Assessment Of CHADS2 And CHA2DS2-VASc Scores In Predicting Stroke And Death In Patients With Sick Sinus Syndrome

Background and Objectives:There was limited data about the risk of stroke and death in Chinese patients with Sick Sinus Syndrome(SSS)and implanted pacemaker.The value of CHADS2 and CHA2DS2-VASc scores in predicting stroke and death in SSS patients was not clear.No study has evaluated the predictive ability of combining pacing mode with both clinical scores above for the risk of stroke and death.So the objectives of this study were: 1.To investigate the morbidity of stroke and the major stroke risk factors in Chinese patients with SSS and implanted pacemaker.2.To further evaluate the prognostic performance of CHADS2 and CHA2DS2-VASc scores for prediction of stroke in subjects with pacemakers and SSS.3.To test whether combining pacing mode with both clinical scores would improve the predictive ability for the risk of stroke and death.Methods:SSS patients who underwent pacemaker implantation(DDD or VVI)in our hospital from January 2004 to December 2014 in our department were included and patients received regular follow-up.We calculated the CHADS2 score(congestive heart failure[HF],hypertension,age ?75 years,diabetes,and prior stroke/transient ischemic attack[TIA][double score])and CHA2DS2-VASc score(congestive heart failure,hypertension,age ?75 years[double score],diabetes,stroke/TIA/ thromboembolism[double score],vascular disease[prior myocardial infarction,peripheral artery disease,or aortic plaque],age 65-75 years,sex category [female])by reviewing medical history in our HIS system.The outcomes of patients(stroke and death)were collected by pacemaker clinic,telephone follow-up and hospitalization.Multivariate analysis was performed with the Cox stepwise regression analysis.With CHADS2 and CHA2DS2-VASc scores as continuous variables,we evaluated the relationship between scores and outcome(stroke and death)using cox regression analysis.The discriminative power of the scores for stroke and death was evaluated by the area under the receiver operating characteristic curve(ROC).Results:Over 2151 person-years of follow-up,46 of 481 patients suffered a stroke(2.1 events per 100 person-years).The incidence of stroke were above 4 events per 100 person-years in patients with CHADS2 ? 3 or CHA2DS2-VASc ? 5.In a multivariate analysis,age(hazard ratio [HR] 1.04,95% CI 1.03-1.08,P = 0.035),VVI pacing(HR 1.99,95% CI 1.06-3.70,P = 0.031)and previous stroke/TIA(HR 3.07,95% CI 1.50-6.31,P = 0.002)were independent risk factors for stroke,while age(HR 1.10,95% CI 1.05-1.14,P < 0.001),VVI pacing(HR 2.78,95% CI 1.58-4.87,P < 0.001),HF(HR 2.31,95% CI 1.30-4.12,P = 0.005)and previous stroke/TIA(HR 2.10,95% CI 1.05-4.21,P =0.037)were independent risk factors for death.CHADS2(HR 1.52,95% CI 1.23-1.88,P < 0.001)and CHA2DS2-VASc(HR 1.48,95% CI 1.24-1.77,P < 0.001)scores showed a significant association with the development of stroke.CHADS2(HR 1.61,95% CI 1.33-1.95,P < 0.001)and CHA2DS2-VASc(HR 1.45,95% CI 1.23-1.71,P < 0.001)scores were also significantly associated with death.The C-statistic for prediction of incident stroke was 0.68(95% CI 0.61-0.75)and 0.69(95% CI 0.62-0.77)for CHADS2-VVI and CHA2DS2-VASc-VVI scores respectively,with slight improvement compared with the C-statistic(0.66 and 0.67)of the original scores.The C-statistic for prediction of incident death was 0.74(95% CI 0.68-0.81)and 0.73(95% CI 0.66-0.79)for CHADS2-VVI and CHA2DS2-VASc-VVI scores respectively,with a marked improvement compared with the C-statistic(0.68 and 0.66)of the original scores(DeLong test P= 0.022 and P = 0.009).Conclusions:SSS patients have a relatively high stroke rate.The incidence of stroke are above 4 events per 100 person-years in patients with CHADS2 ? 3 or CHA2DS2-VASc ? 5.Both CHADS2 and CHA2DS2-VASc scores predict stroke and death in patients paced for SSS regardless of AF history.VVI pacing is an independent risk factor for stroke and death.Adding VVI pacing to the CHADS2 or CHA2DS2-VASc score improves the predictive ability for stroke slightly and improves the predictive ability for death remarkably.It would be an more efficient way to refine stroke and death risk stratification by combining specific risk factors of stroke and death in SSS patients with CHADS2 and CHA2DS2-VASc scores.