NHS heart failure survey: a survey of acute heart failure admissions in England, Wales and Northern Ireland

OBJECTIVES

To obtain national data on demographics, investigation, treatment and short-term outcome for patients admitted with acute heart failure.

DESIGN

Retrospective survey of emergency admissions with acute heart failure from October 2005 to March 2006.

SETTING

Acute NHS trusts in England, Wales and Northern Ireland.

MAIN OUTCOME MEASURES

Patient demographics, referral source, admission characteristics, admission pathway, patient heart failure treatment on admission, length of stay, short-term mortality, discharge heart failure treatment, specialist follow-up and delayed discharge.

RESULTS

176/177 (99%) acute trusts responded and 9387 records were surveyed. Patients mean age was 77 (SD 11) years, 50% were women and 56% had prior history of heart failure. On average, women were 5 years older than men (80 vs 75 years, p<0.001), were less likely to have had echocardiography (52% vs 60%, p<0.001), and if previously diagnosed with heart failure less likely to be treated with ACE inhibitors (58.3% vs 66.8%, p<0.001), beta-blockers (30.1% vs 35.5%, p = 0.033) or aldosterone antagonists (18.9% vs 22.5%, p<0.001) at admission. In-hospital mortality was 15%. Age-adjusted mortality was higher in men (16% vs 14%, p = 0.042). 75% of patients were admitted with moderate to severe symptoms (NYHA class III or IV). Women were less likely to be prescribed anti-failure medication, except diuretics, on discharge (ACE-I/AIIRA 66.5% vs 73.4%, beta-blocker 31.3% vs 37.5%, aldosterone antagonists 23.4% vs 30.1%, all p<0.001). Only 20% of patients had planned specialist heart failure follow-up, with <1% referred for rehabilitation or specialist palliative care.

CONCLUSION

Many patients admitted to acute hospitals in England, Wales and Northern Ireland are not being managed fully in accordance with international evidence-based guidelines. In comparison with earlier UK studies, the use of echocardiography and ACE-I and beta-blockers has increased, and length of stay reduced. Only a minority of patients are seen, or followed up, by a specialist service. Women seem to be less well managed against recommended guidelines. Significant and sustained effort is required to address gender inequalities in the provision of heart failure care.

Should Pre-operative Troponin be a Standard Requirement in Patients Undergoing Major Lower Extremity Amputation?

OBJECTIVES

The objective of this study was to ascertain the benefit of routine pre-operative cardiac troponin I (cTnI) measurement in patients undergoing major lower extremity amputation for critical limb ischaemia.

DESIGN

This was a prospective, blinded observational study.

METHODS

All patients scheduled for lower extremity amputation, without evidence of unstable coronary artery disease were recruited prospectively over a period of 1 year. In addition to routine pre-operative evaluation, a blood sample was taken for measurement of serum cTnI. Post-operative screening was conducted for cardiac events with patients followed up to 6 weeks.

RESULTS

Ten of the 44 patients included suffered a non-fatal myocardial infarction or died from a cardiac cause post-operatively. A rise in pre-operative cTnI was associated with a very poor outcome (two cardiac deaths and one post-operative myocardial infarction) and was the only significant predictor of post-operative cardiac events.

CONCLUSION

Routine pre-operative cTnI measurement may be of use to identify patients at high risk of cardiac complication who would benefit from optimization of cardiac status or in whom surgery could be deferred.

Economic evaluation of the impact of nicorandil in angina (IONA) trial

OBJECTIVE

To estimate the net cost of adding nicorandil to usual treatment for patients with angina and to compare this with indicators of health benefit.

DESIGN

Cost effectiveness analysis.

SETTING

Based on results of the IONA (impact of nicorandil on angina) trial.

PATIENTS

Patients with angina fulfilling the entry criteria for the IONA trial.

INTERVENTIONS

In one arm of the trial nicorandil was added to existing antianginal treatment and compared with existing treatment alone.

MAIN OUTCOME MEASURES

Costs were for use of hospital resources (for cardiovascular, cerebrovascular, and gastrointestinal reasons), nicorandil, and care after hospital discharge. Benefits were assessed in three ways: (1) IONA trial primary outcome (coronary heart disease (CHD) death, non-fatal myocardial infarction, or hospital admission for cardiac chest pain); (2) acute coronary syndrome (CHD death, non-fatal myocardial infarction, or unstable angina); and (3) event-free survivors at the end of the trial.

RESULTS

The net cost for each additional IONA trial end point averted was -5 pounds sterling (-7 euros). The net cost for each case of acute coronary syndrome averted was -8 pounds sterling (-12 euros). The net cost for each event-free survivor was -5 pounds sterling (-7 euros). These figures are based on gastrointestinal events that were judged definitely or probably related to nicorandil. When all gastrointestinal events were included these three ratios rose to 567 pounds sterling (835 euros), 886 pounds sterling (1305 euros), and 516 pounds sterling (760 euros), respectively.

CONCLUSIONS

A substantial amount of the additional cost of nicorandil is offset by reduced use of hospital services. The limited comparisons possible with other CHD interventions suggest that nicorandil compares favourably.

Rosiglitazone Evaluated for Cardiac Outcomes and Regulation of Glycaemia in Diabetes (RECORD): study design and protocol

AIMS/HYPOTHESIS

Studies suggest that in addition to blood glucose concentrations, thiazolidinediones such as rosiglitazone improve some cardiovascular (CV) risk factors and surrogate markers, that are abnormal in type 2 diabetes. However, fluid retention might lead to cardiac failure in a minority of people. The aim of the Rosiglitazone Evaluated for Cardiac Outcomes and Regulation of Glycaemia in Diabetes (RECORD) study is to evaluate the long-term impact of these effects on CV outcomes, as well as on long-term glycaemic control, in people with type 2 diabetes.

MATERIALS AND METHODS

RECORD is a 6-year, randomised, open-label study in type 2 diabetic patients with inadequate blood glucose control (HbA1c 7.1-9.0%) on metformin or sulphonylurea alone. The study is being performed in 327 centres in Europe and Australasia. After a 4-week run-in, participants were randomised by current treatment stratum to add-on rosiglitazone, metformin or sulphonylurea, with dose titration to a target HbA1c of < or = 7.0%. If confirmed HbA1c rises to > or = 8.5%, either a third glucose-lowering drug is added (rosiglitazone-treated group) or insulin is started (non-rosiglitazone group). The same criterion for failure of triple oral drug therapy in the rosiglitazone-treated group is used for starting insulin in this group. The primary endpoint is the time to first CV hospitalisation or death, blindly adjudicated by a central endpoints committee. The study aim is to evaluate non-inferiority of the rosiglitazone group vs the non-rosiglitazone group with respect to CV outcomes. Safety, tolerability and study conduct are monitored by an independent board. All CV endpoint and safety data are held and analysed by a clinical trials organisation, and are not available to the study investigators while data collection is open.

RESULTS

Over a 2-year period a total of 7,428 people were screened in 25 countries. Of these, 4,458 were randomised; 2,228 on background metformin, 2,230 on background sulphonylurea. Approximately half of the participants are male (52%) and almost all are Caucasian (99%).

CONCLUSIONS/INTERPRETATION

The RECORD study should provide robust data on the extent to which rosiglitazone, in combination with metformin or sulphonylurea therapy, affects CV outcomes and progression of diabetes in the long term.

Heart failure post-myocardial infarction: a review of the issues

In most patients with heart failure due to left ventricular systolic dysfunction, the underlying cause is coronary heart disease. To reduce progression to heart failure in a patient with acute myocardial infarction, it is important to achieve the earliest possible reperfusion, whether by thrombolysis or primary percutaneous coronary intervention. Every patient with acute myocardial infarction should have an assessment of their left ventricular function, the potential for reversibility should be considered, and reversible ischaemia should be identified. Left ventricular dysfunction does not only occur with ST segment elevation myocardial infarction but is also commonly associated with non-ST segment elevation myocardial infarction. Secondary prevention is crucial and this requires long term commitment by the patient and the health care system. Heart failure and left ventricular dysfunction are treatable but require a multidisciplinary, integrated network approach.

Heart rate and cardiac rhythm relationships with bisoprolol benefit in chronic heart failure in CIBIS II Trial

BACKGROUND

beta-Blockade-induced benefit in heart failure (HF) could be related to baseline heart rate and treatment-induced heart rate reduction, but no such relationships have been demonstrated.

METHODS AND RESULTS

In CIBIS II, we studied the relationships between baseline heart rate (BHR), heart rate changes at 2 months (HRC), nature of cardiac rhythm (sinus rhythm or atrial fibrillation), and outcomes (mortality and hospitalization for HF). Multivariate analysis of CIBIS II showed that in addition to beta-blocker treatment, BHR and HRC were both significantly related to survival and hospitalization for worsening HF, the lowest BHR and the greatest HRC being associated with best survival and reduction of hospital admissions. No interaction between the 3 variables was observed, meaning that on one hand, HRC-related improvement in survival was similar at all levels of BHR, and on the other hand, bisoprolol-induced benefit over placebo for survival was observed to a similar extent at any level of both BHR and HRC. Bisoprolol reduced mortality in patients with sinus rhythm (relative risk 0.58, P:<0.001) but not in patients with atrial fibrillation (relative risk 1.16, P:=NS). A similar result was observed for cardiovascular mortality and hospitalization for HF worsening.

CONCLUSIONS

BHR and HRC are significantly related to prognosis in heart failure. beta-Blockade with bisoprolol further improves survival at any level of BHR and HRC and to a similar extent. The benefit of bisoprolol is questionable, however, in patients with atrial fibrillation.

Alterations in vascular reactivity in isolated vessel segments from dogs with naturally occurring heart failure

To investigate if functional vascular reactivity is altered in heart failure, the reactivity of isolated canine saphenous vein (SV) and femoral artery (FA) rings, from control dogs and dogs with naturally occurring heart failure was examined. In both vessels, relaxation responses to the endothelium-dependent vasodilator, acetylcholine were unaffected by heart failure. In the FA, in heart failure, there was a significant reduction in the potency of the agonist noradrenaline (pEC(50)6.05+/-0.07 (N = 8) and 5.54 +/- 0.13 (N = 7) for control and heart failure respectively). There was no significant alteration in potency in the SV. In addition, in the FA the maximum responses to both noradrenaline (control 3.64 +/- 0.31 KPa, (N = 8); failure 5.11 +/- 0.35 KPa, (N = 7) P = 0.004) and potassium chloride (control 2.18 +/- 0.26 KPa, (N = 8); failure 4.46 +/- 0.25 KPa, (N = 7) P = 0.001) were significantly increased in heart failure. It is suggested that enhanced agonist induced responses, in the femoral artery, in dogs with heart failure, may limit blood flow to exercising skeletal muscle and subsequently reduce exercise tolerance.

Diagnosis and assessment in heart failure

Heart failure is a common and growing problem. Its optimal and effective management and the evaluation of new therapies require assessment of underlying etiology, type of cardiac dysfunction, severity, prognosis, and response to therapy. Unfortunately, the lack of a universally agreed definition of heart failure and uniform criteria make an accurate and complete diagnosis of heart failure difficult. Currently, a wide range of investigations and assessments is available, including assessment of symptoms, exercise performance, and cardiac function. In particular, left ventricular (LV) ejection fraction (EF) is widely used and a good marker of the severity of LV dysfunction and prognosis. It is now being recognized that the early identification and treatment of patients with asymptomatic LV dysfunction may prevent subsequent progression to symptomatic heart failure. Recently, attention has focused on the neurohormonal activation that occurs early in heart failure, and especially increasing evidence suggests that plasma levels of neurohormones and brain natriuretic peptides, may be useful biochemical markers in the diagnosis and assessment of heart failure at an early stage. Further evaluation of this neurohormonal activation and treatments directed towards it may provide considerable benefits in improving patient morbidity and mortality. (c)1999 by CHF, Inc.

A comparison of the reproducibility and the sensitivity to change of visual analogue scales, Borg scales, and Likert scales in normal subjects during submaximal exercise

OBJECTIVE

To assess which subjective scale, the visual analogue scale (VAS), the Borg CR10 (Borg) scale, or the Likert scale (LS), if any, is decidedly more reproducible and sensitive to change in the assessment of symptoms.

DESIGN

Prospective clinical study.

SETTING

Exercise laboratory.

PARTICIPANTS

Twenty-three physically active male subjects (mean +/- SD age of 30 +/- 4 years old) were recruited.

INTERVENTION

Each subject attended the exercise laboratory on four occasions at intervals of 1 week. Three subjective scales were used: (1) the VAS (continuous scale); (2) the Borg scale (12 fixed points); and (3) the Likert scale (LS; 5 fixed points). Four identical submaximal tests were given (2 min at 60% maximum oxygen uptake [VO(2)max] and 6 min at 70% VO(2)max). Two tests were undertaken to assess the reproducibility of scores that were obtained with each subjective scale. Two other tests were undertaken to assess the sensitivity of each scale to a change in symptom perception: a double-blind treatment with propranolol, 80 mg, (ie, active therapy; to increase the sensation of breathlessness and general fatigue during exercise) or matching placebo. The subjective scale scores were measured at 1 min 30 s, 5 min 30 s, and 7 min 15 s of exercise. Reproducibility was defined as the proportion of total variance (ie, between-subject plus within-subject variance) explained by the between-subject variance given as a percentage. Sensitivity was defined as the effect of the active drug therapy over the variation within subjects.

RESULTS

Overall, the VAS performed best in terms of reproducibility for breathlessness and general fatigue, with reproducibility coefficients as high as 78%. For sensitivity, the VAS was best for breathlessness (ratio, 2.7) and the Borg scale was most sensitive for general fatigue (ratio, 3.0). The relationships between the respective psychological and physiologic variables were reasonably stable throughout the testing procedure, with overall typical correlations of 0.73 to 0.82

CONCLUSION

This study suggests that subjective scales can reproducibly measure symptoms during steady-state exercise and can detect the effect of a drug intervention. The VAS and Borg scales appear to be the best subjective scales for this purpose.

Doppler assessment of hypoxic pulmonary vasoconstriction and susceptibility to high altitude pulmonary oedema

BACKGROUND

Subjects with previous high altitude pulmonary oedema may have stronger than normal hypoxic pulmonary vasoconstriction. Susceptibility to high altitude pulmonary oedema may be detectable by echo Doppler assessment of the pulmonary vascular reactivity to breathing a hypoxic gas mixture at sea level.

METHODS

The study included 20 healthy controls, seven subjects with a previous episode of high altitude pulmonary oedema, and nine who had successfully climbed to altitudes of 6000-8842 m during the 40th anniversary British expedition to Mount Everest. Echo Doppler measurements of pulmonary blood flow acceleration time (AT) and ejection time (ET), and of the peak velocity of the tricuspid regurgitation jet (TR), were obtained under normobaric conditions of normoxia (fraction of inspired oxygen, FIO2, 0.21), of hyperoxia (FIO2 1.0), and of hypoxia (FIO2 0.125).

RESULTS

Hypoxia decreased AT/ET by mean (SE) 0.06 (0.01) in the control subjects, by 0.11 (0.01) in those susceptible to high altitude pulmonary oedema, and by 0.02 (0.02) in the successful high altitude climbers. Hypoxia increased TR in the three groups by 0.22 (0.06) (n = 14), 0.56 (0.13) (n = 5), and 0.18 (0.1) (n = 7) m/s, respectively. However, AT/ET and/or TR measurements outside the normal range, defined as mean +/- 2 SD of measurements obtained in the controls under hypoxia, were observed in only two of the subjects susceptible to high altitude pulmonary oedema and in five of the successful high altitude climbers.

CONCLUSIONS

Pulmonary vascular reactivity to hypoxia is enhanced in subjects with previous high altitude pulmonary oedema and decreased in successful high altitude climbers. However, echo Doppler estimates of hypoxic pulmonary vaso-constriction at sea level cannot reliably identify subjects susceptible to high altitude pulmonary oedema or successful high altitude climbers from a normal control population.

Infarct-related heart failure: the choice of ACE inhibitor does not matter

Angiotensin converting enzyme (ACE) inhibitors are effective across the whole spectrum of heart failure from mild to severe but there are little data on the use of ACE inhibitors specifically in patients with postinfarct heart failure. Pharmacological properties that might potentially be relevant to the choice of drug after myocardial infarction include differences in metabolism, possession of a sulphydryl group, tissue binding, duration of action, and side effect profile. Of these duration of action is probably the most important, as longer acting drugs generally cause more prolonged first-dose hypotension that shorter acting agents and first-dose hypotension is a particular concern in the early postinfarct period. In the SAVE study captopril was effective in reducing mortality and delaying the onset of symptomatic heart failure after myocardial infarction. Similarly, ramipril reduced mortality in the AIRE study. In contrast, enalapril was largely ineffective in CONSENSUS II. These differences result largely from study design and do not indicate an inherent superiority of captopril or ramipril over enalapril. Nonetheless, a short-acting agent should probably be used for the initial dose in postinfarct heart failure to minimize the risks of prolonged hypotension. This aside, the choice of agent is far less important than appropriate patient selection and appropriate maintenance dosages.

Trimetazidine: a new concept in the treatment of angina. Comparison with propranolol in patients with stable angina. Trimetazidine European Multicenter Study Group

1. Trimetazidine has a direct anti-ischaemic effect on the myocardium without altering the rate x pressure product or coronary blood flow. 2. The effects of trimetazidine (20 mg three times daily) were compared with those of propranolol (40 mg three times daily) in a double-blind parallel group multicentre study in 149 men with stable angina. 3. Reproducibility of exercise performance was verified during a 3 week run-in placebo washout period. All patients had > 1 mm ST-depression on exercise test. 4. After 3 months, similar anti-anginal efficacy was observed between the trimetazidine (n = 71) and propranolol (n = 78) groups. No significant differences were observed between trimetazidine and propranolol as regards anginal attack rate per week (mean difference P-TMZ: 2; 95% CI: -4.4, 0.5) and exercise duration (mean difference P-TMZ: 0 s; 95% CI: -33, 34) or time to 1 mm ST segment depression (mean difference P-TMZ: 13 s; 95% CI: -24, 51). Heart rate and rate x pressure product at rest and at peak exercise remained unchanged in the trimetazidine group but significantly decreased with propranolol (P < 0.001 in all cases). With both drugs there was a trend to decreased ischaemic episodes in the 46% patients who experienced ambulatory ischaemia on Holter monitoring. Six patients stopped trimetazidine and 12 propranolol. Of these, five in each group were withdrawn because of deterioration in cardiovascular status. 5. The results suggest that trimetazidine and propranolol at the doses studied have similar efficacy in patients with stable angina pectoris.(ABSTRACT TRUNCATED AT 250 WORDS)

Sympathetic activity and regional blood flow in heart failure

The syndrome of heart failure results from inappropriate sodium and water retention by the kidneys which results, at least in part, from changes in renal haemodynamics. Renal blood flow at rest in heart failure is reduced in proportion to the reduction in cardiac output and falls dramatically during exercise as the cardiac output is redistributed to the exercising muscles. Both these phenomena are associated with a rise in plasma noradrenaline concentration. Afferent arteriolar tone is partly controlled by alpha-adrenoceptor stimulation while stimulation of beta 2-receptors will stimulate renal release of renin; through the elaboration of angiotensin II, profound effects on extra- and intra-renal vascular tone can occur. Although alpha-adrenoceptor stimulation can result in coronary vasoconstriction and a fall in coronary blood flow in patients with heart failure due to underlying atheromatous coronary heart disease, increased myocardial oxygen demand as the result of beta 1 (and cardiac beta 2) simulation may be more relevant. The control of limb blood flow is of great importance symptomatically. The systemic vasoconstriction that typifies the severe heart failure state has been a target for many vasodilatory interventions including alpha 1-receptor blockade and beta 2-receptor stimulation. Unfortunately, there is little evidence that such treatment leads to any specific increase in muscle blood flow either at rest or during exercise. In severe heart failure, sympathetic activity is increased at rest leading to vasoconstriction in several vascular beds, while in milder heart failure, excessive sympathetic stimulation is evident only during exercise. In either circumstance, however, it is evident that certain advantages may accrue from modulation of this excessive sympathetic activity.

Effect of marathon training on the plasma lactate response to submaximal exercise in middle-aged men

Twenty-one previously sedentary male volunteers (aged 35-50 years) undertook a defined marathon training programme lasting 30 weeks. At weeks 0 (T1), 15 (T2) and 30 (T3) they underwent measurement of maximal oxygen uptake (VO2 max), submaximal VO2 and submaximal plasma lactate concentration during cycle ergometry. No exercise was taken for 24-48 hours prior to testing. During training aerobic power increased significantly (p less than 0.001) from an initial VO2 max at T1 of 33.9 +/- 6 (mean +/- sd) ml.kg-1min-1 to 39 +/- 5.6 ml.kg-1min-1 at T2 but the T3 value of 39.2 +/- 5.2 ml.kg-1min-1 was not significantly different from that at T2. Plasma lactate concentration of 4 mmol.l-1 (OBLAw) occurred at a significantly (P less than 0.05) higher workload (155 +/- 28 w) at T2 compared with T1 (132 +/- 30 w) but the T3 figure was 137 +/- 34 w. OBLA VO2 at T1 was 2.04 +/- 0.42 l.min-1, at T2 was 2.24 +/- 0.04 l.min-1 but at T3 was 2.03 +/- 0.30 l.min-1 (T1:T2 P less than 0.05, T1:T3 NS). OBLA % VO2 max at T1 was 75 +/- 12%, at T2 was 73 +/- 11% but at T3 was 62 +/- 10% (T1:T2 NS, T1:T3 P less than 0.01).

Combination of verapamil and beta blockers in systemic hypertension

The efficacy and safety of verapamil and propranolol were examined in 14 hypertensive patients (mean age 51.2, range 30 to 65) in a double-blind, randomized, crossover study of verapamil, 360 mg, propranolol, 240 mg, these 2 formulations in combination and placebo, each given for 4 weeks. Supine blood pressure, heart rate, atrioventricular conduction (PR interval) and left ventricular function were measured. All treatments reduced diastolic blood pressure (mean +/- standard deviation) (p less than 0.001): placebo to 106.6 +/- 8.1 mm Hg; propranolol to 93.8 +/- 7.7; verapamil to 89.8 +/- 7.8; the combination to 84.1 +/- 6.1, but the effect of the combination was significantly greater than that of either drug alone (p less than 0.05). Heart rate at rest (placebo, 80.2 +/- 12.2 beats/min) was reduced by propranolol (63.3 +/- 9.4, p less than 0.001), but not by verapamil (79.0 +/- 8.9). However, the addition of verapamil to propranolol led to a further reduction in heart rate (56.9 +/- 8.4, p less than 0.005). PR interval was prolonged significantly by the combination (185.5 +/- 35.3 ms) when compared with placebo (154.0 +/- 22.7); propranolol (159.1 +/- 21.2) and verapamil (165.5 +/- 32.4) (p less than 0.005 for each). The active drugs increased end-diastolic dimension and end-systolic dimension. For each variable, the effect of the combination was statistically significant (p less than 0.01). Fractional shortening was not altered significantly by any of the treatments. Thus verapamil plus propranolol is a very effective antihypertensive combination but heart rate, atrioventricular conduction and left ventricular function may be affected adversely, necessitating careful monitoring of therapy.

Serum lactate dehydrogenase and creatine kinase during marathon training

Serum total creatine kinase (CK) and the lactate dehydrogenase (LDH) isoenzymes were studied in 38 sedentary middle-aged men (aged 35-50 yrs) during a 30 week marathon training programme. Basal CK activity rose by 33% after 15 weeks but a significant rise (27%) in LDH activity took 30 weeks to occur. Post-exercise (maximum test on a bicycle ergometer) CK and LDH activities were higher than pre-exercise levels but the increment in enzyme activity following exercise did not change. LDH1 and LDH2 isoenzyme activity increased by 2.5% and 4% of total LDH respectively while LDH3 and LDH5 decreased by 3.9% and 2.4% respectively over 30 weeks. Post marathon total CK did not correlate with finishing time at 30 mins or 30 hrs post race. The range of CK MB isoenzyme activity at 30 mins post race was 1.8-9.8% of total CK with 11 subjects having a value above 6%. The training programme appears not to have affected muscle CK and LDH release during exercise but isoenzyme distribution changes reflect the adaptations known to occur in muscle during endurance training. Unfortunately only 16 subjects were available for all the investigations, and it is these upon whom most of the data were obtained.

Angiotensin II levels, hemodynamics, and sympathoadrenal function after low-dose captopril in heart failure

The angiotensin converting enzyme inhibitor captopril improves the altered hemodynamics in many patients with chronic heart failure, but the first dose may precipitate hypotension. Ten patients with chronic heart failure were studied, nine with high plasma concentrations of renin and one with a low concentration. Frequent measurements of plasma concentrations of angiotensin II, renin, and catecholamines were made over 60 minutes after a small dose (6.25 mg) of captopril and related to concurrently measured hemodynamic variables. Captopril caused a decrease in systemic and pulmonary artery pressure and an increase in cardiac index, and these changes coincided with reductions in the plasma concentrations of angiotensin II and increases in plasma concentrations of renin. The hemodynamic changes were accompanied by reductions in the plasma concentrations of norepinephrine but transient increases in plasma concentrations of epinephrine in patients in whom vasomotor syncope developed. The patient with a low plasma renin concentration showed little hemodynamic response to the drug. It is concluded that vasomotor syncope occurs quite frequently in patients with severe chronic heart failure after captopril in a small dose and is associated with a selective increase in epinephrine secretion from the adrenal medulla.

Role of calcium antagonists in cardiovascular therapy

The development of drugs which selectively block the "slow" channels by which calcium enters the cell (calcium antagonists) has provided valuable information about the role of transmembrane calcium exchange in man and has offered new therapeutic approaches. The principal effect on the cardiovascular system is relaxation of vascular smooth muscle but some of these drugs also have electrophysiological effects, especially slowing of conduction in the atrioventricular node; verapamil is the agent of choice in supraventricular tachycardia. Significant myocardial depression does not usually occur with doses used clinically. The calcium antagonists have specific value in variant angina. By causing peripheral vasodilatation they are also effective hypotensive agents and do not cause reflex tachycardia in chronic use. Their value in hypertrophic cardiomyopathy and in the protection of ischaemic myocardium remains to be proven.

Objective assessment of antianginal treatment: a double-blind comparison of propranolol, nifedipine, and their combination

In a double-blind clinical trial the antianginal effects of nifedipine (30 and 60 mg/day) and propranolol 240 and 480 mg/day) and a combination of both drugs were compared with those of placebo in 16 patients with severe exertional angina pectoris. Response to treatment was assessed by the objective criteria of 16-point precordial exercise mapping and 48-hour ambulatory electrocardiographic monitoring and subjectively by analysis of patients' daily diaries of episodes of angina and consumption of glyceryl trintrate. The incidence of pain and consumption of glyceryl trinitrate were significantly decreased by each drug compared with placebo, and the combination produced a further significant improvement. Objectively the total area and amount of ST depression on the precordial exercise map and the total number of episodes of ST depression detected on ambulatory monitoring confirmed the efficacy of each treatment regimen; the combination was significantly better than either drug alone (p <0.005). The objective methods permitted greater separation of treatment efficacy and showed reliably that the combination of propranolol and nifedipine was significantly better than either drug alone. Thus this combination is a safe and effective form of treatment for angina.

Production of 6-oxo-PGF1 alpha by human lung in vivo

The production of 6-oxo-PGF1 alpha, a stable hydrolysis product of prostacyclin (PGI2), by human lung was demonstrated in five adults. The lowest increase in 6-oxo-PGF1 alpha on passage through the lung was noted in a woman on oral contraceptives.

Myocardial ischaemia in patients with frequent angina pectoris

One hundred patients with angina pectoris underwent 16-point electrocardiographic (ECG) mapping of the left hemithorax during a standardised exercise test. Forty-five patients had maximum ST-segment depression at position V5, while 35 had no ECG signs of ischaemia at this position. In 20 V5 was on the edge of the precordial area, which showed less severe ST-depression than the central positions. An Oxford ECG recorder and highspeed analyser were modified and used in 50 of the patients with daily angina for recording ST-segment changes over 24 hours. Serial 24-hour ambulatory recordings from the edge of the precordial area of ischaemia identified during exercise detected a mean of only 14 +/- SD 3% of the episodes of ST-segment changes recorded from the centre of the same area. Only 16 +/- 2% of the episodes detected by ECG were accompanied by chest pain. More episodes occurred between 4 am and 6 am than at any other time during the night. This study shows the importance of recording ECG evidence of ischaemia from the precordial position showing maximum changes during exercise. ECG evidence of ischaemia occurs more frequently than anginal pain. These objective measurements add important information to the frequency of chest pain reported by patients with ischaemic heart disease.