Effect of the second-generation calcium channel blocker nisoldipine on left ventricular contractility in cardiac failure

The clinical significance of neurohormonal activation

Progressive heart disease after the onset of left ventricular dysfunction has typically been attributed to hemodynamic factors. As left ventricular function declines, decreased cardiac output and tissue hypoperfusion lead to compensatory increases in afterload, preload, and heart rate. The purpose of these compensatory responses is to increase cardiac output and maintain tissue perfusion; however, they may also create hemodynamic stress for the failing heart. However, this does not explain the progression of heart failure despite hemodynamic maintenance with pharmacologic therapy. Activation of neurohormonal systems that are essential for homeostasis in the normal heart plays a key role in the progression of heart failure. In acute heart failure, these systems have beneficial effects, but in chronic heart failure their activation produces deleterious effects by increasing the load on the left ventricle and promoting structural remodeling, which may further impair left ventricular function. The issue of neurohormonal activation is an important one in cardiovascular medicine, not only for patients with heart failure but also for patients with hypertension and ischemic heart disease when left ventricular dysfunction is present. As neurohormonal activation may play a pathogenic role in the long-term outcome of patients, interventions that have favorable hemodynamic but unfavorable neurohormonal effects can actually exacerbate cardiac disease and may increase cardiovascular morbidity and mortality. As neurohormonal activation appears to parallel the severity of heart failure, whether assessed according to symptoms or prognosis, an understanding of neurohormonal activation and its interaction with hemodynamic factors is essential for optimizing pharmacologic therapy for cardiovascular disease.

Calcium antagonists in patients with left ventricular dysfunction: back on the bridge?

Calcium antagonists have a useful role in the management of patients with cardiac disease, producing coronary and systemic vasodilatation and an additional possibly beneficial effect on ventricular diastolic function. On the other hand, the myocardial depressant effect of the first-generation drugs and the abrupt changes in blood pressure, with neurohormonal activation, have been associated with worsening heart failure in certain patients. The present review summarizes the data currently available, with emphasis on the newer slow-release and long-acting calcium antagonists. Use of these drugs minimizes the peak and trough effect associated with short-acting preparations, and particularly when administered against a background of digoxin, diuretic and angiotensin converting enzyme inhibitors, may be associated with better long-term results in patients with ventricular dysfunction. The DEFIANT studies, using nisoldipine-coat core, showed that nisoldipine-CC improved diastolic ventricular function and had a significant anti-ischemic effect in patients with mild-moderate ventricular dysfunction after acute myocardial infarction. The VHeFT III trial showed that felodipine had no effect on exercise capacity or survival in patients with Class 2-3 heart failure. In the PRAISE study of Class 3-4 patients, amlodipine was neutral in patients with ischemic disease, but a strikingly beneficial effect was observed in non-ischemic heart failure (45% decrease in mortality). The precise mechanism for the beneficial effect of amlodipine in these patients is unknown. Further studies are needed to examine the issue of survival benefit in patients with non-ischemic heart failure and the mechanisms involved.

Short- and long-term effects of nisoldipine on cardiac function and exercise tolerance in patients with hypertrophic cardiomyopathy

Nisoldipine is a second generation dihydropyridine calcium antagonist having characteristics of strong coronary artery dilating effect and less negative inotropic action. The purpose of this study was to evaluate the effect of nisoldipine on the cardiac function (systolic and diastolic) and the exercise tolerance, in patients with hypertrophic cardiomyopathy (HCM).

SUBJECTS

Twenty-three patients with HCM were studied.

METHODS

We measured the following indices using M-mode and pulsed wave Doppler echocardiography before and after nisoldipine therapy; left ventricular fractional shortening (LVFS), isometric relaxation time (IRT), deceleration half-time (DHT) of early diastolic mitral (E) flow, late diastolic mitral (A) flow and A/E ratio. Symptom-limited treadmill exercise test was performed. Exercise tolerance (EX) time was measured. Nisoldipine of 10 mg/day was orally administered. Same tests were repeated on day 14 and after 6 months.

RESULTS

1) Short-term effects; LVFS did not change (55.9 +/- 5.9%-->57.0 +/- 7.4%, NS) after 2 weeks. However, LV diastolic function significantly improved (IRT; 92.1 +/- 7.7 ms-->85.2 +/- 11.6 ms, p < 0.05, DHT; 70.7 +/- 16.2 ms-->63.3 +/- 3.7 ms, p < 0.05). EX time increased (8.9 +/- 2.6 min-->10.0 +/- 3.3 min, p < 0.05), 2) Long-term effects; LV diastolic function had a tendency toward improvement, but is statistically not significant (IRT; 91.1 +/- 7.6-->83.8 +/- 11.6 ms, DHT; 73.1 +/- 23.4-->61.0 +/- 11.4 ms, A/E; 1.26 +/- 0.29-->1.11 +/- 0.36) after 6 months. EX time was significantly increased (9.4 +/- 1.7--> 10.1 +/- 1.7 min, p < 0.05).

CONCLUSIONS

Nisoldipine improved LV diastolic dysfunction and exercise tolerance in patients with HCM. These effects were similar to the first generation calcium antagonists. LV diastolic dysfunction may be improved due to the reduction of intracellular calcium concentration and the relief of myocardial ischemia by strong coronary artery dilating effect. However, nisoldipine did not affect the LV systolic function because of its less negative inotropic effect.

Efficacy and safety of nisoldipine coat core in the management of angina pectoris, systemic hypertension, and ischemic ventricular dysfunction

The effects of the long-acting dihydropyridine calcium antagonist nisoldipine coat core (CC) have been investigated in > 3,500 patients with angina pectoris, hypertension, and ischemic ventricular dysfunction. In patients with angina pectoris, nisoldipine CC improved total treadmill exercise duration (p = 0.027), delayed the onset of angina pectoris (p = 0.009), and increased time to exercise-induced ST-segment depression (p = 0.061). In general, nisoldipine 20-40 mg was effective, and the dose-response curve flattened thereafter. In patients with hypertension, 10-40 mg once daily as monotherapy reduced blood pressure (p < 0.05), with a fall in diastolic pressure of > or = 10 mm Hg or a final diastolic pressure of < 90 mm Hg in 35-63% of patients. In most patients followed for a year, nisoldipine CC was continued as monotherapy. Efficacy was similar in patients < 65 and > 65 years of age. In the Doppler Flow and Echocardiography in Functional Cardiac Insufficiency: Assessment of Nisoldipine Therapy (DEFIANT-I) study of patients recovering from myocardial infarction, nisoldipine CC had a salutary effect on diastolic ventricular function, with a higher transmitral early filling velocity and shorter isovolumic relaxation time than in patients receiving placebo. Bicycle exercise capacity was greater (by 12 W; 95% confidence interval, 0.8-23.3) and exercise-induced ischemia occurred less frequently. The nisoldipine CC data pool (3,679 patients) showed that the drug was well tolerated with a low incidence of side effects.(ABSTRACT TRUNCATED AT 250 WORDS)

The DEFIANT study of left ventricular function and exercise performance after acute myocardial infarction. Doppler Flow and Echocardiology in Functional Cardiac Insufficiency: Assessment of Nisoldipine Therapy Study Group

The DEFIANT-I study (Doppler Flow and Echocardiography in Functional cardiac Insufficiency: Assessment of Nisoldipine Therapy) was a multicenter, multinational double-blind randomized study of the effects of the new calcium channel blocking drug nisoldipine on left ventricular (LV) size and function after acute myocardial infarction. Randomization to placebo or to long-acting nisoldipine core coat (20 mg once daily) was performed in 135 eligible patients with mild to moderate systolic LV dysfunction (LV ejection fraction < or = 50%) 20 days (range 7-35) after infarction, with serial clinical, echocardiographic, and Doppler cardiographic measurements during a 4 week follow-up period. At the end of the follow-up period, exercise capacity was determined by bicycle ergometry. Nisoldipine improved indices of diastolic LV function. Early diastolic transmitral blood flow velocity increased, with an increase in peak E wave of 0.06 m/sec (95% confidence intervals [CI], 0.01, 0.11) and an increase in time velocity integral of 1.2 cm (95% CI, 0.16, 2.27). Isovolumic relaxation time was reduced by 14.7 msec (95% CI, -22.5, -6.9), a change not explained by the very small (and not significant) changes in systemic arterial pressure, heart rate, or cardiac output. There was no change in systolic and diastolic LV volume, nor in LV ejection fraction. Exercise capacity was greater by 12 watts (95% CI, 0.8, 23.3) in patients receiving nisoldipine, while the incidence of > or = 1 mm ST-segment depression (relative occurrence 0.54, 95% CI, 0.30-0.97) and the incidence of angina pectoris (relative occurrence 0.67, 95% CI, 0.42-1.08) during exercise testing tended to be lower in this group. Although the relations were not exact, peak exercise workload 7 weeks after infarction correlated with resting measurements of diastolic LV function. Exercise workload was inversely related to peak late diastolic transmitral blood flow velocity (A wave, slope, -86.6; 95% CI, -120.9, -52.2) and directly to the E/A ratio (slope, 20.5, 95% CI, 6.0, 35.1). The relations between exercise workload and peak late diastolic flow velocity remained significant after correction for age, sex, resting heart rate, and usage of beta-blocking drugs or nisoldipine. Exercise capacity was not related to measurements of systolic LV function (LV end-diastolic and end-systolic volume, LV ejection fraction, stroke volume, cardiac index). In summary, the calcium channel blocker nisoldipine improved measurements of diastolic LV function in patients recovering from acute myocardial infarction. Exercise capacity was higher in patients receiving the drug, and there was less exercise induced ischemia.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of nisoldipine on myocardial ischemia during exercise and during daily activity

The antiischemic properties of nisoldipine, a dihydropyridine calcium antagonist, were assessed in a multicenter, double-blind, placebo-controlled trial by repeated exercise testing and 72-hour ambulatory electrocardiographic monitoring in 82 patients with coronary artery disease. Patients with positive treadmill stress test results and greater than or equal to 2 ischemic episodes per 24 hours were included in this study. Administration of all chronic antiischemic medications except beta blockers were discontinued. During the first week all patients received placebo twice daily. During the second and third weeks, 41 patients received nisoldipine 10 mg and 41 patients received placebo twice daily. In the placebo group there were no changes in exercise parameters or in ambulatory electrocardiographic parameters. In the nisoldipine group, exercise duration increased from 403 to 448 seconds (p = 0.0035), time to 1 mm of ST depression increased from 224 to 298 seconds (p = 0.002), time to pain increased from 241 to 321 seconds (p = 0.01), and maximal ST depression was reduced from 2.6 to 2.3 mm (p = 0.002). Among the ambulatory electrocardiographic parameters in the nisoldipine group, only the number of episodes was reduced, from 14.4 to 11.6 (p = 0.0013) per patient. There was no significant reduction in total ischemic time (132 vs 120 minutes per patient). No significant side effects were observed. This is the largest clinical trial to date on the effects of nisoldipine on myocardial ischemia. The results indicate that nisoldipine was effective in improving all exercise parameters and only partially effective in suppressing ischemia during daily activity.

Acute hemodynamic effects of intravenous diperdipine, a new dihydropyridine derivative, in coronary heart disease

The acute hemodynamic effects of a new dihydropyridine calcium channel blocker, diperdipine, which is suitable for intravenous administration, were studied by right and left cardiac catheterization in 16 patients with coronary heart disease. Diperdipine markedly reduced systemic vascular resistance and improved stroke index and left ventricular ejection fraction. Mean pulmonary artery and wedge pressures were slightly increased as a possible consequence of enhanced venous return, whereas right atrial and left ventricular end-diastolic pressures were not significantly changed. Nevertheless, an increase in preload was clearly indicated by an augmented left ventricular end-diastolic volume index after administration of diperdipine. Left ventricular contractility, which was estimated by the end-systolic pressure-volume ratio and by dP/dt max was not significantly changed, though analysis of individual data suggests a minimally negative inotropic effect. However, such a minor effect on left ventricular contractility was largely counterbalanced by the marked reduction of afterload, which produced a sharp improvement of stroke index. Enhancement of left ventricular ejection fraction and reduction in systemic vascular resistance were inversely and directly correlated to control values. Overall, diperdipine was well tolerated, but one patient had a major untoward reaction that consisted of an ischemic episode that was possibly related to drug administration. In conclusion, intravenous diperdipine appears to be a potent arteriolar dilating agent that does not affect left ventricular contractility.

Preservation of left ventricular performance with reduced ischemic dysfunction by intravenous nisoldipine

The effect of intravenous nisoldipine on cardiac performance was examined during pacing-induced ischemia in 14 patients with coronary artery disease. The relative contributions of afterload reduction or prevention of myocardial ischemia were assessed using load-independent global (peak-systolic pressure/end-systolic volume) and regional (peak-systolic pressure/end-systolic radial length) "contractile" indexes. Nisoldipine decreased aortic pressure (predrug, 109 +/- 14 vs postdrug, 88 +/- 13 mm Hg, p less than 0.01) and prevented elevation of left ventricular end-diastolic pressure during rapid atrial pacing (predrug, 7.9 +/- 5.7 vs postdrug, -0.5 +/- 4.9 mm Hg, p less than 0.001). Resting cardiac index (predrug, 3.3 +/- 0.6 vs postdrug, 4.2 +/- 0.7 liters/min/m2, p less than 0.05), and left ventricular ejection fraction (predrug, 68.1 +/- 9.0 vs postdrug, 74.2 +/- 9.4%, p less than 0.05) increased after nisoldipine, which also prevented the deterioration in left ventricular ejection fraction (predrug, -8.1 +/- 7.9 vs postdrug, -1.0 +/- 3.7%, p less than 0.05) and fractional radial shortening (predrug, -8.7 +/- 13.1 vs postdrug, 3.7 +/- 16.4%, p less than 0.01) during rapid atrial pacing. Under these conditions, nisoldipine preserved myocardial function, as determined by global peak-systolic pressure/end-systolic volume (predrug, -0.82 +/- 0.39 vs postdrug, 0.17 +/- 1.54 mm Hg/ml, p less than 0.05) and regional (peak-systolic pressure/end-systolic radial length, predrug, -23.8 +/- 36.1 vs postdrug, 12.7 +/- 36.3 mm Hg/cm, p less than 0.01) "contractile" indexes. Intravenous nisoldipine maintains ventricular performance during rapid atrial pacing via a combination of systemic vasodilation and amelioration of ischemic myocardial dysfunction.

Comparative haemodynamic effects of intravenous nisoldipine and hydralazine in congestive heart failure

The acute haemodynamic effects of intravenous nisoldipine and hydralazine were compared in nine patients with heart failure. Both agents caused qualitatively similar effects, reducing both left ventricular preload and afterload, with reductions in systemic vascular resistance and increases in cardiac output. However, the effect of hydralazine was significantly greater and of longer duration than nisoldipine, and was associated with side effects in four patients. This, and previously reported data, suggests that nisoldipine may be useful in patients with ischaemia and concomitant heart failure.

Effect of the second-generation calcium channel blocking drug nisoldipine on diastolic left ventricular dysfunction in heart failure

The effect of intravenous nisoldipine (0.12 microgram/kg/min) on diastolic left ventricular (LV) dysfunction was studied from simultaneous hemodynamic and radionuclide measurements in 12 patients with New York Heart Association class II to IV cardiac failure. The initial LV filling fraction was low, the peak LV filling rate normalized for end-diastolic volume was decreased, and the pulmonary capillary wedge pressure (PCWP) was high and associated with clinical shortness of breath. Nisoldipine produced an increase in LV filling fraction from 36 +/- 17% to 43 +/- 20% (p = 0.003). The increase in filling took place in both early and late diastole: peak early filling rate (PFR) increased in 11 of the 12 patients (p = 0.02) and late diastolic filling rate (atrial [A] wave in eight of them (NS). When the determinants of these changes, were examined further, it was found that in the control state PFR was inversely related to LV end-systolic volume (r = 0.77), whereas the A wave was related in exponential fashion to PCWP (preload) (r = 0.79). Nisoldipine did not change the slope of these relationships, and it did not alter the end-diastolic pressure-volume relationship, implying that inherent myocardial relaxation and distensibility were unaltered by the drug. In summary, nisoldipine improved measurements of diastolic LV dysfunction in patients with cardiac failure. This study illustrates the importance of considering ventricular loading conditions when analyzing and interpreting measurements of diastolic ventricular dysfunction. The measured changes in diastolic LV function during infusion of nisoldipine appear to be due to alterations in ventricular loading conditions rather than to a direct myocardial effect of the drug.

The acute effects of intravenous nisoldipine on left ventricular function 24 to 72 hours after uncomplicated acute myocardial infarction

The acute effects on left ventricular function of nisoldipine were studied in six patients 56 +/- 12 hours (range 44 to 72 hours) after the onset of uncomplicated acute myocardial infarction. Nisoldipine was administered as a 4.5 micrograms/kg intravenous bolus over 3 minutes followed by an infusion of 0.2 microgram/kg during 60 minutes. Radionuclide angiography and two-dimensional echocardiography were performed before and during infusion with nisoldipine. The left ventricular ejection fraction increased significantly from 38% +/- 10% to 49% +/- 10% (P = 0.028) during nisoldipine infusion. Regional wall motion index was determined both by radionuclide and by two-dimensional echocardiography and showed a significant change during nisoldipine infusion from 1.9 +/- 0.3 to 1.5 +/- 0.3 (p = 0.028, radionuclide angiography) and from 0.7 +/- 0.2 to 0.3 +/- 0.2 (p = 0.043, two dimensional echocardiography). Heart rate increased significantly from 78 +/- 12 min-1 to 92 +/- 13 min-1 (p = 0.028), but mean double product did not change significantly during nisoldipine infusion. It is concluded that nisoldipine significantly improves global and regional left ventricular function in patients shortly after acute myocardial infarction. This beneficial effect may, however, be partially offset by an increase in heart rate. Since mean double product did not change, it is suggested that nisoldipine may improve coronary blood flow in patients with acute myocardial infarction.