Prevalence Of Structural Issues In STEMI Patients And Their Clinical Associations

BackgroundMyocardial infarction(MI)remains the primary cause of morbidity and mortality worldwide.It usually results from thrombotic occlusion of a coronary artery at the site of a ruptured or eroded plaque.Acute coronary syndrome(ACS)is a term applied to patients in whom there is a suspicion or confirmation of acute myocardial ischemia or infarction.Non-ST elevation myocardial infarction(NSTEMI),unstable angina,and ST-elevation myocardial infarction(STEMI)are the three types of ACS.ST-elevation myocardial infarction(STEMI)is a clinical syndrome defined by characteristic symptoms of myocardial ischemia in association with persistent electrocardiographic ST elevation(STE)and subsequent release of biomarkers of myocardial necrosis.It is diagnosed in an appropriate clinical setting with the finding of≥1mm(0.1mV)ST elevation in at least two contiguous leads of an electrocardiogram associated with cardiac biomarker elevation.Electrocardiography(ECG)is the initial investigation,and the blood investigation of the cardiac biomarkers proves that the patient has a myocardial infarction.Echocardiography(ECHO)is considered as the diagnostic tool for all acute myocardial infarction patients further to diagnose the new and late complications of myocardial infarction.Echocardiography is a non-invasive diagnostic technique that provides information regarding cardiac function and hemodynamics and evaluation of patients with the mechanical complications of AMI.The major mechanical complications of AMI are ventricular free wall rupture,ventricular septal rupture,and papillary muscle rupture with severe mitral regurgitation.Structural heart disease is defined as a condition in which a patient has either congenital or acquired defects or both,compromising the integrity of the heart’s valves or chambers.Mechanical complications of STEMI can lead to structural heart disease.Most of the patients with AMI complicate to papillary muscle rupture.Rupture of papillary muscle results in severe mitral regurgitation(MR).MR is ultimately leading to right heart failure and tricuspid regurgitation(TR).So,MR and TR are the major structural issue as the severe complication of STEMI.ObjectivesThe objective of this study is to determine the prevalence of the structural issues i.e.,ischemic mitral regurgitation,aortic regurgitation,and tricuspid regurgitation in STEMI patients by studying the echocardiography report.MethodsAll the patients presented with STEMI in the first affiliated hospital of Jilin University in the first four months of 2018,i.e.,January,February,March,and April,were included in the study.The total number of patients in the study was 358 STEMI patients.The data were collected from the patient’s history,which includes age,sex,myocardial wall involved,history of diabetes,hypertension,and cerebral infarction.After discharge,the duration of hospital stay was calculated.The baseline investigations which sent soon after hospital admission were recorded,whereas the first echocardiography reports are done within seven days of hospital admission were only included in the study.The echocardiography of seriously ill patients was done at bedside within seven days of hospital admission.The term structural heart disease was defined for the study.The STEMI patients with regurgitate area of≥4cm~2 in any of the valve,i.e.,mitral,aortic,or tricuspid valve during color Doppler study in echocardiography was considered as the patients with structural heart disease.The patients were divided into two groups:structural heart disease with regurgitate area≥4cm~2 and non-structural heart disease<4cm~2regurgitate backflow area in any valve.Similarly,the patients were divided as mitral regurgitation“MR”and without mitral regurgitation“no MR.”MR patients were the patients with regurgitate area≥4cm~2 in the mitral valve,and no MR patients were the patients with<4cm~2 regurgitate area.Aortic regurgitation“AR”and without aortic regurgitation“no AR”;tricuspid regurgitation“TR”and without tricuspid regurgitation“no TR”were also divided similarly.Collected data were analyses were conducted using SPSS 21.Continuous variables were described as mean±standard deviation,and categorical variables were represented as frequency(percentage).Continuous measurements were compared using the paired t-test.A Chi-square analysis was used to compare the categorical variables.Statistical tests were two-tailed,and P-values<0.05 were considered statistically significant.ResultsThe study population was 358 STEMI patients.Among the population of the study,258 patients(72.1%)were male,and 100 patients(27.9%)were female.162 patients(45.3%)presented with inferior STEMI and 194 patients(54.2%)presented with anterior STEMI,and 2 patients(0.6%)presented other than anterior and inferior STEM.158 patients(44.1%)had a history of hypertension;90 patients(25.1%)presented with Diabetes mellitus,14 patients(3.9%)had a history of cerebral infarct.71 patients(19.8%)had Major Adverse Cardiovascular Events(MACE).3 STEMI patients(0.837%)died on the day of hospital admission,6 STEMI patients(1.67%)died within 30 days;altogether,13 patients(3.63%)died within the follow-up period;among them,10 STEMI patients(76.92%)died because of cardiogenic cause.7patients(1.96%)again had subsequent episode myocardial infarction.59 STEMI patients(16.48%)get hospitalized after the first hospitalization,6 patients(1.67%)hospitalized because of stroke,7 patients(1.95%)presented with heart failure.The mean age of the patients with STEMI was 58.72±11.429 years,and the length of the hospital stay of the STEMI patients was 7.16±2.995 days.The mean value of white blood count was 13.35±2.307(10^9/L).The mean value of cardiac enzyme troponin I was 192.02±115.059 ng/ml.A comparative study was done between patients with structural heart disease and non-structural heart disease.78 patients had structural heart disease,and 280 patients were with non-structural heart disease.Patients with anterior wall MI have more prevalence of structural heart disease(P=0.019).The age of STEMI patients with structural heart disease is older than the age of STEMI patients with non-structural heart disease(P=0.001).Urea level of STEMI patients with structural heart disease is slightly higher than with non-structural heart disease(p=0.043).The left atrial size of STEMI patients with structural heart disease is slightly larger than the left atrial size of STEMI patients with non-structural heart disease(P=0.002).FS%and EF%are lower in STEMI patients with structural heart disease than non-structural heart disease(p<0.0001).STEMI patients with structural heart disease show higher MV E peak(cm/s)than non-structural heart disease(P=0.03).The pulmonary valve peak flow of STEMI patients with structural disease is higher than non-structural heart disease(P=0.003).The regurgitate area of mitral,aortic,and tricuspid valve are greater in structural heart disease than in non-structural heart disease(p<0.0001).56 patients(15.6%)were found to have mitral regurgitation(≥4cm~2 regurgitate area in the mitral valve).Comparative study between“MR”and“no MR”showed a similar result as the comparative study of structural heart disease and non-structural heart disease.Most of the patients with structural heart disease were found to have mitral regurgitation.Tricuspid regurgitation occurred concurrently with mitral regurgitation.Anterior wall MI have a higher prevalence than inferior MI in patients with MR(P=0.018).The prevalence of TR is more common in patients with MR than with no MR(P<0.0001).4 patients(1.1%)have the structural issue(≥4 cm~2 regurgitate area)on the aortic valve,which includes 1 patient with MR and 1 patient with TR.The regurgitate area of the aortic valve with AR(4.650±0.3512 cm~2)and with no AR(1.299±1.0347 cm~2)shows a significant difference(p<0.0001).31 patients(8.7%)had the structural issue on the tricuspid valve,which includes 13 patients with MR and 1 patient with AR.Length of hospital stay lengthens more in STEMI patients with TR than with no TR(P=0.0004).RBC count in the STEMI patients with TR is slightly less(P=0.001).Hemoglobin level is also less in STEMI patients with TR than with no TR(P=0.003).Comparatively,the level of urea is slightly higher in STEMI patients with TR(P=0.029).Right Ventricular(RV)diameter is slightly increased in STEMI patients with TR than with no TR,which is a very significant finding(P<0.0001).LVDD is slightly decreased in STEMI patients with TR(P=0.037).Pulmonary valve peak flow significantly decreases in STEMI patients with TR(P=0.024).The regurgitate area of mitral(4.2519±2.66117cm~2)and tricuspid valve(6.484±2.9443 cm~2)is significantly higher in STEMI patients with TR than with no TR(P<0.0001).Conclusion The study was done to find out the prevalence of the structural issues in STEMI patients.In conclusion,this study showed that mechanical structural issues,i.e.,mitral regurgitation and tricuspid regurgitation,are the most common mechanical complication of ST elevated myocardial infarction.The prevalence of the structural issue in ST elevated patients is more common in older patients.Tricuspid regurgitation is usually associated with Mitral regurgitation.Long-standing mitral regurgitation causes right-sided ventricular dilatation causing tricuspid regurgitation.This study also helped to find out some of the biochemical parameters and its clinical associations with STEMI patients.Echocardiography reports of STEMI patients were helpful in finding out hemodynamic changes that occur as complications of myocardial infarction.