Prevalence and clinical impact of electrocardiographic abnormalities in patients with chronic kidney disease

BackgroundChronic kidney disease (CKD) is a strong risk factor for cardiovascular disease. Electrocardiogram (ECG) is the basic test for screening cardiovascular disease. However, the impact of ECG abnormalities on cardiovascular prognosis in patients with CKD is largely unknown.MethodsA total of 1,295 patients with CKD (stage 3, 4, and 5) who underwent ECG between 2013 and 2015 were selected from the tertiary hospital in Korea. ECG abnormalities were defined using the Minnesota classification. Five-year major adverse cerebrocardiovascular event (MACCE), a composite of death, myocardial infarction (MI) and stroke, was analyzed after excluding 251 patients (n=1,044) with prior MI or stroke.ResultsThe higher the CKD stage, the higher the proportion of patients with a major ECG abnormality. Five-year MACCE incidences were 34%, 23.9%, and 21.7% in patients with major, minor and no ECG abnormalities. MACCE and MI incidences were significantly higher in patients with severe ECG abnormalities (log-rank p < 0.001). Major ECG abnormalities were significantly associated with MACCE (adjusted HR 1.48, 95% CI 1.11-1.97). In particular, atrial fibrillation, atrial premature complex, and QT interval prolongation were identified as important ECG diagnoses. The accuracy of cardiovascular risk stratification was improved when ECG diagnosis was added to the conventional SCORE model (net reclassification index 0.09).ConclusionsMajor ECG abnormality was a significant predictor of cardiovascular events in CKD patients. ECG diagnosis can be useful in evaluating the risk of cardiovascular disease in CKD patients when applied in addition to the conventional risk stratification model.