EFFECT OF POST-MYOCARDIAL INFARCTION STREPTOKINASE (SK) THERAPY, ON MYOCARDIAL VIABILITY – EVALUATION WITH THALLIUM-201 SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY (TL-201 SPECT)

Abstract

Objective: To evaluate the effect of post-myocardial infarction Streptokinase therapy on myocardial viability, employing Thallium-201 single photon emission computed tomography (TL-201 SPECT).
Design: Retrospective, experimental study.
Place and duration of study: The Nuclear Cardiology Department, Armed Forces Institute of Cardiology / National Institute of Heart Diseases, Rawalpindi, from 1st April 2009 to 31st October 2009.
Patients and Methods: Male patients, who had suffered from acute myocardial infarction (AMI), in an area supplied by the left anterior descending (LAD) artery, had infarct-related electrocardiogram (ECG) changes and received or did not receive Streptokinase therapy, were included. Those with a normal ECG, or history of revascularisation, or non-ST elevation MI, or more than one MIs, were excluded. The patients were divided into groups 1 (who received Streptokinase) and 2 (who did not receive Streptokinase). Each group contained 42 patients and all underwent scintigraphic viability study through intravenous injection of 3.0 mCi (123 MBq) of TL-201, followed by rest-redistribution SPECT imaging on a dual head, dedicated cardiac gamma camera system (Philips Cardio MD ®). Emory’s cardiac toolbox ® and AutoQUANT ® were used for data processing and quantitative estimation of viable myocardium. Empirical scores from 0 to 2 were assigned to each of the scans, in the order of increasing viability, and these were compared across the two groups.
Result: Group 1 contained 42 patients (age range = 38 to 80 years, mean = 53.98 ± 11.26 years), in whom empirical viability scoring was done. Score 0 was seen in 2 patients, score 1 was seen in 15 patients and score 2 was seen in 25 patients form this group. Group 2 also contained 42 patients (age range = 38 to 80 years, mean = 56.71 ± 9.05 years), in whom viability score of 0 was seen in 3 patients, score 1 was seen in 11 patients and score 2 was seen in 28 patients form this group. Age difference between the two groups was statistically insignificant (p = 0.223). The myocardial viability results analysed by 3 x 2 contingency table applying chi-square (χ²) test also showed no significant difference between groups 1 and 2 (p = 0.611).
Conclusion: This study did not find any significant difference in myocardial viability – post-myocardial infarction – in patients who received or did not receive Streptokinase therapy.