A new study finds Chinese patients with coronary artery disease (CAD) and chronic kidney disease (CKD) experience high rates of cardiovascular events and early death compared with patients with CAD alone. Long-term statin therapy, however, appears to be protective.
For the retrospective study, investigators led by Yugang Dong, MD, of Sun Yat-sen University in Guangzhou, China, examined the effects of long-term statin therapy in a specialized population of 570 Chinese patients diagnosed with CAD at their hospital between 2005 and 2008. Some patients received a stent or a coronary artery bypass graft. Of the patients, 57.5% also had CKD with an estimated glomerular filtration rate below 60 mL/min/1.73m2. Long-term statin therapy was defined as taking statins on 50% of days or more during follow-up. Those taking statins less frequently were categorized as non-users. For comparison, the investigators also examined outcomes in 147 patients with CKD only.
According to results published in Disease Markers, the risks of early death from any cause and sudden cardiac death were double for patients with CAD and CKD compared with patients with CAD alone: 24.4% and 20.4% for CAD and CKD patients versus 10.7% and 9.1% for CAD-only patients, respectively. CAD is a risk factor for CKD and vice versa, the researchers noted, and both have adverse impact on each other.
Long-term statin treatment, however, reduced the rate of major adverse cardiovascular events by 20.5% and all-cause mortality and cardiac death by 28.6% and 27.7%, respectively, in patients with both CAD and CKD over an average 5.79 years. Most of the patients had end-stage renal disease with accelerated atherosclerosis, the researchers noted, so it is not surprising that they would experience the greatest benefits. CKD-only patients by comparison had no major adverse events, surprisingly, and did not see a benefit from statin therapy. These results were more dramatic than seen in studies of Japanese patients, the investigators pointed out.
“Chinese CAD patients with CKD had dramatically high rates of adverse clinical outcomes; for them, long-term statin therapies were exceptionally effective in improving morbidity and mortality,” they concluded. “CKD patients who had no cardiovascular disease initially can prognose good clinical outcomes and do not require statin treatment.”
The investigators acknowledged that they were unable to examine outcomes by CKD stage or by statin type and dosage. Future prospective studies on the subject with larger, more representative populations are warranted.