Aims: Rho-kinase activity in circulating leucocytes is a useful biomarker for diagnosis and disease activity assessment of vasospastic angina (VSA). The present study aimed to examine the long-term prognostic impact of Rho-kinase activity in circulating leucocytes in VSA patients.
Methods and results: We prospectively enrolled 174 consecutive patients with VSA and 50 non-VSA patients, in whom we measured Rho-kinase activity in circulating leucocytes, and they were followed for a median of 16 months. The primary endpoint was cardiac events including cardiac death, non-fatal myocardial infarction, and hospitalization for unstable angina. During the follow-up period, cardiac events occurred in 10 VSA patients (5.7%) but in none of the non-VSA patients. When we divided VSA patients into two groups by a median value of their Rho-kinase activity, the Kaplan-Meier survival analysis showed a significantly worse prognosis in VSA patients with high Rho-kinase activity compared with those with low activity or non-VSA patients (log-rank; P < 0.05, respectively). Receiver-operating characteristic curve analysis showed that Rho-kinase activity value of 1.24 was the best cut-off level to predict cardiac events in VSA patients, and multivariable analysis showed that a value above the cut-off point had the largest hazard ratio to predict poor outcome in VSA patients [hazard ratio (95% confidence interval) 11.19 (1.41-88.95); P = 0.022]. Importantly, combination of the Japanese Coronary Spasm Association risk score and Rho-kinase activity significantly improved the prognostic impact in VSA patients as compared with either alone.
Conclusion: Rho-kinase activity in circulating leucocytes is useful for prognostic stratification of VSA patients.