Does the exercise protocol matter when assessing the anti-anginal effects of drug therapy?

Four exercise test protocols (Bruce, Balke, Ellestad and Steep) were compared in 16 patients with proven coronary artery disease in demonstrating the anti-anginal effects of sublingual glyceryl trinitrate in a randomization double-blind trial. Glyceryl trinitrate significantly improved the time, heart rate and rate pressure product to peak exercise, onset of angina and 1 mm ST segment depression in all four protocols (P < 0.05) (except rate pressure product to angina in the Balke protocol). The increase in exercise time was greatest for the Balke protocol at peak exercise (188.1 +/- 187.1) (mean +/- SD in s), at onset of angina (251.9 +/- 247.1) and at 1 mm ST depression (233.6 +/- 243.8), followed by the Steep and Bruce protocols, and was lowest for the Ellestad protocol 41.9 +/- 42.4, 96.5 +/- 65.8, 82.6 +/- 74.0, respectively. Increase in time to peak exercise with glyceryl trinitrate was significantly greater for the Balke protocol in comparison with the other three protocols and for the Bruce and Steep protocols when compared to the Ellestad protocol. Time to 1 mm ST depression with treatment was significantly greater on the Balke and Bruce protocols than the Ellestad protocol, and to onset of angina for the Balke compared to other three protocols. There were no significant differences between the Bruce and Steep protocols for any of the endpoints. The magnitude of treatment effect in the different protocols was accompanied by correspondingly greater inter-patient variability such that no protocol was more, or less, sensitive than another in detecting treatment effect. Changes in heart rate and rate pressure product with treatment were generally similar between the different protocols. In conclusion, a protocol with small and frequent increments (Balke), although able to show greater increase in exercise duration with glyceryl trinitrate than more aggressive protocols, is no more sensitive at detecting treatment effect.

Circadian rhythms and the onset of myocardial infarction: clinical implications

There is much current interest in the development of therapeutic strategies which may alter the circadian pattern of cardiovascular events such as myocardial infarction and sudden cardiac death. It is not known whether manipulating rhythmic processes and providing active medication at the most vulnerable periods during the day or night will protect patients and reduce the risk of death. This review examines the evidence from the limited available data and assess the feasibility of implementing such strategies.

The planovalgus rheumatoid foot--is tibialis posterior tendon rupture a factor?

The purpose of this study was to assess gross tibialis posterior tendon (TPT) integrity in a series of patients with a planovalgus foot deformity secondary to rheumatoid arthritis. This was done by means of contrast tenography. Our findings of an intact tendon in all of the seventeen patients studied suggest that complete rupture of the TPT is not the primary aetiology in the planovalgus rheumatoid foot.

Low level laser therapy: a prospective double blind trial of its use in an orthopaedic population

We have conducted a prospective, double blind trial of low level laser therapy (LLLT) in musculoskeletal injuries to assess its efficacy. We assigned patients with a variety of painful skeletal soft tissue conditions to one of two treatment groups, treatment from a functional machine, placebo treatment from an inactive machine. Both machines were identical and both appeared functional. The operative status of each machine was unknown to both the therapist and the patient. The results suggest that LLLT has no significant therapeutic effect and acts primarily as a placebo.

Detection of ambulatory ischaemia is not of practical clinical value in the routine management of patients with stable angina. A long-term follow-up study

It has been reported that medically treated patients with stable angina and positive exercise test for ischaemia have an adverse 1-2 year outlook if they are shown also to have transient, and predominantly silent, ischaemic episodes detected by ambulatory ST segment monitoring during their daily activities: it has been suggested that this investigation could be used to identify patients more likely to benefit from early investigation and treatment. We assessed the long-term (up to 65 months) prognostic significance of transient ischaemic episodes during daily activities in 172 patients routinely attending cardiac outpatients with medically treated stable angina who had undergone exercise testing and 48 h of ambulatory ST segment monitoring between February 1988 and August 1989 for this purpose. A positive exercise test for ischaemia was not a prerequisite for inclusion. One hundred and four patients (60.5%) had a positive exercise test for ischaemia and 72 (42%) had transient ischaemia during daily activities (63 had both tests positive). Over a median 50-month follow-up period 54 patients suffered at least one cardiac event (primary event: cardiac death n = 7; non-fatal myocardial infarction n = 11; unstable angina n = 18; elective CABG/PTCA n = 18). Two further patients suffered non-cardiac death. Cardiac events, either objective (cardiac death or non-fatal myocardial infarction) or subjective (unstable angina or revascularisation) were no more likely to occur in those with transient ischaemia during daily life when compared with those without, at follow-up times up to 65 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Negative radioisotope bone scan in a patient with a fractured neck of femur

Radioisotope bone scanning is a sensitive and specific method of detecting occult fractures of the femoral neck but may occasionally give false negative results. It would appear that patients with renal failure are more likely to have a false negative test and this is probably related to avascularity of the femoral head.

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.

Circadian variations in cardiovascular disease: implications for treatment

This review describes circadian patterns in cardiovascular disease processes and analyses the findings of recent studies. The awareness of an increased incidence of myocardial infarction and sudden cardiac death in the early morning hours, shortly after waking, has stimulated an interest in the relationship of these events and the occurrence of both silent and symptomatic myocardial ischaemia. A number of studies have been reported that examine both the physiological triggers and the underlying causes of these events. Beta-adrenergic blockers have been shown to abolish the early morning peak of myocardial infarction and blunt the morning peak in sudden cardiac death. Newer calcium antagonists, such as amlodipine, have been demonstrated to control angina throughout a 24-hour period. Aspirin is effective in preventing morning infarction. It is a reasonable aim for investigators to extend progress in the treatment of cardiovascular disease to include prevention.

Collateral growth between left internal mammary and left anterior descending coronary arteries following coronary artery bypass surgery

A case is described in which new collateral vessels grew between the left internal mammary artery and the left anterior descending coronary artery following coronary artery bypass surgery. Collateralization of the coronary arteries by extra-cardiac arteries has not been previously described following bypass surgery and may have implications for the mechanisms of angiogenesis.

Unstable and stable angina

Treatment of both stable and unstable angina depends on initially defining the pathophysiological mechanisms. The goal of treatment is to prevent the development of angina pectoris and possibly also to improve the prognosis. beta-blockade is effective in treating effort-related angina, as are calcium antagonists, which are also effective in treating coronary spasm. Combination therapy may be synergistic, but evidence to support this is controversial. In unstable angina the main goal of treatment is the prevention of myocardial infarction and death. While calcium antagonists have not been shown to improve the prognosis, there is more evidence to support the use of beta-blockers, particularly in combination with a calcium antagonist. Aspirin and possibly heparin should be considered as routine treatment.

Prognostic significance of transient ST segment changes after coronary artery bypass surgery: a long-term (4-10 year) follow up study

OBJECTIVE

To assess the long-term (four to 10 years) prognostic significance of transient ST segment changes on ambulatory ST segment monitoring after coronary artery bypass grafting (CABG).

PATIENTS AND METHODS

76 patients (67 men, nine women) underwent CABG between 1982 and 1984 (n = 31) and between 1987 and 1988 (n = 45) and at a mean age of 57. All underwent 48 hours of ambulatory ST segment monitoring at a mean of 19 weeks after surgery. The results were available for assessment. All general practitioners were contacted and patients' notes reviewed. Patients were contacted by telephone. Details were recorded of intervening events (acute myocardial infarction, unstable angina, need for further revascularisation, and deaths). Event free survival curves were produced for those with and without transient ST segment changes during routine postoperative ambulatory ST segment monitoring.

RESULTS

During 3213 hours of monitoring after CABG, 21 (27.6%) of 76 patients had transient ST segment changes, of which 70% were silent. Over a mean 70 month follow up period, patients with such ischaemic changes were no more likely to have either an objective (myocardial infarction or cardiac death) or subjective (unstable angina or another revascularisation) event than those patients without ischaemic changes. This finding was the same in patients operated on between 1987 and 1988 and between 1982 and 1984.

CONCLUSIONS

Although ambulatory ST segment monitoring is becoming increasingly popular in some countries as a routine investigation for ischaemia in various coronary subgroups, the findings of such an investigation, when performed after CABG, do not help to identify a subgroup more likely to have an adverse outcome during up to 10 years of follow up. There seems to be no reason to perform this investigation after surgery, and particularly to refer patients for reinvestigation because of the detection of predominantly silent ST segment changes of uncertain relevance.

Atenolol or nicardipine alone is as efficacious in stable angina as their combination: a double blind randomised trial

BACKGROUND

Beta blockers and calcium antagonists are widely used in the management of angina pectoris in the belief that the combination is more efficacious than either drug alone.

METHODS

This double blind randomised crossover placebo controlled study compares the effects of nicardipine, atenolol and their combination in 30 patients with chronic stable angina. Each treatment period lasted 6 weeks with dose titration after 3 weeks. Symptom limited treadmill exercise testing and radionuclide ventriculography at rest was carried out at the end of each treatment period.

RESULTS

Total exercise duration and time to 1-mm ST-segment depression was significantly prolonged by nicardipine and atenolol when compared to placebo, the combination offered no additional benefit. Time to onset of angina was significantly prolonged by nicardipine and the combination but not by atenolol. Indices of left ventricular function were not significantly affected by any treatment other than an increase in left ventricular end diastolic volume on atenolol and the combination.

CONCLUSIONS

Nicardipine and atenolol are equally effective in prolonging exercise duration and time to onset of ischemia in patients with chronic stable angina while the combination appeared to offer no additional benefit. Nicardipine prolonged the time to onset of angina significantly; again there was no further improvement with the combination. Neither drug appears to have an important effect on the parameters of diastolic function studied in patients with chronic stable angina.

Silent ischaemia--to treat or not to treat?

The authors summarise published data concerning silent myocardial ischaemia: they review the studies showing the poor prognosis of this type of myocardial ischaemia but pose the question of whether this is due to the severity of the lesions causing the ischaemia or to the ischaemia itself. To answer this question, it would be necessary to set up a therapeutic trial showing that treatment preventing the electrocardiographic changes of silent ischaemia is associated with an improved prognosis. In the absence of solid evidence on this point, the authors present the case for and against treatment of silent ischaemia without drawing any formal conclusions.

Long term follow up of severely ill patients who underwent urgent cardiac transplantation

OBJECTIVE

To assess long term survival (> 5 years) and quality of life in severely ill patients referred for urgent cardiac transplantation.

SETTING

Tertiary referral centres: before transplantation at the National Heart Hospital (late 1984 to end 1986); after transplantation at Harefield Hospital.

SUBJECTS

Eighteen patients (15 men; three women) who had required intensive support in hospital before cardiac transplantation and were alive at short term follow up.

INTERVENTIONS

Intravenous infusions of cardiac drugs (mean 2.2 infusions), intravenous diuretics (17 patients), and many other drugs before transplantation. Intra-aortic balloon counterpulsation (four patients), temporary pacing (two), and resuscitation from cardiac arrest (three). Patients had specialised nursing care on a medical intensive care unit in almost every case.

MAIN OUTCOME MEASURES

Long term survival in patients after urgent cardiac transplantation and perceived quality of life.

RESULTS

Of 18 patients who were alive at short term follow up (mean (range) 19.4 (10-33) months), 14 were still alive in 1992 (69 (61-83) months). Ten still worked full time, and 11 reported no restrictions in their daily activities. Three of four patients who died in the intervening period survived > 5 years after transplantation. Overall, 17 of 18 patients survived at least 5 years.

CONCLUSIONS

In severely ill patients who undergo urgent cardiac transplantation and survive in the short term, long term (5-7 year) survival and quality of life seem good.