Effects of lacidipine on peak oxygen consumption, neurohormones and invasive haemodynamics in patients with mild to moderate chronic heart failure

Effects of amlodipine and lacidipine on heart rate variability in hypertensive patients with stable angina pectoris and isolated left ventricular diastolic dysfunction

OBJECTIVE

To estimate the influence of therapy with amlodipine (A) or lacidipine (L) on heart rate variability (HRV) time and frequency domain parameters in hypertensive patients with stable angina pectoris and isolated left ventricular diastolic dysfunction.

METHODS

After a 1-week washout period, the patients were randomized to receive amlodipine 10 mg (30 patients) or lacidipine 6 mg (30 patients) once-daily for 4 weeks. HRV parameters were determined over a period of 24 h, echocardiography and exercise test were performed before and after treatment.

RESULTS

All HRV time domain parameters after applying amlodipine did not change significantly. A reliable decrease only of the root mean square of differences between adjacent normal-to-normal intervals (RMSSD)-32.9 +/- 13 vs. 27.5 +/- 9-was noticed after treatment with lacidipine. In the lacidipine group, the change of RMSSD negatively correlated with the extent of ST segment depression during exercise testing (R = -0.43; P < 0.05). Both drugs reduced total power (A, 2234 +/- 1270 vs. 1813 +/- 889; L, 2205 +/- 1151 vs. 1825 +/- 896; P < 0.01), very low (A, 1451 +/- 733 vs. 1143 +/- 534; L, 1413 +/- 759 vs. 1213 +/- 616; P < 0.05), and low frequency power (A, 610 +/- 459 vs. 447 +/- 321; L, 569 +/- 323 vs. 442 +/- 241; P < 0.01). After amlodipine, high frequency power remained unchanged, whereas low-high frequency ratio decreased (4.54 +/- 1.72 vs. 3.77+/-1.73; P < 0.05). After lacidipine, high frequency power decreased (178.8 +/- 153.2 vs. 132.1 +/- 79.3; P < 0.05), whereas the ratio of low frequency to high frequency did not change.

CONCLUSIONS

Amlodipine and lacidipine reduce the influence of humoral control and sympathetic autonomic nervous system activity. The autonomic balance becomes shifted toward the increased vagal activity only by amlodipine.

Effects of low-dose treatment with felodipine versus fosinopril in Chinese patients with nonischemic heart failure and normal blood pressure: A double-blind, randomized, crossover study

BACKGROUND

Two second-generation calcium channel blockers, felodipine and amlodipine besylate, have been associated with similar high mortality rates in patients with ischemic heart failure (HF) but not in patients with nonischemic causes of HF. In patients with nonischemic HF, amlodipine might have a beneficial effect on survival. However, no difference in mortality rates was found between felodipine and placebo in a nonischemic HF group. Felodipine 10 mg/d was used in 1 large study, a dose considered high for nonischemic HF usually associated with normal blood pressure (BP).

OBJECTIVE

The aim of this study was to compare the effects of 12-week, low-dose treatment with felodipine versus those of an angiotensin-converting enzyme inhibitor, fosinopril sodium, in patients with nonischemic HF and normal BP.

METHODS

This double-blind, randomized, crossover trial was conducted at Taipei Medical University Hospital (Taipei, Taiwan). Patients aged ≥ 18 years with angiographically proved, nonischemic HF and normal BP who were being treated with an optimal regimen of digitalis and diuretics were enrolled. After a 2-week run-in period, patients were randomized to first receive 12 weeks of treatment with felodipine tablets (2.5 mg/d) or fosinopril tablets (7.5 mg/d) and, after a 2-week washout period, were crossed over to the opposite treatment. Efficacy analysis was performed before (baseline) and after treatment and included symptomatic assessment using a 7-grade clinical scale; 2-dimensional echocardiography (2-D echo); exercise tests; and neurohumoral data, including plasma renin activity, plasma aldosterone, and 24-hour urinary epinephrine (E) and norepinephrine (NE) measurements. The primary end point was death due to HF, and the secondary end point was hospital admission due to worsening HF. Compliance was measured using a pill count at the end of each treatment period.

RESULTS

We enrolled 33 patients. One developed worsening HF during the run-in period and was admitted. A total of 32 patients entered the study (18 men, 14 women; mean [SD] age, 48.2 [6.3] years [range, 34-56 years]; mean [SD] systolic BP, 117.2 [9.8] mm Hg [range, 100-138 mm Hg]; mean [SD] diastolic BP, 59.4 [5.7] mm Hg [range, 50-72 mm Hg]). No hospital admission or cardiac death due to HF occurred during 12 weeks of treatment. Twenty-seven patients were included in the felodipine assessment, and 30 patients were included in the fosinopril assessment. Significant improvement in clinical score was noted in both treatment groups (both P < 0.01). The clinical scores did not differ significantly between the 2 treatments. No significant differences were found in 2-D echo parameters between treatments or within groups after treatment versus baseline. Significant improvement in exercise duration was noted with both study drugs after treatment versus baseline (both P < 0.01). No significant difference in exercise duration was found between the 2 treatments. Urinary E and NE were not significantly different between treatments or after treatment with either study drug compared with baseline.

CONCLUSION

The present findings suggest that, in Chinese patients with moderate to severe HF who have normal BP and insignificant coronary artery disease and were being treated with diuretics and digitalis, a 12-week, low-dose course of felodipine (2.5 mg/d) as a vasodilator was associated with as satisfactory an outcome as standard treatment with fosinopril (7.5 mg/d).

De la première à la quatrième génération de dihydropyridines : vers une meilleure efficacité et une meilleure tolérance

Dihydropyridines are among the most widely used drugs for the management of cardiovascular disease. Introduced in the 1960s, dihydropyridines have undergone several changes to optimise their efficacy and safety. Four generations of dihydropyridines are now available. The first-generation (nicardipine) agents have proven efficacy against hypertension. However, because of their short duration and rapid onset of vasodilator action, these drugs were more likely to be associated with adverse effects. The pharmaceutical industry responded to this problem by designing slow-release preparations of the short-acting drugs. These new preparations (second generation) allowed better control of the therapeutic effect and a reduction in some adverse effects. Pharmacodynamic innovation with regard to the dihydropyridines began with the third-generation agents (amlodipine, nitrendipine). These drugs exhibit more stable pharmacokinetics, are less cardioselective and, consequently, well tolerated in patients with heart failure. Highly lipophilic dihydropyridines are now available (lercanidipine, lacidipine). These fourth-generation agents provide a real degree of therapeutic comfort in terms of stable activity, a reduction in adverse effects and a broad therapeutic spectrum, especially in myocardial ischaemia and potentially in congestive heart failure.

Meta-analysis of efficacy and safety of second-generation dihydropyridine calcium channel blockers in heart failure

Second-generation dihydropyridine calcium channel blockers slightly increase cardiac index, left ventricular ejection fraction, and exercise treadmill tests in patients with chronic heart failure, and do not increase norepinephrine levels; these drugs seem to be safe and beneficial in this category of patients. A 6% reduction in mortality was found, which, although not significantly different from 0%, does indicate that these drugs do not increase mortality in this category of patients.

Impact of calcium antagonists on the cardiovascular system: experience with lacidipine

The evaluation of haemodynamic patterns in hypertensive patients by radionuclide techniques and a tomographic gamma camera has revealed differences between older and younger patients. In younger hypertensive patients, the hyperkinetic state is reflected in an increase in heart rate and, consequently, an increased cardiac index and left ventricular ejection fraction (LVEF) in comparison with normotensive controls. Older hypertensive patients, however, show a different haemodynamic pattern, with reduced systolic and diastolic function at rest compared with normotensive elderly people, and marked depression of cardiac reserve during exercise. Elderly hypertensive patients also show strikingly higher hyperresistance and reduced peripheral perfusion in comparison with younger hypertensive patients. These haemodynamic differences need to be taken into account when considering antihypertensive treatment. In a study in elderly hypertensive patients, lacidipine treatment (4 mg/day for 90 days) produced a significant decrease in total peripheral resistance and blood pressure, together with a reduction in left ventricular (LV) afterload and an increase in cardiac output and LVEF (tending towards normal values). The LV peak filling rate was also increased, and evaluation of systolic and diastolic cardiac reserve during exercise showed positive changes in cardiac performance. The haemodynamic changes with lacidipine were similar to those produced by other long-acting dihydropyridines [nifedipine gastrointestinal therapeutic system (GITS) and nitrendipine], but changes occurring with nisoldipine were less significant. The reduction in left ventricular hypertrophy (LVH) is an obvious goal of antihypertensive therapy, and several studies have demonstrated the effectiveness of lacidipine treatment in decreasing LVH in hypertensive patients. In hypertensive patients with associated LV dysfunction, favourable effects on global parameters of LV function similar to those with amlodipine have been noted with lacidipine. Myocardial blood flow was strikingly increased during lacidipine treatment and coronary resistance was significantly decreased, both at baseline and after maximal vasodilatation with dipyridamole. Thus, lacidipine's vasodilatory and anti-ischaemic profile makes it an appropriate choice for the treatment of hypertension.

Role of a third generation calcium antagonist in the management of hypertension

Calcium antagonists are uniquely suitable for managing hypertension by virtue of their efficacy, metabolic neutrality and their ability to countervail counterregulatory adaptive changes, thereby enhancing blood pressure lowering. Recent evidence has accrued underscoring the concept that calcium antagonists are heterogeneous and consist of chemically dissimilar agents. The difference in formulations and pharmacokinetics affect clinical events including the effect on blood pressure, heart rate and the degree with which sympathetic activity is activated. Lacidipine is a new calcium antagonist that is the prototype of the lipophilic dihydropyridines. Of great importance, lacidipine has a slow onset of vasodilator/antihypertensive effect and does not promote an excessive sympathetic drive. These attributes commend its selection as an antihypertensive agent.

Calcium channel blockers in cardiac failure

Congestive cardiac failure is an increasingly prevalent syndrome associated with a high morbidity and mortality. The role of calcium channel blockers in the treatment of heart failure is unclear. The potential benefits of these agents derive not only from their vasodilator properties, but also from anti-ischemic effects, beneficial effects on endothelial function and the development of atherosclerosis, and favorable effects on calcium cycling at a molecular level. Pitted against this array of potential benefits are direct negative inotropic effects and the potential for neuroendocrine activation. Treatment with short-acting dihydropyridine agents has not resulted in long-term clinical benefits in patients with cardiac failure. Diltiazem may be beneficial in patients with nonischemic heart failure, and verapamil has a neutral effect in cardiac failure, although it may have a role in combination with ace inhibition. To date, amlodipine has been associated with the most promising results, with evidence of a mortality benefit in nonischemic heart failure. Mibefradil is of no benefit in the management of heart failure, although the trend toward increased mortality in the treatment arm of the Mortality Assessment in Congestive Heart Failure (MACH)-1 trial may have been due to drug interactions. The potential role of calcium blockers in diastolic dysfunction and in combination with ace-inhibition requires further study.

The classification of calcium antagonists and their selection in the treatment of hypertension. A reappraisal

Calcium antagonists have become one of the most important advances in the treatment of hypertension since their introduction over 20 years ago. The increase in the number of available calcium antagonists (as new formulations of pre-existing drugs or new chemical entities) over recent years has contributed to an ever-changing scenario regarding their appropriate use compared with other antihypertensive agents. As a consequence of this evolving situation, several authors have proposed a 3-generation classification of calcium antagonists currently, or soon to be, marketed in several counties. The classification system is based among other variables, on chemical structure, tissue selectivity, administration frequency and duration of action. In this article, this classification is reviewed and updated on the basis of new information that is available. In addition, factors which influence the selection of calcium antagonists in the treatment of hypertension in specific patient populations are discussed. As well as pharmacodynamic and pharmacokinetic considerations, these factors also include previous experience with particular drugs in specific patient populations, cost of treatment and drug interactions. Among the dihydropyridine calcium antagonists, the first generation compounds have been clearly superseded and are not recommended for use in hypertensive patients. Whilst the second generation agents represent an adequate treatment, third generation calcium antagonists possess distinct advantages. Definitive confirmation of the role of calcium antagonists in hypertension lies in several ongoing large multicentre trials.

Effects of amlodipine on endothelial function in rats with chronic heart failure after experimental myocardial infarction

In chronic heart failure, the role of endothelial dysfunction is not yet well established. As calcium metabolism plays an important role in the endothelium, it might be suggested that calcium channel blockers influence endothelial function. Although calcium channel blockers are generally contraindicated in chronic heart failure, because they are believed to stimulate neurohumoral mechanisms and to exert negative inotropic effects, recently it has been suggested that amlodipine might have a favorable affect on mortality in patients with heart failure. The mechanism of amlodipine that contributes to this beneficial effect is not known. Therefore we investigated whether 10 weeks of amlodipine treatment could influence endothelial function in rats with congestive heart failure induced by myocardial infarction. The main finding of our study was that amlodipine, when administered for 10 weeks to rats after a myocardial infarction had been induced, had no significant effects on in vitro and in vivo hemodynamics or neurohormones. The effect of amlodipine on endothelium-intact, norepinephrine-precontracted aortic rings appears to differ from the placebo treatment with respect to the endothelium-dependent relaxation, whereas no differences are seen in endothelium-independent relaxation. We conclude that our data do not support a beneficial role of amlodipine on endothelial function in chronic heart failure.