol/L,?4.50 mmol/L)(OR=0.154,95%CI=0.034-0.561,P=0.005),systolic pressure<100mmHg(OR=0.964,95%CI=0.938-0.991,P=0.009),and Killip III~IV(OR=0.217,95%CI=0.059-0.794,P=0.021).The patients were divided into death group and survival group according to the occurrence of death during hospitalization,The comparison between the two groups showed that the total mortality rate was 9.91%(23/232),female mortality rate was 17.60%(12/68),male mortality rate was 6.70%(11/164),there has differences between the two groups in gender(female),age,Killip;There was no difference between the two groups in complications;The percentage of reperfusion in the death group was lower than that in the survival group.There was no significant difference between the two groups in the immediate admission of blood potassium,There were significant differences in erythrocyte,hemoglobin,creatinine and urea nitrogen between the two groups.The mortality rate of the patients with extensive anterior wall was significantly higher than others and non ST elevation myocardial infarction has a lower mortality rate.There were statistical differences in ventricular fibrillation and shock between two groups,but ventricular tachycardia,atrial fibrillation and bradycardia were not statistically different.The direct cause of death: cardiogenic shock or heart failure in 17 cases(73.91%),ventricular aneurysm rupture in 1 cases(4.34%),3 cases of cardiac arrest(13.04%),of which 1 cases of ventricular fibrillation,ventricular standstill in 2 cases,2 cases of ischemic stroke(8.71%).Multivariate analysis showed: ventricular fibrillation(OR=0.148,95%CI=0.029~0.76,P=0.023),cardiogenic shock(OR=0.096,95%CI=0.027~0.339,P<0.001)and extensive anterior myocardial infarction(OR=0.171,95%CI=0.032~0.920,P=0.040)will increase the risk of death in hospital,PCI(OR=4.899,95%CI=0.872~27.525,P=0.039)treatment is a protective factor.Conclusion: the abnormal potassium(<3.50 mmol/l,?4.50 mmol/L)increased risk of malignant arrhythmia in patients with acute myocardial infarction in hospital,the serum potassium in patients with myocardial infarction should be maintained at 3.50 mmol/1 to 4.50 mmol/1;blood potassium anomalies do not directly affect in-hospital mortality,but it can increase mortality risk by the incidence of ventricular fibrillation.