Prognostic significance of P-wave morphology in patients with coronary artery disease.

INTRODUCTION: The prognostic significance of P-wave morphology in patients with coronary artery disease (CAD) is not well-known. METHODS: A total of 1946 patients with angiographically verified CAD were included in the Innovation to reduce Cardiovascular Complications of Diabetes at the Intersection (ARTEMIS) study. The P-wave morphology could be analyzed in 1797 patients. RESULTS: During 7.4 ± 2.0 years, a total of 168 (9.3%) patients died or experienced resuscitation from sudden cardiac arrest (SCA), 43 (2.4%) patients experienced sudden cardiac death (SCD) or were resuscitated from SCA, 37 (2.1%) patients succumbed to non-SCD (NSCD), and 88 (4.9%) patients to noncardiac death (NCD). Of the P-wave parameters, the absolute P-wave residuum (PWR), the heterogeneity of the P-wave morphology (PWH), and the P-wave duration (Pdur) had the closest univariate association with the risk of SCD/SCA (0.0038 ± 0.0026 vs 0.0022 ± 0.0017, P < .001; 11.0 ± 5.2 vs 8.6 ± 3.6, P < .01; 142.7 ± 16.9 vs 134.8 ± 14.3 milliseconds, P < .01; SCD/SCA vs no SCD/SCA, respectively). After adjustments with factors that were associated with the risk of SCD/SCA, such as diabetes, smoking, left bundle branch block, high-sensitivity C-reactive protein, and high-sensitivity troponin T, PWR (P < .001), PWH (P < .05), and Pdur (P < 0.01) still predicted SCD/SCA but not non-sudden cardiac death. When these parameters were added to the SCD/SCA clinical risk model, the discrimination and reclassification accuracy of the risk model increased significantly (P < .05, P < .001) and the C-index increased from 0.745 to 0.787. CONCLUSION: The P-wave morphology parameters independently predict SCD/SCA in patients with CAD.

Impaired cardiac autonomic regulation and long-term risk of atrial fibrillation in patients with coronary artery disease.

BACKGROUND: The influence of autonomic cardiac regulation on long-term risk of new-onset atrial fibrillation (AF) in coronary artery disease (CAD) is not well established. OBJECTIVE: The purpose of this study was to evaluate the value of heart rate variability, a marker of cardiac autonomic regulation, in predicting new-onset AF in CAD. METHODS: The Innovation to Reduce Cardiovascular Complications of Diabetes at the Intersection study population consisted of 1946 patients with CAD. After exclusions, the present analysis included 1710 patients. Those patients had a 24-hour electrocardiographic recording at baseline. RESULTS: A total of 143 cases (8.4%) of new-onset AF were observed during a follow-up of 5.6 ± 1.5 years. The lower values of the short-term scaling exponent of the detrended fluctuation analysis (DFA1) and the ratio of the low-frequency and high-frequency components of the power spectrum (LF/HF ratio) remained the strongest heart rate variability predictors of the development of AF after relevant adjustments in Cox multivariate regression analysis (P < .001 for both). The accuracy of these parameters in prediction of AF was even better (area under the receiver operating characteristic curve 0.630 and 0.631, respectively) than that of echocardiographic left atrial diameter (area under the curve 0.618). Including DFA1 and LF/HF ratio in the AF risk model increased the C-index from 0.630 (95% confidence interval 0.569-0.692) to 0.666 (95% confidence interval 0.612-0.720). CONCLUSION: Impaired cardiac autonomic regulation measured by DFA1 and LF/HF ratio predicts the development of new-onset AF as well as or even better than left atrial diameter in patients with CAD.

Association of sST2 and hs-CRP levels with new-onset atrial fibrillation in coronary artery disease.

BACKGROUND: The data on biomarkers as predictors of atrial fibrillation (AF) in patients with coronary artery disease (CAD) are limited. METHODS: A total of 1946 patients with CAD were recruited to the ARTEMIS study. At baseline, the study patients underwent clinical and echocardiographic examinations and had laboratory tests. The patients (n=1710) with the information about the occurrence of new-onset AF during the follow-up were included in the present analysis. RESULTS: During 5.7±1.5years of follow-up, 143 (8.4%) patients developed a new-onset AF. Higher values of soluble ST2 (sST2) (20.2±10.8 vs. 17.5±7.2ng/mL, p=0.005), high-sensitivity troponin T (hs-TnT) (11.9±10.2 vs. 10.3±8.3ng/L, p=0.005), high-sensitivity C-reactive protein (hs-CRP) (3.3±5.9 vs. 2.0±4.4mg/L, p<0.001) and brain natriuretic peptide (BNP) (85.6±77.5 vs. 64.9±73.5ng/L, p<0.001) had significant associations with the occurrence of new-onset AF. In the Cox clinical hazards model, higher age (p=0.004), greater weight (p=0.045), larger left atrial diameter (p=0.001), use of asthma/chronic obstructive pulmonary disease medication (p=0.001) and lack of cholesterol lowering medication (p=0.008) had a significant association with the increased risk of AF. When the biomarkers were tested in the Cox clinical hazards model, sST2 (HR=1.025, 95% CI=1.007-1.043, p=0.006) and hs-CRP (HR=1.027, 95% CI=1.008-1.047, p=0.006) retained their significant power in predicting AF. CONCLUSION: A biomarker of fibrosis, sST2, and a biomarker of inflammation, hs-CRP, predict the risk of occurrence of new-onset AF in patients with CAD. These biomarkers contributed to the discrimination of the AF risk model, but did not improve it markedly.

Supraventricular premature beats and risk of new-onset atrial fibrillation in coronary artery disease.

INTRODUCTION: The significance of premature atrial contraction (PAC) count and supraventricular runs (SVR) for the risk of development of new-onset atrial fibrillation (AF) in patients with coronary artery disease (CAD) is not well established. METHODS: The Innovation to Reduce Cardiovascular Complications of Diabetes at the Intersection (ARTEMIS) study cohort consisted of 1,946 patients with CAD who underwent clinical and echocardiographic examinations, 24-hour ambulatory ECG monitoring, and laboratory tests. After excluding patients who were not in sinus rhythm at baseline or were lost from the follow-up, the present study included 1,710 patients. SVR was defined as at least four PACs in a row with a duration <30 seconds. RESULTS: During a follow-up for an average 5.6 ± 1.5 years, new-onset AF was identified in 143 (8.4%) patients. In the univariate analysis, both SVR and PAC count were associated with the development of new-onset AF. When SVR and PAC count were adjusted with the established AF risk markers of the modified CHARGE-AF model in the Cox multivariate regression analysis, both parameters remained significant predictors of the occurrence of new-onset AF (HR = 2.529, 95 % CI = 1.763-3.628, P ˂ 0.001 and HR = 8.139 for ≥1,409 PACs [the fourth quartile] vs. ≤507 PACs [the first quartile], 95 % CI = 3.967-16.696, P ˂ 0.001, respectively). Together these parameters improved the C-index of the established AF risk model from 0.649 to 0.718, P < 0.001. CONCLUSION: Including SVR and PAC count to the established AF risk model improves the discrimination accuracy in predicting AF in patients with CAD.

Ambulatory Blood Pressure Characteristics and Long-Term Risk for Atrial Fibrillation.

BACKGROUND: We hypothesized that elevated nighttime systolic ambulatory blood pressure (ABP) yields additional information compared with daytime systolic ABP for the long-term risk of atrial fibrillation (AF) and perhaps should be taken into account in treatment strategies for preventing the increasing burden of AF during aging. METHODS: A total of 903 subjects with or without hypertension aged 40 to 59 years, who were recruited to the Oulu Project Elucidating Risk of Atherosclerosis (OPERA) study, underwent ABP monitoring, thorough clinical examinations and laboratory tests. RESULTS: After an average of 16.4 ± 3.6 years of follow-up, 91 (10%) of the study subjects had experienced a new-onset AF requiring a hospital emergency room or hospital visit. Of the components of baseline ABP, the nighttime mean systolic blood pressure had the strongest univariable association with the occurrence of AF (120.8 ± 15.9 vs. 116.4 ± 14.1 mm Hg, P = 0.006, in subjects with vs. without the occurrence AF). When the univariable predictors of AF, such as age, sex, body mass index, height, smoking history, alanine aminotransferase, uric acid, and fasting plasma glucose, were entered in the multivariable Cox hazards model, age (P < 0.001), and body mass index (P = 0.014) retained their significant predictive power. After adjustments in this clinical hazards model, the nighttime mean systolic blood pressure still predicted the occurrence of AF (hazards ratio = 1.07 per every 5 mm Hg increase, 95% confidence intervals = 1.004-1.15, P = 0.038). CONCLUSION: Of the baseline ABP characteristics, the nighttime systolic blood pressure is a significant independent contributor to the long-term risk of new-onset AF requiring a hospital visit.