The QTc interval, autonomic neuropathy and mortality in hypoxaemic COPD

Relationship between a Prolonged Corrected QT Interval and Mortality in Patients Presenting with Syncope at the Emergency Department

Background

Syncope is a common symptom in emergency department patients. Among various etiological factors, cardiac causes have the highest risk of mortality. The corrected QT interval is considered an independent predictor of mortality for many diseases.

Objectives

Analyze QT interval analysis of patients presenting to the emergency department with syncope.

Methods

In this prospective observational study, patients who presented to the emergency department with syncope between January 1, 2018, and January 1, 2019 were included.

Results

The median age was 64 (49-78) years, and 58.8% of patients were male. The corrected QT interval (QTc) in patients with coronary artery disease and chronic obstructive pulmonary disease was longer than those without. There was no statistically significant association between hypertension, diabetes, stroke, thyroid disease, and prolonged QTc. Patients who did not survive had significantly prolonged QT intervals. According to ROC analysis, sensitivity of >440.5 ms QTc values in predicting mortality was 86% and specificity was 71% (AUC = 0.815; 95%CI = 0.71 − 0.91; p < 0.001).

Conclusions

Patients admitted to emergency department with syncope and a prolonged QTc are associated with a higher mortality rate and thus can provide us with an important guide for the management of these patients.

Effect of disease-modifying agents and their association with mortality in multi-morbid patients with heart failure with reduced ejection fraction

AIMS

An increasing proportion of patients with heart failure with reduced ejection fraction (HFrEF) have co-morbidities. The effect of these co-morbidities on modes of death and the effect of disease-modifying agents in multi-morbid patients is unknown.

METHODS AND RESULTS

We performed a prospective cohort study of ambulatory patients with HFrEF to assess predictors of outcomes. We identified four key co-morbidities-ischaemic aetiology of heart failure, diabetes mellitus, chronic obstructive pulmonary disease (COPD), and chronic kidney disease (CKD)-that were highly prevalent and associated with an increased risk of all-cause mortality. We used these data to explore modes of death and the utilization of disease-modifying agents in patients with and without these co-morbidities. The cohort included 1789 consecutively recruited patients who had an average age of 69.6 ± 12.5 years, and 1307 (73%) were male. Ischaemic aetiology of heart failure was the most common co-morbidity, occurring in 1061 (59%) patients; 503 (28%) patients had diabetes mellitus, 283 (16%) had COPD, and 140 (8%) had CKD stage IV/V. During mean follow-up of 3.8 ± 1.6 years, 737 (41.5%) patients died, classified as progressive heart failure (n = 227, 32%), sudden (n = 112, 16%), and non-cardiovascular deaths (n = 314, 44%). Multi-morbid patients were older (P < 0.001), more likely to be male (P < 0.001), and had higher New York Heart Association class (P < 0.001), despite having higher left ventricular (LV) ejection fraction (P = 0.001) and lower LV end-diastolic diameter (P = 0.001). Multi-morbid patients were prescribed lower doses of disease-modifying agents, especially patients with COPD who received lower doses of beta-adrenoceptor antagonists (2.7 ± 3.0 vs. 4.1 ± 3.4 mg, P < 0.001) and were less likely to be implanted with internal cardioverter defibrillators (7% vs. 13%, P < 0.001). In multivariate analysis, COPD and diabetes mellitus conferred a >2.5-fold and 1.5-fold increased risk of sudden death, whilst higher doses of beta-adrenoceptor antagonists were protective (hazard ratio per milligram 0.92, 95% confidence interval 0.86-0.98, P = 0.009). Each milligram of bisoprolol-equivalent beta-adrenoceptor antagonist was associated with 9% (P = 0.001) and 11% (P = 0.023) reduction of sudden deaths in patients with <2 and ≥2 co-morbidities, respectively.

CONCLUSIONS

Higher doses of beta-adrenoceptor antagonist are associated with greater protection from sudden death, most evident in multi-morbid patients. Patients with COPD who appear to be at the highest risk of sudden death are prescribed the lowest doses and less likely to be implanted with implantable cardioverter defibrillators, which might represent a missed opportunity to optimize safe and proven therapies for these patients.

ECG changes at rest and during exercise in lowlanders with COPD travelling to 3100 m

BACKGROUND

The incidence and magnitude of cardiac ischemia and arrhythmias in patients with chronic obstructive pulmonary disease (COPD) during exposure to hypobaric hypoxia is insufficiently studied. We investigated electrocardiogram (ECG) markers of ischemia at rest and during incremental exercise testing (IET) in COPD-patients travelling to 3100 m.

STUDY DESIGN AND METHODS

Lowlanders (residence <800 m) with COPD (forced volume in the first second of expiration (FEV₁) 40-80% predicted, oxygen saturation (SpO₂) ≥92%, arterial partial pressure of carbon dioxide (PaCO₂) <6 kPa at 760 m) aged 18 to 75 years, without history of cardiovascular disease underwent 12‑lead ECG recordings at rest and during cycle IET to exhaustion at 760 m and after acute exposure of 3 h to 3100 m. Mean ST-changes in ECGs averaged over 10s were analyzed for signs of ischemia (≥1 mm horizontal or downsloping ST-segment depression) at rest, peak exercise and 2-min recovery.

RESULTS

80 COPD-patients (51% women, mean ± SD, 56.2 ± 9.6 years, body mass index (BMI) 27.0 ± 4.5 kg/m², SpO₂ 94 ± 2%, FEV₁ 63 ± 10% prEd.) were included. At 3100 m, 2 of 53 (3.8%) patients revealed ≥1 mm horizontal ST-depression during IET vs 0 of 64 at 760 m (p = 0.203). Multivariable mixed regression revealed minor but significant ST-depressions associated with altitude, peak exercise or recovery and rate pressure product (RPP) in multiple leads.

CONCLUSION

In this study, ECG recordings at rest and during IET in COPD-patients do not suggest an increased incidence of signs of ischemia with ascent to 3100 m. Whether statistically significant ST changes below the standard threshold of clinical relevance detected in multiple leads reflect a risk of ischemia during prolonged exposure remains to be elucidated.

Evaluation of TP-E Interval and TP-E/QT Ratio in Panic Disorder

Background and Objectives: The autonomic nervous system (ANS) is involved in panic disorders. ANS dysfunction has been shown to be associated with ventricular arrhythmia and increased heterogeneity of ventricular repolarization. However, there remains limited evidence of the relationship between panic disorders and ventricular depolarization markers, including the Tp-e interval and Tp-e/QT ratio. This study aimed to evaluate ventricular repolarization parameters in patients with panic disorder. Materials and Methods: In total, 40 patients with panic disorder, diagnosed using the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria, were included in the study group. The control group comprised of 50 age- and sex-matched healthy individuals. A standard 12 lead electrocardiogram was recorded on all participants, and heart rate, QT interval, QRS duration, Tp-e interval, and Tp-e/QT ratio were measured. Results: QRS durations and QT intervals were similar in the study and control groups. Compared to the control group, QTd, Tp-e, and cTp-e intervals as well as Tp-e/QT and Tp-e/QTc ratios were significantly increased in patients with panic disorder (p < 0.05 for all). In the study group, the Severity Measure for Panic Disorder-Adult score had a significant positive correlation with the Tp-e interval (r = 0.369, p < 0001), cTp-e interval (r = 0.531, p < 0.001), Tp-e/QT ratio (r = 0.358, p = 0.001), and Tp-e/QTc ratio (r = 0.351, p = 0.001). Conclusion: These findings indicate that panic disorders are associated with increased ventricular repolarization heterogeneity, which may be attributed to ANS dysregulation.

Evaluation of the Tp-Te interval, Tp-Te/QTc ratio, and QT dispersion in patients with Turner syndrome

Objective:

To evaluate ventricular repolarization parameters using the interval from the peak to the end of the T wave (Tp–Te), together with QT and corrected QT (QTc) intervals, QT dispersion (QTd), and Tp-Te/QTc ratio in patients with Turner syndrome (pwTS) and to compare the results with those from healthy controls.

Methods:

In total, 38 patients previously diagnosed with Turner syndrome (TS) and 35 healthy girls (controls) were included in our cross-sectional study. Twelve-lead electrocardiography (ECG) and echocardiography after a 30-min rest were performed. The QT, QTc, QTd, Tp-Te interval, and Tp-Te/QTc ratio were determined.

Results:

No differences in age or sex were observed between the groups. QT intervals were similar in both groups [pwTS: 354.76±25.33 ms, controls (C): 353.29±17.51 ms, p=0.775]. pwTS had significantly longer QTc and QTd than controls (411.87±22.66 ms vs. 392.06±13.21 ms, p<0.001 and 40.31±2.02 ms vs. 37.54±1.83 ms, p<0.001, respectively). Similarly, the Tp-Te interval and Tp-Te/QTc ratio were significantly longer in pwTS than in controls (71.89±3.39 ms vs. 65.34±2.88 ms, p<0.001 and 0.17±0.01 vs. 0.16±0.01, p=0.01).

Conclusion:

As pwTS have longer QTc, QTd, Tp–Te interval, and Tp-Te/QTc ratio, an annual follow-up with ECG can provide awareness and even prevent sudden death in them. Also avoiding the use of drugs that makes repolarization anomaly and having knowledge about the side effects of these drugs are essential in pwTS.

T wave peak-to-end interval in COPD

Introduction

The interval from the peak to the end of the electrocardiographic (ECG) T wave (Tp–Te) can estimate cardiovascular mortality and ventricular tachyarrhythmias.

Objectives

In this study, we aimed to define a new ECG parameter in patients with COPD.

Methods

This was a cross-sectional observational study that included COPD patients who were diagnosed previously and followed up in the outpatient clinic. All data of the patients’ demographic features, history, spirometry, and electrocardiographs were analyzed.

Results

We enrolled 134 patients with COPD and 40 healthy volunteers as controls in our study. Patients already known to be having COPD who were under follow-up for their COPD and diagnosed as having COPD according to the Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria were included. Men comprised 82.8% of the COPD group and 73.2% of controls. The mean age in the COPD and control group was 60.2±9.4 and 58.2±6.7 years, respectively. There was no significant difference between the groups for age or sex (p=0.207, p=0.267, respectively). There were 46 (34.3%) patients in group A, 23 (17.2%) patients in group B, 26 (19.4%) patients in group C, and 46 (29.1%) patients in group D as COPD group. There was a significant increase in Tp–Te results in all precordial leads in the COPD group compared with the control group (p<0.05). Precordial V4 lead has the most extensive area under the curve (0.831; sensitivity 76.5%, specificity 89.6%).

Conclusion

We present strong evidence that Tp–Te intervals were increased in patients with COPD, which suggests that there may be an association between COPD and ventricular arrhythmias and cardiac morbidity.

Elastic Tubing Resistance Training and Autonomic Modulation in Subjects with Chronic Obstructive Pulmonary Disease

This study addresses evidence concerning elastic tubing resistance training (ET) on autonomic modulation in patients with chronic obstructive pulmonary disease (COPD). Autonomic dysfunction is common in COPD and contributes to the development of arrhythmias and sudden death. Along with autonomic dysfunction, muscle dysfunction is related to functional limitations and prognosis of the disease. This study investigated the effects of ET on autonomic modulation, muscle strength, and walking distance in COPD. Subjects were divided into two groups, ET (n = 20; 66,5 ± 8,9 y; 25,5 ± 3,5 kg/m2; FEV1/FVC: 50,3 ± 11,0) and conventional training (n = 19; 66,0 ± 6,9; 27,1 ± 4,3; FEV1/FVC: 55,05 ± 9,56). Both groups undertook 24 sessions for 60 minutes, 3 times in a week. The significance level was p ≤ 0,05. Autonomic modulation was evaluated using heart rate variability in the time (rMSSD, ms) and frequency domain (HF, ms). Strength for upper and lower limbs was measured using dynamometry and walking distance was measured using a 6-minute walking test. There were no significant differences in the outcomes between groups. There was an increment to rMSSD [(16,7 ± 11,0 versus 20,8 ± 14,9) versus (14,2 ± 10,0 versus 17,4 ± 12,1)], HF [(141,9 ± 191,3 versus 234,9 ± 335,7) versus (94,1 ± 123,5 versus 177,6 ± 275,5)], shoulder abduction [(50,1 ± 19,6 versus 56,9 ± 20,4) versus (50,5 ± 19,0 versus 56,9 ± 19,3)], knee flexion [(101,9 ± 34,0 versus 116,8 ± 43,3) versus (98,6 ± 21,5 versus 115,1 ± 30,8)], and walking test [(433,0 ± 84,8 versus 468,9 ± 90,8) versus (397,4 ± 99,8 versus 426,3 ± 101,6)] after training for ET and conventional training, respectively. In conclusion, ET improves autonomic modulation in COPD with additional benefits for strength and cardiorespiratory capacity similar to conventional training.

QTc prolongation in Black diabetic subjects with cardiac autonomic neuropathy

BACKGROUND

Prolonged corrected QT (QTc) has been identified as a risk factor for malignant arrhythmias and sudden cardiac death. Caucasian studies have shown a definite relationship between QTc prolongation and Cardiac Autonomic Neuropathy (CAN) in diabetic subjects.

OBJECTIVE

To determine the prevalence of prolonged QTc in Black diabetic individuals with CAN and to ascertain how prolonged QTc correlated with the severity of CAN among these patients.

METHODS

A total of 176 adult diabetic subjects were studied, 87 males and 89 females. There was a control group of non-diabetic individuals. Cardiac autonomic function was assessed using five cardiovascular autonomic function tests. CAN was diagnosed if 2 or more of these tests were abnormal. Severity of CAN was determined according to the number of abnormal tests. QTc > 0.440 was regarded as prolonged.

RESULTS

Fifty-one out of the 176 diabetic subjects (29%) had CAN. The prevalence of prolonged QTc in diabetic subjects with CAN was 12%. QTc was prolonged in 1.6% and 0.6% of diabetic individuals without CAN and controls respectively. Although QTc correlated strongly with cardiac autonomic function neuropathy, there was no definite relationship between QTc prolongation and severity of CAN.

CONCLUSION

This study in a Black population is in agreement with the well-known relationship between QTc prolongation and CAN reported in Caucasian studies. In view of the wide variability of QTc in this study population, it is suggested that relative QTc increase may be a better indicator of CAN than a definite QTc prolongation of greater than 0.440.

Relation of Chronic Obstructive Pulmonary Disease to Cardiovascular Disease in the General Population

Chronic obstructive pulmonary disease (COPD) is a major health problem that contributes to substantial morbidity and mortality globally. This study investigated the relation between COPD and the risk of cardiovascular disease in the general population. We evaluated the cardiovascular effect of COPD using Korean National Health Insurance Service data from 2002 to 2013. We compared selected cardiovascular disease risk factors depending on pulmonary function using the Korean Health and Nutritional Examination Survey (KNHANES, n = 24,429) data. COPD was diagnosed in 11,771 patients (2.4%) in the National Health Insurance Service cohort. During the follow-up period (45.5 ± 14.9 months), subjects with COPD had lower cumulative survival rate for all-cause mortality, cardiovascular mortality, and sudden cardiac death (SCD, all p values <0.001). COPD was associated with an increased risk of all-cause mortality even after adjustment for potential confounding variables (hazard ratio [HR] 1.43, 95% confidence interval [CI] 1.33 to 1.55, p <0.001). However, COPD did not significantly increase the risk of cardiovascular mortality (HR 1.02, 95% CI 0.84 to 1.22, p = 0.876) and SCD (HR 1.07, 95% CI 0.79 to 1.44, p = 0.664) when adjusted for potential confounding variables. Analysis of the KNHANES cohort showed that systolic blood pressure, current smoking status, and Framingham risk score increased progressively with a decrease in pulmonary function (all p <0.001). In conclusion, COPD was associated with all-cause mortality, but not with cardiovascular mortality and SCD, whereas poor pulmonary function was associated with a heightened cardiovascular risk.

Chronic obstructive pulmonary disease and atrial fibrillation: An unknown relationship

Chronic obstructive pulmonary disease (COPD) is independently associated with atrial fibrillation (AF). Decreased oxygenation, hypercapnia, pulmonary hypertension, diastolic dysfunction, oxidative stress, inflammation, changes in atrial size by altered respiratory physiology, increased arrhythmogenicity from nonpulmonary vein foci commonly located in the right atrium, and respiratory drugs have been implicated in the pathogenesis of AF in COPD. The understanding of the relationship between COPD and AF is of particular importance, as the presence of the arrhythmia has significant impact on mortality, especially in COPD exacerbations. On the other hand, COPD in AF is associated with AF progression, success of cardioversion, recurrence of AF after catheter ablation, and increased cardiovascular and all-cause mortality. Treatment of the underlying pulmonary disease and correction of hypoxia and acid-base imbalance represents first-line therapy for COPD patients who develop AF. Cardioselective β-blockers are safe and can be routinely used in COPD. In addition, AF ablation was proved to be efficient and safe, and improves quality of life in these patients. This review presents the association between COPD and AF, describes the pathophysiological mechanisms implicated in AF development in COPD, underlines the prognostic significance of AF in COPD patients and vice versa, and highlights emerging therapeutic approaches in this setting.

Lung function, percent emphysema, and QT duration: The Multi-Ethnic Study of Atherosclerosis (MESA) lung study

BACKGROUND

The QT interval on electrocardiogram (ECG) reflects ventricular repolarization; a prolonged QT interval is associated with increased mortality risk. Prior studies suggest an association between chronic obstructive pulmonary disease (COPD) and prolonged QT interval. However, these studies were small and often enrolled hospital-based samples. We tested the hypotheses that lower lung function and increased percent emphysema on computed tomography (CT) are associated with a prolonged QT interval in a general population sample and additionally in those with COPD.

METHODS

As part of the Multi-Ethnic Study of Atherosclerosis (MESA) Lung Study, we assessed spirometry, full-lung CT scans, and ECGs in participants aged 45-84 years. The QT on ECGs was corrected for heart rate (QTc) using the Framingham formula. QTc values = 460 msec in women and ≥450 msec in men were considered abnormal (prolonged QT_C). Multivariate regression models were used to examine the cross-sectional association between pulmonary measures and QT_C. RESULTS: The mean age of the sample of 2585 participants was 69 years, and 47% were men. There was an inverse association between FEV₁%, FVC%, FEV₁/FVC%, emphysema, QTc duration and prolonged QTc. Gender was a significant interaction term, even among never smokers. Having severe COPD was also associated with QTc prolongation.

CONCLUSIONS

Our analysis revealed a significant association between lower lung function and longer QTc in men but not in women in a population-based sample. Our findings suggest the possibility of gender differences in the risk of QTc-associated arrhythmias in a population-based sample.

Deceleration and Acceleration Capacities in Risk Stratification for Arrhythmias in Patients With Chronic Obstructive Pulmonary Disease

BACKGROUND

Patients with chronic obstructive pulmonary disease (COPD) have an increased risk for both supraventricular and ventricular arrhythmias. Autonomic dysregulation may be responsible for the development of arrhythmias in these patients, and its analysis could be useful for identifying those at high risk for arrhythmias.

STUDY QUESTION

Our purpose is to analyze the role of acceleration capacity (AC) and deceleration capacity (DC), novel markers of the autonomic balance, as potential arrhythmic risk predictors in patients with COPD.

STUDY DESIGN

We prospectively included 47 patients diagnosed with COPD, and a control group of 64 age-matched subjects without COPD. AC and DC values were obtained using 24-hour Holter monitoring. The arrhythmias were isolated premature atrial complexes, supraventricular tachycardias, isolated premature ventricular beats (PVC), and combined ventricular arrhythmias consisting in ventricular tachycardias or more than 10 PVC per hour.

RESULTS

Supraventricular arrhythmias and isolated PVC were more frequent in the COPD group. The DC was significantly lower (3.10 vs. 5.60, P < 0.0001) and AC higher (-4.60 vs. -6.60, P = 0.002) in patients with COPD. DC was identified as a predictor of arrhythmic events with an area under the curve (AUC) for premature atrial complexes >70/d of 0.72 (0.56-0.87, P = 0.013), for supraventricular tachycardias 0.76 (0.62-0.90, P = 0.002), and for combined ventricular arrhythmias 0.69 (0.54-0.82, P = 0.025). AC was predictor only for combined ventricular arrhythmias with an AUC of 0.74 (0.58-0.85, P = 0.002).

CONCLUSIONS

Patients with COPD associate a significant autonomic imbalance and a higher incidence of arrhythmias. DC could be a strong predictor for supraventricular and ventricular arrhythmias in patients with COPD with no clinically apparent cardiac disease. AC could be useful alongside with DC regarding the risk for ventricular arrhythmias, but seems to have lesser value as a predictor for supraventricular arrhythmias.

Chronic obstructive pulmonary disease and sudden cardiac death: the Rotterdam study

AIMS

Both sudden cardiac death (SCD) and chronic obstructive pulmonary disease (COPD) are common conditions in the elderly. Previous studies have identified an association between COPD and cardiovascular disease, and with SCD in specific patient groups. Our aim was to investigate whether there is an association between COPD and SCD in the general population.

METHODS AND RESULTS

The Rotterdam study is a population-based cohort study among 14 926 subjects aged 45 years and older with up to 24 years of follow-up. Analyses were performed with a (time dependent) Cox proportional hazard model adjusted for age, sex, and smoking. Of the 13 471 persons included in the analysis; 1615 had a diagnosis of COPD and there were 551 cases of SCD. Chronic obstructive pulmonary disease was associated with an increased risk of SCD (age- and sex-adjusted hazard ratio, HR, 1.34, 95% CI 1.06-1.70). The risk particularly increased in the period 2000 days (5.48 years) after the diagnosis of COPD (age- and sex-adjusted HR 2.12, 95% CI 1.60-2.82) and increased further to a more than three-fold higher risk in COPD subjects with frequent exacerbations during this period (age- and sex-adjusted HR 3.58, 95% CI 2.35-5.44). Analyses restricted to persons without prevalent myocardial infarction or heart failure yielded similar results.

CONCLUSION

Chronic obstructive pulmonary disease is associated with an increased risk for SCD. The risk especially increases in persons with frequent exacerbations 5 years after the diagnosis of COPD. This risk indicator could provide new directions for better-targeted actions to prevent SCD.

Multiple logistic regression analysis of risk factors in elderly pneumonia patients: QTc interval prolongation as a prognostic factor

Background

Acute pneumonia is a serious problem in the elderly and various risk factors have already been reported, but the involvement of QTc interval prolongation remains uncertain. The aim of this study was to elucidate the prognostic factors for the development of pneumonia in elderly patients and to study the possible involvement of QTc interval prolongation.

Methods

The subjects were 249 hospitalized pneumonia patients more than 65 years old in Aki-Ohta Hospital from January 2010 to December 2013. Community-acquired pneumonia patients and nursing care and healthcare-associated pneumonia patients were included in the study. The pneumonia severity index, vital signs, blood chemistry data and ECG findings were retrospectively compared using multiple logistic regression analysis.

Results

39 patients died within 30 days from onset. The clinical features related to poor prognosis were: advanced age, past history of cerebral vascular disease and/or diabetes mellitus, decreased serum albumin level, higher CURB-65 or PORT index scores and QTc interval prolongation. Patients showing a prolonged QTc interval had a higher mortality than those with a normal QTc interval. A prolonged QTc interval was not related to serum calcium concentration and/or treatment with QTc prolongation drug, clarithromycin or azithromycin, but related to age, lower albumin concentration and past history of diabetes mellitus.

Conclusions

These findings suggest potential prognostic factors for pneumonia in elderly patients, including a prolonged QTc interval (> 0.44 seconds).

High prevalence of altered cardiac repolarization in patients with COPD

BACKGROUND

Altered cardiac repolarization and increased dispersion of repolarization have been identified as risk factors for sudden cardiac death (SCD). The prevalence of and the mechanisms contributing to altered cardiac repolarization are currently unknown in COPD.

METHODS

In 91 COPD patients, 32 controls matched for age, cardiovascular risk and medication, and 41 healthy subjects, measures of cardiac repolarization and dispersion of repolarization (QTc interval, QT dispersion) were derived from 12-lead electrocardiography (ECG). Prevalence rates of heart rate corrected QT (QTc) >450ms and QT dispersion >60ms were determined to assess the number of subjects at risk for SCD. Univariate and multivariate analyses were used to identify possible factors contributing to altered cardiac repolarization.

RESULTS

QTc was found to be prolonged in 31.9% and QT dispersion in 24.2% of the COPD patients compared to 12.5% in matched controls and 0% in healthy subjects. The QTc interval was longer in COPD patients compared to matched and healthy controls respectively (437.9 ± 29.5 vs. 420.1 ± 25.3 ms, p = 0.001 and vs. 413.4 ± 18.2 ms, p < 0.001). QT dispersion was significantly increased in COPD patients compared to healthy subjects (45.4 (34.8 , 59.5) vs. 39.7 (29.3 , 54.8) ms, p = 0.049). Only oxygen saturation was independently associated with QTc duration in multivariate analysis (β = -0.29, p = 0.015).

CONCLUSION

One third of a typical COPD population has altered cardiac repolarization and increased dispersion of repolarization, which may be related to hypoxia. Altered cardiac repolarization may expose these patients to an increased risk for malignant ventricular arrhythmias and SCD.

Predicted heart rate effect of inhaled PF-00610355, a long acting β-adrenoceptor agonist, in volunteers and patients with chronic obstructive pulmonary disease

AIM

To assess the cardiovascular effects of a new inhaled long-acting β-adrenoceptor agonist PF-00610355 in COPD patients.

METHODS

Thirteen thousand and sixty-two heart rate measurements collected in 10 clinical studies from 579 healthy volunteers, asthma and COPD patients were analyzed. The relationship between heart rate profiles and predicted plasma concentration profiles, patient status, demographics and concomitant medication was evaluated using non-linear mixed-effects models. The median heart rate increase in COPD patients for doses of PF-00610355 up to 280 μg once daily was simulated with the final pharmacokinetic/pharmacodynamic (PKPD) model.

RESULTS

An Emax model accounting for delayed on-and off-set of the PF-00610355-induced change in heart rate was developed. The predicted potency in COPD patients was three-fold lower compared with healthy volunteers, while no difference in maximum drug effect was identified. Simulations suggested a maximum placebo-corrected increase of 2.7 (0.90-4.82) beats min(-1) in COPD patients for a PF-00610355 dose of 280 μg once daily, with 19% subjects experiencing a heart rate increase of more than 20 beats min(-1) compared with 8% in the placebo group.

CONCLUSIONS

This PKPD analysis supports the clinical observation that no relevant effects of PF-00610355 on heart rate in COPD patients should be expected for doses up to 280 μg once daily.

Chronic obstructive pulmonary disease and cardiovascular disease

Chronic obstructive pulmonary disease (COPD) is an inflammatory disease of the lung associated with progressive airflow limitation and punctuated by episodes of acute exacerbation. There is growing recognition that the inflammatory state associated with COPD is not confined to the lungs but also involves the systemic circulation and can impact nonpulmonary organs. Epidemiologic and mechanistic studies indicate that COPD is associated with a high frequency of coronary artery disease, congestive heart failure and cardiac arrhythmias, independent of shared risk factors. Possible pathways include complex interrelationships between chronic low-grade systemic inflammation and oxidative stress as well as shared risk factors such as age, cigarette smoking, and environmental pollutants. In this review, we provide an overview of the epidemiologic data linking COPD with cardiovascular disease, comment on the interrelationships among COPD, inflammation, and cardiovascular disease, and highlight diagnostic and therapeutic challenges.

Arrhythmias as trigger for acute exacerbations of chronic obstructive pulmonary disease

PURPOSE

Acute exacerbations of chronic obstructive pulmonary disease (COPD) sometimes appear to occur without a precipitating cause. Heterogeneous repolarization and arrhythmias occur in COPD patients. Given the close inter-relation between heart and lung, we hypothesized that unrecognized arrhythmias might be precipitants of acute exacerbations.

METHODS

Electrocardiograms (ECG) of thirty patients during acute exacerbations were compared with ECG during stable phase. P wave dispersion was used to assess atrial depolarization heterogeneity, and dispersion of QT interval to assess ventricular repolarization. p < 0.05 was considered significant. Frequent exacerbations were defined as two or more exacerbations in a year.

RESULTS

Mean age of patients was 70.3 ± 11.8 SD years. P wave dispersion was greater during acute exacerbation than during stable phase (56.7 ± 19.2 vs 47.7 ± 15.9 ms, p = 0.009). There was a trend toward greater QTc dispersion (108.3 ± 61.7 vs 90.3 ± 47.0 ms, p = 0.13) in acute exacerbation compared to stable phase. Sixteen (53%) had frequent exacerbations. There was a significant difference in PR interval during stable phase between those with frequent exacerbations and those without (163.9 + 17.4 vs. 145.1 + 22.8; p = 0.02). The P wave dispersion during stable phase was greater in those with frequent exacerbations, but did not reach statistical significance (52.6 + 18.8 vs. 42.2 + 9.8 ms; p = 0.06).

CONCLUSIONS

P wave dispersion is more in the acute phase than in stable phase, and is greater in patients with more frequent exacerbations. This does not prove, but suggests an intriguing possibility that P wave dispersion predates acute exacerbations. This might be a new target for prediction, prevention and therapy of acute exacerbations of COPD.

Prognostic value of FEV1/FEV6 in elderly people

BACKGROUND

  The ratio of forced expiratory volume in 1 s and forced expiratory volume in 6 s (FEV1/FEV6) has been proposed as an alternative for FEV1/forced vital capacity (FVC) to diagnose obstructive diseases with less effort during spirometry; however, its prognostic value is unknown. We evaluated whether FEV1/FEV6 is a significant predictor of mortality in elderly subjects and compared its prognostic value with that of FEV1/FVC and FEV1.

METHODS

  One thousand nine hundred and seventy-one subjects, aged >65 years, participated in the population-based SA.R.A. study. During the baseline exam, a multidimensional assessment included spirometry. Vital status was determined during 6 years of follow-up. Association of all-cause, cardio-pulmonary (CP) and non-CP mortality with a low FEV1/FEV6, FEV1/FVC and FEV1 was evaluated.

RESULTS

  Among subjects with both survival data and acceptable spirometry including FEV6, all-cause unadjusted mortality rates were 7·00 and 2·46 per 100 person-years in subjects with FEV1/FEV6 less than and greater than or equal to lower limit of normal (LLN), respectively (mortality rate ratio: 2·84, 95%CI: 2·12-3·84). After adjustment for age, gender, FVC, smoke exposure and main comorbidities, the risk of all-cause mortality remained significantly increased in subjects with FEV1/FEV6<LLN [hazard ratio (HR): 1·87, 95%CI: 1·35-2·58] as well as in subjects with FEV1/FVC<LLN (HR: 2·01, 95%CI: 1·51-2·90) and FEV1<LLN (HR: 2·17, 95%CI: 1·32-3·57). Similar results were found for CP mortality, but not for non-CP mortality.

CONCLUSIONS

  A low FEV1/FEV6 is a significant predictor of mortality in older individuals. Its prognostic value is comparable to that of a low FEV1/FVC and FEV1.

Deep breathing heart rate variability is associated with respiratory muscle weakness in patients with chronic obstructive pulmonary disease

BACKGROUND

A synchronism exists between the respiratory and cardiac cycles. However, the influence of the inspiratory muscle weakness in chronic obstructive pulmonary disease (COPD) on cardiac autonomic control is unknown. The purpose of the present investigation was to evaluate the influence of respiratory muscle strength on autonomic control in these patients.

METHODS

Ten chronic obstructive pulmonary disease patients (69+/-9 years; FEV(1)/FVC 59+/-12% and FEV(1) 41+/-11% predicted) and nine age-matched healthy volunteers (64+/-5 years) participated in this study. Heart-rate variability (HRV) was obtained at rest and during respiratory sinusal arrhythmia maneuver (RSA-M) by electrocardiograph.

RESULTS

Chronic obstructive pulmonary disease patients demonstrated impaired cardiac autonomic modulation at rest and during RSA-M when compared with healthy subjects (p<0.05). Moreover, significant and positive correlations between maximal inspiratory pressure (MIP) and the inspiratory-expiratory difference (DeltaIE) (r = 0.60, p<0.01) were found.

CONCLUSION

Patients with chronic obstructive pulmonary disease presented impaired sympathetic-vagal balance at rest. In addition, cardiac autonomic control of heart rate was associated with inspiratory muscle weakness in chronic obstructive pulmonary disease. Based on this evidence, future research applications of respiratory muscle training may bring to light a potentially valuable target for rehabilitation.

Long-acting beta2-agonists (LABA) in chronic obstructive pulmonary disease: efficacy and safety

COPD is characterized by progressive airflow obstruction which does not fully reverse to inhaled or oral pharmacotherapy. The management of patients with COPD has taken a totally new direction over the past 20 years, thank to the use of novel therapies aimed to improve and modify the natural history of COPD. Long-acting bronchodilators, including long-acting β₂-agonists (LABAs), were introduced several years ago in order to enhance improvements in lung function, health status related quality of life, and reduce the rate of exacerbations. These effects can be boosted by the combination of LABAs with long-acting anticholinergic, and/or with inhaled corticosteroids. Inhaled LABAs are commonly well tolerated although adverse effects such as tremor and palpitations are occasionally troublesome.

Arrhythmias in patients with chronic obstructive pulmonary disease (COPD): occurrence frequency and the effect of treatment with the inhaled long-acting beta2-agonists arformoterol and salmeterol

Beta-adrenergic stimulation may increase heart rate and the potential for cardiac arrhythmias. The effect of inhaled long-acting beta2-agonists (LABAs) on these outcomes was evaluated in patients with chronic obstructive pulmonary disease (COPD) in 2 double-blind randomized clinical trials. The pretreatment arrhythmia occurrence frequency in these patients was also described. In this analysis, 24-hour Holter monitoring data were pooled from 2 identically designed Phase III trials. Patients were randomized to LABA treatment or placebo for 12 weeks: a) nebulized arformoterol 15 microg BID, b) 25 microg BID, or c) 50 microg QD; d) salmeterol metered dose inhaler 42 microg BID; or e) placebo. The 24-hour Holter monitoring was performed pretreatment and at Weeks 0 (first day of dosing), 6, and 12. We assessed the proportion of patients with each of 4 arrhythmias: atrial tachycardia, atrial fibrillation/flutter, and "nonsustained"; (4-10 beats) and "sustained"; (>10 beats) ventricular tachycardia. There were 5226 Holter recordings in 1429 treated patients. At baseline, there was a low frequency of occurrence of atrial fibrillation/flutter (0.1%), nonsustained ventricular tachycardia (3.1%), and >10 beat ventricular tachycardia (0.3%). Atrial tachycardia occurred frequently (41.8%). The proportion of patients with treatment-emergent atrial tachycardia ranged from 27% to 32% and was non-significantly higher, by approximately 2%-5% (p = 0.70), in the LABA groups compared with the placebo group. The rates of the other more serious arrhythmias did not increase with LABA treatment and were similar to placebo. All treatment groups (LABA and placebo) had consistent small decreases from baseline in mean 24-hour and maximum hourly heart rate. In conclusion, in this large cohort of COPD patients with no or stable cardiac comorbidities, a high proportion ( approximately 40%) of patients were observed to have atrial tachycardia before treatment, which increased by 2%-5% with LABA treatment. More serious arrhythmias were infrequent and did not increase with inhaled LABA therapy. LABA administration did not increase mean heart rate.

Formoterol fumarate inhalation solution (Perforomist) for COPD

Formoterol fumarate is an effective treatment for chronic obstructive pulmonary disease (COPD) patients with moderate or greater severity of airflow obstruction. Published studies indicate that formoterol has a rapid onset of bronchodilation, which may enhance compliance, and sustained bronchodilation over 12 h, which produces a cumulative effect when inhaled twice daily. With long-term use, formoterol fumarate increases trough forced expiratory volume in 1 s and improves measures of hyperinflation, which correlate with relief of symptoms and a decreased need for additional short-acting bronchodilators as rescue treatment. The combination of formoterol with anticholinergic bronchodilators, especially the long-acting anticholinergic tiotropium, appears to further improve bronchodilation, decrease hyperinflation, improve symptoms and decrease the need for rescue therapy, compared with either agent alone. The availability of formoterol fumarate inhalation solution (Perforomist) for treatment of COPD now extends these benefits to patients who prefer nebulizer therapy and/or cannot use metered-dose or dry-powder inhalers effectively.

Noninvasive ventilation acutely modifies heart rate variability in chronic obstructive pulmonary disease patients

OBJECTIVE

The purpose of present study was to evaluate the acute effects of bi-level positive airway pressure (BiPAP) on heart rate variability (HRV) of stable chronic obstructive pulmonary disease patients (COPD).

METHODS

Nineteen males with COPD (69+/-8 years and with forced expiratory volume in 1s <50% of predicted) and eight healthy sedentary age-matched (69 years) males in the control group (CG) were evaluated during two conditions of controlled respiratory rate: spontaneous breathing (SB) and BiPAP (inspiratory and expiratory levels between 12-14 cmH(2)O and 4-6 cmH(2)O, respectively). Peripheral oxygen saturation (SpO(2)), end-tidal of carbon dioxide (ETCO(2)), systolic blood pressure (SBP) and R-R interval were obtained. HRV was analyzed by time (RMSSD and SDNN index) and frequency domains (high frequency - HF, low frequency - LF and HF/LF ratio).

RESULTS

Significant reduction of ETCO(2) and SBP in both groups and increase of SpO(2) in COPD group was observed during BiPAP ventilation (p<0.05). During spontaneous breathing, patients with COPD presented lower values of LF, LF/HF and higher values of HF when compared to CG (p<0.05). However, HF was significantly reduced and LF increased during BiPAP ventilation (58+/-19-48+/-15 and 41+/-19-52+/-15 un, respectively) in COPD group. Significant correlations between delta BiPAP-SB (Delta) ETCO(2) and DeltaHF were found (r=0.89).

CONCLUSIONS

Sympathetic and parasympathetic neural control of heart rate is altered in COPD patients and that BiPAP acutely improves ventilation, enhances sympathetic response and decreases vagal tonus. The improvement of ventilation caused by BiPAP was associated with reduced cardiac vagal activity in stable moderate-to-severe COPD patients.

Cardiac safety profile of nebulized formoterol in adults with COPD: a 12-week, multicenter, randomized, double- blind, double-dummy, placebo- and active-controlled trial

BACKGROUND

Recently, there have been concerns about the tolerability of long-acting (2)-agonists, including possible adverse cardiovascular effects-a particular concern in patients with chronic obstructive pulmonary disease (COPD), who are at elevated risk for cardiovascular disease.

OBJECTIVE

The aim of this study was to assess the cardiac safety profile of nebulized formoterol fumarate inhalation solution.

METHODS

Cardiac safety was assessed as part of a 12-week, randomized, double-blind, double-dummy, placebo- and active-controlled trial that was conducted at 38 centers across the United States. Male and female patients aged >/=40 years with COPD and without other significant disease were enrolled. After a 4- to 14-day, single-blind placebo run-in period, patients with COPD were randomly assigned to receive formoterol fumarate inhalation solution 20 microg BID via nebulizer (FFIS group), formoterol fumarate 12 microg BID via dry powder inhaler (FA group), or placebo. Cardiac effects-measured by changes in heart rate (HR) and ventricular premature beats; incidence of proarrhythmic events; change in corrected QT (QTc) interval; and incidence of maximum mean change in QTc >/=60 ms-were assessed using 24-hour Holter monitoring at baseline and 12 weeks; 12-lead electrocardiography at screening and weeks 4, 8, and 12; and patient diary cards.

RESULTS

A total of 351 patients with COPD were randomized (mean age, 62.8 years; 56.1% male; mean postbronchodilator forced expiratory volume in 1 second, 1.5 L). Holter monitoring found no clinically meaningful effects of FFIS or FA treatment on mean or maximum HR, ventricular premature beats, or inci dence of arrhythmic events compared with placebo. At week 12, mean (SD) changes from baseline in mean HR were -0.6 (10.9), +0.1 (11.6), and -1.4 (9.4) bpm in the FFIS, FA, and placebo groups, respectively. The incidence of mean maximum changes in QTc >/=60 ms at any time during the 12-week treatment period were 1.6%, 1.8%, and 1.8% with FFIS, FA, and placebo, respectively. Treatment-emergent cardiac adverse events (AEs) occurred in 4.1%, 3.5%, and 4.4% of patients in the FFIS, FA, and placebo groups; withdrawals due to possible cardiac AEs occurred in 1 patient per treatment group. No deaths or serious cardiac AEs occurred during the treatment period.

CONCLUSION

In this COPD population, no clinically significant cardiac effects were found with twicedaily treatment with nebulized formoterol fumarate inhalation solution.

Global Initiative on Obstructive Lung Disease (GOLD) classification of lung disease and mortality: findings from the Atherosclerosis Risk in Communities (ARIC) study

OBJECTIVE

To determine whether a modified Global Initiative on Obstructive Lung Diseases (GOLD) classification of chronic obstructive pulmonary disease (COPD) predicts mortality in a cohort of subjects followed for up to 11 years.

METHODS

We analyzed data from 15,759 adult participants, aged 43-66 years at baseline, in the Atherosclerosis Risk in Communities (ARIC) study. All baseline and follow-up data were available for 15,440 (97.9%) of the initial participants. We classified subjects using a modification of the GOLD criteria for COPD (prebronchodilator forced expiratory volume in 1s (FEV(1)) stratification of disease severity), and added a "restricted" category (FEV(1)/FVC>70% and FVC<80% predicted). We used Cox proportional hazard models to determine the risk of impaired lung function on subsequent mortality, after adjusting for age, race, sex and smoking status.

RESULTS

1242 (8.0%) subjects died by the end of 1997. The overall rate of death was 8.9 per 1000 person years, but varied from 5.4/1000 among normal subjects to 42.9/1000 among subjects with GOLD Stage 3 or 4 COPD. After adjusting for covariates, all GOLD categories, along with the restricted category, predicted a higher risk of death: GOLD Stage 3 or 4, hazard ratio (HR) 5.7, 95% confidence interval (CI) 4.4, 7.3; GOLD Stage 2 HR 2.4, 95% CI 2.0, 2.9; GOLD Stage 1 HR 1.4, 95% CI 1.1, 1.6; GOLD Stage 0 HR 1.5, 95% CI 1.3, 1.8; and restricted HR 2.3, 95% CI 1.9, 2.8.

CONCLUSION

The modified GOLD classification system of COPD predicts mortality in this cohort of middle-aged Americans followed for up to 11 years.

Inhaled beta2-adrenoceptor agonists: cardiovascular safety in patients with obstructive lung disease

Although large surveys have documented the favourable safety profile of beta(2)-adrenoceptor agonists (beta(2)-agonists) and, above all, that of the long-acting agents, the presence in the literature of reports of adverse cardiovascular events in patients with obstructive airway disease must induce physicians to consider this eventuality. The coexistence of beta(1)- and beta(2)-adrenoceptors in the heart clearly indicates that beta(2)-agonists do have some effect on the heart, even when they are highly selective. It should also be taken into account that the beta(2)-agonists utilised in clinical practice have differing selectivities and potencies. beta(2)-agonist use has, in effect, been associated with an increased risk of myocardial infarction, congestive heart failure, cardiac arrest and sudden cardiac death. Moreover, patients who have either asthma or chronic obstructive pulmonary disease may be at increased risk of cardiovascular complications because these diseases amplify the impact of these agents on the heart and, unfortunately, are a confounding factor when the impact of beta(2)-agonists on the heart is evaluated. Whatever the case may be, this effect is of particular concern for those patients with underlying cardiac conditions. Therefore, beta(2)-agonists must always be used with caution in patients with cardiopathies because these agents may precipitate the concomitant cardiac disease.

Hypoxemia and autonomic nervous dysfunction in patients with chronic obstructive pulmonary disease

OBJECTIVE

Hypoxemia is known to be associated with abnormal heart rate variability (HRV) that can reflect the severity of the illness and may have prognostic value in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to examine the relationship between the derangements in cardiac autonomic nervous function and the oxygenation status or degree of airflow obstruction in COPD patients by using HRV analysis.

METHODS

Thirty clinically stable COPD patients and 18 age-matched normal subjects were included in this study. The normalized high-frequency power (nHFP) and the low-/high-frequency power ratio (LFP/HFP) were used as indices of vagal activity and sympathovagal balance, respectively.

RESULTS

Although global HRV measures were all significantly decreased, the nHFP and LFP/HFP of COPD patients were not significantly different from those of normal controls. There was a negative correlation between nHFP and arterial partial pressure of O2 (PaO2) and a positive correlation between LFP/HFP and PaO2 in COPD patients. No correlation existed between forced expiratory volume in 1.0 s/forced vital capacity (FEV1/FVC), % predicted of FEV1 (%FEV1) and nHFP or LFP/HFP in COPD patients.

CONCLUSIONS

The resting autonomic nervous function of COPD patients is not different from that of normal controls. Though the degree of airway narrowing is not related to the cardiac autonomic nervous function, chronic hypoxemia can lead to enhanced cardiac vagal activity and depressed sympathetic activity in COPD patients. A worse oxygenation status is associated with increased cardiac vagal and decreased cardiac sympathetic activities in COPD patients.

Increased QT dispersion: a negative prognostic finding in chronic obstructive pulmonary disease

OBJECTIVE

Chronic obstructive pulmonary disease (COPD) is a highly prevalent syndrome, deeply affecting the cardiovascular system as well as the lungs. We investigated the prognostic role of the QT interval and QT dispersion (QTD) in predicting all-cause, respiratory and cardiovascular mortality in COPD, and the relationship between these electrocardiographic parameters and pulmonary function in a prospective longitudinal study.

METHODS

We studied 246 COPD patients without significant co-morbidities, with a mild to moderate functional impairment, admitted to the Department of Internal Medicine from January 1995 to December 2001, performing a 5-year mean follow-up (5-116 months) up to August 2004. After clinical stabilisation, an electrocardiogram and functional respiratory tests were obtained, allowing measurement of the QT interval and QTD, forced vital capacity (FVC), forced expiratory volume at 1 s (FEV1), inspiratory capacity, FEV1/FVC ratio, partial oxygen pressure and partial carbon dioxide pressure in arterial blood.

RESULTS

At the end of the follow-up period, 81 patients were dead, 165 still alive; 36 died because of respiratory causes, 23 because of cardio-cerebrovascular events, 21 because of cancer (mainly lung cancer). A significant high incidence of sudden cardiac death was observed. QTD and QTcD showed a significant relationship with respiratory functional parameters. Maximal QT interval, QTcD and QTD appear to be independent predictors of all-cause, cardiovascular and respiratory mortality (relative risk 1.94, 3.22, 2.88, respectively). Age > 65 years, partial oxygen pressure < 60 mmHg and inspiratory capacity < 80% of the predicted value were the only other independent predictive parameters.

CONCLUSIONS

Maximal QT interval, QTD and QTcD are independent predictors of mortality. A significant incidence of cardiac sudden death was observed. These findings suggest the need for a global and multidisciplinary risk assessment in COPD patients. Intriguing relationships between the QTD and functional respiratory parameters were also observed.

Neurohumoral activation as a link to systemic manifestations of chronic lung disease

COPD is a major cause of death and disability worldwide. Treatment of COPD improves lung function but is unlikely to slow the steady downhill course of the disease or reduce mortality. In COPD, numerous abnormalities can be found outside the lung. These include systemic inflammation, cachexia, and skeletal muscle dysfunction. Thus, COPD has been called a systemic disease. Convincing data demonstrate that COPD causes neurohumoral activation. By precedents derived from chronic heart failure and other diseases characterized by neurohumoral activation, we propose that the negative consequences of neurohumoral activation, namely inflammation, cachexia, effects on ventilation, and skeletal muscle dysfunction, give rise to a self-perpetuating cycle that contributes to the pathogenesis of COPD, and which may involve respiratory muscle dysfunction as well as systemic inflammation. This concept may further help explain the increased cardiovascular morbidity and mortality in COPD patients. Currently, little is known about the effect of treatments directed at neurohumoral activation and COPD. As this aspect of COPD becomes better understood, new insights may direct novel therapeutic approaches.

Relationship between the frequency of autonomic dysfunction and the severity of chronic obstructive pulmonary disease

OBJECTIVE

The relationship between the frequency of autonomic dysfunction (AD) and the severity of chronic obstructive pulmonary disease (COPD) has not been exactly known, despite its importance in the pathogenesis of COPD. Therefore, we aimed to evaluate the relationship between the clinical stage severity of the disease and the frequency of AD in COPD patients.

METHODS

The frequency and type of AD were determined according to the clinical severity of 35 stable COPD patients. The results were compared between the mild and moderate-severe COPD groups. Sympathetic system (SS) was evaluated with sympathetic skin response (SSR), QT and QTc intervals (ms) analyses. Parasympathetic system was evaluated with the heart rate interval variations (RRIV).

RESULTS

For the total group, an AD was detected in 20 patients (57%), a parasympathetic dysfunction (PD) in 14 (40%), a mixed-type dysfunction in five (14%) and a sympathetic dysfunction (SD) in only one patient (3%). For the 12 mildly affected patients, there were cases of isolated SD in only one patient (8.5%), isolated PD in five (42%) and AD in six patients (50%). For the 23 moderate-severe COPD patients, mixed AD was detected in five patients (22%), isolated PD in nine (39%) and AD in 14 patients (61%). There were no significant differences between the two patient groups, neither for isolated parasympathetic and sympathetic, mixed form nor for total AD (P>0.05).

CONCLUSIONS

The results suggested that PD was dominant in patients with COPD. However, the frequencies of autonomic parasympathetic and sympathetic dysfunction did not increase significantly with the severity of COPD. The severity of hypoxemia and/or airflow limitation may not be the only unique or definite reason for AD in COPD, as there was not an exact correlation between the presence of AD and the severity of airflow limitation and hypoxemia.

Post-exercise heart rate recovery and mortality in chronic obstructive pulmonary disease

Abnormal heart rate recovery (HRR) after exercise, a marker of cardiac autonomic dysfunction, is associated with poor prognosis in various populations. As chronic obstructive pulmonary disease (COPD) is associated with cardiac autonomic dysfunction, we tested the hypothesis that patients with COPD have a lower HRR than healthy people, and evaluated whether a delay in HRR is associated with an increased risk of mortality in COPD. The records of 147 COPD patients were reviewed (65.1+/-9.1 years, mean+/-sd, 42 women/105 men, forced expiratory volume in 1s (FEV1): 42+/-15% predicted) and compared to 25 healthy subjects (61.6+/-4.5 years, 5 women/20 men, FEV1: 100+/-14% predicted) during recovery after an exercise test. Heart rate was measured at peak exercise and at 1-min recovery, the difference between the two being defined as HRR (11+/-9 beats in COPD patients vs. 20+/-9 beats in healthy subjects, P < 0.0001). During a mean follow-up of 43.1+/-22.0 months, 32 patients died. Abnormal HRR (14 beats) was a strong predictor of mortality in COPD patients (adjusted hazard ratio: 5.12, 95% CI [1.54-17.00]). In conclusion, COPD patients have a lower HRR than healthy subjects, and have a worse prognosis when presenting abnormal HRR.

The pulmonary and extra-pulmonary effects of high-dose formoterol in COPD: a comparison with salbutamol

OBJECTIVES

Formoterol, a beta(2) agonist with a rapid onset of effect and long duration of action, can be used as maintenance and reliever medication for asthma and COPD. We compared the pulmonary and extra-pulmonary effects of cumulative doses of formoterol and salbutamol in patients with COPD to assess efficacy and safety.

METHODOLOGY

In a randomized, double-blind, cross-over study, 12 patients with moderate to severe COPD inhaled, via Turbuhaler, 10 doses of formoterol (total metered dose, 120 microg, equivalent to a 90- microg delivered dose), salbutamol (total metered dose 2000 microg) or placebo at 2-min intervals on separate days. The effects on lung function (FEV(1) and PEF), heart rate, blood pressure, oxygen saturation, corrected QT interval (QTc), T-wave height and plasma potassium were assessed before each dose, 15 min after each dose, and at half-hourly intervals for 3 h following the final dose.

RESULTS

Inhalation of formoterol or salbutamol resulted in significant improvement in lung function (measured 30 min after the last dose) when compared with placebo. There were no clinically important or statistically significant changes in heart rate, QTc, T-wave height, plasma potassium, oxygen saturation, or systolic and diastolic blood pressures with formoterol or salbutamol. One patient developed ventricular trigeminy after both formoterol and salbutamol. She had had ventricular ectopics on her screening electrocardiogram.

CONCLUSION

Formoterol and salbutamol both produced significant improvement in lung function and were similarly well tolerated in high doses, as might be taken by a patient for relief of COPD symptoms.

Acute antiarrhythmic effects of bi-level positive airway pressure ventilation in patients with acute respiratory failure caused by chronic obstructive pulmonary disease: a randomized clinical trial

BACKGROUND

Cardiac arrhythmias are common in patients with chronic obstructive pulmonary disease (COPD) and acute respiratory failure (ARF) and may be life threatening. Recently, non-invasive positive pressure ventilation has been advanced as a useful tool in COPD patients with ARF. This method can affect global cardiac performance through its effects on many determinants of cardiac function and may be helpful in reducing arrhythmias.

OBJECTIVE

To assess the role of bi-level positive pressure ventilation (BiPAP) in the management of cardiac arrhythmias in patients with ARF caused by COPD.

METHODS

We studied 30 consecutive patients with ARF related to COPD diagnosed according to American Thoracic Society criteria. All subjects were smokers; the mean age was 68 +/- 7 years. They were randomly assigned to receive BiPAP plus standard therapy (group 1) or standard therapy alone (group 2). Patients randomized to receive BiPAP were first fitted with a nasal mask, and BiPAP was administered after 12 h of standard therapy. All subjects were studied using a computerized 24-hour Holter ECG. Blood gases, plasma electrolytes, respiratory rate and blood pressure were measured at study entry, at 30, 60 and 120 min and then every 3 h.

RESULTS

Heart rate decreased from 86.08 +/- 7.86 to 74.92 +/- 5.39 in group 1 (p < 0.001) versus 82.77 +/- 8.78 to 75.82 +/- 6.76 in group 2 (p = 0.033). Ventricular premature complexes decreased from 564.38 +/- 737.36 to 166.15 +/- 266.26 in group 1 (p < 0.001) versus 523.38 +/- 685.75 to 353.54 +/- 469.93 in group 2 (p = 0.021). Atrial premature complexes decreased from 570.00 +/- 630.36 to 152.31 +/- 168.88 in group 1 (p < 0.001) versus 513.77 +/- 553.81 to 328.62 +/- 400.81 in group 2 (p = 0.021).

CONCLUSIONS

Cardiac arrhythmias decreased significantly in both groups after the start of both treatments, although data obtained from group 1 revealed a more important statistical significance. Our data seem to support the hypothesis that BiPAP may be a useful tool in managing COPD patients with ARF and mild arrhythmias.

Association of an abnormal exercise heart rate recovery with pulmonary function abnormalities

BACKGROUND

Heart rate recovery (HRR) after exercise correlates with decreased vagal tone and mortality. Patients with COPD may have altered autonomic tone. We sought to determine the association of HRR with spirometry measures of pulmonary function.

METHODS

We analyzed 627 patients (mean [+/- SD] age, 58 +/- 12 years; 65% men; mean FEV(1), 2.6 +/- 0.9 L, 80 +/- 20% predicted; patients receiving inhaled beta(2) agonist therapy, 10%; patients receiving inhaled anticholinergic therapy, 3%; patients receiving inhaled steroids, 5%; patients receiving oral prednisone, 4%) who had undergone maximal exercise testing and had undergone pulmonary function tests < 1 year apart. Patients with heart failure, pacemakers, and atrial fibrillation were excluded. Abnormal HRR was defined as a fall in heart rate during the first minute after exercise of <or= 12 beats/min (<or= 18 beats/min with stress echocardiography). Patients were divided into quartiles based on FEV(1) percent predicted.

RESULTS

An abnormal HRR was seen in 229 patients (36%). The mean FEV(1) values broken into quartiles 1 to 4 were 54 +/- 11% predicted, 74 +/- 3% predicted, 87 +/- 4% predicted, and 106 +/- 10% predicted. In smokers and nonsmokers, a worsening FEV(1) percent predicted was associated with an abnormal HRR. In a multivariable model accounting for confounding factors including medications and functional capacity, the predictors of an abnormal HRR included FEV(1) percent predicted (adjusted odds ratio for 1 SD decrease, 1.32; 95% confidence interval, 1.07 to 1.65; p = 0.0004), impaired functional capacity, male gender, and age.

CONCLUSIONS

Abnormalities found on spirometry are associated with abnormal HRR, which may reflect an altered autonomic tone associated with pulmonary dysfunction, either obstructive or restrictive in nature.

Cardiovascular safety of salmeterol in COPD

BACKGROUND

Patients with COPD have an increased risk of cardiovascular disease. Despite the clinical benefits of long-acting beta-agonist agents in the treatment of COPD, patients may be at an increased risk of cardiovascular toxicity, including tachyarrhythmia due to beta-adrenergic stimulation.

OBJECTIVE

To evaluate the cardiovascular safety of salmeterol in COPD patients by conducting a pooled analysis of cardiovascular safety data.

DESIGN

Randomized, double-blind, parallel group, multiple-dose studies, which included salmeterol, 50 micro g bid, and placebo arms.

STUDY SELECTION

Seven of a total of 17 studies met the predefined inclusion requirements and were pooled. A total of 1,443 patients received placebo, while 1,410 patients received salmeterol, 50 micro g bid. The median duration of treatment was 24 weeks (range, 12 to 52 weeks).

RESULTS

Treatment with salmeterol, 50 micro g bid, showed no increased risk of cardiovascular adverse events (AEs) compared with placebo (relative risk, 1.03; 95% confidence interval, 0.8 to 1.3; p = 0.838). Both groups had a similar incidence of cardiovascular events (8%), including cardiovascular deaths. The incidence of cardiovascular AEs increased with age, concurrent cardiovascular conditions, and treatment with antiarrhythmic/bradycardic agents, although increases were comparable in both treatment groups. There were no episodes of sustained ventricular tachycardia, and no clinically significant differences were observed in 24-h heart rate, ventricular and supraventricular ectopic events, qualitative ECGs, QT intervals, or vital signs between the salmeterol, 50 micro g bid, group and the placebo group. Similar findings were observed when patients were stratified for age of > 65 years or the known presence of cardiovascular disease.

CONCLUSIONS

Treatment with salmeterol, 50 micro g bid, does not increase the risk of cardiovascular AEs in this population of COPD patients compared with placebo.

Lung function and mortality in the United States: data from the First National Health and Nutrition Examination Survey follow up study

BACKGROUND

A study was undertaken to define the risk of death among a national cohort of US adults both with and without lung disease.

METHODS

Participants in the first National Health and Nutrition Examination Survey (NHANES I) followed for up to 22 years were studied. Subjects were classified using a modification of the Global Initiative for Chronic Obstructive Lung Disease criteria for chronic obstructive pulmonary disease (COPD) into the following mutually exclusive categories using the forced expiratory volume in 1 second (FEV(1)), forced vital capacity (FVC), FEV(1)/FVC ratio, and the presence of respiratory symptoms: severe COPD, moderate COPD, mild COPD, respiratory symptoms only, restrictive lung disease, and no lung disease. Proportional hazard models were developed that controlled for age, race, sex, education, smoking status, pack years of smoking, years since quitting smoking, and body mass index.

RESULTS

A total of 1301 deaths occurred in the 5542 adults in the cohort. In the adjusted proportional hazards model the presence of severe or moderate COPD was associated with a higher risk of death (hazard ratios (HR) 2.7 and 1.6, 95% confidence intervals (CI) 2.1 to 3.5 and 1.4 to 2.0), as was restrictive lung disease (HR 1.7, 95% CI 1.4 to 2.0).

CONCLUSIONS

The presence of both obstructive and restrictive lung disease is a significant predictor of earlier death in long term follow up.