Prognostic significance of coronary sinus filling time in patients with angina and normal coronaries at one year follow up

BACKGROUND: Coronary sinus filling time (CSFT) has been proposed as a simple method for assessment of coronary microvascular function in patients with angina and normal coronaries. But its correlation with inducible ischemia and prognostic significance in predicting future cardiovascular events has not been studied. The present study assessed the prognostic significance of CSFT during one year of follow up. METHODS: We compared coronary sinus filling time of patients with angina and normal coronaries with that of control population. Control group was formed by those patients with supraventricular arrhythmia undergoing radiofrequency ablation and having normal coronaries. Baseline treadmill test (TMT) parameters like workload, duration and Duke Score were assessed. Patients were followed up for one year and a composite of cardiovascular mortality and non-fatal myocardial infarction was analyzed. Number of patients presenting to emergency or outpatient department with recurrent chest pain symptoms during one year follow up was considered for secondary outcome analysis. Coronary sinus filling time was analyzed with respect to cardiovascular events, repeat hospitalization for recurrent angina and TMT parameters. RESULTS: Total 72 patients and 16 controls were studied. Mean CSFT value in the study group was 5.31 ± 1.03 sec and in the control group was 4.16 ± 0.72 sec and the difference was significant (p value = 0.0001). No correlation was found between baseline and repeat TMT parameters with CSFT. There was no cardiovascular mortality or hospitalization for non-fatal MI during one year follow up. But patients with frequent emergency or outpatient department visits with chest pain had a high CSFT compared with asymptomatic patients (p value = 0.005). CONCLUSION: Coronary sinus filling time may be used as a simple marker of microvascular dysfunction in patients with angina and normal coronaries. Patients with recurrent chest pain symptoms after one year follow up were found to have high CSFT compared to asymptomatic patients.