Acute and long-term effects on myocardial ischemia of intermittent and continuous transdermal nitrate therapy in stable angina

Value and limitations of ambulatory ECG monitoring for assessment of myocardial ischemia

Ambulatory ECG monitoring (AEM) is the only available method to assess the presence and severity of myocardial ischemia during daily life. Several investigators have shown that the recording systems currently used can detect ischemic changes with similar accuracy as treadmill exercise testing. Ischemic changes on AEM are, however, present in only 40%-60% of patients with coronary artery disease (CAD) and positive exercise tests. For this reason, and because of the high day-to-day variability in daily ischemic changes, AEM cannot be used as a screening tool for detecting CAD or for evaluating severity of ischemia in individual patients. In patients with proven CAD, ischemic changes on AEM are associated with an adverse outcome in patients with stable and unstable ischemic syndromes, and in postmyocardial infarction patients. Suppression of daily ischemia seems to be associated with improved outcome. The mechanism of daily ischemia is not identical to exercise-induced ischemia. In addition to increased demand, which is a major contributor to AEM detected-ischemia, increased coronary tone also seems to play a major role. AEM has been shown to be a useful and reliable tool to assess the efficacy of various antiischemic drugs.

40 mg pantoprazole and 40 mg esomeprazole are equivalent in the healing of esophageal lesions and relief from gastroesophageal reflux disease-related symptoms

BACKGROUND

Proton pump inhibitors are regarded as the most effective class of acid suppressive medication for gastroesophageal reflux disease treatment. There is considerable interest regarding the dose equivalence between various proton pump inhibitors.

GOALS

To compare the efficacy of pantoprazole and esomeprazole with regard to healing and relief from gastroesophageal reflux disease-related symptoms.

STUDY

Multicenter, randomized, double-blind study. Patients with gastroesophageal reflux disease grades B/C (Los Angeles classification) received 40 mg pantoprazole daily (n = 113) or 40 mg esomeprazole daily (n = 114). Healing (endoscopy) and relief from gastroesophageal reflux disease-related symptoms (direct questioning) were assessed at first and final visit (after 4, 6, 8, or 10 weeks of treatment).

RESULTS

Overall healing in both treatment groups was 88% of patients (intention-to-treat population), 95% (pantoprazole), and 90% (esomeprazole) (per-protocol population); statistically, this indicates "at least equivalence" between treatments. Overall relief from gastroesophageal reflux disease-related symptoms was similar for pantoprazole (55%) and esomeprazole (51%, per-protoco). No correlation between healing and symptom relief was seen. The majority of reported adverse events were assessed as "not related" to the study drug. Pantoprazole and esomeprazole have comparably good safety and tolerability.

CONCLUSION

In patients with gastroesophageal reflux disease, 40 mg pantoprazole daily and 40 mg esomeprazole daily are equally effective for healing of esophageal lesions and relieving gastroesophageal reflux disease-related symptoms.

Once-daily pantoprazole 40 mg and esomeprazole 40 mg have equivalent overall efficacy in relieving GERD-related symptoms

AIM

To compare the efficacy of pantoprazole and esomeprazole for the treatment of gastro-oesophageal reflux disease- (GERD-) related symptoms.

METHODS

In this multicentre, randomized, double-blind study 217 patients [intention-to-treat (ITT) population] diagnosed with endoscopically proven GERD grade B/C received pantoprazole (40 mg once daily (o.d.), n = 112] or esomeprazole (40 mg o.d/, n = 105) for 4 weeks. Patients recorded GERD-related symptoms (daytime and night-time) using diaries (daily), and/or by telephone interviews (every third day) and completed the Gastrointestinal Symptom Rating Scale (GSRS) questionnaire. The area under the time curve (AUC) for the sum score of GERD-related symptoms (symptom load of each patient during the treatment) and the time to reach adequate relief from GERD-related symptoms were calculated.

RESULTS

Patients reported first adequate relief from daytime GERD-related symptoms after a mean of 3.7 (pantoprazole) and 5.9 days (esomeprazole) (P = 0.034); the values for the night-time were 1.7 and 3.5 days, respectively (P = 0.012, ITT). The AUCs for the single symptoms and the sum scores were comparable.

CONCLUSIONS

Treatment with pantoprazole resulted in significantly faster first-time relief from daytime and night-time GERD-related symptoms than esomeprazole. Pantoprazole and esomeprazole were similar with respect to reduction of load of GERD-related symptoms.

[Quality of life and angina pectoris. Comparison of the effects of 2 nitrate derivatives administered discontinuously: transdermal 10 mg nitroglycerine patch (12 hours) and long-acting oral 40 mg isosorbide-5-mononitrate (once a day)]

A comparative, randomised, 12-week (two periods of six weeks) cross-over study including 150 patients (mean age: 63.4 years) suffering from stable but symptomatic (a minimum of three attacks per week) angina pectoris was performed in order to compare the effect on quality of life of two discontinuous nitrate treatments: transdermal 10 mg nitroglycerine patch (12 hours) and long-acting oral 40 mg isosorbide-5-mononitrate (once a day). The efficacy and safety were also compared. The two treatments equally and significantly improved patients' quality of life. The number of attacks and sublingual nitrate consumption significantly decreased under treatment. Attack severity was lower under nitroglycerine than isosorbide-5-mononitrate treatment. Finally, even though nitroglycerine more frequently induced headache than did isosorbide-5-mononitrate (13 cases versus 8), patients, and in particular those having received nitroglycerine treatment in the second period of the study, preferred the transdermal nitroglycerine treatment. In conclusion, results did not show any relevant difference in terms of efficacy or tolerability between the two treatments. Nevertheless, the facility of use and the feeling of protection were better under transdermal nitroglycerine patch than oral isosorbide-5-mononitrate treatment.

Role of beta blockade in the treatment of myocardial ischemia

A number of antianginal drugs and therapeutic strategies are now available for the treatment of patients with coronary artery disease (CAD) and myocardial ischemia. Of the available antianginal drugs, beta blockers appear to be most effective in suppressing myocardial ischemia. The superior anti-ischemic efficacy of beta blockers can be explained by their beneficial actions on hemodynamic parameters, vasomotion, and platelet function. Compared with other anti-ischemic drugs, beta blockers appear to be more efficacious in reducing the magnitude of myocardial ischemia during routine daily activities. In addition, the results of recent studies indicate that treatment with beta blockers not only suppresses myocardial ischemia, but also improves the clinical outcome in patients with CAD. These beneficial effects, along with the well-demonstrated cardioprotective effects of beta blockade in the postinfarction period, clearly suggest that this class of anti-ischemic drugs is an ideal therapeutic choice in most patients with CAD.

Abrupt cessation of short-term continuous treatment with isosorbide dinitrate may cause a rebound increase in silent myocardial ischaemia in patients with stable angina pectoris

OBJECTIVE

To examine by Holter electrocardiographic monitoring the effect of abruptly stopping nitrate treatment in patients with stable angina pectoris.

PATIENTS

12 men with confirmed ischaemic heart disease and stable exertional class 3 angina (Canadian). All had episodes of horizontal or down sloping ST segment depression during 24 hour electrocardiographic monitoring. All were nitrate responders.

DESIGN

Each patient was given isosorbide dinitrate (10-30 mg four times a day) and placebo (four times a day) for three days in a randomised crossover trial. There was a washout period of 3-5 days between the two treatment periods. Holter monitoring was performed on the third day of isosorbide dinitrate and placebo administration and on the first day of their withdrawal.

RESULTS

When treatment with isosorbide dinitrate was stopped there was a significant increase in the total number and duration of painless episodes of myocardial ischaemia. During placebo and isosorbide dinitrate administration 8 patients had episodes of painless myocardial ischaemia whereas after isosorbide dinitrate cessation they were recorded in all 12 patients. Episodes of silent myocardial ischaemia at rest appeared in 4 patients after isosorbide dinitrate withdrawal.

CONCLUSION

Abrupt cessation of short-term continuous nitrate treatment in patients with severe angina may cause a rebound increase in myocardial ischaemia which is predominantly silent.

Well-being and gastrointestinal symptoms among patients referred to endoscopy owing to suspected duodenal ulcer

BACKGROUND

Few studies have evaluated quality of of life (QoL) in patients with upper gastrointestinal diseases, and there is a lack of validated measures for use in gastroenterology.

METHODS

The applicability and relevance of self-administered questionnaires such as the Psychological General Well-Being (PGWB) index and the Gastrointestinal Symptoms referred to endoscopy because of suspected duodenal ulcer were evaluated.

RESULTS

In total, 1526 patients with suspected duodenal ulcer were screened for inclusion in a clinical study. On the basis of medical history and endoscopy, 1424 patients who completed the questionnaire before endoscopy were classified in five diagnostic groups: oesophagitis, gastric ulcer, duodenal ulcer, negative endoscopy, and gastritis duodenitis. Irrespective of diagnosis, all patient groups reported a considerable decrease in their general well-being (mean score, 85, compared with 105 in healthy populations) with no significant differences between the groups. The results of the GSRS, however, showed statistically significant differences between the groups in dimensions depicting Abdominal pain, Reflux, Indigestion, and Diarrhoea Syndrome.

CONCLUSIONS

The results of the study showed that, irrespective of endoscopic findings, patients complaining of upper gastrointestinal symptoms have a low degree of general well-being. The symptoms profiles in the different diagnostic groups vary considerably.

Relationship between quality of life and exercise test findings after coronary artery bypass surgery

We studied the correlation between quality of life and exercise testing in 554 patients 2 years after coronary artery bypass surgery. Quality of life constitutes a person's perceptions of physical and mental functional capacity, health and symptoms. Traditionally, evaluations after coronary bypass surgery have focused on physical performance, medication and anginal symptoms, which cannot be said to represent quality of life. We used the Physical Activity Score, the Nottingham Health Profile and the Psychological General Well-being Index for evaluation of quality of life. Significant correlations were found between quality of life and exercise capacity (P < 0.0001), and quality of life and chest pain at exercise for all questionnaires (P < 0.0001). Significant correlations, although of small or moderate magnitude, were found between exercise capacity, chest pain and most subscales of quality of life, with the highest correlation coefficients for dimensions reflecting physical abilities and pain. We conclude that quality of life correlates significantly with exercise capacity and chest pain during exercise 2 years after coronary bypass surgery. However, only dimensions of pain and physical performance are reasonably well correlated with exercise test results. Several aspects of quality of life are only weakly related to exercise test results and may escape identification in an exercise test.

Intermittent transdermal nitrates do not improve ischemia in patients taking beta-blockers or calcium antagonists: potential role of rebound ischemia during the nitrate-free period

OBJECTIVES

This study was conducted to determine whether rebound ischemia occurs during nitrate-free periods with intermittent cutaneous nitroglycerin therapy in patients with angina pectoris who are receiving background antianginal therapy.

BACKGROUND

Rebound angina has been suggested to be a complication of the nitrate-free period with long-term cutaneous nitroglycerin therapy given intermittently to prevent tolerance.

METHODS

Fifty-two patients with stable effort angina taking either a beta-adrenergic blocking agent (n = 25) or diltiazem (n = 22) or their combination (n = 5) completed a randomized, double-blind, placebo-controlled crossover study of cutaneous nitroglycerin patches (50 mg). Active or placebo patches were worn for 1 week, applied at 8 AM and removed at 10 PM to provide a 10-h daily nitrate-free (or placebo-free) period. During the last 48 h of each study phase, a Holter monitor was used to detect ischemia.

RESULTS

Only 31 patients experienced ischemia during either phase of the study (23 during the patch-off period). A total of 463 ischemic episodes were recorded: 246 during placebo and 217 during nitroglycerin (p = 0.8, for per patient comparison). The majority (88%) of ischemic episodes were silent. Mean (+/- SEM) duration of ischemia during the total 48-h period was similar during active and placebo phases (35.5 +/- 15.0 min/24 h for active therapy vs. 29.7 +/- 9.8 for placebo, p = 0.8). This was due to an increase in duration of ischemia with active therapy during the patch-off period (46.9 +/- 17.9 min/24 h for active therapy vs. 22.5 +/- 9.2 for placebo, p = 0.07) and a decrease during the patch-on period (27.5 +/- 14.0 min/24 h for active therapy vs. 34.5 +/- 11.0 min/24 h for placebo, p = 0.16). The pattern of diurnal distribution of ischemic episodes differed between active and placebo phases. During placebo there was a nadir in the incidence of ischemia in the overnight patch-off period, with a significantly lower incidence between midnight and 6 AM (25 episodes) compared with the mean number of episodes during the three other 6-h periods (73 episodes, p < 0.001). During the nitroglycerin patch-off period, there was a loss of this overnight nadir, with the same incidence of ischemia between midnight and 6 AM (53 episodes) as the mean number of episodes for the three other 6-h periods (54 episodes).

CONCLUSIONS

The majority of patients taking background antianginal therapy experienced no ischemia during the patch-off period. In the 44% of patients with ischemia during this period, there was a nonsignificant increase in the duration of ischemia with active therapy. Although this result was statistically inconclusive, the change in the distribution of diurnal ischemia offers suggestive evidence that rebound ischemia may be a problem with regard to intermittent cutaneous nitroglycerin.

Nitrates in silent ischemia

In recent years it has become clear that episodes of transient myocardial ischemia commonly occur in patients with coronary artery disease in the absence of chest pain or angina equivalent. These episodes of "silent myocardial ischemia" are particularly well documented during continuous ambulatory electrocardiographic monitoring in daily life. Evidence suggests that these episodes represent true ischemia, and appear to be a marker of unfavorable outcome. While the pathophysiology is not completely understood, it appears as though the mechanisms of angina and silent ischemia are the same. Both forms of ischemia respond to conventional antianginal medication. While long-acting nitrates are effective in reducing or preventing myocardial ischemia, because of their propensity to cause tolerance they should be used intermittently and in association with either beta-blockers or calcium antagonists. Nitrates are safe and comparatively inexpensive, and will continue to play an important role in the treatment and prevention of angina. However, in the light of current knowledge, there is no specific indication for the treatment of silent ischemia by nitrates.

Ointments and transdermal nitroglycerin patches for stable angina pectoris

Nitroglycerin (NTG) ointment is used for the prophylaxis against angina pectoris, but there are no data to support its effectiveness during long-term therapy. Continuous, once-daily application of isosorbide dinitrate cream produces tolerance with complete loss of efficacy within 1 week. Nitroglycerin patches are very popular and continuous once-daily application is still claimed by some investigators to provide 24 hour antiischemic and antianginal efficacy. This claim is based on data from postmarketing studies in a very large number of patients and placebo-controlled studies in smaller groups of patients from Italy, Yugoslavia, Greece, and Germany. In contrast, studies from the United States, Canada, England, and some centers in Germany have failed to show superiority of patches over placebo during continuous therapy. This controversy was addressed by the NTG cooperative study group, in which a total of 562 patients who were responders to sublingual nitroglycerin were studied. Patients received either placebo or NTG patches delivering low (15-30 mg/24 hr), moderate (45-60 mg/24 hr), or large (75 and 105 mg/24 hr) amounts of NTG. Four hours after the initial application, NTG patches increased exercise duration compared to placebo, but this beneficial effect had disappeared by 24 hours. Furthermore, after 8 weeks of continuous therapy, none of the NTG patches were superior to placebo, whether patients were or were not taking concomitant beta-blockers. Therefore, current opinion is that continuous therapy with NTG patches produces pharmacologic tolerance and is ineffective.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk of rebound phenomenon during nitrate withdrawal

Organic nitrates are first-line drugs in the therapy and prevention of angina. These compounds, are acutely effective yet some formulations demonstrate a rapid decline in effect with chronic use. In this review the mechanisms of development of nitrate tolerance and the different strategies to prevent it are considered. If frequent dosing, high dosages and long acting preparations giving constant 24 h plasma GTN levels are more likely to cause tolerance, nitrate-low periods seem to be effective in restoring the drug's efficacy. Intermittent therapy with GTN patches, an effective way to prevent tolerance, raises the problem of the rebound phenomenon during the removal period. Considerable variations in its occurrence have been reported and in this review the factors that may influence the incidence of the rebound are discussed. The dangers of rebound can be lessened by concomitant anti-anginal drugs or avoiding any abrupt decline in blood nitrate concentrations. The use of beta-blockers or calcium channel blockers during intermittent therapy with GTN patches and oral preparations of isosorbide dinitrate or isosorbide 5-mononitrate seem to be effective for this purpose.