The aim of our study was to determine whether combinations of ultrasound echocardiography (UCG) and electrocardiography (EKG) parameters correlated with the functional status of ischemic cardiomyopathy (ICM) patients according to the New York Heart Association (NYHA) classification system.
We assessed 536 elderly Chinese ICM patients according to the NYHA criteria, which included 196 patients with type 2 diabetes mellitus (T2DM). All of the patients underwent UCG. Transmural dispersion of ventricular repolarization was examined using EKG. Cumulative odds logistic regression was performed to evaluate associations between NYHA class and the demographic, clinical, UCG, and EKG variables based on the odds ratio (OR) and 95% confidence interval (CI). A Pearson analysis was also performed to examine correlations between the NYHA classification and the UCG and EKG variables.
Based on the NYHA assessment, 140, 147, 138, and 111 patients were identified as class I, II, III and IV, respectively. A comparison of UCG and EKG variables based on T2DM status showed that CO and Tp-e differed significantly between all NYHA classes (P < .05 for all), with values of each increasing with increasing NYHA class regardless of T2DM status. Multivariate logistic regression analysis showed that the disease course (OR: 1.30; 95% CI: 1.20–1.40), heart rate (OR: 1.16; 95% CI: 1.12–1.21), T wave peak to endpoint (Tp-e; OR: 1.22; 95% CI: 1.18–1.27), dispersion of the QT interval (OR: 0.98; 95% CI: 0.95–1.22), left ventricular fractional shortening (OR: 0.82; 95% CI: 0.78–0.87), cardiac output (CO; OR: 5.58; 95% CI: 3.08–10.13) were significantly associated with the NYHA class (P < .0001 for all). A Pearson correlation analysis showed that Tp-e (r = 0.75982, P < .0001), CO (r = 0.56072, P < .0001), and stroke volume (r = −0.14839, P = .0006) significantly correlated with the NYHA class.
An index consisting of Tp-e and CO will be useful for corroborating the results of the NYHA assessment of ICM patients.