CHADS2 and CHA2DS2-VASc Scoring Systems for Predicting Atrial Fibrillation following Cardiac Valve Surgery

April CHADS2 and CHA2DS2-VASc Scoring Systems for Predicting Atrial Fibrillation following Cardiac Valve Surgery Liang Yin 0 1 2 Xinyu Ling 0 1 2 Yufeng Zhang 0 1 2 Hua Shen 0 1 2 Jie Min 0 1 2 Wang Xi 0 1 2 Jing Wang 0 1 2 Zhinong Wang 0 1 2 0 Funding: This work was supported by the National Nature Science Foundation of China (NO. 81170232 and 81300102). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript 1 Academic Editor: Umberto Benedetto, Harefield Hospital , UNITED KINGDOM 2 Department of Cardiothoracic Surgery, Changzheng Hospital, Second Military Medical University , Shanghai, 200003 , China These authors contributed equally to this work. * Clinical use of CHADS2 and CHA2DS2-VASc scoring systems for predicting AF following cardiac surgery have been reported in previous studies and demonstrated well-validated predictive value. We sought to investigate whether the two scoring systems are effective for predicting new-onset of AF following cardiac valve surgery and to demonstrate its potential utility of clinical assessment. Medical records of all patients underwent cardiac valve surgeries during the period of January 2003 and December 2013 without preoperative AF at the cardiac center of our university were reviewed. The main outcome end point of our study was the early new-onset of AF following cardiac valve surgery. There were overall 518 patients involved in this study, with 234 (45.17%) developed POAF following valve surgery. Patients with POAF had older age (P=0.23) and higher BMI (P=0.013) than those without POAF. History of heart failure (P=0.025), hypertension (P=0.021), previous stroke or TIA (P=0.032), coronary artery disease (P=0.001), carotid artery disease (P=0.024) and preoperative medication of statins (P=0.021) were significantly more recorded in POAF group. Patients with POAF also had higher LAD (P=0.013) and E/e' ratio (P<0.001). The CHADS2 and CHA2DS2-VASc scores were significantly higher in patients with POAF (P=0.002; P<0.001), and under univariate and multivariate regression analysis the CHADS2 and CHA2DS2-VASc scores were significant predictors of POAF (P=0.001; P<0.001). Based on stratification of CHADS2 and CHA2DS2-VASc scores, the Kaplan-Meier analysis obtained a higher POAF rate on patients with higher stratification of CHADS2 and CHA2DS2-VASc scores (P<0.001; P<0.001). - In conclusion, CHADS2 and CHA2DS2-VASc scores were directly associated with the incidence of POAF following valve surgery and a higher score was strongly predictive of POAF. Atrial fibrillation (AF) is the one of the most common complications after cardiac surgery, and postoperative atrial fibrillation (POAF) following cardiac surgery is one of the most predictors of high mortality in the long-term[1]. Although the exact cause and mechanism of POAF have not been demonstrated and testified, injury of the atrium and systematic inflammation may play important roles in this postoperative arrhythmia process [24]. POAF is usually well tolerated, but may result in hypotension, heart failure, stroke, longer hospital stay and increased hospital costs[5]. POAF usually occurs within the first 5 days after cardiac surgery, with a peak incidence on days 2 and 3[6]. Predictors, such as older age, number of bridge vessels in coronary artery bypass grafting (CABG) and left ventricular (LV)hypertrophy had been verified in highly incidence of POAF following cardiac surgery[7]. But only several scattered indicators and lack of systematic scoring system for predicting POAF deter the assessing process preoperatively, and increased perioperative morbidity and long-term mortality may occur in concerned patients. Originally, the CHADS2 [8] [cardiac failure, hypertension, age, diabetes, stroke (doubled)] risk index, a point system in which 2 points are assigned for a history of stroke or transient ischemic attack (TIA) and 1 point each is assigned for age 75 years, a history of hypertension, diabetes, or recent heart failure, is an easy-to-remember means of assessing stroke risk of patients with AF. CHA2DS2-VASc [9] [congestive heart failure, hypertension, age 75 (doubled), diabetes, stroke (doubled), vascular disease, age 6574, and sex category (female)], a newly adjusted scheme recommended by European Society of Cardiology (ESC) is based on a point system in which 2 points are assigned for a history of stroke or TIA, or age 75; and 1 point each is assigned for age 6574 years, a history of hypertension, diabetes, recent heart failure, vascular disease (myocardial infarction, complex aortic plaque, and peripheral arterial disease (PAD), including prior revascularization, amputation due to PAD, or angiographic evidence of PAD, etc.), and female sex[1012]. The CHADS2 and CHA2DS2-VASc scores can provide easy and effective assessment of patients with AF in which circumstances they can occur stroke or other thrombus-embolism events[13]. Only limited studies have investigate the association between CHADS2 or CHA2DS2-VASc score and prediction of POAF, one of the studies[14] mentioned that assessment using CHADS2 and CHA2DS2-VASc scores is predictive of POAF after cardiac surgery and may be helpful for identifying high-risk patients, but differentiation on types of surgery have not been studied in this report. In this study, we sought to explore the potential association between CHADS2 and CHA2DS2-VASc scores and its utility of assessment for predicting POAF following cardiac valve surgery. Concerning the difficulties in meeting with each patient and some patients were not convenient to be offered with written informed consent, written informed consent was not utilized in our study, permission of medical data extraction was obtained by verbal informed consent from each patient, which was recorded by telephone for each patient included in our study, and the consent procedure of our study and this study were approved by Ethics Committee of Shanghai Changzheng Hospital. This study included a series of 518 patients in our center from January 2003 and December 2013 who underwent cardiac valve surgeries (valve repair or valve replacement) without preoperative AF, whose baseline characteristics are shown in Table 1. This series belongs to a consecutive series who were carried out cardiac valve surgeries with or without CABG, non-valve surgeries were excluded because their immediate and late outcomes are likely to differ from those who were underwent valve surgeries. Patients with preoperative AF, pacemaker implantation, Cox maze or radiofrequency ablation procedure for atrial arrhythmia were also excluded from our study. CHADS2 and CHA2DS2-VASc scores of each patient, echocardiographic reports and complete medical records were collected to investigate the association between CHADS2 and CHA2DS2-VASc scores and the occurrence of POAF following valve surgery. CHADS2 and CHA2DS2-VASc Scores and Endpoint The CHADS2 score was calcul (...truncated)