Correlation of In-Hospital Outcome with Myocardial Performance Index and Left Ventricular Systolic Function

Introduction: Acute myocardial infarction (AMI) remains the leading cause of morbidity and mortality worldwide. Left ventricular dysfunction is a common consequence of acute coronary events and has important prognostic implications. In hospital complications of myocardial infarction include arrhythmia, heart failure, post infarction angina and death.

Objective: To assess the Correlation of in-hospital outcome with myocardial performance index and left ventricular systolic function.

Methods: This cross-sectional analytical study was conducted in Dpt. Of Cardiology, Mymensingh Medical College Hospital, Mymensingh, Bangladesh from October 2023 to March 2024. Total 100 patients who sustained first attack of ST elevated myocardial infarction were included in the study considering inclusion and exclusion criteria. Purposive sampling was done using a structured case record form. Study population was divided into three groups to study and compare myocardial performance index (MPI) with left ventricular systolic function depicted as left ventricular ejection fraction (LVEF).

Results: Total 100 patients were included considering inclusion and exclusion criteria. Majority of the study population were in the 41-50 years age group. Then 51-60 years group & 31-40 years group subsequently. Statistical analysis showed significant age difference between the groups (p<0.05). Majority of the study population were male (87.5%). Statistical analysis showed significant sex difference between the groups (p<0.001). It showed group-III people were more obese than rest of the groups. Statistical analysis showed significant difference between the groups (p<0.05). It showed majority of the study population were dyslipidaemic & hypertensive. Then diabetic, current smoker & asthmatic. Statistical analysis showed diabetic, dyslipidaemia, smoking & bronchial asthma were significantly different between the groups (p<0.05). It showed group-III were high in total cholesterol, LDL, HDL & triglyceride. Statistical analysis showed significant difference between the groups (p<0.05). Troponin-I & BNP level of the study population. It showed people of the group-III had the highest level of Troponin-I & NT- pro BNP level. Statistical analysis showed significant difference between the groups (p<0.05). Majority of the lowest indices of cardiac function & highest MPI level. On the other hand, group-I study population had the highest indices of cardiac function but lowest MPI level. Statistically significant difference was found between the groups (p<0.05). ST segment resolution <50% causes more complications than ST segment resolution >50%. Out of 100 patients who had LVEF <40%, mean LV MPI value was 0.53 as compared with a mean LV MPI of 0.50 in patients with LVEF >40% at the time of presentation. Even though this difference was not significant at the time of presentation, a significant difference was found on the 5th day (MPI 0.43 in LVEF <40% group, compared to 0.49 among those with LVEF >40% (p=0.031).

Conclusion: Myocardial performance index was also able to give a hint for adverse cardiac events during the hospital stay. ST-elevation myocardial infarction patients, poor left ventricular ejection fraction and higher myocardial performance index at presentation and on 5th day significantly correlated with in-hospital outcome. Myocardial performance index was also able to give a hint for adverse cardiac events during the hospital stay.

Keywords: Left ventricular ejection fraction, Myocardial performance index, ST elevated myocardial infarction.