Background: Cystatin-C, a sensitive marker for preclinical state of renal dysfunction, has been reported to be associated with the development of cardiovascular diseases. Interestingly, recent study suggested that elevated cystatin-C levels were also associated with higher incidence of vasospastic angina (VA). We aimed to investigate the impact of high levels of cystatin-C on the incidence and angiographic characteristics of VA in Korean patients, using the data-sets of VA-KOREA (Vasospastic Angina in KOREA) registry.
Methods: Total 11 centers of 9 universities participated in prospective, observational, web-based VA-KOREA registry and a total of 2107 patients who underwent the angiographic VA provocation test were registered. As the subgroup study of this registry, a total of 549 patients who underwent the ergonovine provocation tests in hospitals in Incheon, in and Seoul from January 2012 to May 2013 were consecutively enrolled into this analysis and their baseline levels of cystatin-C were checked before angiography. The association between the levels of cystatin-C and the incidence of VA, clinical and angiographic characteristics were assessed in these study subjects.
Results: According to the results of the VA provocation, the study subjects were classified into 2 groups: the "VA group" (n=149, 27.1%) and the "non-VA group" (n=400, 72.9%). The prevalence of male, current smokers, diabetes, and dyslipidemia were significantly higher in the VA group (p<0.05). The VA group also had higher levels of triglyceride and uric acid (p<0.05). Although the levels of estimated GFR and serum creatinine were similar between both groups, the VA group demonstrated the higher cystatin-C level compared to the non-VA group (p<0.001). Multivariate logistic regression indicated that cystatin-C levels (HR 1.947, 95% CI [1.132-2.719], p=0.003), current smoking (HR 2.710 [1.415-4.098], p<0.001) were independent predictors for the incidence of VA. An additional analysis only for the VA group, the high level of cystatin-C (tertile, >0.96 mg/L) was independently associated with the multi-vessel coronary vasospasm (HR 2.608 [1.061-4.596], p=0.037).
Conclusions: Elevated cystatin-C level was an independent predictor for the higher incidence of VA in Korean patients. Moreover, the high level of cyctatin-C was independently associated with the multi-vessel spasm reported as the high risk type of coronary spasm. Our results suggest that the proactive investigations for VA should be considered for the patients with mild renal dysfunction indicated by the high level of cystatin-C.