Frequency of Elevated Creatine Phosphokinase–Cardiac Isoenzyme and High-Sensitivity Cardiac Troponin I in Patients with Acute Coronary Syndrome

Abstract

Objectives: This study aimed to determine the frequency of elevated creatine phosphokinase–cardiac isoenzyme (CK-MB) and high-sensitivity cardiac troponin I (hs-cTnI) among patients presenting with acute coronary syndrome (ACS). Methodology: A descriptive cross-sectional study was conducted at the Department of Chemical Pathology, in collaboration with the Accident and Emergency Department of Bahawal Victoria Hospital, Bahawalpur, from November 2022 to July 2023. A total of 122 patients aged 35–70 years with ACS were enrolled using non-probability consecutive sampling. Serum CK-MB and hs-cTnI levels were measured 4–6 hours after symptom onset. Diagnostic cutoffs included CK-MB >2× upper reference range and hs-cTnI ≥0.04 ng/mL. Clinical and demographic variables such as age, gender, diabetes, hypertension, and dyslipidemia were documented. Data were analyzed using SPSS v26, applying descriptive statistics and stratification with Chi-square testing, considering p<0.05 as significant. Results: Among 122 patients, 88 (72.1%) were male and 34 (27.9%) female, with a mean age of 43.83 ± 7.23 years. Diabetes, hypertension, and dyslipidemia were present in 31.1%, 50.0%, and 27.0% of patients, respectively. Mean CK-MB and hs-cTnI levels were 55.99 ± 26.55 IU/L and 0.51 ± 0.45 ng/mL, respectively. Based on CK-MB, AMI was diagnosed in 62 (50.8%) patients, while hs-cTnI identified 72 (59.0%) AMI cases. Male gender and ST elevation were significantly associated with AMI in both biomarkers, whereas comorbidities showed no significant associations. Conclusion: High-sensitivity troponin I (hs-cTnI) identified more cases of AMI compared to CK-MB, reflecting its superior sensitivity in diagnosing myocardial injury. Routine reliance on CK-MB should be reconsidered, and hs-cTnI should be prioritized in acute care settings for accurate and timely diagnosis.