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

Efficacy and Tolerability of Nisoldipine Coat-Core vs Diltiazem Retard in Combination with a Beta-Blocker in Patients with Stable Exertional Angina Pectoris

A randomised, double-blind, placebo-controlled, parallel-group trial with forced titration study to investigate possible equivalence of efficacy and tolerability between nisoldipine coat-core (CC) 40mg once daily, and diltiazem retard 120mg twice daily, was carried out in 176 patients with stable angina pectoris who were already receiving beta-blocker therapy. A total of 164 patients were included in the tolerability analysis and 135 patients were evaluable for efficacy (nisoldipine CC, n = 69; diltiazem retard, n = 66). During bicycle exercise tolerance tests, time to 1mm ST-segment depression, total exercise time, and time to angina were assessed at baseline and at the end of the treatment period. The number of angina attacks and of consumed nitroglycerin tablets were recorded in weekly diaries. Time to onset of 1mm ST-segment depression increased by 69.4 +/- 100.0 seconds with nisoldipine CC and by 65.9 +/- 87.6 seconds with diltiazem retard. The two treatment regimens were equally effective in time to onset of 1mm ST-segment depression, time to angina pectoris, and in exercise duration. A beneficial effect on angina attacks and nitroglycerin consumption was achieved with both treatments. Patient compliance, as assessed by the number of returned tablets, was high, at over 80%. Six patients withdrew from the treatment because of adverse events. Mild and transient adverse events were reported by 24 patients during treatment. One patient experienced a severe circulatory shock on the combination of diltiazem retard and atenolol. Peripheral oedema and headache were more common on nisoldipine CC. We concluded that the two treatments were equally efficacious and tolerated in patients with stable angina pectoris.

Assessment of ischemic changes by ambulatory ECG-monitoring: comparison with 12-lead ECG during exercise testing

The accuracy of commercially available ambulatory electrocardiographic monitoring (AEM) systems for reproducing ischemic changes has been questioned. Since these systems are widely used for evaluation of ST-segment changes, both for prognostic purposes and for assessment of the efficacy of antiischemic drugs, such doubts must be clarified. For this purpose, we recorded electrocardiograms (ECGs) during exercise testing, using split leads, simultaneously with a 12-lead electrocardiograph and with the Marquette AEM recorder. We studied 29 patients with proven coronary artery disease and positive exercise tests and 19 individuals with low likelihood of coronary artery disease and negative stress tests. All 29 patients who had ST-segment depression during exercise as recorded on the 12-lead ECG had ST-segment depression in at least one of the three AEM leads (resembling the V5, V3, and aVF leads of the 12-lead system). The maximal degree of ST-segment depression with AEM was similar to 12-lead ECG (2.3 mm and 2.1 mm, respectively). The best lead for ischemia detection with AEM was the V5 type, which detected ischemic changes in 26 of the 29 patients, while the 12-lead V5 detected ischemia in 24 patients. The inferior AEM lead detected ischemia in only 4 patients, while the aVF lead of the 12-lead ECG detected ischemia in 23 patients. Of the 19 patients with negative exercise tests only 1 patient had a 1-mm ST-segment depression on AEM. Thus, of the 48 patients studied, similar responses were observed in 47. The results of indicate that the Marquette AEM system is as accurate as the 12-lead ECG in detecting ischemic changes and in assessing their severity.

Comparison between metoprolol orally osmotic once daily and metoprolol two or three times daily in suppressing exercise-induced and daily myocardial ischemia

Metoprolol is a widely used anti-ischemic drug with a relatively short half-life. To improve patient' compliance and to provide 24-hour coverage, its once daily ORally OSmotic (OROS) formulation was developed. In this multicenter double-blind study, the anti-ischemic effects of metoprolol OROS given once daily at doses of 190 and 285 mg were compared to the regular metoprolol formulation of 100 mg 2 or 3 times daily. Sixty-five patients with stable coronary artery disease, positive exercise tests, and ischemic episodes during daily activity as recorded by ambulatory electrocardiographic monitoring (AEM) were included. In the OROS group, 23 patients completed all 3 treatment periods. In these patients, the number of myocardial ischemic episodes decreased from 239 on placebo to 128 during the 190 mg/day dose (p < 0.0001) and to 86 during the 285 mg/day treatment period (p < 0.0001). In the metoprolol group, there were 204 episodes at baseline and 142 and 140 during the 100 mg 2 or 3 times daily treatment periods (p < 0.0001 for both). During exercise testing, time to 1-mm ST depression increased significantly in the OROS group from 6.3 minutes at baseline to 7.1 and 9.6 minutes during 190- and 285-mg treatment periods. In the metoprolol group, it increased from 5.8 to 7.2 and 8.2 minutes, respectively. Both formulations of metoprolol were well tolerated. The OROS formulation was highly effective in suppressing daily and exercise-induced ischemia and exerted its effect throughout the 24-hour period.

Clinical application of three-dimensional myocardial imaging: evaluation of efficacy of medical treatment on myocardial perfusion

To investigate the clinical applicability of the three-dimensional (3D) myocardial imaging using a newly developed system (the Application Visualization System-Medical Viewer), thallium-201 myocardial single photon emission computed tomography was performed in 19 patients with previous myocardial infarction before and after treatment with nisoldipine. We have developed a new method for automatically reconstructing 3D imaging for the stereoscopic evaluation of myocardial perfusion. The left ventricular myocardial volume with a radioisotope count > or = 50% of maximum was calculated by using the conventional surface rendering method. With these images, the effect of nisoldipine on myocardial perfusion was assessed and the myocardial volume with a radioisotope count > or = 50% of maximum was compared. In fifteen (88%) of 19 patients, myocardial perfusion increased in the infarct areas after nisoldipine treatment. Nisoldipine significantly increased the myocardial volume with a radioisotope count > or = 50% of maximum from 141 +/- 17 to 153 +/- 18 ml on the stress 3D imagings. These findings indicate that nisoldipine improved myocardial perfusion during exercise. 3D imaging provided stereoscopic assessment of the changes in myocardial perfusion following treatment with nisoldipine and also detected transient enlargement of the left ventricular lumen induced by exercise.

Effects of nisoldipine in silent myocardial ischemia after healing of acute myocardial infarction

Silent myocardial ischemia occurring after acute myocardial infarction is classified as Cohn type II and has a frequency of 20-30% in all patients with acute myocardial infarction. Follow-up data of patients with either silent or anginal ischemia show a poor prognosis. Thus, all ischemic episodes occurring after myocardial infarction should be treated aggressively. Many multicenter studies have evaluated whether drug treatment can improve prognosis or protect from a nonfatal second attack. Calcium antagonists, especially those that increase heart rate, have not been considered as drugs of choice for this purpose, despite the many beneficial effects shown on myocardial tissue in experimental studies. In the study reported here, the effect of nisoldipine on postinfarction silent myocardial ischemia was evaluated by ambulatory left ventricular function monitoring. Ten patients were selected for study who showed silent myocardial ischemia after their first acute infarction. Blood pressure fell significantly (p < 0.05) after 4 weeks of treatment with nisoldipine (5-10 mg/day), but heart rate showed no change at rest. Exercise time improved (p < 0.05), with increased peak double products. During exercise, there was no significant change in end-diastolic volume but there was a marked improvement in end-systolic volume, and at the submaximal point the ejection fraction was significantly (p < 0.05) increased. Ejection fraction at rest also improved. The deterioration in ejection fraction due to dipyridamole was ameliorated by nisoldipine. Ejection fraction and blood pressure improved during the calculation test, and work performance also improved.(ABSTRACT TRUNCATED AT 250 WORDS)

Improvement of ischemic myocardial dysfunction by nisoldipine

We examined the cardioprotective effect of nisoldipine against myocardial dysfunction during ischemia and reperfusion in Langendorff perfused rabbit hearts. Nisoldipine was administered to the hearts before 60 minutes of global ischemia. This agent inhibited the increase of end-diastolic pressure during ischemia and also improved the recovery of left ventricular developed pressure and coronary flow during reperfusion in a concentration-dependent manner. The maximal cardioprotective effect was observed in 10(-8) M nisoldipine. The beneficial effect was associated with an increase of coronary flow during reperfusion. Therefore, both the nisoldipine-increased coronary flow during reperfusion and the inhibition of ischemic contracture by nisoldipine seem to play a crucial role in improving myocardial dysfunction of ischemic-reperfused hearts.

Circadian variations in ischemic threshold and their relation to the occurrence of ischemic episodes

BACKGROUND

The occurrence of ischemic episodes during daily activity has been reported to exhibit a bimodal circadian distribution, yet its relation to the ischemic threshold (heart rate at 1-mm ST segment depression) has not been explored.

METHODS AND RESULTS

To determine whether the ischemic threshold during daily activity exhibits a circadian pattern that might relate to the frequency of occurrence of ischemic episodes, we studied the time of occurrence and the heart rate at onset of ischemia in 1,371 ischemic episodes recorded in 41 patients with stable coronary disease, positive exercise testing, and repeated ischemic episodes during ambulatory ECG monitoring (AEM). All patients had 7 days of AEM; 23 were off any anti-ischemic therapy, while 18 were on low dose of beta-blockers. The occurrence of ischemic episodes exhibited the typical bimodal circadian distribution with a prominent peak between 7:00 and 11:00 AM and a second less prominent peak between 6:00 and 9:00 PM. The threshold of myocardial ischemia exhibited a different single-peaked circadian distribution; it was lowest between 1:00 and 3:00 AM and highest between 10 AM and 1 PM. Time series analyses indicated a strong hour-by-hour trend of each of the two circadian distributions, whereas the two series cross-correlated maximally at a lag of zero hours (p < 0.01), indicating a complex interplay between myocardial oxygen demand and supply in determining the occurrence of ischemic episodes during daily activity. The morning increase in the frequency of ischemic episodes could not be attributed to a reduced threshold but rather to an increase in demand. The low threshold at night-time might probably indicate that the mechanism of ischemia during these hours is reduced coronary flow due to increased coronary tone. Secondary analyses for several predefined patients' subsets gave similar results. Patients who received low-dose beta-blockers maintained the bimodal circadian distribution of the occurrence of ischemic episodes, whereas the ischemic threshold exhibited a constant pattern with no circadian changes.

CONCLUSIONS

Our results demonstrate that myocardial oxygen demand is a major determinant of daily ischemia, yet changes in the ischemic threshold that probably reflect dynamic changes in coronary tone play also an important role. The relative contribution of increased demand and decreased threshold to the genesis of ischemic episodes during daily activity can be assessed by AEM and may help to optimize medical therapy.