Exercise-Induced Ventricular Ectopy and Cardiovascular Mortality in Asymptomatic Individuals.

BACKGROUND: The prognosis of exercise-induced premature ventricular contractions (PVCs) in asymptomatic individuals is unclear. OBJECTIVES: This study sought to investigate whether high-grade PVCs during stress testing predict mortality in asymptomatic individuals. METHODS: A cohort of 5,486 asymptomatic individuals who took part in the Lipid Research Clinics prospective cohort had baseline interview, physical examination, blood tests, and underwent Bruce protocol treadmill testing. Adjusted Cox survival models evaluated the association of exercise-induced high-grade PVCs (defined as either frequent (>10 per minute), multifocal, R-on-T type, or ≥2 PVCs in a row) with all-cause and cardiovascular mortality. RESULTS: Mean baseline age was 45.4 ± 10.8 years; 42% were women. During a mean follow-up of 20.2 ± 3.9 years, 840 deaths occurred, including 311 cardiovascular deaths. High-grade PVCs occurred during exercise in 1.8% of individuals, during recovery in 2.4%, and during both in 0.8%. After adjusting for age, sex, diabetes, hypertension, lipids, smoking, body mass index, and family history of premature coronary disease, high-grade PVCs during recovery were associated with cardiovascular mortality (hazard ratio [HR]: 1.82; 95% CI: 1.19-2.79; P = 0.006), which remained significant after further adjusting for exercise duration, heart rate recovery, achieving target heart rate, and ST-segment depression (HR: 1.68; 95% CI: 1.09-2.60; P = 0.020). Results were similar by clinical subgroups. High-grade PVCs occurring during the exercise phase were not associated with increased risk. Recovery PVCs did not improve 20-year cardiovascular mortality risk discrimination beyond clinical variables. CONCLUSIONS: High-grade PVCs occurring during recovery were associated with long-term risk of cardiovascular mortality in asymptomatic individuals, whereas PVCs occurring only during exercise were not associated with increased risk.

Diagnostic and prognostic significance of premature ventricular complexes in community and hospital-based participants: A scoping review.

BACKGROUND: While there are published studies that have examined premature ventricular complexes (PVCs) among patients with and without cardiac disease, there has not been a comprehensive review of the literature examining the diagnostic and prognostic significance of PVCs. This could help guide both community and hospital-based research and clinical practice. METHODS: Scoping review frameworks by Arksey and O'Malley and the Joanna Briggs Institute (JBI) were used. A systematic search of the literature using four databases (CINAHL, Embase, PubMed, and Web of Science) was conducted. The review was prepared adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis Extension for Scoping Review (PRISMA-ScR). RESULTS: A total of 71 relevant articles were identified, 66 (93%) were observational, and five (7%) were secondary analyses from randomized clinical trials. Three studies (4%) examined the diagnostic importance of PVC origin (left/right ventricle) and QRS morphology in the diagnosis of acute myocardial ischemia (MI). The majority of the studies examined prognostic outcomes including left ventricular dysfunction, heart failure, arrhythmias, ischemic heart diseases, and mortality by PVCs frequency, burden, and QRS morphology. CONCLUSIONS: Very few studies have evaluated the diagnostic significance of PVCs and all are decades old. No hospital setting only studies were identified. Community-based longitudinal studies, which make up most of the literature, show that PVCs are associated with structural and coronary heart disease, lethal arrhythmias, atrial fibrillation, stroke, all-cause and cardiac mortality. However, a causal association between PVCs and these outcomes cannot be established due to the purely observational study designs employed.

Prognosis After Finding Incidental Ventricular Tachycardia on Ambulatory Electrocardiogram-recording.

The prognostic significance of incidental non-sustained ventricular tachycardia (NSVT) in subjects without apparent heart disease is unknown. We aimed to evaluate short- and long-term prognosis of NSVT in the Copenhagen Holter Study cohort. From the study, 678 middle-aged and elderly subjects had minimum 48 hours of Holter-recording, laboratory testing and physician-based examination and questionnaire performed. Median follow-up time was 14.7 years. NSVT was defined as runs of minimum three premature ventricular complexes. The primary end-point was a combination of cardiovascular mortality, acute myocardial infarction, coronary revascularization or stroke. Secondary endpoints were all-cause mortality and components of the primary end-point. We found that 72 (10.6%) had minimum one NSVT event on 48-hour Holter-recording. The primary end-point occurred more frequently in patients with NSVT than those without: 38.3 versus 17.7 events per 1,000 patient-years, hazard ratio 2.1, 95% CI 1.37 to 3.20 after adjustment for risk factors. Secondary end-points also occurred more frequently in the NSVT-group. A shorter-term follow-up revealed similar event rates for the primary outcome; 47.5 versus 21.2 events per 1,000 patient-years, hazard ratio 1.9, 95% CI 0.69 to 5.24. Besides stroke other secondary end-points occurred more frequently in the short-term follow-up. The prognosis in subjects with NSVT was not dependent of the length of the VT. In conclusion, incidental asymptomatic NSVT on Holter-recording in subjects without apparent or manifest structural heart disease is associated with increased risk of mortality and cardiovascular events, however the increased risk is not imminent but with a slow and steady pace over time.

Prevalence, correlates, and mortality impacts of ventricular arrhythmia among older men and women: a population-based cohort study in Moscow.

BACKGROUND: In Russia, cardiovascular disease (CVD) mortality is high and the mortality gap between men and women is large. Conventional risk factors cannot explain these phenomena. Ventricular arrhythmia (VA) is an important contributor to the death toll in community-based populations. The study examines the prevalence and the mortality impacts of VA in men and women and the role of VA in the male mortality excess at older ages. METHODS: This is a secondary analysis of data from the Stress, Aging, and Health in Russia (SAHR) study that was fielded in 2007-9 in Moscow (1800 individuals, mean age 68.8 years), with mean mortality follow-up of 7.4 years (416 deaths, 248 CVD deaths). Indicators reflecting the frequency and the complexity of VA were derived from 24-h ambulatory ECG recordings. Other covariates were: socio-demographic characteristics, conventional risk factors, markers of inflammation, reported myocardial infarction, and stroke. The impacts of VA and other variables on CVD and all-cause mortality among men and women were estimated with the proportional hazard models. We assessed the contributions of VAs to the male-female mortality gap using hazard models that do and do not include groups of the predictors. Logistic models were used to assess the associations between VA and other biomarkers. RESULTS: VAs were about twice as prevalent among men as among women. In both sexes, they were significantly associated with CVD and all-cause mortality independently of conventional risk factors. The highest hazard ratios (HRs) for CVD death were found for the runs of ventricular premature complexes (VPCs) HR = 2.45, 95% CI 1.63-3.68 for men and 2.75, 95% CI 1.18-6.40 for women. The mortality impacts of the polymorphic VPCs were significant among men only (HR = 1.50, 95% CI 1.08-2.07). VA indicators can potentially explain 12.3% and 9.1% of the male-female gaps in mortality from CVD and all causes, respectively. VAs were associated with ECG-registered ischemic problems and reported MI, particularly among men. CONCLUSIONS: VA indicators predicted mortality in older Muscovites independently of other risk factors, and have the potential to explain a non-trivial share of the excess male mortality. The latter may be related to more severe coronary problems in men compared to women.

Electrical Substrate Ablation for Refractory Ventricular Fibrillation: Results of the AVATAR Study.

[Figure: see text].

J-Wave Elevation in the Inferior Leads Predicts Lethal Ventricular Arrhythmia Initiated by Premature Ventricular Contractions With Right Bundle Branch Block and Superior Axis.

BACKGROUND: Lethal ventricular arrhythmia (VA) can be initiated by idiopathic premature ventricular contractions (PVCs) originating from the left ventricular (LV) inferior wall. Furthermore, J-wave elevation in the inferior leads on ECG is sometimes associated with lethal VA. However, the relationship between these PVCs and J-wave elevation in patients with lethal VA is unclear, so we investigated it in the present study.Methods and Results:We studied 32 consecutive patients who underwent radiofrequency (RF) ablation of idiopathic PVCs with right bundle branch block (RBBB) and superior axis. Thee PVCs were originating from the inferior wall of the LV. Lethal VA was defined as ventricular fibrillation (VF) or ventricular tachycardia (VT) with loss of consciousness (LOC). Among 32 patients, 3 had VF and 2 had VT with LOC. Other 27 had non-lethal VA. Baseline clinical characteristics were not significantly difference between lethal and non-lethal VA. The ratio of J-wave elevation in lethal VA was significantly higher as compared with non-lethal VA (100% vs. 11.1%, P<0.0001). Furthermore, no patients with J-wave elevation in the inferior leads had recurrence of lethal VA after RF ablation of the PVCs. CONCLUSIONS: We speculate that J-wave elevation in the inferior leads might be a predictor of lethal VA initiated by PVCs with RBBB and superior axis. RF ablation of these PVCs was a useful method of treating lethal VA.

Mortality and morbidity reduction after frequent premature ventricular complexes ablation in patients with left ventricular systolic dysfunction.

AIMS: Ablation of frequent premature ventricular complexes (PVCs) improves left ventricular ejection fraction in patients with left ventricular (LV) systolic dysfunction. This study aims to evaluate the long-term hard outcomes and potential prognostic variables in this population. METHODS AND RESULTS: Prospective multicentre study including 101 consecutive patients [56 ± 12 years old, 62 (61%) men] with LV systolic dysfunction and frequent PVCs who underwent PVC ablation before November 2015. The last evaluation performed was considered the long-term follow-up (LTFUP) evaluation. Mean follow-up was 34 ± 16 months (range 24-84 months). Ablation was successful in 95 (94%) patients. There was a significant reduction in the PVC burden from 21 ± 12% at baseline to 3.8 ± 6% at LTFUP, P < 0.001. Left ventricular ejection fraction improved from 32 ± 8% at baseline to 39 ± 12% at LTFUP (P < 0.001) and New York Heart Association class from 2.2 ± 0.6% to 1.3 ± 0.6% (P < 0.001). Brain natriuretic peptide levels decreased from 136 (78-321) to 68 (32-144) pg/mL (P = 0.007). Most of this improvement occurs during the first 6 months after ablation. Persistent abolition of at least 18 points of the baseline PVC burden was independently and inversely associated with the composite endpoint of cardiac mortality, cardiac transplantation, or hospitalization for heart failure during follow-up [hazard ratio 0.18 (0.05-0.66), P = 0.01]. CONCLUSION: In patients with LV systolic dysfunction, ablation of frequent PVCs induces a significant improvement in functional, structural, and neurohormonal status, which persists at LTFUP. A sustained reduction in the baseline PVC burden is associated with a lower risk of cardiac mortality, cardiac transplantation, or hospitalization for heart failure during follow-up.

Combining noninvasive risk stratification parameters improves the prediction of mortality and appropriate ICD shocks.

BACKGROUND: Sudden cardiac death (SCD) results from a complex interplay of abnormalities in autonomic function, myocardial substrate and vulnerability. We studied whether a combination of noninvasive risk stratification tests reflecting these key players could improve risk stratification. METHODS: Patients implanted with an ICD in whom 24-hr holter recordings were available prior to implant were included. QRS fragmentation (fQRS) was selected as measure of myocardial substrate and a high ventricular premature beat count (VPB >10/hr) for arrhythmic vulnerability. From receiver operating characteristics analysis, detrended fluctuation analysis (DFA), turbulence slope, and deceleration capacity were selected for autonomic function. Adjusted Cox regression analysis with comparison of C-statistics was performed to predict first appropriate shock (AS) and total mortality. RESULTS: A total of 220 patients were included in the analysis with an overall follow-up of 4.3 ± 3.1 years. A model including VPB >10/hr, inferior fQRS, and abnormal nonedited DFA was the best for prediction of AS after 1 year of follow-up with a trends toward improvement of the C-statistics compared to baseline (p = 0.055). The risk increased significantly with every abnormal test (HR 1.793, 95%CI 1.255-2.564). A model including fQRS in any region and abnormal edited DFA was the best for prediction of mortality after 3 years of follow-up with significant improvement of the C-statistics (p = 0.023). Each abnormal test was associated with a significant increase in mortality (HR 5.069, 95%CI 1.978-12.994). CONCLUSION: Combining noninvasive risk stratification tests according to their physiological background can improve the risk prediction of SCD and mortality.

The safety of catheter ablation for premature ventricular contractions in patients without structural heart disease.

BACKGROUND: Patients with frequent premature ventricular contractions (PVCs) are often symptomatic. Catheter ablation was usually indicated to eliminate symptoms in patients with PVCs-induced cardiomyopathy. Currently, PVCs-ablation is also applied for patients with PVCs and no structural heart diseases (SHD); however, the safety and efficacy of ablation in these patients remains unclear. METHODS: In this retrospective study, data from patients who underwent ablation for PVCs from January 2010 to December 2016 at our hospital was retrieved. Predictors of complications and acute procedural success were evaluated. RESULTS: A total of 1231 patients (mean age 47.8 ± 16.8 years, 59% female) were included. The overall complication rate was 2.7%, and the most common complication was hydropericardium. Two ablation-related mortalities occurred. One patient died of coronary artery injury during the procedure and the other died from infectious endocarditis. Location (left ventricle and epicardium) was the main predictor of complications, with right ventricular outflow tract (RVOT) predicting fewer complications. The acute procedural success rate was 94.1% in all patients. The main predictor of acute procedural success was RVOT origin, while an epicardial origin was a predictor of procedural failure. CONCLUSION: Locations of left ventricle and epicardium were predictors of procedural complications for patients with PVCs. Therefore, ablation is not recommended in these patients. For other origins of PVCs, particularly RVOT origin, ablation is a safety and effective treatment.

Comparison of Complications of Catheter Ablation for Ventricular Arrhythmias in Adults With Versus Without Structural Heart Disease.

Catheter ablation (CA) is an effective treatment for ventricular arrhythmias (VA), with a potential for complications. The presence of structural heart disease (SHD) is associated with a higher complication rate although there is no data comparing CA of VA between patients with SHD and those without. We aimed to compare trends, morbidity, and mortality associated with real world practice of CA for VA (ventricular tachycardia and premature ventricular contraction) based on the presence of SHD. Using weighted sampling in the National Inpatient Sample database, we collected and compared characteristics and outcomes of patients with or without SHD that underwent CA of VA. Among 34,907 patients that underwent CA for VA (1999-2013), 18,014 (51.6%) had SHD. Major and all complications occurred among 1,135/18,014 (6.3%) and 2139/18,014 (11.9%) patients with SHD respectively compared with 355/16,893 (2.1%) and 739/16,893 (4.4%) for patients without SHD, p < 0.001 for both comparisons. Furthermore, 452/18,014 (2.51%) with SHD died versus 20/16,893 (0.12%) without SHD, p < 0.001. Heart failure was associated with an odds ratio (OR) of 3.09 for major complications (95%CI: 1.53-6.27, p = 0.002) for patients with SHD while coronary artery disease OR for major complications was 2.47 (95%CI: 1.44-4.23, p = 0.001) for patients without SHD. There was a significant increase in major complications over the 15-year study period in patients with SHD, p < 0.001. In conclusion, the presence of SHD during CA for VA increased the complication rate of major and any complications by approximately threefold for both and the hospital mortality by >20-fold compared with patients without SHD.

Myocardial bridging is associated with exercise-induced ventricular arrhythmia and increases in QT dispersion.

BACKGROUND: A myocardial bridge (MB) has been associated with ventricular arrhythmia and sudden death during exercise. QT dispersion (QTd) is a measure of abnormal repolarization and may predict ventricular arrhythmia. We investigated the frequency of ventricular arrhythmias during exercise and the QTd at rest and after exercise, in patients with an MB compared to a normal cohort. METHODS: We studied the rest and stress ECG tracings of patients with an MB suspected by focal septal buckling on exercise echocardiography (EE) (Echo-MB group, N = 510), those with an MB confirmed by another examination (MB group, N = 110), and healthy controls (Control group, N = 198). RESULTS: The frequency of exercise-induced premature ventricular contractions (PVCs) was significantly higher in the Echo-MB and MB groups compared with the Control group (both p < .001). In all, 25 patients (4.9%) in the Echo-MB group, seven patients (6.4%) in the MB group and no patients in the Control group had exercise-induced non-sustained ventricular tachycardia (NSVT). There was no difference in the baseline QTd between the groups. In the Echo-MB and MB groups, QTd postexercise increased significantly when compared with baseline (both p < .001). Patients with NSVT had a higher frequency of male gender and an even greater increase in QTd with exercise compared with the non-NSVT group. DISCUSSION: There is an increased frequency of exercise-induced PVCs and NSVT in patients with MBs. Exercise significantly increases QTd in MB patients, with an even greater increase in QTd in MB patients with NSVT. Exercise in MB patients results in ventricular arrhythmias and abnormalities in repolarization.

Long-term prognostic significance of right bundle-branch morphology ventricular ectopy induced during stress test in patients with intermediate to high probability of coronary artery disease.

Aims: Stress-induced right bundle-branch block morphology ventricular ectopy (SI-RBVE) may be caused by left ventricular myocardial anomalies. While frequent ventricular ectopy (FVE) has been linked to poor outcomes, the prognostic value of SI-RBVE has not been established. The study aims to determine whether SI-RBVE is associated with increased mortality. Methods and results: Three hundred forty-three patients with an intermediate to high probability of coronary artery disease were prospectively included. Patients were referred for a single-photon emission computed tomography and underwent a stress test according to standard protocols. Stress-induced right bundle-branch block morphology ventricular ectopy (VE) was defined as one or more induced premature beats with positive predominance in V1. Frequent VE was defined as the presence of seven or more ventricular premature beats per minute or any organized ventricular arrhythmia. During a mean follow-up of 4.5 ± 1.3 years, 59 deaths occurred. The death rate was higher in the SI-RBVE group (23.4% vs. 14.0%, P = 0.021). Age [odds ratio (OR) = 1.09 (95% CI: 1.06-1.13), P < 0.001] and peripheral artery disease [OR = 2.47 (95% CI: 1.35-4.50) P = 0.003] were independent factors of mortality, but single-photon emission computed tomography findings were not. There was an interaction between SI-RBVE and left ventricular ejection fraction (LVEF). In patients with LVEF > 50%, SI-RBVE was an incremental risk factor for mortality [OR = 2.83 (95% CI: 1.40-5.74), P = 0.004]. Stress-induced right bundle-branch block morphology VE patients also presented higher rates of known coronary artery disease, ischaemia, scar, and ST-segment changes. Frequent VE was not related to mortality. Conclusion: Stress-induced right bundle-branch block morphology VE is associated with an increased mortality in patients with preserved LVEF.

Systematic Review for the 2017 AHA/ACC/HRS Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society.

BACKGROUND: Although large randomized clinical trials have found that primary prevention use of an implantable cardioverter-defibrillator (ICD) improves survival in patients with cardiomyopathy and heart failure symptoms, patients who receive ICDs in practice are often older and have more comorbidities than patients who were enrolled in the clinical trials. In addition, there is a debate among clinicians on the usefulness of electrophysiological study for risk stratification of asymptomatic patients with Brugada syndrome. AIM: Our analysis has 2 objectives. First, to evaluate whether ventricular arrhythmias (VAs) induced with programmed electrostimulation in asymptomatic patients with Brugada syndrome identify a higher risk group that may require additional testing or therapies. Second, to evaluate whether implantation of an ICD is associated with a clinical benefit in older patients and patients with comorbidities who would otherwise benefit on the basis of left ventricular ejection fraction and heart failure symptoms. METHODS: Traditional statistical approaches were used to address 1) whether programmed ventricular stimulation identifies a higher-risk group in asymptomatic patients with Brugada syndrome and 2) whether ICD implantation for primary prevention is associated with improved outcomes in older patients (>75 years of age) and patients with significant comorbidities who would otherwise meet criteria for ICD implantation on the basis of symptoms or left ventricular function. RESULTS: Evidence from 6 studies of 1138 asymptomatic patients were identified. Brugada syndrome with inducible VA on electrophysiological study was identified in 390 (34.3%) patients. To minimize patient overlap, the primary analysis used 5 of the 6 studies and found an odds ratio of 2.3 (95% CI: 0.63-8.66; P=0.2) for major arrhythmic events (sustained VAs, sudden cardiac death, or appropriate ICD therapy) in asymptomatic patients with Brugada syndrome and inducible VA on electrophysiological study versus those without inducible VA. Ten studies were reviewed that evaluated ICD use in older patients and 4 studies that evaluated unique patient populations were identified. In our analysis, ICD implantation was associated with improved survival (overall hazard ratio: 0.75; 95% confidence interval: 0.67-0.83; P<0.001). Ten studies were identified that evaluated ICD use in patients with various comorbidities including renal disease, chronic obstructive pulmonary disease, atrial fibrillation, heart disease, and others. A random effects model demonstrated that ICD use was associated with reduced all-cause mortality (overall hazard ratio: 0.72; 95% confidence interval: 0.65-0.79; P<0.0001), and a second "minimal overlap" analysis also found that ICD use was associated with reduced all-cause mortality (overall hazard ratio: 0.71; 95% confidence interval: 0.61-0.82; P<0.0001). In 5 studies that included data on renal dysfunction, ICD implantation was associated with reduced all-cause mortality (overall hazard ratio: 0.71; 95% confidence interval: 0.60-0.85; P<0.001).

Idiopathic malignant premature ventricular contractions.

The presence of premature ventricular contractions (PVCs) in patients with structurally normal hearts was once considered a benign phenomenon. However, in susceptible patients, these "benign" or idiopathic PVCs may develop malignant potential and trigger ventricular fibrillation and result in sudden cardiac death. Alternatively, idiopathic PVCs can also induce cardiomyopathy. Clinical recognition of these entities can lead to effective targeted therapy. In the first instance, treatment consists of ablating the PVC source and implanting a defibrillator, whereas in the second scenario, ablating the PVC origin can normalize left ventricular function.

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.

Prognostic indices among hypertensive heart failure patients in Nigeria: the roles of 24-hour Holter electrocardiography and 6-minute walk test.

BACKGROUND: Hypertensive heart failure (HHF) is associated with a poor prognosis. There is paucity of data in Nigeria on prognosis among HHF patients elucidating the role of 24-hour Holter electrocardiogram (ECG) in concert with other risk factors. OBJECTIVE: The aim of this study was to determine the prognostic utility of 24-hour Holter ECG, the 6-minute walk test (6-MWT), echocardiography, clinical and laboratory parameters among HHF patients. METHODS: A total of 113 HHF patients were recruited and followed up for 6 months. Thirteen of these patients were lost to follow-up, and as a result only 100 HHF patients were analyzed. All the patients underwent baseline laboratory tests, echocardiography, 24-hour Holter ECG and the 6-MWT. HHF patients were analyzed as "mortality vs alive" and as "events vs no-events" based on the outcome at the end of 6 months. Events was defined as HHF patients who were rehospitalized for heart failure (HF), had prolonged hospital stay or died. No-events group was defined as HHF patients who did not meet the criteria for the events group. RESULTS: HHF patients in the mortality group (n = 7) had significantly higher serum urea (5.71 ± 2.07 mmol/L vs 3.93 ± 1.45 mmol/L, p = 0.003) than that in those alive. After logistic regression, high serum urea conferred increased mortality risk (p = 0.035). Significant premature ventricular complexes (PVCs) on 24-hour Holter ECG following logistic regression were also significantly higher (p = 0.015) in the mortality group than in the "alive" group (n = 93) at the end of the 6-month follow-up period. The 6-minute walk distance (6-MWD) was least among the HHF patients who died (167.26 m ± 85.24 m). However, following logistic regression, the 6-MWT was not significant (p = 0.777) for predicting adverse outcomes among HHF patients. Patients in the events group (n = 41) had significantly higher New York Heart Association (NYHA) class (p = 0.001), Holter-detected ventricular tachycardia (VT; p = 0.009), Holter-detected atrial fibrillation (AF; p = 0.028) and PVCs (p = 0.017) following logistic regression than those in the no-events group (n = 59). CONCLUSION: High NYHA class, elevated serum urea, Holter ECG-detected AF and ventricular arrhythmias are predictive of a poor outcome among HHF patients. The 6-MWT was not a useful prognostic index in this study.