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PubMed2004

Reduction in hospitalization rates following cardiac resynchronisation therapy in cardiac failure: experience from a single centre.

AIMS: Frequent, lengthy hospital admissions for congestive cardiac failure (CCF) result in excessive health care costs. Cardiac resynchronisation therapy (CRT) is a novel treatment option for patients with CCF and associated cardiac conduction defects. We investigated whether CRT resulted in significant improvements in New York Heart Association (NYHA) symptom class, exercise tolerance, and hospitalization rates in such patients. METHODS: Twenty-seven patients who underwent CRT in a single centre were studied, with NYHA symptom class, exercise tolerance and hospitalization rates noted in the 12 months prior to and following CRT. RESULTS: Following 12 months of CRT, NYHA symptom class improved from 3.3 +/- 0.5 to 2.1 +/- 0.4 (P < 0.05). Exercise tolerance, assessed by 6 min hall walk test increased by 64% from 195 +/- 114 m to 320 +/- 85 m (P = 0.007). Days in hospital for stabilisation of cardiac failure decreased by 98% from 472 to 9 days (P < 0.001). Significant hospitalization cost savings of 201,684 euros were calculated, with an overall saving of 12,420 euros. CONCLUSIONS: These data demonstrate that CRT results in significant improvement in clinical parameters, and considerable reductions in hospital admissions, and costs in patients with CCF.

Aged↗
PubMedDate not supplied

[Effects of positive oscillatory expiratory pressure on functional condition of patients with chronic diseases of the lungs].

Clinical and cardiorespiratory findings in patients with chronic obstructive pulmonary disease (COPD) stage I and IIA and the results of exercise tolerance tests in patients with mild and moderate bronchial asthma (BA) at a remission stage were studied for effects of positive oscillatory expiratory pressure created in respiration through flatter on exercise adaptation. It was proved that breathing through flatter before exercise tolerance test raises tolerance to exercise in COPD patients, modifies a cardiorespiratory response in direction of its optimization and lowers nonspecific bronchial hyperreactivity in BA patients.

Adult↗
PubMedDate not supplied

A comparison of the effects of unilateral thyroarytenoid lateralization versus cricoarytenoid laryngoplasty on the area of the rima glottidis and clinical outcome in dogs with laryngeal paralysis.

OBJECTIVE: To compare the clinical effects of unilateral thyroarytenoid lateralization versus unilateral cricoarytenoid laryngoplasty for the treatment of canine laryngeal paralysis. Study Design-A prospective, clinical trial. ANIMALS: Twenty client-owned dogs admitted to Glasgow University Veterinary Hospital (GUVH) between 1997 and 1999 with a diagnosis of laryngeal paralysis. METHODS: A thorough evaluation of each dog was undertaken that included history, physical and neurologic examinations, complete blood count, serum biochemistry profile, serum thyroxine (T4) level, and thyroid-stimulating hormone (TSH) assay. The exercise tolerance of each dog was investigated by assessing respiratory rate and arterial blood gas analysis at rest and after 5 minutes of mild exercise. Animals were included in the study on the basis of a definitive diagnosis of laryngeal paralysis made by endoscopic observation of the larynx in the lightly anesthetized patient. The animals were randomly assigned to 1 of 2 treatment groups: unilateral thyroarytenoid lateralization or unilateral cricoarytenoid laryngoplasty, with all procedures being performed by the same surgeon. Video images of the rima glottidis were recorded pre- and postoperatively using video endoscopy. Video images were digitized and the area of the rima glottidis measured using image-analysis software. An increase in the area of the rima glottidis was expressed as a percentage of the preoperative area. All animals were reassessed 6 weeks' postoperatively, and exercise tolerance tests were repeated. RESULTS: The mean increase in the area of the rima glottidis postoperatively when compared with the preoperative area was 140% for those animals undergoing unilateral thyroarytenoid lateralization (range, 120%-158%) and 207% for those animals undergoing unilateral cricoarytenoid laryngoplasty (range, 183%-228%). This difference was statistically significant (P < .0001). At the 6-week postoperative examination, there was no significant difference in improvement between the 2 groups when compared on either a clinical basis or exercise tolerance tests. The mean surgical time in the 2 groups was 25 minutes for thyroarytenoid lateralization and 43 minutes for cricoarytenoid laryngoplasty. This was a statistically significant difference (P = .002). CONCLUSION: Although increase in area of the rima glottidis was significantly greater after unilateral cricoarytenoid laryngoplasty compared with unilateral thyroarytenoid lateralization, no difference in clinical outcome could be detected. However, the cricoarytenoid laryngoplasty procedure required significantly more surgical time. CLINICAL RELEVANCE: Both unilateral cricoarytenoid laryngoplasty and unilateral thyroarytenoid lateralization are successful methods for the treatment of laryngeal paralysis; however, thyroarytenoid lateralization requires less surgical time to perform.

Animals↗
PubMed1994

Randomised controlled trial of respiratory rehabilitation.

Disability associated with chronic obstructive pulmonary disease has led to the development of rehabilitation programmes that aim to increase exercise tolerance and improve quality of life. Many reports of the benefits of rehabilitation have been from uncontrolled trials and unsupervised programmes. In view of the commitment asked of patients, their families, and health-care professionals, rehabilitation should be justified by a demonstration of sustained improvement over conventional treatment. We undertook a prospective randomised controlled trial of respiratory rehabilitation in 89 subjects (44 men, 45 women) aged 66 (SD 7) years with severe but stable chronic obstructive pulmonary disease who received rehabilitation or conventional community care. The treatment group were rehabilitated as inpatients for 8 weeks and supervised as outpatients for 16 weeks. Primary outcome measures of exercise tolerance and quality of life were made at baseline and repeated at 12, 18, and 24 weeks. The difference between baseline and last follow-up was significant for 6 min walk distance (37.9 m [95% CI 10.8-65.0], p = 0.0067) and submaximal cycle time (4.7 min [2.1-7.3]). There were also significant differences in questionnaire assessment of dyspnoea (p = 0.0061), emotional function (p = 0.0150), mastery (p = 0.0002), and dyspnoea index (p = 0.0053). Improvements in exercise tolerance and quality of life can be achieved and sustained for 6 months in patients undergoing respiratory rehabilitation compared with those receiving conventional care.

Aged↗
PubMed1999

[Functional activity of platelet guanylate cyclase and cardiac hemodynamics in patients with chronic heart failure and relevant changes after treatment with isosorbide-5-mononitrate].

AIM: To study effects of long-term administration of isosorbide-5-mononitrate (monochinquare retard-MR) on functional activity of soluble guanylate cyclase (GC), cardiohemodynamics and exercise tolerance in patients with coronary heart disease (CHD) complicated by chronic cardiac failure (CCF). MATERIALS AND METHODS: The trial included 20 males aged 58 to 77 years with CHD, effort angina (NYHA class II-III), CCF (NYHA class I-II). Endothelial function was assessed before the treatment and 12 weeks after it by indirect measurement of production of endothelial relaxing factor (NO)--by activation of platelet soluble GC in the presence of its activators: L-arginine, disulphide, sodium nitroprusside and protoporfirine IX. Hemodynamic parameters, morphofunctional condition of the heart, exercise tolerance test results were compared with changes in GC functional activity after 12 weeks of MR monotherapy. RESULTS: Two types of the changes were revealed. Type I (n = 14): high GC basal activity and low activity before the treatment with normalization of all the parameters after the treatment. Type II (n = 6): initially normal basal activity and GC activation with their lowering after the treatment. MR in a single daily dose 50 mg given for 12 weeks has improved morphofunctional cardiac parameters with a reduction of left ventricular volume, a 8.3% increase in the ejection fraction and a 117% increase in exercise tolerance. GC activity inhibition was recorded in some cases, in angina class III, in particular. In patients with normalization of GC activity the response was higher than in those who demonstrated inhibition of GC activity. CONCLUSION: MR therapeutic action may be due to enhancement of soluble GC activity which was observed in 70% of the cases.

Administration, Oral↗
PubMed1993

[Comparison of the effects and safety of atenolol and nifedipine in the treatment of angina pectoris].

The effects of atenolol (100 mg/day) and nifedipine (60 mg/day) on angina symptoms and exercise tolerance were compared in an open, randomized study. Twelve-week treatment period was compared with two weeks of placebo treatment in 51 patients with chronic stable angina pectoris. Mean frequency of angina attacks decreased significantly from 8.3 to 1.6 attacks per week after atenolol treatment (p < or = 0.05). Both drugs increased exercise tolerance to development of signs of ischemia on electrocardiogram (p < or = 0.05) and increased maximal exercise tolerance as well (p < or = 0.05). Mean ST segment depressions at peak exercise were significantly decreased after treatment with atenolol and nifedipine (p < or = 0.05). Both drugs also increased total exercise capacity in comparison with placebo period, stated as 100%:192% after atenolol and to 191% after nifedipine. No significant changes of heart rate and blood pressure were noted during treatment period. Twelve patients did not finished study, two of them suffered myocardial infarction with death in one of them (atenolol group, other one nifedipine group). Thus, atenolol in one daily dose is as effective as nifedipine in chronic stable angina patients when administered as single therapy.

Adult↗
PubMed1982

Effects of combined alpha- and beta-blockade by labetalol in patients with coronary artery disease.

1 The effect of labetalol 100 mg orally twice daily on exercise tolerance has been compared with placebo in 19 normotensive subjects with angiographic evidence of coronary artery disease. 2 Labetalol, at the same work load as during placebo exercise, significantly reduced systolic and diastolic blood pressures, as well as heart rate and rate-pressure product. 3 Similarly, ST segment depression was reduced by labetalol from 2.0 +/- 0.4 to 1.36 +/- 0.6 mm (P less than 0.001), thus enabling an increase in exercise tolerance from a control value of 83.7 +/- 18 to 95.3 +/- 19 W (P less than 0.005). 4 In seven other patients, also with coronary artery disease, the haemodynamic effects of a single 0.6 mg/kg intravenous dose of the drug was evaluated during exercise. 5 Compared with conditions during control exercise, labetalol induced a significant reduction in rate-pressure product from 17228 +/- 2375 to 13445 +/- 2404 mmHg/min (P less than 0.005) and in peripheral vascular resistance from 612.0 +/- 61.2 to 512.7 +/- 36.2 dyn cm-5 m-2 (P less than 0.0025). These events were not accompanied by any change in cardiac index and in dP/dT left ventricular end-diastolic pressure (LVEDP) ratio. 6 These data suggest that labetalol may induce reduction in myocardial oxygen consumption, thereby increasing exercise tolerance in patients with coronary artery disease, without impairment of left ventricular performance.

Adult↗
PubMed1991

[Cardiac contractility in males with post-infarction cardiac sclerosis as evidenced by ultrasonic scanning].

The relationship was examined between the severity of heart failure, the degree of asynergy and exercise tolerance in 40 males under 60 years with postinfarction cardiosclerosis. Fifteen healthy males were matched for as a control. Echocardiography was performed before and after bicycle ergometer exercise test, allowing the patients to be divided into 4 groups: Groups 1 and 2 without an ischemic response in the absence or presence of akinesia or dyskinesia, respectively; Groups 3 and 4 with an ischemic response in the absence or presence of akinesia or dyskinesia, respectively. The lowest exercise tolerance was observed in Group 4. Echographic findings showed that the overall left ventricular contractility was diminished in all the patients; there was no noticeable quantitative difference in the values between the groups. No differences were found in segmental ejection fractions. The combination of ischemic response to exercise tolerance and akinesia-dyskinesia asynergy indicates a more severe disease of the coronary bed and myocardium.

Adult↗
PubMed1997

Effects of psychotherapy in moderately severe COPD: a pilot study.

Anxiety is common in the "pink puffer" syndrome associated with chronic obstructive pulmonary disease (COPD). The degree of anxiety correlates well with perceived dyspnoea. This pilot study examines the effect of group psychotherapy on anxiety, exercise tolerance, dyspnoea and quality of life. Ten patients with moderately severe, stable COPD (mean forced expiratory volume in one second (FEV1)-1.15 L) had six 90 min sessions of cognitive and behavioural psychotherapy at weekly intervals. Patients completed the Hospital Anxiety and Depression Scale (HADS), Medical Research Council Questionnaire (MRCQ) and St George's Respiratory Questionnaires (SGRQ), 1 week before and after therapy. FEV1, forced vital capacity (FVC), slow vital capacity (SVC), blood gas tensions and 6 min walking distance (6MWD) were measured. Eight control patients attended weekly for lung function and 6MWD for 6 weeks, but had no psychotherapy. Mean baseline HADS score was significantly higher in the psychotherapy group (12) than in controls (7), but otherwise there were no differences in lung function, blood gas tensions, 6MWD, or the other questionnaire scores between groups. After treatment, the physiological and psychological parameters where unchanged in both groups with the exception of the mean 6MWD, which had improved in the psychotherapy group only, from 351 to 423 m (p<0.001), an increase of 24%. Three months after treatment, the 6MWD was still 16% above the baseline value (p=0.02). In conclusion, six sessions of cognitive and behavioural psychotherapy produced a sustained improvement in exercise tolerance in a group of 10 anxious patients with severe chronic obstructive pulmonary disease, without any change in anxiety scores on the Hospital Anxiety and Depression Scale. Further studies of more prolonged, intensive psychotherapy would establish whether better symptom and quality of life scores accompany more dramatic increases in exercise tolerance in "pink puffers".

Aged↗
PubMed2001

Multivariable assessment of the 6-min walking test in patients with chronic obstructive pulmonary disease.

Functional exercise tolerance in patients with chronic obstructive pulmonary disease (COPD) is often assessed by the 6-min walking test (6MWT). To assess if the use of multiple factors adds to walking distance in describing performance in the 6MWT, an exploratory factor analysis was performed on physiological measurements and dyspnea ratings recorded during testing. Eighty-three patients with mild to severe COPD performed repeated 6MWTs before inpatient pulmonary rehabilitation. Factor analysis on 15 variables yielded a stable four-factor structure explaining 78.4% of the total variance. Recorded heart rate variables contributed to factor 1 (heart rate pattern), walking distance, heart rate increase, and decrease contributed to factor 2 (endurance capacity), oxygen desaturation variables contributed to factor 3 (impairment of oxygen transport), and dyspnea and effort variables contributed to factor 4 (perceived symptoms). Walking distance decreased in half of the 53 patients measured posttreatment, but self-perceived change in exercise tolerance improved in 84% and was explained by change in walking distance, by less desaturation, and by less dyspnea (R(2) = 0.55, p = 0.005). Qualitative analysis showed that 29 of 53 patients improved in three or four factors. Performance in the 6MWT can be described with four statistically independent and clinically interpretable factors. Because clinically relevant changes consist of more than only walking distance, assessment of functional exercise tolerance in patients with COPD improves by reporting multiple variables.

Adult↗
PubMed1980

[Evaluation criteria for load tests with ischemic heart disease patients with intact coronary arteries and with ones affected by arteriosclerosis].

Examination of 65 patients with ischemic heart disease (61 males and 4 females) whose ages ranged from 29 to 59 was conducted. Selective coronarography demonstrated stenosing atherosclerosis of the coronary arteries in 34 patients and intact coronary vessels in 31. Correlation analysis of the exercise tolerance value depending on the degree of the overall affection of the heart arteries revealed a reverse dependence (r = -0.68) between these indices. The criterion for discontinuing exercise tolerance tests on a bicycle ergometer in patients with involvement of the coronary arteries in atherosclerosis were changes in the ECG in 67.6% and an attack of angina pectoris in 85,3% of cases. In the group of individuals with intact coronary vessels and positive exercise tolerance test 41.7% had changes on the ECG and 79,6% had an attack of angina. It is shown that in patients with ischemic heart disease whose coronary arteries are intact or involved in atherosclerosis, angina pectoris is more sensitive as a criterion of myocardial ischemia than the changes on the ECG.

Adult↗
PubMed1990

Randomised, double-blind, three-way cross-over study of dilevalol 200 and 400 mg and atenolol 100 mg once-daily in patients with chronic stable angina pectoris.

Eighteen male patients (aged 40-66 years) with confirmed ischaemic heart disease and a minimum of four angina attacks per week were included in a double-blind comparison of dilevalol 200 mg, dilevalol 400 mg and atenolol 100 mg. Following a one-week placebo run-in period patients were randomly allocated to one of the three treatments, after which they crossed to the remaining two treatments according to a balanced Latin square design. Each treatment was given once-daily over four weeks. Symptom-limited treadmill exercise testing using a modified Bruce protocol was performed at the end of placebo, and after each treatment around 24 hours post-dosing. The mean exercise time on placebo was 7.0 (+/- 0.91) minutes which changed to 7.8 (+/- 0.93) minutes on dilevalol 200 mg, 7.3 (+/- 0.88) minutes on dilevalol 400 mg and 8.2 minutes (+/- 1.06) on atenolol 100 mg. Nine patients had a greater exercise tolerance on dilevalol (200 or 400 mg), and nine a greater exercise tolerance on atenolol. Maximum exercise heart rate on placebo was 113 (+/- 5.0) beats per minute (bpm) which was reduced to 101 (+/- 3.6), 96 (+/- 2.7) and 98 (+/- 4.9) bpm. on dilevalol 200 mg, dilevalol 400 mg and atenolol 100 mg, respectively. Correspondingly, the rate-pressure product was reduced from 18.1 (x 10(3)) units on placebo to 14.8, 13.4 and 14.4 (x 10(3)) units on each treatment. Pairwise comparisons by the least square mean procedure showed no significant differences between treatments for any of the measured parameters. All treatments caused a reduction in both angina attack rates and trinitrate consumption.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMedDate not supplied

Electrical spinal-cord stimulation for painful diabetic peripheral neuropathy.

BACKGROUND: Conventional treatment for painful peripheral diabetic neuropathy is largely symptomatic and often ineffective, with unacceptable side-effects. We tested electrical spinal-cord stimulation for the management of chronic neuropathic pain. METHODS: Ten diabetic patients who did not respond to conventional treatment (mean age 51 [SD 9.3] years, six with type II diabetes, mean duration of diabetes 12 [6.3] years, mean duration of neuropathy 5 [2.1] years) were studied. The electrode was implanted in the thoracic/lumbar epidural space. Immediate neuropathic pain relief was assessed by visual analogue scale (VAS) after connecting the electrode, in a random order, to a percutaneous electrical stimulator or to a placebo stimulator. Exercise tolerance was assessed on a treadmill. FINDINGS: Eight subjects had statistically significant pain relief with the electrical stimulator (p < 0.02) and were therefore converted to a permanent system. Statistically significant relief of both background and peak neuropathic pain was achieved at 3 months (n = 7, p = 0.016), at 6 months (n = 7, p = 0.03), and at the end of the study (14 months, n = 7, background pain p = 0.06, peak pain p = 0.03). One patient died 2 months after the start of the study of unrelated cause while continuing to benefit from treatment and another patient ceased to benefit at 4 months. McGill pain questionnaire scores with the stimulator turned off did not change significantly from baseline scores, indicating that the severity of the underlying pain was unaltered. However, with the stimulator turned on, there was a statistically significant (p < 0.05) improvement in all four components of the score, by the end of the study. At the end of the study, six patients continued to gain significant pain relief and used the stimulator as the sole treatment for their neuropathic pain. For example, median background and peak pain scores at the end of study, were, respectively, 77 and 81 with the stimulator off and 23 and 20 with the stimulator on. Exercise tolerance significantly improved at 3 months (n = 7, median % increase 85 [IQR, 62-360], p = 0.015) and at 6 months (n = 6, 163 [61-425], p = 0.0007). Electrophysiological tests, vibration perception-threshold, and glycaemic control were unchanged. INTERPRETATION: Electrical spinal-cord stimulation offers a new and effective way of relieving chronic diabetic neuropathic pain and improves exercise tolerance. The technique should be considered in patients with neuropathic pain who do not respond to conventional treatment.

Chronic Disease↗
PubMed1992

Single lung transplantation in rats with chemically induced pulmonary hypertension.

Physiologic effects of single lung transplantation on pulmonary hypertension were studied in rats with monocrotaline-induced pulmonary hypertension. Inbred rats treated with monocrotaline (40 mg/kg) received a left lung isograft from a normal donor 2 weeks later, when pulmonary hypertension became significant (transplant group; n = 6). These rats and control rats treated with monocrotaline (mediated control group; n = 11) or vehicle alone (normal control group; n = 9) were followed up weekly by metabolic treadmill testing for exercise tolerance and oxygen consumption up to 6 weeks after monocrotaline (4 weeks after transplantation), when all rats underwent hemodynamic and histologic examinations. Whereas maximal oxygen consumption and exercise tolerance consistently deteriorated in the medicated control group of rats, indices in the transplant group stopped deteriorating 2 weeks after lung transplantation and remained at levels similar to those of normal control rats. Severe pulmonary hypertension (68 +/- 19 mm Hg) and right ventricular hypertrophy (right ventricular/left ventricular weight ratio, 0.95 +/- 0.19) were confirmed in medicated control rats in contrast to transplant animals, in which these two indices remained at normal control levels. Whereas left-to-right lung perfusion ratio was constant among rats not receiving transplants (0.69 +/- 0.16), it was significantly elevated (2.27 +/- 0.65; p less than 0.001) in those receiving transplants, suggesting preferential flow through the lung isograft. The results suggest that, in the early phase of pulmonary hypertension, single lung transplantation shifts pulmonary perfusion to the grafted lung, avoiding right ventricular pressure overload and thereby preserving exercise tolerance at a nearly normal level in rats with monocrotaline-induced pulmonary hypertension.

Animals↗
PubMed1992

Physical training in patients with congestive heart failure.

Multiple compensatory mechanisms operate to preserve exercise tolerance in patients with left ventricular failure. Exercise capacity of most patients with chronic heart failure is limited by dyspnea or fatigue, or both. Maximal stress testing with direct assessment of peak O2 uptake is an essential measurement in planning exercise conditioning programs, which are now attracting patients with chronic heart failure. The biochemical and histologic patterns of skeletal muscle changes seen in chronic heart failure patients are consistent with the effects of long-term exercise deconditioning in normal subjects. Recent studies have suggested beneficial effects of training in subjects with moderate or even severe left ventricular dysfunction by showing increased exercise tolerance or peak O2 consumption, anaerobic threshold, peak leg blood flow, peak central arteriovenous oxygen difference and decreased lactate accumulation. However, a number of questions remain unanswered. Exercise training for the treatment of chronic heart failure should be determined on an individual basis and used with caution.

Exercise↗
PubMed1997

Effect of the calcium antagonist felodipine as supplementary vasodilator therapy in patients with chronic heart failure treated with enalapril: V-HeFT III. Vasodilator-Heart Failure Trial (V-HeFT) Study Group.

BACKGROUND: Despite therapy with diuretics, ACE inhibitors and digoxin morbidity and mortality in heart failure remain high and might respond favorably to an additional vasodilator. METHODS AND RESULTS: Male patients (n=450) with chronic heart failure (cardiac dysfunction and impaired exercise performance) on optimal current therapy (97% enalapril, 89% diuretics) were randomly assigned to double-blind treatment with felodipine extended release (5 mg BID) or placebo for 3 to 39 months (average, 18 months). Felodipine significantly reduced blood pressure and, at 3 months, increased ejection fraction (2.1% versus -0.1% units in the placebo group, P=.001) and reduced plasma atrial natriuretic peptide levels (-2.9 versus 26.9 pg/mL in the placebo group, P=.01) but did not improve exercise tolerance, quality of life, or the need for hospitalization. During long-term follow-up, the favorable effects on ejection fraction and atrial peptide did not persist, but felodipine prevented worsening exercise tolerance and quality of life. In the felodipine and placebo groups, mortality (13.8% versus 12.8%, respectively) and hospitalization (43% versus 42%) rates were similar, and a higher incidence of peripheral edema was the only apparent side effect of felodipine therapy. CONCLUSIONS: Felodipine exerts a well-tolerated additional sustained vasodilator effect in patients with heart failure treated with enalapril, but the only possible long-term benefit was a trend for better exercise tolerance and less depression of quality of life in the second year of treatment. The drug appears to be safe but not clearly efficacious in patients with heart failure.

Adult↗
PubMed2003

Antianginal and antiischemic effects of ivabradine, an I(f) inhibitor, in stable angina: a randomized, double-blind, multicentered, placebo-controlled trial.

BACKGROUND: Heart rate reduction should benefit patients with chronic stable angina by improving myocardial perfusion and reducing myocardial oxygen demand. This study evaluated the antianginal and antiischemic effects of ivabradine, a new heart rate-lowering agent that acts specifically on the sinoatrial node. METHODS AND RESULTS: In a double-blind, placebo-controlled trial, 360 patients with a > or =3-month history of chronic stable angina were randomly assigned to receive ivabradine (2.5, 5, or 10 mg BID) or placebo for 2 weeks, followed by an open-label 2- or 3-month extension on ivabradine (10 mg BID) and a 1-week randomized withdrawal to ivabradine (10 mg BID) or placebo. Primary efficacy criteria were changes in time to 1-mm ST-segment depression and time to limiting angina during bicycle exercise (exercise tolerance tests), performed at trough of drug activity. In the per-protocol population (n=257), time to 1-mm ST-segment depression increased in the 5 and 10 mg BID groups (P<0.005); time to limiting angina increased in the 10 mg BID group (P<0.05). Deterioration in all exercise tolerance test parameters occurred in patients who received placebo during randomized withdrawal (all P<0.02) but not in those still receiving ivabradine. No rebound phenomena were observed on treatment cessation. CONCLUSIONS: Ivabradine produces dose-dependent improvements in exercise tolerance and time to development of ischemia during exercise. These results suggest that ivabradine, representing a novel class of antianginal drugs, is effective and safe during 3 months of use; longer-term safety requires additional assessment.

Adult↗