Heart rate and premature atrial contractions at 24hECG independently predict atrial fibrillation in a population-based study.

BACKGROUND: Low resting heart rate and premature atrial contractions (PACs) predict incident atrial fibrillation (AF) and could be interdependent, since PACs occur in the gaps between normal beats. OBJECTIVE: To study the association between low heart rate at 24hECG, PACs and incident AF in a prospective population-based cohort. METHODS: In the Malmö Diet and Cancer study, 24hECGs were performed in 377 AF-free subjects. The endpoint was clinical AF retrieved from national hospital (mean follow-up 17 years). The interaction between increased supraventricular activity (SVA) top quartile of either PACs/hour or supraventricular tachycardias/hour) and mean heart rate (mHR) as regards AF risk was assessed in multivariable Cox regression analyses adjusted for age, sex, height, BMI, systolic blood pressure, antihypertensive medication, smoking and homeostasis model assessment of insulin resistance. RESULTS: There were 80 (21%) incident cases of AF. Below median mHR (80 bpm/75 bpm for women/men) was associated with increased AF incidence (HR: 1.89, 95% CI 1.18 to 3.02, p=0.008). There was no correlation between mHR and SVA (p=0.6) or evidence of a multiplicative interaction between these factors for AF risk (p for interaction=0.6) In the group with both increased SVA and below median mHR (17% of the population) the relative risk of AF was very high (HR 4.5, 95% CI 2.2 to 9.1, p=0.001). CONCLUSION: Low mHR at 24hECG independently predicts AF, but there is no association between mHR and SVA, and these factors are independent as regards AF risk. Subjects with both low mHR and increased SVA have high AF risk.

Efficacy and safety of edoxaban compared with warfarin according to the burden of diseases in patients with atrial fibrillation: insights from the ENGAGE AF-TIMI 48 trial.

AIMS: Non-vitamin K antagonist oral anticoagulants represent a new option for prevention of embolic events in patients with atrial fibrillation (AF). However, little is known about the impact of non-cardiac comorbidities on the efficacy and safety profile of these drugs. METHODS AND RESULTS: In a post hoc analysis of the ENGAGE AF-TIMI 48 trial, we analysed 21 105 patients with AF followed for an average of 2.8 years and randomized to either a higher-dose edoxaban regimen (HDER), a lower-dose edoxaban regimen, or warfarin. We used the updated Charlson Comorbidity Index (CCI) to stratify the patients according to the burden of concomitant disease (CCI = 0, 1, 2, 3, and ≥4). The treatment groups were then compared for safety, efficacy, and net clinical outcomes across CCI categories. There were 32.0%, 7.3%, 42.1%, 12.7%, and 6.0% of patients with CCI scores of 0, 1, 2, 3, and ≥4, respectively. A CCI score ≥4 was associated with significantly higher rates of thromboembolic events, bleeding, and death compared to CCI = 0 (P < 0.05 for each). The annualized rates of the primary net clinical outcome (stroke/systemic embolism, major bleeding, or death) for CCI = 0, 1, 2, 3, or ≥4 were 5.9%, 8.7%, 6.6%, 10.3%, and 13.6% (Ptrend < 0.001). There were no significant interactions between treatment with HDER vs. warfarin and efficacy, safety, and net outcomes across the CCI groups (P-interaction > 0.10 for each). CONCLUSION: Although increasing CCI scores are associated with worse outcomes, the efficacy, safety, and net clinical outcomes of edoxaban vs. warfarin were independent of the degree of comorbidity present.

Irregularity and lack of p waves in short tachycardia episodes predict atrial fibrillation and ischemic stroke.

BACKGROUND: Atrial fibrillation (AF) is defined as an irregular supraventricular tachycardia (SVT) without p waves, with duration >30 seconds. Whether AF characteristics during short SVT episodes predict AF and stroke is not known. OBJECTIVE: The purpose of this study was to determine whether irregularity and lack of p waves, alone or in combination, during short SVT episodes increase the risk of incident AF and ischemic stroke. METHODS: The population-based Malmö Diet and Cancer study includes 24-hour ECG screening of 377 AF-free individuals (mean age 64.5 years; 43% men) who were prospectively followed for >13 years. There were 65 AF events and 25 ischemic stroke events during follow-up. Subjects with an SVT episode ≥5 beats were identified, and the longest SVT episode was assessed for irregularity and lack of p waves. The association between SVT classification and AF and stroke was assessed using multivariable adjusted Cox regression. RESULTS: The incidence of AF increased with increasing abnormality of the SVTs. The risk-factor adjusted hazard ratio for AF was 4.95 (95% confidence interval 2.06-11.9; P <.0001) for those with short irregular SVTs (<70 beats) without p waves. The incidence of ischemic stroke was highest in the group with regular SVT episodes without p waves (hazard ratio 14.2; 95% confidence interval 3.76-57.6; P <.0001, adjusted for age and sex). CONCLUSION: Characteristics of short SVT episodes detected at 24-hour ECG screening are associated with incident AF and ischemic stroke. Short irregular SVTs without p waves likely represent early stages of AF or atrial myopathy. Twenty-four-hour ECG could identify subjects suitable for primary prevention efforts.

ST segment depression on 24-hour electrocardiography predicts incident atrial fibrillation in two population-based cohorts.

Aims: ST-depression at 24hECG has not been studied in relation to atrial fibrillation (AF) risk. We aimed to determine whether ST-depression at 24hECG was associated with incident AF in two Swedish population-based cohorts - a sub-cohort of the Malmö Diet and Cancer study (MDCS), and the cohort 'Men born in 1914', and to determine whether 24hECG could be used to predict AF development. Methods and results: There were 378 acceptable 24hECG recordings in the MDCS (mean age 64.5 years, 43% men) and 394 acceptable recordings in 'Men born in 1914' (mean age 68.8 years). Incidence of AF was monitored using national registers of hospitalizations and outpatient visits in Sweden. Mean follow-up ± SD (cumulative incidence) was 10.4 ± 2 years (11.3%) in MDCS, and 10.9 ± 4 years (7.3%) in 'Men born in 1914'. ST-depressions were independently associated with incident AF; hazard ratio (HR) (95% CI) 2.41 (1.29-4.50, P = 0.006) and 2.28 (1.05-4.95, P = 0.038) after adjustment [age, sex, height, weight, systolic blood pressure, smoking, anti-hypertensive drugs, LDL/total cholesterol, and HOMA-IR (in MDCS)]. AF incidence was substantially lower in individuals who had neither ST-depressions or high supraventricular activity (SVA, negative predictive value 0.97 and 0.94, in MDCS and 'Men born in 1914', respectively), and similar in men and women. Conclusion: ST-depression at 24h-ECG is independently associated with incident AF, and incidence is substantially lower in individuals with neither ST-depression or high SVA. 24hECG can be used not only to diagnose AF but also to identify individuals at high and low AF risk.

Efficacy and Safety of Vernakalant for Cardioversion of Recent-onset Atrial Fibrillation in the Asia-Pacific Region: A Phase 3 Randomized Controlled Trial.

Atrial fibrillation (AF) is a common clinically significant cardiac arrhythmia. This phase 3 randomized, double-blind, placebo-controlled trial assessed the efficacy and safety of vernakalant hydrochloride for the pharmacological conversion of AF to sinus rhythm in patients with recent-onset (>3 hours to ≤7 days) symptomatic AF from the Asia-Pacific region. Patients received an infusion of vernakalant (3 mg/kg) or placebo for 10 minutes. If AF had not been terminated 15 minutes later, a second infusion of vernakalant (2 mg/kg) or placebo for 15 minutes was administered. The primary efficacy end point was conversion of AF to sinus rhythm for >1 minute within 90 minutes. The study was terminated early for administrative reasons; 123 patients from Korea, Taiwan, and India were randomized to receive vernakalant (n = 55) or placebo (n = 56). A greater proportion of patients who received vernakalant (52.7%) than placebo (12.5%) met the primary end point (P < 0.001), and cardioversion was faster in the vernakalant group than in the placebo group (P < 0.001). Vernakalant was generally well tolerated; the incidence of treatment-emergent adverse events was similar between the groups. We conclude that vernakalant is efficacious in the rapid cardioversion of recent-onset AF in patients from the Asia-Pacific region.

A roadmap to improve the quality of atrial fibrillation management: proceedings from the fifth Atrial Fibrillation Network/European Heart Rhythm Association consensus conference.

At least 30 million people worldwide carry a diagnosis of atrial fibrillation (AF), and many more suffer from undiagnosed, subclinical, or 'silent' AF. Atrial fibrillation-related cardiovascular mortality and morbidity, including cardiovascular deaths, heart failure, stroke, and hospitalizations, remain unacceptably high, even when evidence-based therapies such as anticoagulation and rate control are used. Furthermore, it is still necessary to define how best to prevent AF, largely due to a lack of clinical measures that would allow identification of treatable causes of AF in any given patient. Hence, there are important unmet clinical and research needs in the evaluation and management of AF patients. The ensuing needs and opportunities for improving the quality of AF care were discussed during the fifth Atrial Fibrillation Network/European Heart Rhythm Association consensus conference in Nice, France, on 22 and 23 January 2015. Here, we report the outcome of this conference, with a focus on (i) learning from our 'neighbours' to improve AF care, (ii) patient-centred approaches to AF management, (iii) structured care of AF patients, (iv) improving the quality of AF treatment, and (v) personalization of AF management. This report ends with a list of priorities for research in AF patients.

A prospective study of supraventricular activity and incidence of atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) episodes are thought to be started by an electrical trigger reaching susceptible atria. Such a trigger could be present long before the occurrence of sustained symptomatic arrhythmia. OBJECTIVE: We sought to determine whether supraventricular extrasystoles (SVESs) and supraventricular tachycardias (SVTs) measured at 24-hour Holter electrocardiogram were associated with an increased incidence of AF. METHODS: In 1998-2000, 389 individuals (44% men; mean age 65 years) were examined using 24-hour Holter electrocardiogram. Six individuals with known prevalent AF were excluded. After a mean follow-up of 10.3 years, there were 45 cases of incident AF. Hazard ratios (HRs) were computed using multivariable Cox regression adjusting for age, sex, systolic blood pressure, height, weight, smoking, and homeostatic model assessment of insulin resistance. RESULTS: Frequency of SVESs as well as SVT episodes per hour were independent predictors of incident AF (HR per log unit 1.38; 95% confidence interval 1.14-1.68; P = .001 and HR 1.95; 95% confidence interval 1.21-3.13; P = .006, respectively). Further adjustment for education level, alcohol use, use of medication, and physical activity did not substantially alter the results, nor did analysis using competing risks regression accounting for a competing risk of death. The maximum duration of SVT or the heart rate at SVT was not significantly associated with the incidence of AF. CONCLUSION: SVESs and SVTs independently predict AF. The prognostic significance was similar for SVESs, SVTs, and a combination of the two. Repeated efforts to detect AF could be of merit in individuals with frequent supraventricular activity.

Efficacy and safety of vernakalant in patients with atrial flutter: a randomized, double-blind, placebo-controlled trial.

AIMS: Vernakalant is a novel, relatively atrial-selective antiarrhythmic agent for conversion of atrial fibrillation (AF) to sinus rhythm. This study examined the safety and efficacy of vernakalant in converting atrial flutter (AFL) to sinus rhythm. METHODS AND RESULTS: This was a phase 2/3, randomized, double-blind, placebo-controlled trial. Adults with AFL received either a 10 min infusion of 3.0 mg/kg vernakalant (n = 39) or placebo (n = 15). If AFL or AF persisted at the end of a 15 min observation period, a second 10 min infusion of 2.0 mg/kg vernakalant or placebo was administered. The primary efficacy outcome was the proportion of patients who had treatment-induced conversion of AFL to sinus rhythm for a minimum duration of 1 min within 90 min after the start of the first infusion. No patient in the placebo group met the primary outcome. Only one patient receiving vernakalant (1 of 39, 3%) converted to sinus rhythm. A reduced mean absolute ventricular response rate occurred within 50 min in patients receiving vernakalant (mean change from baseline -8.2 b.p.m.) vs. patients receiving placebo (-0.2 b.p.m.) (P = 0.037). A post-hoc analysis revealed that vernakalant increased AFL cycle length by an average of 55 ms, whereas the AFL cycle length was unchanged in the placebo group (P < 0.001). There was no occurrence of 1 : 1 atrio-ventricular conduction. Dysgeusia and sneezing were the most common treatment-related adverse events, consistent with previous reports. CONCLUSION: Vernakalant did not restore sinus rhythm in patients with AFL. Vernakalant modestly slowed AFL and ventricular response rates, and was well tolerated.

Adrenergic and cardiac dysfunction in primary hyperparathyroidism.

OBJECTIVE: Primary hyperparathyroidism (PHPT) is associated with cardiovascular morbidity and premature death, but the underlying mechanisms are incompletely understood. The aim of this study was to investigate whether adrenergic dysfunction may be a contributing factor. PATIENTS AND METHODS: Forty-nine patients with mild PHPT (serum calcium 2·7 ± 0·1 mM) and 48 control subjects, matched for age and sex, were examined; patients within 1 month before parathyroidectomy (PTX) and 6 months postoperatively; control subjects at inclusion. Heart rate variability (HRV) was analysed in 24-h electrocardiograms, and plasma concentrations of epinephrine and norepinephrine were measured at rest and immediately after standardized physical tests. RESULTS: At baseline, the patients showed, compared to the controls, reduced stress-related increase of circulating epinephrine (P < 0·05) and norepinephrine (P < 0·05). No significant change was observed 6 months after PTX. At baseline, there were no significant differences between patients and controls in HRV or heart rate, but 6 months after curative PTX, the patients showed significantly reduced HRV in both frequency and time domain, and their maximum and average heart rate had decreased (P = 0·011 and P = 0·018, respectively). The patients with the highest preoperative levels of circulating parathyroid hormone showed the greatest changes in heart rate and HRV postoperatively. CONCLUSIONS: This study demonstrates a previously unknown impairment of catecholamine response to physical stress in PHPT along with changes of HRV, also indicating adrenergic dysfunction. These factors should be considered in the ongoing controversy regarding the management of patients with mild 'asymptomatic' PHPT.

Usefulness of vernakalant hydrochloride injection for rapid conversion of atrial fibrillation.

The objective of the present study was to assess the safety and effectiveness of vernakalant hydrochloride injection (RSD1235), a novel antiarrhythmic drug, for the conversion of atrial fibrillation (AF) or atrial flutter to sinus rhythm (SR). Patients with either AF or atrial flutter were randomized in a 1:1 ratio to receive vernakalant (n = 138) or placebo (n = 138) and were stratified by an arrhythmia duration of >3 hours to ≤7 days (short duration) and 8 to ≤45 days (long duration). The first infusion of placebo or vernakalant (3 mg/kg) was given for 10 minutes followed by a second infusion of placebo or vernakalant (2 mg/kg) 15 minutes later if the arrhythmia had not terminated. A total of 265 patients were randomized and received treatment. The primary end point was conversion of AF to SR for ≥1 minute within 90 minutes of the start of the drug infusion in the short-duration AF group. Of the 86 patients receiving vernakalant in the short-duration AF group, 44 (51.2%) demonstrated conversion to SR compared to 3 (3.6%) of the 84 in the placebo group (p <0.0001). The median interval to conversion of short-duration AF to SR in the responders given vernakalant was 8 minutes. Of the entire AF population (short- and long-duration AF), 47 (39.8%) of the 118 vernakalant patients experienced conversion of AF to SR compared to 4 (3.3%) of the 121 placebo patients (p <0.0001). Transient dysgeusia and sneezing were the most common adverse events in the vernakalant patients. One vernakalant patient who had severe aortic stenosis experienced hypotension and ventricular fibrillation and died. In conclusion, vernakalant demonstrated a rapid and high rate of conversion for short-duration AF and was well tolerated.

A dedicated investigation unit improves management of syncopal attacks (Syncope Study of Unselected Population in Malmo--SYSTEMA I).

AIMS: To investigate whether a systematic approach to unexplained syncopal attacks based on the European Society of Cardiology guidelines would improve the diagnostic and therapeutic outcomes. METHODS AND RESULTS: Patients presenting with transient loss of consciousness to the Emergency Department of Skåne University Hospital in Malmö were registered by triage staff. Those with established cardiac, neurological, or other definite aetiology and those with advanced dementia were excluded. The remaining patients were offered evaluation based on an expanded head-up tilt test protocol, which included carotid sinus massage, and nitroglycerine challenge if needed. Out of 201 patients registered over a period of 6 months, 129 (64.2%) were found to be eligible; of these, 101 (38.6% men, mean age 66.3 +/- 18.4 years) decided to participate in the study. Head-up tilt test allowed diagnoses in 91 cases (90.1%). Vasovagal syncope (VVS) was detected in 45, carotid sinus hypersensitivity (CSH) in 27, and orthostatic hypotension (OH) in 51 patients. Twelve patients with VVS and 15 with CSH also had OH, whereas 25 were diagnosed with OH only. In a multivariate logistic regression, OH was independently associated with age [OR (per year): 1.05, 95% CI 1.02-1.08, P = 0.001], history of hypertension (2.73, 1.05-7.09, P = 0.039), lowered estimated glomerular filtration rate (per 10 mL/min/1.73 m(2): 1.17, 1.01-1.33, P = 0.032), use of loop diuretics (10.44, 1.22-89.08, P = 0.032), and calcium-channel blockers (5.29, 1.03-27.14, P = 0.046), while CSH with age [(per year) 1.12, 1.05-1.19, P < 0.001), use of angiotensin-converting enzyme inhibitor/angiotensin receptor blocker (4.46, 1.22-16.24, P = 0.023), and nitrates (27.88, 1.99-389.81, P = 0.013). CONCLUSION: A systematic approach to patients presenting with unexplained syncopal attacks considerably increased diagnostic efficacy and accuracy. Potential syncope diagnoses have a tendency to overlap and show diversity in demographic, anamnestic, and pharmacological determinants.

Vernakalant hydrochloride for rapid conversion of atrial fibrillation: a phase 3, randomized, placebo-controlled trial.

BACKGROUND: The present study assessed the efficacy and safety of vernakalant hydrochloride (RSD1235), a novel compound, for the conversion of atrial fibrillation (AF). METHODS AND RESULTS: Patients were randomized in a 2:1 ratio to receive vernakalant or placebo and were stratified by AF duration of 3 hours to 7 days (short duration) and 8 to 45 days (long duration). A first infusion of placebo or vernakalant (3 mg/kg) was given for 10 minutes, followed by a second infusion of placebo or vernakalant (2 mg/kg) 15 minutes later if AF was not terminated. The primary end point was conversion of AF to sinus rhythm for at least 1 minute within 90 minutes of the start of drug infusion in the short-duration AF group. A total of 336 patients were randomized and received treatment (short duration, n=220; long duration, n=116). Of the 145 vernakalant patients, 75 (51.7%) in the short-duration AF group converted to sinus rhythm (median time, 11 minutes) compared with 3 of the 75 placebo patients (4.0%; P<0.001). Overall, in the short- and long-duration AF groups, 83 of the 221 vernakalant patients (37.6%) experienced termination of AF compared with 3 of the 115 placebo patients (2.6%; P<0.001). Transient dysgeusia and sneezing were the most common side effects in vernakalant-treated patients. Four vernakalant-related serious adverse events (hypotension [2 events], complete atrioventricular block, and cardiogenic shock) occurred in 3 patients. CONCLUSIONS: Vernakalant demonstrated rapid conversion of short-duration AF and was well tolerated.

Can patients at elevated risk of stroke treated with anticoagulants be further risk stratified?

BACKGROUND AND PURPOSE: Patients with atrial fibrillation have a varied risk of stroke, depending on age and comorbid conditions. The objective of this study was to assess the predictive value of stroke risk classification schemes and to identify patients with atrial fibrillation who are at substantial risk of stroke despite optimal anticoagulant therapy. METHODS: Seven recognized classification schemes-the American College of Chest Physicians 2001, American College of Chest Physicians 2004, Stroke Prevention in Atrial Fibrillation (SPAF), Atrial Fibrillation Investigators, Framingham, van Walraven, and CHADS(2)-were compared for their ability to predict ischemic stroke in patients receiving anticoagulant therapy. Data came from the Stroke Prevention using an ORal Thrombin Inhibitor in atrial Fibrillation III and V trials, which compared the efficacy of adjusted-dose warfarin and the direct thrombin inhibitor ximelagatran (36 mg twice daily) in preventing thromboembolic events in 7329 patients with chronic or paroxysmal nonvalvular atrial fibrillation who were at moderate or high risk of ischemic stroke. The main outcome measure was ischemic stroke, as determined by a central event adjudication committee. RESULTS: During 11 245 patient-years of follow-up, 159 patients had an ischemic stroke (1.4%/year). As indicated by c statistics and hazard ratios, 3 of the classification schemes predicted stroke significantly better than chance: Framingham (c=0.64), CHADS(2) (c=0.65), and SPAF (c=0.61). CONCLUSIONS: In a large cohort of atrial fibrillation patients at moderate or high risk of ischemic stroke treated with warfarin or ximelagatran, the CHADS(2), SPAF, and Framingham schemes had greater predictive accuracy than chance. This predictive ability may allow clinicians to target high-risk patients for more aggressive intervention.

Fifteen-year risk of major coronary events predicted by Holter ST-monitoring in asymptomatic middle-aged men.

BACKGROUND: Ambulatory electrocardiogram monitoring (Holter) with ST-analysis as a measure of myocardial ischemia has in populations with coronary heart disease been shown to predict major coronary events: death, myocardial infarction or coronary revascularization. There has, however, been conflicting evidence regarding the usefulness of this technique in identification of healthy subjects with increased risk for coronary heart disease. The aim of this study was to assess if Holter monitoring with ST-analysis could be used to predict future major coronary events in asymptomatic middle-aged men with a defined aggregation of traditional risk factors for coronary heart disease. METHODS: One hundred and fifty-five asymptomatic participants from the city of Malmö, Sweden, with known levels of conventional cardiovascular risk factors underwent Holter monitoring for analysis of transient ST-segment depression at the age of 55 years. Fifteen years after the Holter monitoring, hospital records, diagnosis and death registries were revisited for major coronary events. RESULTS: An ST-segment depression of 1 mm or greater (0.1 mV) was considered significant for myocardial ischemia and was found in 54 of the 155 men. There were no significant differences in risk factors in the two groups at baseline. The 15-year incidence of a first major coronary event was significantly higher in men with ST-segment depression (39%) than in men without ST-segment depression (20%) (P<0.015). A Holter electrocardiogram could predict future major coronary events with a positive and negative predictive value of 35 and 80%, respectively. CONCLUSIONS: Holter monitoring can be used as a complement to conventional risk factor evaluation in deciding whether or not to treat risk factors for CHD in asymptomatic subjects.

No effects on myocardial ischaemia in patients with stable ischaemic heart disease after treatment with ramipril for 6 months.

OBJECTIVE: To assess the effects of a 6-month angiotensin-converting enzyme (ACE) inhibitor intervention on myocardial ischaemia. METHOD: We randomized 389 patients with stable coronary artery disease to double-blind treatment with ramipril 5 mg/day (n = 133), ramipril 1.25 mg/day (n = 133), or placebo (n = 123). Forty-eight-hour ambulatory electrocardiography was performed at baseline, and after 1 and 6 months. RESULTS: Relevant baseline variables were similar in all groups. Changes over 6 months in duration of >/= 1 mm ST-segment depression (STD), total ischaemic burden and maximum STD did not differ significantly between the treatment groups. There was no difference in the frequency of adverse events between the groups. CONCLUSION: ACE inhibitor treatment has little impact on incidence and severity of myocardial ischaemia in patients with stable ischaemic heart disease.