Premature Atrial Contractions and Their Association with Stroke Features and Outcome.

BACKGROUND: Frequent premature atrial contractions (PACs) are associated with atrial fibrillation, stroke, and mortality. However, the cut-off value for PAC counts that could identify patients with different stroke features is unclear, and the association of PACs to outcome is not determined. METHODS: The study retrospectively included patients with acute ischemic stroke who had underwent both a 24 h Holter recording and a brain MRI in Taipei Veterans General Hospital from January 2015 to May 2016. Patients were categorized into four groups according to their PAC frequencies on 24 h Holter recording. We compared the clinical severity, neuroimage features, stroke subtypes, and functional outcome among the four groups of patients. RESULTS: Among the 278 patients, the lower, middle, and upper quartiles of the PAC counts were 23, 74, and 459.5, respectively. In contrast to the 1st quartile of patients, the 3rd (PAC 75-459/24 h) and the 4th (PAC ≥460/24 h) quartiles of patients had higher NIH Stroke Scale (NIHSS) at admission (p = 0.014 and p = 0.002, respectively). The frequencies of cryptogenic stroke were not different among the 4 quartiles of the patients, but cryptogenic stroke patients with ≥ 75PACs/24hours had higher stroke severity compared to those with PACs < 75counts/24 h (NIHSS 9.1 vs. 5.2, p = 0.043). There was an increased trend in infarcts of multiple vascular territories and in mortality at 1 year among the four groups of patients with increased PAC frequency (p = 0.045 and p = 0.002, respectively). The 4th PAC quartile was associated with poor functional outcome (modified Rankin Scale ≥ 4) at 3 months in univariate analysis (OR: 5.66, CI: 2.69-11.91, p < 0.001), but was not an independent predictor after controlling for initial stroke severity. CONCLUSIONS: PACs ≥ 75 counts/24 h was associated with higher clinical severity in patients with acute ischemic stroke.

Excessive Supraventricular Ectopic Activity and Adverse Cardiovascular Outcomes: a Systematic Review and Meta-analysis.

PURPOSE OF REVIEW: Excessive supraventricular ectopic activity (ESVEA), in the form of frequent premature atrial contractions (PACs) and runs of PACs, is commonly observed in clinical practice and is frequently considered to be benign. Yet, recent studies have demonstrated a link between ESVEA and adverse cardiovascular outcomes. The aim of this meta-analysis was to examine the association between ESVEA and the risk of atrial fibrillation (AF), stroke, and mortality. RECENT FINDINGS: A systematic search was performed in PubMed, EMBASE, and the Cochrane Library up to December 2017 to identify studies assessing adverse cardiovascular outcomes in patients with ESVEA, recorded on ambulatory electrocardiography. ESVEA was defined as a burden of PACs > 30 PACs/h or any runs of ≥20 PACs. The risk estimates for EVSEA and each clinical endpoint were pooled and analyzed separately. RESULTS: Five studies comprising 7545 participants were included in this meta-analysis. The pooled analysis showed that ESVEA doubled the risk of AF (HR 2.19, 95% CI 1.70-2.82). ESVEA was also associated with a higher incidence of stroke (HR 2.23, 95% CI 1.24-4.02). Finally, ESVEA was associated with higher all-cause mortality (HR 1.61, 95% CI 1.25-2.07). Our meta-analysis found that ESVEA is closely associated with AF, stroke, and all-cause mortality. Further studies are required to examine the implication of therapeutic strategies in patients with ESVEA, in order to prevent potential subsequent adverse cardiovascular outcomes.

Supraventricular Extrasystoles on Standard 12-lead Electrocardiogram Predict New Incident Atrial Fibrillation after Embolic Stroke of Undetermined Source: The AF-ESUS Study.

BACKGROUND: The diagnosis of covert atrial fibrillation (AF) remains a major challenge to guide secondary prevention of patients with embolic stroke of undetermined source (ESUS). AIMS: We analyzed consecutive ESUS patients from 3 prospective stroke registries to assess whether the presence of supraventricular extrasystoles (SVE) on standard 12-lead electrocardiogram (ECG) is associated with the detection of AF (primary outcome), stroke recurrence and death (secondary outcomes) during follow-up. METHODS: We measured the number of SVEs in all available ECGs of patients hospitalized for ESUS. Multivariate stepwise regression with forward selection of covariates assessed the association between SVE (classified in 4 groups according to their number per 10 seconds of ECG: no SVE, >0-1SVEs, >1-2SVEs, and >2SVEs) and outcomes during follow-up. The Kaplan-Meier product limit method estimated the 10-year cumulative probabilities of outcomes in each SVE group. We calculated the negative prognostic value (NPV) of the presence of any SVE to predict new AF, defined as the probability that AF will not be detected during follow-up if there is no SVE. RESULTS: Among 853 ESUS patients followed for 2857 patient-years (median age: 67 years, 43.0% women), 226 (26.5%) patients had at least 1 SVE at the standard 12-lead ECGs performed during hospitalization. AF was detected in 125 (14.7%) of patients in the overall population during follow-up: 8.9%, 22.5%, 28.1%, and 48.3% in patients with no SVE, greater than 0-1SVE, greater than 1-2SVE and greater than 2SVE respectively. In multivariate regression analysis, compared to patients with no SVEs, the corresponding hazard-ratios were 1.80 [95% confidence intervals (95%CI):1.06-3.05], 2.26 (95%CI:1.28-4.01) and 3.19 (95%CI:1.93-5.27). The NPV of the presence of any SVE for the prediction of new AF was 91.4%. There was no statistically significant association of SVE with the risk of ischemic stroke recurrence and death. CONCLUSIONS: In ESUS patients without SVEs during hospitalization, the probability that AF will not be detected during a follow-up of 3.4 years is more than 91%.

Burden of Premature Atrial Complexes and Risk of Recurrent Stroke and Death in Patients with Mild to Moderate Ischemic Stroke.

BACKGROUND: Premature atrial complexes (PACs) meet increased attention as a potential intermediary between sinus rhythm and atrial fibrillation (AF). Patients with even high numbers of PACs do not fulfill current guidelines for oral anticoagulation treatment though an associated stroke risk is suspected. OBJECTIVE: We aimed to determine whether a high number of PACs or runs of AF less than 30 seconds in 2-day continuous electrocardiogram (ECG) recording was associated with risk of recurrent ischemic stroke/transient ischemic attack (TIA) or death in a large cohort of patients with acute ischemic stroke or TIA and no prior AF. METHODS: We performed 48 hours continuous ECG recording within 1 week after ischemic stroke/TIA. PACs were reported as mean number of PACs per hour. Patients were followed in Danish Stroke Registry, Danish Civil Registration System, and Danish National Patient Registry. Cox Regression analysis was used to calculate hazard ratios. RESULTS: We included 1507 patients with TIA (40%) or ischemic stroke (60%), of which 98.7% had mild to moderate strokes. Mean age was 72.9 (7.8) years, 43.4% were females. Follow-up was 2.3 (1.3) years. Hazard ratio for recurrent stroke/TIA or death did not differ between quartiles of PAC burden, nor did any of the 2 components of this composite endpoint. Nonsustained AF less than 30 seconds was not associated with higher risk of recurrent stroke/TIA or death. CONCLUSIONS: In a large cohort of patients with recent ischemic stroke or TIA, burden of PACs or nonsustained AF less than 30 seconds were not associated to higher risk of recurrent stroke/TIA or death.

Frequent premature atrial contractions are associated with atrial fibrillation, brain ischaemia, and mortality: a systematic review and meta-analysis.

AIMS: Premature atrial contractions (PACs) are a common cardiac phenomenon, traditionally considered to be of little clinical significance. Recent studies, however, suggest that PACs are associated with atrial fibrillation (AF), as well as ischaemic stroke, transient ischaemic attack, and mortality. This systematic review aims to investigate the association between PACs on standard electrocardiogram (ECG) as well as PAC-count on Holter monitor and future detection of AF, brain ischaemia, and all-cause mortality in patients without a history of AF. METHODS AND RESULTS: We searched PubMed, Embase (OVID), and Cochrane Database of Systematic Reviews from inception through 11 April 2018 and performed a systematic review and meta-analysis. We assessed risk of bias using a modified Quality In Prognosis Studies tool. The primary expression of associations in meta-analysis was the unadjusted hazard ratio (HR) using a random effects model. We identified 33 eligible studies including 198 876 patients from Western and East Asian populations with mean age ranging 52-76 years. Frequent PACs on 24-48 h Holter was associated with AF [HR 2.96, 95% confidence interval (CI) 2.33-3.76; 15 cohorts, n = 16 613], first stroke (HR 2.54, 95% CI 1.68-3.83; 3 cohorts, n = 1468), and all-cause mortality (HR 2.14, 95% CI 1.94-2.37; 6 cohorts, n = 7571). There was insufficient evidence to conclude that presence of ≥1 PAC on standard 12-lead ECG is associated with future AF detection. CONCLUSION: In older patients without a history of AF, frequent PACs on 24-48 h Holter are significantly associated with AF, first stroke, and mortality.

Ectopy on a Single 12-Lead ECG, Incident Cardiac Myopathy, and Death in the Community.

BACKGROUND: Atrial fibrillation and heart failure are 2 of the most common diseases, yet ready means to identify individuals at risk are lacking. The 12-lead ECG is one of the most accessible tests in medicine. Our objective was to determine whether a premature atrial contraction observed on a standard 12-lead ECG would predict atrial fibrillation and mortality and whether a premature ventricular contraction would predict heart failure and mortality. METHODS AND RESULTS: We utilized the CHS (Cardiovascular Health) Study, which followed 5577 participants for a median of 12 years, as the primary cohort. The ARIC (Atherosclerosis Risk in Communities Study), the replication cohort, captured data from 15 792 participants over a median of 22 years. In the CHS, multivariable analyses revealed that a baseline 12-lead ECG premature atrial contraction predicted a 60% increased risk of atrial fibrillation (hazard ratio, 1.6; 95% CI, 1.3-2.0; P<0.001) and a premature ventricular contraction predicted a 30% increased risk of heart failure (hazard ratio, 1.3; 95% CI, 1.0-1.6; P=0.021). In the negative control analyses, neither predicted incident myocardial infarction. A premature atrial contraction was associated with a 30% increased risk of death (hazard ratio, 1.3; 95% CI, 1.1-1.5; P=0.008) and a premature ventricular contraction was associated with a 20% increased risk of death (hazard ratio, 1.2; 95% CI, 1.0-1.3; P=0.044). Similarly statistically significant results for each analysis were also observed in ARIC. CONCLUSIONS: Based on a single standard ECG, a premature atrial contraction predicted incident atrial fibrillation and death and a premature ventricular contraction predicted incident heart failure and death, suggesting that this commonly used test may predict future disease.

Relation of premature atrial complexes with stroke and death: Systematic review and meta-analysis.

Frequent premature atrial complexes (PACs) are universal in the general population; however, their clinical significance is unclear. We hypothesize that frequent PACs are associated with increased risk of stroke and death. The PubMed (from 1966 to April 2017) and Embase (from 1974 to April 2017) databases were searched for longitudinal studies that reported the relation of PACs with incidence of stroke and death with various etiologies. Study quality was evaluated, and the relative risks (RR) of unfavorable outcomes in subjects with frequent PACs vs those without were calculated. Eleven studies with overall high quality were eligible according to inclusion criteria. The meta-analysis demonstrated that frequent PACs were associated with an increased risk of stroke (unadjusted RR: 2.20, 95% confidence interval [CI]: 1.79-2.70; adjusted RR: 1.41, 95% CI: 1.25-1.60) and death from all causes (unadjusted RR: 2.17, 95% CI: 1.80-2.63; adjusted RR: 1.26, 95% CI: 1.13-1.41), cardiovascular diseases (unadjusted RR: 2.89, 95% CI: 2.20-3.79; adjusted RR: 1.38, 95% CI: 1.24-1.54), and coronary artery disease (unadjusted RR: 2.74, 95% CI: 1.64-4.58; adjusted RR: 1.74, 95% CI: 1.27-2.37). No significant publication bias was detected. The association was robust in sensitivity analysis, subgroup analysis, and pooled analysis of estimates adjusting for confounding factors. Frequent PACs are not benign phenomena; they are associated with higher risk of unfavorable outcomes. Further research on the optimal management of subjects with frequent PACs is urgently required.

Excessive Premature Atrial Complexes and the Risk of Recurrent Stroke or Death in an Ischemic Stroke Population.

BACKGROUND: Our aim was to investigate the association of premature atrial complexes and the risk of recurrent stroke or death in patients with ischemic stroke in sinus rhythm. METHODS: In a prospective cohort study, we used 24-hour Holter recordings to evaluate premature atrial complexes in patients consecutively admitted with ischemic strokes. Excessive premature atrial complexes were defined as >14 premature atrial complexes per hour and 3 or more runs of premature atrial complexes per 24 hours. During follow-up, 48-hour Holter recordings were performed after 6 and 12 months. Among patients in sinus rhythm, the association of excessive premature atrial complexes and the primary end point of recurrent stroke or death were estimated in both crude and adjusted Cox proportional hazards models. We further evaluated excessive premature atrial complexes contra atrial fibrillation in relation to the primary end point. RESULTS: Of the 256 patients included, 89 had atrial fibrillation. Of the patients in sinus rhythm (n = 167), 31 had excessive premature atrial complexes. During a median follow-up of 32 months, 50 patients (30% of patients in sinus rhythm) had recurrent strokes (n = 20) or died (n = 30). In both crude and adjusted models, excessive premature atrial complexes were associated with the primary end point, but not with newly diagnosed atrial fibrillation. Compared with patients in atrial fibrillation, those with excessive premature atrial complexes had similarly high risks of the primary end point. CONCLUSIONS: In patients with ischemic stroke and sinus rhythm, excessive premature atrial complexes were associated with a higher risk of recurrent stroke or death.

Atrial ectopy and N-terminal pro-B-type natriuretic peptide as predictors of atrial fibrillation: a population-based cohort study.

AIMS: The risk of incident atrial fibrillation (AF) can be estimated by clinical parameters in the Framingham AF risk model. Elevated N-terminal pro-B-type natriuretic peptide (NT-proBNP) and increased rate of premature atrial contractions (PACs) have been shown to be associated with AF, but the additive value of both of these biomarkers in the Framingham AF risk model has not been fully examined. METHODS AND RESULTS: A total of 646 subjects from the Copenhagen Holter Study (mean age 64.4 ± 6.8 years, 41.6% women) with no history of prior AF, stroke or cardiovascular disease were followed for the diagnosis of incident AF or death (median follow-up time 14.4 years). Median NT-proBNP was 6.7 pmol/L (IQR: 3.6-13.5), median PAC count was 1.4 beats/h (IQR: 0.6-4.5), 71 (11.0%) subjects developed AF, and 244 (37.8%) died. Multiple Cox regression including Framingham AF risk score, log-transformed NT-proBNP, and log-transformed PAC showed a significant increase in AF hazard risk [hazard ratio (HR) 1.45, 95% confidence interval (CI) 1.14-1.85, P = 0.002; HR 1.23, 95% CI 1.09-1.39, P = 0.001]. The addition of PAC to the Framingham AF risk model significantly improved the time-dependent area under the receiver operating characteristic curve (AUC 65.6 vs. 72.6; P = 0.008), while the addition of NT-proBNP did not. CONCLUSION: Atrial fibrillation risk discrimination was significantly improved by the addition of PAC to the Framingham AF risk model, but not by the addition of NT-proBNP.

Prevalence and Prognostic Significance of Runs of Premature Atrial Complexes in Ischemic Stroke Patients.

BACKGROUND AND PURPOSE: Runs of premature atrial complexes (PACs) are common in stroke patients and perceived to be clinically insignificant, but their prognostic significance is unclear. This study investigated the association between runs of PACs in ischemic stroke patients and the risk of recurrent ischemic strokes/transient ischemic attacks (TIAs) or death. METHODS: The study included consecutive patients admitted with an ischemic stroke from August 2008 to April 2011. Patients with known and newly detected atrial fibrillation were excluded. Runs of PACs were defined as 3 or more PACs lasting less than 30 seconds during 48 hours of continuous inpatient cardiac telemetry. The patients were followed for 4 years or until death, whichever came first. They were stratified according to stroke severity. The combined primary endpoint was a recurrent ischemic stroke/TIA or death. RESULTS: Of the 565 patients included in the study, 28% had runs of PACs. Patients with runs of PACs were likely to be older, female, and to have experienced more severe strokes. During the follow-up, 210 (37%) patients had a recurrent ischemic stroke/TIA (n = 73) or died (n = 137) respectively. Among the 489 patients who had mild-to-moderate strokes, runs of PACs were associated with recurrent ischemic strokes/TIAs or death (hazard ratio = 1.47; 95% CI 1.06-2.04; P = .023). CONCLUSION: Runs of PACs were frequent in patients with acute ischemic strokes and sinus rhythm, and they were independently associated with an increased risk of recurrent ischemic strokes/TIAs or death in patients with mild-to-moderate strokes.

Ambulatory cardiac arrhythmias in relation to mild hypokalaemia and prognosis in community dwelling middle-aged and elderly subjects.

AIMS: Severe hypokalaemia can aggravate arrhythmia tendency and prognosis, but less is known about risk of mild hypokalaemia, which is a frequent finding. We examined the associations between mild hypokalaemia and ambulatory cardiac arrhythmias and their prognosis. METHODS AND RESULTS: Subjects from the cohort of the 'Copenhagen Holter Study' (n = 671), with no history of manifest cardiovascular (CV) disease or stroke, were studied. All had laboratory tests and 48-h ambulatory electrocardiogram (ECG) recording. The median follow-up was 6.3 years. p-Potassium was inversely associated with frequency of premature ventricular complexes (PVCs) especially in combination with diuretic treatment (r = -0.22, P = 0.015). Hypokalaemia was not associated with supraventricular arrhythmias. Subjects at lowest quintile of p-potassium (mean 3.42, range 2.7-3.6 mmol/L) were defined as hypokalaemic. Cardiovascular mortality was higher in the hypokalaemic group (hazard ratio and 95% confidence intervals: 2.62 (1.11-6.18) after relevant adjustments). Hypokalaemia in combination with excessive PVC worsened the prognosis synergistically; event rates: 83 per 1000 patient-year in subjects with both abnormalities, 10 and 15 per 1000 patient-year in those with one abnormality, and 3 per 1000 patient-year in subjects with no abnormality. One variable combining hypokalaemia with excessive supraventricular arrhythmias gave similar results in univariate analysis, but not after multivariate adjustments. CONCLUSION: In middle-aged and elderly subjects with no manifest heart disease, mild hypokalaemia is associated with increased rate of ventricular but not supraventricular arrhythmias. Hypokalaemia interacts synergistically with increased ventricular ectopy to increase the risk of adverse events.

Prognostic Significance of Premature Atrial Complexes Burden in Prediction of Long-Term Outcome.

BACKGROUND: The prognostic significance of premature atrial complex (PAC) burden is not fully elucidated. We aimed to investigate the relationship between the burden of PACs and long-term outcome. METHODS AND RESULTS: We investigated the clinical characteristics of 5371 consecutive patients without atrial fibrillation (AF) or a permanent pacemaker (PPM) at baseline who underwent 24-hour electrocardiography monitoring between January 1, 2002, and December 31, 2004. Clinical event data were retrieved from the Bureau of National Health Insurance of Taiwan. During a mean follow-up duration of 10±1 years, there were 1209 deaths, 1166 cardiovascular-related hospitalizations, 3104 hospitalizations for any reason, 418 cases of new-onset AF, and 132 PPM implantations. The optimal cut-off of PAC burden for predicting mortality was 76 beats per day, with a sensitivity of 63.1% and a specificity of 63.5%. In multivariate analysis, a PAC burden >76 beats per day was an independent predictor of mortality (hazard ratio: 1.384, 95% CI: 1.230 to 1.558), cardiovascular hospitalization (hazard ratio: 1.284, 95% CI: 1.137 to 1.451), new-onset AF (hazard ratio: 1.757, 95% CI: 1.427 to 2.163), and PPM implantation (hazard ratio: 2.821, 95% CI: 1.898 to 4.192). Patients with frequent PAC had increased risk of mortality attributable to myocardial infarction, heart failure, and sudden cardiac death. Frequent PACs increased risk of PPM implantation owing to sick sinus syndrome, high-degree atrioventricular block, and/or AF. CONCLUSIONS: The burden of PACs is independently associated with mortality, cardiovascular hospitalization, new-onset AF, and PPM implantation in the long term.

Long-term Prognosis of Paroxysmal Atrial Fibrillation and Predictors for Progression to Persistnt or Chronic Atrial Fibrillation in the Korean Population.

Little is known about the long-term prognosis of or predictors for the different clinical types of atrial fibrillation (AF) in Korean populations. The aim of this study was to validate a risk stratification to assess the probability of AF progression from paroxysmal AF (PAF) to persistent AF (PeAF) or permanent AF. A total of 434 patients with PAF were consecutively enrolled (mean age; 71.7 ± 10.7 yr, 60.6% male). PeAF was defined as episodes that are sustained > 7 days and not self-terminating, while permanent AF was defined as an ongoing long-term episode. Atrial arrhythmia during follow-up was defined as atrial premature complex, atrial tachycardia, and atrial flutter. During a mean follow-up of 72.7 ± 58.3 months, 168 patients (38.7%) with PAF progressed to PeAF or permanent AF. The mean annual AF progression was 10.7% per year. In univariate analysis, age at diagnosis, body mass index, atrial arrhythmia during follow-up, left ventricular ejection fraction, concentric left ventricular hypertrophy, left atrial diameter (LAD), and severe mitral regurgitation (MR) were significantly associated with AF progression. In multivariate analysis, age at diagnosis (P = 0.009), atrial arrhythmia during follow-up (P = 0.015), LAD (P = 0.002) and MR grade (P = 0.026) were independent risk factors for AF progression. Patients with younger age at diagnosis, atrial arrhythmia during follow-up, larger left atrial chamber size, and severe MR grade are more likely to progress to PeAF or permanent AF, suggesting more intensive medical therapy with close clinical follow-up would be required in those patients.

Prognostic impact of supraventricular premature complexes in community-based health checkups: the Ibaraki Prefectural Health Study.

AIMS: The long-term prognosis of subjects with supraventricular premature complexes (SVPCs) remains unclear in the general population. The aim of this study was to examine the prognostic significance of SVPCs in community-based health checkups. METHODS AND RESULTS: We assessed 63 197 individuals (mean age, 58.8 ± 9.9 years; 67.6% women) who participated in annual community-based health checkups in 1993 and were followed until 2008. The primary endpoint was stroke death, cardiovascular death (CVD), or all-cause death during a 14-year mean follow-up, and the secondary endpoint was first atrial fibrillation (AF) event in subjects without self-reported heart diseases or AF at baseline. Compared with subjects without SVPCs, the multivariate-adjusted hazard ratios (HRs) [95% confidence interval (CI)] of stroke death, CVD, and all-cause death in subjects with SVPCs were 1.24 (0.98-1.56) for men and 1.63 (1.30-2.05) for women, 1.22 (1.04-1.44) for men and 1.48 (1.25-1.74) for women, and 1.08 (0.99-1.18) for men and 1.21 (1.09-1.34) for women, respectively. Atrial fibrillation occurred in 386 subjects during the follow-up (1.05/1000 person-years). The presence of SVPCs at baseline was the significant predictor of AF onset [HRs (95% CI): 4.87 (3.61-6.57) for men and 3.87 (2.69-5.57) for women]. Propensity score matched analyses also revealed the presence of SVPCs was significantly associated with increased risks of AF incidence and CVD even after adjusting the potential confounders. CONCLUSION: The presence of SVPCs in 12-lead electrocardiograms was a strong predictor of AF development, and associated with increased risk of CVD in general population.

Long-term mortality risk in individuals with atrial or ventricular premature complexes (results from the Third National Health and Nutrition Examination Survey).

Premature ectopic beats are frequently detected on routine 12-lead screening electrocardiograms (ECGs). However, their prognostic importance in subjects without known cardiovascular disease (CVD) is not well established. We evaluated prognostic value of atrial premature complexes (APCs) and ventricular premature complexes (VPCs) detected by a single 12-lead electrocardiography. A prospective cohort of 7,504 participants selected from nationally representative community-dwelling subjects living in the United States, enrolled in the Third National Health and Nutrition Examination Survey III from 1988 to 1994 with follow-up through December 2006 without known CVD. The main outcomes were all-cause mortality, CVD-related mortality, and ischemic heart disease (IHD)-related mortality. Of 7,504 participants (mean age 60 ± 14 years, 47% women, 49% whites), 89 (1.2%) had APCs and 110 (1.5%) had VPCs on 12-lead ECGs. During a follow-up of up to 18 years, 2,386 deaths occurred, of which 963 were due to CVD and 511 were due to IHD. In a multivariate analysis adjusted for demographics, clinical variables, and electrocardiographic measures, APCs were significantly associated with all-cause mortality (hazard ratio [HR] 1.41, 95% confidence interval [CI] 1.08 to 1.80), CVD death (HR 1.78, 95% CI 1.26 to 2.44), and IHD death (HR 2.40, 95% CI 1.59 to 3.47). For VPCs, however, there were no significant associations with all-cause mortality (HR 1.05, 95% CI 0.80 to 1.36), CVD death (HR 0.96, 95% CI 0.62 to 1.43), and IHD death (HR 0.89, 95% CI 0.47 to 1.52). In conclusion, APCs, but not VPCs, on routine screening ECGs are predictive of adverse events in community-dwelling subjects without known CVD.

Long-term outcome of healthy participants with atrial premature complex: a 15-year follow-up of the NIPPON DATA 90 cohort.

BACKGROUND: Atrial premature complexes (APC) are among the most frequently encountered electrocardiographic abnormalities. However, their prognostic value among healthy individuals is unclear. This study aimed to clarify the role of APC in predicting cardiovascular events in a large Japanese community cohort using long-term follow-up data. METHODS: National Integrated Project for Prospective Observation of Non-communicable Disease And its Trends in the Aged, 1990-2005, (NIPPON DATA 90) was a large cohort study of cardiovascular disease (CVD) in Japan. A total of 7692 otherwise healthy participants with no history of myocardial infarction, stroke, atrial fibrillation, or atrial flutter were enrolled (men, 41.5%; mean age, 52.5 ± 13.7 years). RESULTS: A total of 64 (0.8%) participants had at least one beat of APC on screening 12-lead electrocardiogram. During the follow-up of 14.0 ± 2.9 years (total, 107,474 patient-years), 338 deaths occurred due to CVD. The association between APC and CVD outcome was assessed using Cox proportional hazard models. Cox regression analysis revealed that the presence of APC was an independent predictor for CVD deaths (HR: 2.03, 95% CI: 1.12-3.66, P = 0.019). The association of APC on CVD death was more evident in participants with hypertension (P-value for interaction, 0.03). CONCLUSIONS: APC recorded during the screening electrocardiogram are significantly associated with an increased risk of CVD deaths in a Japanese community-dwelling population and are a strong prognostic factor for hypertensive participants.

Frequent premature atrial complexes predict new occurrence of atrial fibrillation and adverse cardiovascular events.

AIMS: To investigate the relation between baseline frequency of premature atrial complexes (PACs) and new atrial fibrillation (AF) and adverse cardiovascular events. METHOD AND RESULTS: Four hundred and twenty-eight patients without AF or structural heart disease undergoing 24 h electrocardiography monitoring for palpitations, dizziness, or syncope were recruited. One hundred and seven patients with number of PACs at the top quartile (i.e. > 100PACs/day) were defined to have frequent PACs. After 6.1-year follow-up, 31 patients (29%) with frequent PACs developed AF compared with 29 patients (9%) with PACs ≤ 100/day (P< 0.01). Cox regression analysis revealed that frequent PACs [hazard ratio (HR): 3.22 (95% confidence interval (CI): 1.9-5.5; P< 0.001)], age >75 years (HR: 2.3; 95% CI: 1.3-3.9; P= 0.004), and coronary artery disease (HR: 2.5; 95% CI: 1.4-4.4; P= 0.002) were independent predictors for new AF. Concerning the composite endpoint (ischaemic stroke, heart failure, and death), patients with frequent PACs were more at risk than those without (34.5 vs. 19.3%) (HR: 1.95; 95% CI: 1.37-3.50; P= 0.001). Cox regression analysis showed that age >75 years (HR: 2.2; 95% CI: 1.47-3.41; P< 0.001), coronary artery disease (HR: 2.2, 95% CI: 1.42-3.44, P< 0.001), and frequent PACs (HR: 1.6; 95% CI: 1.04-2.44; P= 0.03) were independent predictors for the secondary composite endpoint. CONCLUSION: Frequent PACs predict new AF and adverse cardiovascular events.

Relation of atrial and/or ventricular premature complexes on a two-minute rhythm strip to the risk of sudden cardiac death (the Atherosclerosis Risk in Communities [ARIC] study).

Ventricular premature complexes (VPCs) and atrial premature complexes (APCs) are common findings on routinely obtained electrocardiograms. Despite their common occurrence, the significance of these irregular beats is unclear, especially with regard to risk of sudden cardiac death (SCD). In this study, we examined the prospective relation between baseline VPCs or APCs and SCD, myocardial infarction, and fatal coronary heart disease (CHD) in a population-based sample of subjects from the Atherosclerosis Risk in Communities (ARIC) study excluding participants with known history of CHD or stroke. Baseline examination was conducted from 1987 to 1989, with follow-up data regarding clinical cardiac events collected until December 2002. The total study population was 14,574 subjects. Kaplan-Meier curves and computed univariate and multivariate Cox proportional hazard models were employed to estimate the effect of VPC and APC occurrences on incident cardiac events. During the follow-up period, there were 130 incident cases of SCD, 1,657 incident cases of CHD cases, and 288 cases of fatal CHD. Participants with VPC were 2 times as likely to have SCD (hazard ratio [HR] 2.09, 95% confidence interval [CI] 1.22 to 3.56) compared to those without VPC. Presence of APC was not significantly associated with SCD (HR 1.15, 95% CI 0.56 to 2.39). Compared to subjects without VPC and APC, risk of SCD in subjects with VPC and APC was significantly increased (HR 6.39, 95% CI 2.58 to 15.84). In conclusion, our study shows that subjects with VPCs are significantly more likely to die from SCD, despite not having any known history of cardiovascular disease. This effect appears to be additive when APCs occur concurrently.