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.
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.
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.
BACKGROUND: Prediction of stroke and atrial fibrillation in healthy individuals is challenging. We examined whether excessive supraventricular ectopic activity (ESVEA) correlates with risk of stroke, death, and atrial fibrillation in subjects without previous stroke or heart disease. METHODS AND RESULTS: The population-based cohort of the Copenhagen Holter Study, consisting of 678 healthy men and women aged between 55 and 75 years with no history of cardiovascular disease, atrial fibrillation, or stroke, was evaluated. All had fasting laboratory tests and 48-hour ambulatory ECG monitoring. ESVEA was defined as >or=30 supraventricular ectopic complexes (SVEC) per hour or as any episodes with runs of >or=20 SVEC. The primary end point was stroke or death, and the secondary end points were total mortality, stroke, and admissions for atrial fibrillation. Median follow-up was 6.3 years. Seventy subjects had SVEC>or=30/h, and 42 had runs of SVEC with a length of >or=20 SVEC. Together, 99 subjects (14.6%) had ESVEA. The risk of primary end point (death or stroke) was significantly higher in subjects with ESVEA compared with those without ESVEA after adjustment for conventional risk factors (hazard ratio=1.64; 95% confidence interval, 1.03 to 2.60; P=0.036). ESVEA was also associated with admissions for atrial fibrillation (hazard ratio=2.78; 95% confidence interval, 1.08 to 6.99; P=0.033) and stroke (hazard ratio=2.79; 95% confidence interval, 1.23 to 6.30; P=0.014). SVEC, as a continuous variable, was also associated with both the primary end point of stroke or death and admissions for atrial fibrillation. CONCLUSIONS: ESVEA in apparently healthy subjects is associated with development of atrial fibrillation and is associated with a poor prognosis in term of death or stroke.
Stroke is independently associated with the common conditions of hypokalemia and supraventricular ectopy, and we hypothesize that the combination of excessive supraventricular ectopic activity and hypokalemia has a synergistic impact on the prognosis in terms of stroke in the general population.
Subjects (55-75 years old) from the Copenhagen Holter Study cohort (N=671) with no history of atrial fibrillation or stroke were studied-including baseline values of potassium and ambulatory 48-hour Holter monitoring. Excessive supraventricular ectopic activity is defined as =30 premature atrial complexes per hour or any episodes of runs of =20. Hypokalemia was defined as plasma-potassium =3.6 mmol/L. The primary end point was ischemic stroke. Cox models were used.
Hypokalemia was mild (mean, 3.4 mmol/L; range, 2.7-3.6). Hypokalemic subjects were older (67.0±6.94 versus 64.0±6.66 years; P
The study aim was to evaluate patient acceptance and content with remote follow-up (FU) of their implantable cardioverter defibrillator (ICD) and to estimate patients' wish for changes in remote follow-up routines.
Four hundred seventy-four ICD patients at the device follow-up clinic at Rigshospitalet using CareLink® (Medtronic) remote follow-up, who had made =2 transmissions, received a questionnaire.
Three hundred eighty-five patients (81.2%) answered. Mean time with ICD was 56?±?45 months and mean age was 62?±?13 years; 80% was male. Diagnosis related to ICD implant was: ischemic heart disease in 56% and dilated cardiomyopathy in 21%. Twenty-six percent had primary prophylactic indication. Mean time on remote FU was 16.4?±?6.9 months. Mean time spent on in-clinic FU (two-way transport and FU) was 4 h and 36 min?±?7 h and 50 min, excluding 12 patients from Greenland and Faroe Islands. Ninety-five percent of the patients was very content or content with remote FU compared to in-clinic FU; 3% was less content and 2% was not content. For scheduled transmissions, 21% of the patients wished for a faster reply (sms or e-mail) compared to current practice with a letter. Eighty-four percent preferred more detailed information concerning ICD leads, battery status, and ICD therapies. A total of 96 patients (25%) had performed extra unscheduled remote transmissions: 20 due to shock, 20 due to alarm, 35 due to palpitations, and 18 for other or combined reasons.
Ninety-five percent of the patients were content with the remote FU. Only 25% had unscheduled transmissions and most unscheduled transmissions were for appropriate reasons. Eighty-four percent of the patients wished for a more detailed response and 21% wished for a faster reply after routine transmissions.
The aim of this study was to assess the epidemiological features and prognosis of heart failure with preserved ejection fraction (HFPEF) and to compare these findings with those from patients with reduced ejection fraction. Furthermore the effects of N-terminal pro brain natriuretic peptide (NT-proBNP) requirement in the heart failure diagnosis were assessed by repeating the analyses in the subgroup of patients with elevated NT-proBNP.
In 1844 patients admitted, a clinical diagnosis of heart failure was made in 433; amongst these 61% had HFPEF. An elevated NT-proBNP applied to the heart failure diagnosis reduced the number of heart failure patients to 191, and amongst these 29% had preserved ejection fraction. Use of NT-proBNP reduced clinical differences between heart failure patients with preserved and reduced ejection fraction. When not using NT-proBNP, patients with reduced ejection fraction had higher mortality [hazard ratio (HR) 1.24, 95% confidence interval (CI) 1.01-1.52; P = 0.04], even after adjustment for other significant predictors of mortality, except NT-proBNP (HR 1.29, 95% CI 1.04-1.59; P = 0.02). However, no difference in mortality was observed when NT-proBNP was adjusted for (HR 0.90, 95% CI 0.71-1.15; P = 0.4), or used for the heart failure diagnosis (HR 0.96; 95% CI 0.71-1.29; P = 0.8).
Using a heart failure diagnosis requiring elevated NT-proBNP reduces the prevalence of HFPEF and results in a survival similar to that of heart failure with reduced ejection fraction. In contrast, when NT-proBNP is not used for the heart failure diagnosis or adjusted for, HFPEF is associated with a lower mortality in both univariate and multivariate analysis.
AIMS: We aimed to determine the prevalence and prognostic significance of daily-life silent myocardial ischaemia (SMI) in healthy middle-aged and elderly subjects with no previous heart disease. METHODS AND RESULTS: Six hundred and seventy-eight healthy men and women between 55 and 75 years of age and with no history of cardiovascular disease or stroke were included. Baseline examinations included physical examination, fasting laboratory testing, and 48 h ambulatory electrocardiogram monitoring. An episode of ischaemia was defined by a down-sloped or horizontal ST depression of at least 1 mm at a duration of at least 1 min. Seventy-seven subjects (11.4%) had SMI. All participants were followed for up to 5 years. In 77 subjects with SMI, 16 (20.7%) had an event (death or myocardial infarction). In 601 subjects without SMI, 50 (8.3%) had an event. The hazard ratios for SMI in relation to cardiac and combined events after correction for conventional risk factors were 3.1 [(1.24-7.97), P=0.016] and 1.97 [(1.06-3.69), P=0.033], respectively. CONCLUSION: SMI as detected by Holter monitoring was detected in 11.4% of these subjects and was associated with more than three-fold increase in the cardiac event rate after correction for risk factors, implying that this test could be used to identify high-risk individuals among these subjects.
The aim of this study was to evaluate the prognostic value of high sensitive C-reactive protein (CRP) in subjects with silent myocardial ischemia (SMI).
In total, 678 healthy men and women aged 55 to 75 years with no history of cardiovascular disease or stroke were included. High-sensitive CRP and 48-hour ambulatory ECG monitoring were performed. The primary endpoint was the combined endpoint of death and myocardial infarction.
The median follow-up time was 76 months. Seventy-seven subjects (11.4%) had SMI. The combined endpoint occurred in 26% of the subjects with SMI and 14% of the subjects without SMI (P = .005). SMI had a poor prognosis in the group with an elevated CRP = 3.0 µg/mL (hazard ratio, 3.46; 95% confidence interval, 1.67-7.16; P = .001) compared with the group of subjects with SMI and a low CRP
The clinical significance of high heart rate in chronic obstructive pulmonary disease (COPD) is unexplored. We investigated the association between resting heart rate, pulmonary function, and prognosis in subjects with COPD. 16 696 subjects aged =40 years from the Copenhagen City Heart Study, a prospective study of the general population, were followed for 35.3 years, 10 986 deaths occurred. Analyses were performed using time-dependent Cox-models and net reclassification index (NRI). Resting heart rate increased with severity of COPD (p85 bpm was 5.5 years without COPD, 9.8 years in mild (Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage I), 6.7 years in moderate (GOLD stage II) and 5.9 years in severe/very severe COPD (GOLD stage III/IV), (p