Can prolonged P-R interval predict clinical outcomes in non-ST elevation acute coronary syndrome patients?

ABSTRACT

BACKGROUND: The present study aimed to respond to clinical question, can prolonged P-R interval predict clinical outcomes in non-ST elevation acute coronary syndrome patients? METHODS: This descriptive-analytical study was conducted on cardiac patients. All of the non-ST elevation acute coronary syndrome (NSTEACS) including non-ST elevation myocardial infarction (NSTEMI) and unstable angina patients included in the study. Then they divided into two groups prolonged P-R interval and normal P-R interval. The patients who had a history of digoxin and calcium channel blocker use, using antiarrhythmic drugs, known valvular or congenital heart disease and connective tissue, unreadable P-R interval and cardiac block were excluded. Data were collected using the questionnaire consisted demographic data and clinical outcomes and a follow-up part was completed by one of the researchers. RESULTS: Finally, 248 patients completed the study. The results showed both of the two groups had significant differences in terms of the history of myocardial infarction (MI) (p = 0.018), the level of high-density lipoprotein (HDL) (p = 0.004), heart rate (p = 0.042), inverted T wave (p = 0.017), anterior ST- segment depression (p = 0.008), normal report of coronary angiography (CAG) (p = 0.003), three vessels disease (p = 0.043), left main lesion (p = 0.045) and SYNTAX score (p = 0.032) based on the CAG report. The results of six-month follow-up showed although, the frequency of ischemic stroke, coronary artery disease (CAD) and cardiovascular death were higher in prolonged P-R interval groups. The chi-square test showed this difference was statistically non-significant (p > 0.05). The multivariate logistic regression model revealed non-significant relationships between prolonged P-R interval and SYNTAX score, significant CAD, three-vessel disease, inverted T wave, anterior ST depression, heart rate and HDL. CONCLUSIONS: Based on the results of our study the six-month follow-up showed non-significant outcomes. Further studies are recommended to assess the long-term outcomes.