Efficacy of felodipine in congestive heart failure

The efficacy of felodipine, a vasodilating calcium antagonist, was analysed in 23 patients with congestive heart failure, New York Heart Association class III, during an 8-week, double-blind, randomized, placebo-controlled, parallel study. After felodipine, exercise duration increased significantly without changes in oxygen consumption. Heart rate, arterial pressures and rate pressure product decreased at similar submaximal exercise levels. Invasive haemodynamics before and after 8 weeks of therapy revealed arterial vasodilation without reflex tachycardia and no significant reduction in right atrial, pulmonary and capillary wedge pressures. Subjective symptom scores improved and side-effects were minor. Fluid retention, as assessed by body weight and ankle circumference did not occur. Felodipine has a beneficial effect in patients with moderately severe heart failure. Further research is necessary to demonstrate its long-term efficacy and safety.     

Efficacy of felodipine in chronic congestive heart failure: a placebo controlled haemodynamic study at rest and during exercise and orthostatic stress.

A vascular selective calcium antagonist, felodipine, was evaluated in a randomised, double blind, crossover trial in 18 patients with chronic congestive heart failure of ischaemic cause. Felodipine (10 mg twice daily) or a corresponding placebo was added to conventional treatment. After three weeks haemodynamic function was assessed at rest, during a standard supine leg exercise, and during 45 degrees passive upright tilt. In patients in the supine resting position, felodipine reduced the mean arterial pressure (9%) and systemic vascular resistance (24%) and increased the stroke volume (25%) and cardiac index (23%). The heart rate and right and left ventricular filling pressures were unchanged. During felodipine treatment the standard exercise was accomplished at a similar cardiac index but at a substantially lower heart rate (7%), arterial pressure (10%), systemic vascular resistance (17%), and left ventricular filling pressure (19%), and a higher stroke volume (13%). During both placebo and felodipine administration there were substantial reductions in cardiac filling pressure during upright tilting. Upright tilting during the placebo phase did not increase the heart rate. It also caused a greater fall in systemic vascular resistance while the arterial pulse pressure but not the mean pressure was maintained and the cardiac index and stroke volume increased. The reduced cardiac filling pressures during the felodipine upright tilt were accompanied by reductions in arterial pulse pressure and stroke volume and the patients were able to maintain the mean arterial pressure by an increase in both the heart rate and systemic vascular resistance. Thus three weeks treatment with felodipine improved haemodynamic function at rest and during standard exercise and normalised the baroreflex mediated haemodynamic response in patients with congestive heart failure. The haemodynamic efficacy of the drug in such patients may be associated with a baroreceptor mediated effect as well as direct vasodilatation.     

Efficacy of felodipine in chronic congestive heart failure: a placebo controlled haemodynamic study at rest and during exercise and orthostatic stress

A vascular selective calcium antagonist, felodipine, was evaluated in a randomised, double blind, crossover trial in 18 patients with chronic congestive heart failure of ischaemic cause. Felodipine (10 mg twice daily) or a corresponding placebo was added to conventional treatment. After three weeks haemodynamic function was assessed at rest, during a standard supine leg exercise, and during 45 degrees passive upright tilt. In patients in the supine resting position, felodipine reduced the mean arterial pressure (9%) and systemic vascular resistance (24%) and increased the stroke volume (25%) and cardiac index (23%). The heart rate and right and left ventricular filling pressures were unchanged. During felodipine treatment the standard exercise was accomplished at a similar cardiac index but at a substantially lower heart rate (7%), arterial pressure (10%), systemic vascular resistance (17%), and left ventricular filling pressure (19%), and a higher stroke volume (13%). During both placebo and felodipine administration there were substantial reductions in cardiac filling pressure during upright tilting. Upright tilting during the placebo phase did not increase the heart rate. It also caused a greater fall in systemic vascular resistance while the arterial pulse pressure but not the mean pressure was maintained and the cardiac index and stroke volume increased. The reduced cardiac filling pressures during the felodipine upright tilt were accompanied by reductions in arterial pulse pressure and stroke volume and the patients were able to maintain the mean arterial pressure by an increase in both the heart rate and systemic vascular resistance. Thus three weeks treatment with felodipine improved haemodynamic function at rest and during standard exercise and normalised the baroreflex mediated haemodynamic response in patients with congestive heart failure. The haemodynamic efficacy of the drug in such patients may be associated with a baroreceptor mediated effect as well as direct vasodilatation.     

Effects of vasodilator treatment with felodipine on haemodynamic responses to treadmill exercise in congestive heart failure.

Treatment with vasodilators in heart failure has not always produced a useful improvement in the haemodynamic responses to exercise, and in many cases early drug tolerance has further limited the potential of this type of treatment. In a study to evaluate the efficacy of felodipine, a new calcium antagonist with selective vasodilator properties, in the management of congestive heart failure 10 patients with congestive heart failure underwent treadmill exercise testing before and during oral treatment with felodipine 30 mg daily. At every level of exercise felodipine lowered the pulmonary capillary wedge pressure, whereas cardiac index and stroke index increased considerably. The haemodynamic improvement was associated with an increase in the duration of exercise to exhaustion. Importantly, these beneficial effects were sustained throughout four weeks of treatment without evidence of drug tolerance. These observations suggest a useful role for felodipine in the long term management of congestive heart failure.     

Correlates and prognostic implication of exercise capacity in chronic congestive heart failure

Previous studies have shown poor correlations between exercise tolerance and measurements of left ventricular (LV) function during rest in patients with congestive heart failure (CHF). To further evaluate the determinants of exercise tolerance and their relation to prognosis, we performed rest and exercise hemodynamic measurements and blood pool scintigraphy in 27 patients with CHF. All patients were treated with digitalis and diuretic drugs, but not vasodilator drugs. Exercise capacity was assessed by maximal oxygen consumption (VO2max) during upright bicycle ergometry. Both right ventricular (RV) and LV ejection fractions were measured by radionuclide techniques, and arterial, right atrial and pulmonary artery pressures, cardiac output, and derived hemodynamic indexes were determined. As a group, patients with severely impaired exercise tolerance (group 1, VO2max less than 10 ml/min/kg) had significantly higher rest pulmonary capillary wedge and right atrial pressures (30 +/- 4 vs 23 +/- 6 and 12 +/- 4 vs 7 +/- 2 mm Hg, respectively) than those with a VO2max of 10 to 18 ml/min/kg (group 2). They also had lower LV and RV ejection fractions (16 +/- 4% vs 21 +/- 4% and 19 +/- 12% vs 27 +/- 7%, respectively). However, overlap among individual patients was considerable, and only pulmonary capillary wedge pressure at rest correlated significantly (r = 0.69, p less than 0.001) with VO2max.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of vasodilator treatment with felodipine on haemodynamic responses to treadmill exercise in congestive heart failure

Treatment with vasodilators in heart failure has not always produced a useful improvement in the haemodynamic responses to exercise, and in many cases early drug tolerance has further limited the potential of this type of treatment. In a study to evaluate the efficacy of felodipine, a new calcium antagonist with selective vasodilator properties, in the management of congestive heart failure 10 patients with congestive heart failure underwent treadmill exercise testing before and during oral treatment with felodipine 30 mg daily. At every level of exercise felodipine lowered the pulmonary capillary wedge pressure, whereas cardiac index and stroke index increased considerably. The haemodynamic improvement was associated with an increase in the duration of exercise to exhaustion. Importantly, these beneficial effects were sustained throughout four weeks of treatment without evidence of drug tolerance. These observations suggest a useful role for felodipine in the long term management of congestive heart failure.     

Do hemodynamic indices correlate with maximum exercise capacity and oxygen consumption in chronic congestive heart failure?

The mechanism of exercise intolerance in chronic congestive heart failure remains unclear. We correlated resting haemodynamic variables with the peak exercise capacity and maximum oxygen consumption (VO2 max) in patients with congestive heart failure in 27 studies on treadmill exercise testing using the modified Bruce protocol. VO2 max was measured using breath by breath expiratory gas analysis. The patients were in severe congestive heart failure (NYHA class II and III, pulmonary artery wedge pressure 23 +/- 2 mmHg, cardiac index 2.4 +/- 0.21 l/min/m2). VO2 max was 23 +/- 2 ml/kg/min. Fatigue was the commonest symptom limiting the exercise. None of the hemodynamic variables correlated well with VO2 max. [right atrial pressure (r = 0.08), pulmonary artery pressure (r = 0.05), pulmonary artery wedge pressure (r = 0.08), aortic pressure (r = -0.3) & cardiac index (r = 0.29)]. Both uni- and multi-variate analysis failed to show any relation between VO2 max and resting hemodynamic variables. We conclude that unlike the acute heart failure syndromes, resting hemodynamic variables do not correlate with exercise capacity in patients with chronic congestive heart failure. The abnormal resting haemodynamics do not limit exercise in these patients. Peripheral mechanisms may thus be more important.     

Recovery kinetics of oxygen uptake and heart rate in patients with coronary artery disease and heart failure.

BACKGROUND: Patients with congestive heart failure exhibit a prolonged period of recovery to baseline levels of oxygen consumption, but the decline of heart rate during recovery from exercise has been shown to be similar to that in healthy subjects, and the results of studies on the response of ventilation in recovery have been mixed. Patients with coronary artery disease have a reduced exercise capacity, but it is unknown whether the patterns of the decline in oxygen uptake (VO2), ventilation, or heart rate are similar to those in patients with heart failure. METHODS: We performed a cardiopulmonary exercise test with a ramping protocol in 18 healthy subjects, 18 patients with coronary artery disease, 19 patients with class A or B congestive heart failure, and 19 patients with class C congestive heart failure, according to the Weber classification. Peak oxygen uptake and the kinetics of oxygen uptake, ventilation, and heart rate were calculated and expressed as the slope of a single exponential relation between VO2 levels and time during the first 3 min of recovery as y(VO2) = y0Ae(-x/t). RESULTS: A difference in time of recovery of VO2 was found only between healthy subjects and patients with more severe heart failure (class C) (p < 0.05); no significant differences were observed among any of the groups in ventilation or heart rate recovery responses. CONCLUSION: VO2 recovery time is prolonged only in the presence of more severe heart failure. The presence and degree of heart disease has no effect on ventilation or heart rate recovery time.     

Comparison of effects on peak oxygen consumption, quality of life, and neurohormones of felodipine and enalapril in patients with congestive heart failure

Angiotensin-converting enzyme (ACE) inhibition is currently the cornerstone of congestive heart failure (CHF) therapy, but these drugs are not tolerated in up to 20% of patients. For these patients, therapeutic alternatives with comparable efficacy are needed. Felodipine, a vasoselective dihydropyridine calcium antagonist with a slow onset of action and a long plasma half-life, may be such an agent. Therefore, the efficacy and safety or felodipine were examined and compared with enalpril using a double-blind design. We studied 46 patients with a left ventricular ejection fraction <0.40, peak oxygen consumption <20 ml-min⁻¹·kg⁻¹, and symptoms of CHF despite therapy with diuretics and digoxin. After 16 weeks of therapy, there were no statistically significant differences in peak oxygen consumption (felodipine +1.6, enalapril +2.5 ml·min⁻¹·kg⁻¹) and exercise tolerance (felodipine +61 seconds, enalapril +64 seconds). Quality-of-life parameters were affected slightly better by felodipine man by enalapril. Plasma norepinephrine decreased by 143 pg·ml⁻¹ with enalapril and by 12 pg·ml⁻¹ with felodipine (p > 0.20 between groups). Both drugs were generally well tolerated. These data suggest that felodipine and enalapril have comparable effects on exercise parameters in patients with CHF. Neurohumoral activation was not observed with either drug.     

Effects of the replacement of the angiotensin converting enzyme inhibitor enalapril by the angiotensin II receptor blocker telmisartan in patients with congestive heart failure. The replacement of angiotensin converting enzyme inhibition (REPLACE) investigators

AIM: To compare the effects on maximal exercise tolerance of 12 weeks of four dosages of telmisartan (10/20/40/80 mg once daily), an AT(1) specific angiotensin II receptor antagonist, or continuation on the angiotensin converting enzyme inhibitor enalapril, in patients with stable, mild-to-moderate congestive heart failure (NYHA Class II and III and left ventricular ejection fraction < or =40%). DESIGN: Multicenter, double-blind, parallel-group trial in 378 patients, randomized to once-daily treatment with telmisartan 10, 20, 40 mg, 80 mg, or continuation of enalapril 10 mg twice daily for 12 weeks. METHODS: Primary efficacy parameter: change from baseline to final visit in bicycle exercise duration. Secondary efficacy parameters included left ventricular ejection fraction, quality-of-life parameters, arterial blood pressures, neurohormonal changes and NYHA classification. PATIENTS: The mean age of the patients was 64+/-9 years, 89% male, history of myocardial infarction in 68%, NYHA-II: 63%, NYHA-III: 37%, ejection fraction 26.4(7)%, and a reproducible impaired exercise capacity. All patients were on diuretics and enalapril 10 mg twice daily, and 39% were taking digitalis at study entry. RESULTS: No clinically relevant or statistically significant (P<0.05) differences were observed in the primary efficacy parameter: mean changes (s) in exercise tolerance were +8.6, +8.2, +2.2, and +7.1 for the telmisartan 10-, 20-, 40-, and 80-mg groups, respectively, and +1.4 for enalapril. There was a small but significant increase in blood pressure in all but the 80 mg telmisartan groups, compared to enalapril. Telmisartan and enalapril had comparable adverse event profiles. Cough occurred in 5.6% of the enalapril patients and in 3% of the telmisartan patients (NS). CONCLUSIONS: (1) In patients with stable, mild-to-moderate congestive heart failure, enalapril could be replaced by telmisartan for a period of 12 weeks without deterioration in exercise capacity or clinical status. (2) No differences were observed in exercise capacity between the four dosages of telmisartan.     

Impact of serial changes in cardiac hemodynamics on exercise performance in patients with heart failure due to ischemic and nonischemic cardiomyopathy

Although prior studies have examined the role of central and peripheral hemodynamics on exercise tolerance within populations of patients with heart failure, a clear relation between hemodynamics and exercise has not been demonstrated. This may be due to the inability to control for other factors that may influence exercise performance. To isolate the impact of hemodynamics on exercise, we studied the relation between changes in these factors within individual patients studied on 2 occasions. A consecutive series of 133 ambulatory patients with heart failure were evaluated on 2 separate occasions with right-sided cardiac catheterization and treadmill cardiopulmonary exercise testing. Linear regression models were constructed and correlation coefficients were determined to examine the relation between changes in hemodynamic variables and changes in exercise variables over time for each patient. A significant correlation between peak oxygen consumption (VO(2)) and pulmonary arterial wedge pressure was found for both the first (r = -0.316, p <0.001) and second (r = -0.183, p = 0.029) tests. A stronger inverse correlation between the change in pulmonary arterial wedge pressure and change in peak VO(2) was observed in the study patients (r = -0.470, p <0.001). Similar correlations were found between change in peak VO(2) and changes in pulmonary arterial pressures. Changes in left ventricular filling pressure influence exercise tolerance in patients with heart failure due to left ventricular systolic dysfunction. Interpretation of cardiopulmonary exercise testing for the purpose of determining cardiac transplantation eligibility will be improved with knowledge of left ventricular filling pressure.     

Oxygen uptake efficiency slope: an index of exercise performance and cardiopulmonary reserve requiring only submaximal exercise

OBJECTIVES: We sought to evaluate, in adults, the efficacy of the Oxygen Uptake Efficiency Slope (OUES), an index of cardiopulmonary functional reserve that can be based upon a submaximal exercise effort. BACKGROUND: Maximal oxygen uptake (VO2,max), the most reliable measure of exercise capacity, is seldom attained in standard exercise testing. The OUES, which relates oxygen uptake to total ventilation during exercise, was proposed by Baba and coworkers (7) in a study of pediatric cardiac patients. They felt this submaximal index of cardiopulmonary reserve might be more practical than VO2max and more appropriate than the commonly used peak oxygen consumption (VO2 peak). METHODS: Treadmill exercise tests with simultaneous respiratory gas measurement were performed in 998 older subjects free of clinically recognized cardiovascular disease and 12 male patients with congestive heart failure. During incremental exercise, oxygen uptake was plotted against the logarithm of total ventilation, and the OUES was determined. RESULTS: The OUES, when calculated only from the first 75% of the exercise test, differed by 1.9% from the OUES calculated from 100% of exercise time in subjects with a peak respiratory exchange rate > or =1.10. On serial tests the OUES was less variable than exercise duration or VO2 peak. It correlated strongly with VO2max, with forced expiratory volume in 1 s and negatively with a history of current smoking. The OUES declined linearly with age in both women and men. A small sample of patients with congestive heart failure had OUES values much lower than those of older subjects without cardiovascular disease. CONCLUSIONS: The OUES is an objective, reproducible measure of cardiopulmonary reserve that does not require a maximal exercise effort. It integrates cardiovascular, musculoskeletal and respiratory function into a single index that is largely influenced by pulmonary dead space ventilation and exercise-induced lactic acidosis.     

Felodipine in patients with chronic heart failure: discrepant haemodynamic and clinical effects

Previous open studies have suggested that felodipine, a selective calcium antagonist and vasodilator, may be useful in the treatment of heart failure. A double blind placebo controlled crossover trial was therefore conducted to investigate the clinical and haemodynamic effects of felodipine in 15 patients with chronic ischaemic heart failure in New York Heart Association symptom class III. Felodipine significantly increased resting and exercise (25W bicycle ergometry) cardiac output without producing concomitant changes in resting or exercise heart rate or right and left ventricular filling pressures. Felodipine did not significantly improve symptom scores or exercise capacity in the group as a whole. It also resulted in significant fluid retention as shown by a rise in ankle circumference, body weight, and a fall in haematocrit. Further research is required to elucidate the mechanism that is responsible for the discrepancy between the haemodynamic and clinical effects of felodipine in patients with moderately severe heart failure.     

Abnormal heart rate recovery immediately after cardiopulmonary exercise testing in heart failure patients

An attenuated heart rate recovery (HRR) immediately after exercise has been shown to be predictive of mortality. It is not known whether HRR predicts mortality when measured in patients with heart failure. The present study was undertaken to evaluate the ability of HRR to predict mortality in patients with heart failure. We studied 84 NYHA class II or III chronic congestive heart failure patients who had a left ventricular ejection fraction < or = 40%. All patients underwent symptom limited cardiopulmonary exercise testing. The value for the HRR was defined as the difference in heart rate between peak exercise and one-minute later; a value < or = 18 beats per minute was considered abnormal. The patients were divided into 2 groups according to the value of HRR. Those with abnormal HRR were assigned to group I and those with normal HRR were assigned to group II. The 2 groups were compared with each other regarding baseline characteristics and exercise capacity assessed by peak VO2. There were 26 patients (31%) in group I and 58 patients (69%) in group II. Group II patients had better performance on treadmill exercise testing than group I patients. They had greater exercise duration (7.5 +/- 3.8 minutes versus 5 +/- 3.5 minutes, P = 0.006), better heart-rate reserve (79 +/- 25% versus 63 +/- 27%, P = 0.01), and higher values of maximal heart-rate (141 +/- 18 beats/min versus 132 +/- 17 beats/min, P = 0.04). Group II patients also had higher peak VO2 values (16.8 +/- 4.4 mL/kg/min versus 14.4 +/- 3.6 mL/kg/min, P = 0.01). When we separated the groups according to beta-blocker usage, beta-blockers had no prominent effect on HRR. In the follow-up period (mean 14.1 +/- 6.1 months), the presence of abnormal HRR and lower peak VO2 (< or = 14 mL/kg/min) were the only significant predictors of mortality in our patient population (adjusted hazard ratio [HR] 5.2, 95% CI, 1.3 to 24, P = 0.03 and adjusted HR 13, 95% CI, 2.1 to 25.6, P = 0.005, respectively). It seems that the attenuated HRR value one minute after peak exercise appears to be a reliable index of the severity of exercise intolerance in heart failure patients and this study supports the value of HRR as a prognostic marker among heart failure patients referred for cardiopulmonary exercise testing for prediction of prognosis.     

Felodipine in patients with chronic heart failure: discrepant haemodynamic and clinical effects.

Previous open studies have suggested that felodipine, a selective calcium antagonist and vasodilator, may be useful in the treatment of heart failure. A double blind placebo controlled crossover trial was therefore conducted to investigate the clinical and haemodynamic effects of felodipine in 15 patients with chronic ischaemic heart failure in New York Heart Association symptom class III. Felodipine significantly increased resting and exercise (25W bicycle ergometry) cardiac output without producing concomitant changes in resting or exercise heart rate or right and left ventricular filling pressures. Felodipine did not significantly improve symptom scores or exercise capacity in the group as a whole. It also resulted in significant fluid retention as shown by a rise in ankle circumference, body weight, and a fall in haematocrit. Further research is required to elucidate the mechanism that is responsible for the discrepancy between the haemodynamic and clinical effects of felodipine in patients with moderately severe heart failure.     

双心室起搏对慢性心力衰竭患者心肺功能和生活质量的影响

目的:观察双心室起搏对慢性心力衰竭患者心肺功能和生活质量的影响。方法:慢性心力衰竭伴室内传导阻滞患者9例,植入三腔双心室起搏器,比较双心室起搏前、后患者超声心动图检查、心肺功能和生活质量的变化。结果:双心室同步起搏后.患者左室射血分数(%)由术前(21.6±6.7)%增加到(27.3±5.2)%(术后3月,P< 0.05)。(29.5±5.4)%(术后6月,P<0.05);6 min步行距离,由术前(320±97)m增加到(384±103)m(术后3月.P<0.01).(413±110)m(术后6月.P<0.01);峰值氧耗量、氧通气当量(VE/VO2)、二氧化碳通气当量(VE/VCO2)较术前均有显著增加(P<0.05～<0.01);生活质量评分分别改善30%(术后3月,P<0.01),28% (术后6月,P<0.01)。结论:双心室起搏能有效改善慢性心衰患者心肺功能,增加运动贮量,提高生活质量。     

综合康复医疗对慢性心衰患者心肺功能的影响

目的:评价综合康复医疗对慢性心衰患者心肺功能的影响。方法:采用逐级负荷踏车试验检测79例慢性心衰患者的心肺功能,对比观察综合康复医疗组(观察组)与传统疗养组(对照组)治疗前、后心率、血压、心肌耗氧量及6 min步行距离的变化。结果:观察组较对照组6 min步行试验后心率、血压增加值减少,步行距离延长,心肌耗氧量降低(P<0.05).VO2max,VO2max/kg,VO2max/HR,VEmax均值均高于对照组(P<0.05)。结论:综合康复医疗对改善慢性心衰患者心肺功能,提高生存率有益。     

Cardiopulmonary exercise testing in congestive heart failure

Cardiopulmonary exercise testing includes the monitoring of respiratory gases and airflow to determine oxygen uptake, carbon dioxide (CO2) production, respiratory rate, tidal volume, and minute ventilation during a graded maximal exercise test. A plateau in oxygen uptake, which occurs despite an increase in work load, and which is termed maximal oxygen uptake (VO2 max), correlates with the maximal exercise cardiac output and can therefore be used to grade the severity of heart failure. The anaerobic threshold occurs at 60 to 70% of VO2 max and is another indicator of the severity of heart failure and, when attained, indicates that the patient is close to performing a maximal test. We have found VO2 max and anaerobic threshold to be objective measures of efficacy of both investigational and noninvestigational therapy in patients with heart failure. A pulmonary limitation to exercise can be identified by the failure to attain anaerobic threshold or VO2 max, as well as exhaustion of the ventilatory reserve, as estimated by maximal voluntary ventilation. Thus, cardiopulmonary exercise testing can be used to (1) grade the severity of heart failure, (2) objectively follow the response to therapy, and (3) differentiate a cardiac from a pulmonary limitation to exercise.     

Time integral of oxygen pulse for exercise submaximal levels in patients with heart insufficiency--correlation with maximal oxygen consumption]

Maximal oxygen consumption (VO2max) has an important prognostic value in patients with congestive heart failure (CHF). However, it requires a maximal exercise test, not often available for these patients. To overcome this limitation, we examined whether a simple time integral of oxygen pulse (OP) to submaximal exercise levels correlates with VO2max. METHODS: We performed a maximal symptom-limited treadmill exercise test, while measuring breath-by-breath oxygen consumption, using the CAEP protocol, in 24 patients with CHF (51 +/- 11 years, 18 males, sinus rhythm). No exercise was terminated due to ischemia or arrhythmias. All patients attained anaerobic threshold. Besides standard parameters, OP (ml) and time integral of OP (OPTI) were calculated at 2 minutes (OP-2 min and OPTI-2 min) and at 4 minutes (OP-4 min and OPTI-4 min) of exercise. Patients were divided in two groups according to VO2max: group I--VO2max > or = 16 ml/kg/min (14 patients) and group II--VO2max < 16 (10 patients). RESULTS: Age, sex, body surface and CHF etiology were similar in both groups. Exercise duration, maximal OP, time to anaerobic there shold, VO2 and OP at anaerobic there shold were higher in group I (p < 0.05). Comparing group I vs group II--OP-2 min: 6.2 +/- 1.5 vs 5.0 +/- 1.2 ml (p = 0.026); OP-4 min: 7.6 +/- 1.9 vs 5.4 +/- 1.2 (p = 0.001); OPTI-2 min: 3.1 +/- 1.1 vs 2.2 +/- 0.9 (p = 0.021) and OPTI-4 min: 15.2 +/- 4.4 vs 9.3 +/- 3.1 (p = 0.0007). The best correlation with VO2max was obtained for OPTI-4 min (r = 0.696). An OPTI-4 min value > or = 10 occurred in 13 patients of group I and in two patients of group II (p = 0.00013), with a predictive value of 87% for VO2max > 16 (sensitivity = 93%, specificity = 80%)--kappa index = 0.739. CONCLUSIONS: OPTI-4 min can be a useful tool for assessing cardiocirculatory functional status in patients with CHF and unable to perform a maximal exercise test.     

Comparison of enalapril versus digoxin for congestive heart failure

A multicenter, randomized, double-blind, parallel-group trial was conducted to compare the effects of enalapril and digoxin on clinical signs and symptoms, as well as exercise capacity, in 142 patients with congestive heart failure classified as mild to severe (New York Heart Association functional classes II to IV). The patients received optimal treatment with digitalis and diuretics for 2 to 4 weeks. Thereafter, they were randomly assigned to receive either enalapril plus diuretics (n = 72) or digoxin plus diuretics (n = 70). After 8 weeks of treatment, a significant improvement in classification was observed in 22 of 63 patients (35%) in the enalapril group and in 17 of 61 (28%) in the digoxin group (difference not significant [NS]). Similarly, duration of exercise increased in both groups (p less than 0.005; p = NS between groups). Blood pressures decreased in the enalapril group (from 129 +/- 19/80 +/- 10 to 121 +/- 20/78 +/- 11 mm Hg; p less than 0.001), but not in the digoxin group (from 134 +/- 19/82 +/- 12 to 138 +/- 19/85 +/- 10 mm Hg; NS). Serum creatinine and electrolytes did not exhibit any significant change from baseline values, except for serum potassium, which increased slightly in the enalapril group (from 4.24 +/- 0.48 to 4.43 +/- 0.49 mmol/liter; p less than 0.05) and decreased slightly in the digoxin group (from 4.28 +/- 0.47 to 4.18 +/- 0.40 mmol/liter; p less than 0.05). Adverse events were reported in 13 patients (5 withdrawals) in the enalapril group and in 7 patients (2 withdrawals) in the digoxin group (p = NS).(ABSTRACT TRUNCATED AT 250 WORDS)