Predictive value of asymptomatic cervical bruit for carotid artery disease in coronary artery surgery revisited.

OBJECTIVE: To investigate the predictive value of asymptomatic cervical bruit for detecting internal carotid artery disease in consecutive patients undergoing coronary artery bypass grafting (CABG). DESIGN: A prospective cohort study. SETTING: Tertiary referral university hospitals. PATIENTS: 153 consecutive patients (mean age 57 years) undergoing CABG, without previous history of cerebrovascular events. INTERVENTIONS: Patients underwent detailed pre-operative work-up, including coronary angiography and carotid artery duplex scanning. Internal carotid artery diameter stenosis was graded as A: normal; B: < 15%; C: 15%-50%; D: 50-80%; D+: > 80-99% and E=complete occlusion. RESULTS: 72 patients (47.1%) (95% CI: 39%, 55%) had no evidence of internal carotid artery stenosis; 81 (52.9%) (95% CI: 44.9%, 60.9%) had varying grades of disease, unilateral or bilateral. Cervical bruit was detected in 12/153 patients (7.8%) (95% CI: 3.5%, 12.1%) of whom all but one (0.7%) had varying grades of internal carotid artery disease; of these, 4 patients had bilateral cervical bruit (2.6%) (95% CI: 0.06%, 5.2%). The sensitivity, specificity, positive and negative predictive values and overall accuracy of cervical bruit for detection of > or = 50% internal carotid artery stenosis were 23.5%, 95.8%, 25%, 95.5% and 91.8%, respectively. The relative risk of > or = 50% stenosis ipsilateral to cervical bruit in 306 sides was 5.58 (95% CI: 2.0, 15.0) and the odds ratio 7.1 (95% CI: 2.0, 25.0). CONCLUSIONS: Asymptomatic cervical bruit proved a highly specific clinical sign for detection of internal carotid artery stenosis, whether haemodynamically significant (> or = 50%) or otherwise, in patients undergoing myocardial revascularisation. This was matched by a high negative predictive value and overall accuracy for flow limiting atheroma (> or = 50% stenosis). Yet, steering carotid investigations on the basis of cervical bruit alone would result in > or = 80% internal carotid artery stenosis remaining undetected in 3% of overall patients, in whom cervical bruit is absent.

Factors associated with mortality in patients with asymptomatic carotid stenosis: results from the ACSRS Study.

AIM: This study determines the factors associated with mortality in patients with asymptomatic carotid stenosis. METHODS: Patients (n=1,101) with asymptomatic internal carotid artery stenosis greater than 50% in relation to the bulb diameter were followed up for a period of 6 to 84 (median 38) months. Stenosis was graded using duplex scanning and expressed as a percentage of the carotid bulb diameter. Clinical and biochemical risk factors were recorded. The end-points were ipsilateral ischemic stroke, cardiovascular death and all cause mortality. RESULTS: In a Cox multivariate analysis 6 factors emerged as independent predictors of risk. Age, male gender, cardiac failure, left ventricular hypertrophy on electrocardiogram (ECG) and myocardial ischemia on ECG were associated with increased risk. Antiplatelet therapy was associated with decreased risk. Based on these risk factors a high-risk group consisting of one third of the population with a 40% cumulative cardiovascular death rate and a 66% all cause death rate at 7 years could be identified. The remaining 2/3 consisted of a low-risk group with a 10% cumulative cardiovascular death rate and a 21% all cause death rate at 7 years (P<0.0001 compared to the high risk group). There was not any significant difference in the cumulative ipsilateral stroke rate, which was 12% in the low and 13% in the high cardiovascular risk group (Log Rank P>0.05). CONCLUSIONS: The methodology and findings from the ACSRS natural history study need to be applied to randomized controlled trials on the value of carotid endarterectomy or stenting in patients with asymptomatic carotid stenosis. They may help refine the indications for intervention in patients with carotid endarterectomy.

Prevalence and distribution of coronary disease in claudicants using 12-lead precordial stress electrocardiography.

AIMS: to evaluate the prevalence of coronary artery disease (CAD) by means of modified stress electrocardiography in patients presenting with intermittent claudication. METHODS: three hundred consecutive patients (188 male) with intermittent claudication (post-exercise ankle brachial index <0.8), and 100 age and sex-matched controls, were assessed for CAD with resting and stress 12-lead-precordial ECG. A history of angina and previous myocardial infarction (MI) was recorded. EXCLUSION CRITERIA: recent (<1 month) MI; unstable angina; prior coronary intervention; arrhythmias; conduction abnormalities; uncontrolled hypertension; heart failure, digoxin therapy, and inability to perform tests. RESULTS: based on antecedent angina, MI and abnormal resting ECG, CAD prevalence was 47% in claudicants and 6% in controls; on 12-lead-precordial ECG stress testing, CAD prevalence was 46% (95% CI: 40.1-51.7%) in claudicants and 11% (95% CI: 4.8-17.2%) in controls (both p <0.0001). Only 67% of claudicants (n=141) with antecedent angina, MI or an abnormal resting ECG, met the criteria of CAD on stress testing; also 28% of claudicants without antecedent angina, MI and a normal resting ECG (n=159) had evidence of CAD. The odds ratio for CAD in claudicants was 6.9. Based on 12-lead-precordial ECG stress testing we detected the presence of: one-, two- and three-vessel disease in 14.7% (95% CI: 10.6-18.7%), 19% (95% CI: 14.5-23.5%) and in 12.3% (95% CI: 8.6-16%) of claudicants; and in 8, 3 and 0% of controls, respectively. CONCLUSIONS: forty six percent of patients with intermittent claudication had concomitant CAD, and 31% two- or three-vessel disease. In the presence of claudication the odds ratio for CAD is 6.9 (95% CI: 3.5-13.4) and for two- or three-vessel disease 14.8. Non-invasive modified stress electrocardiography by enabling identification of those with multi-vessel CAD and thus by providing cardiac risk stratification may help bridge the gap between clinical evaluation and invasive coronary imaging.

Asymptomatic carotid artery bifurcation disease in patients with claudication.

A study was undertaken to determine the prevalence of asymptomatic atherosclerotic carotid artery bifurcation disease in patients presenting with claudication; thus 263 consecutive patients with intermittent claudication, but without recent or old cerebrovascular symptoms were studied by routine carotid duplex scanning. Of the 263 patients, 124 (47.1%) had a C, D, D+ or E lesion in some vessels of the carotid bifurcation and 54 (20.5%) had a D, D+ or E lesion of the common or internal carotid arteries. Women had a higher prevalence of significant carotid stenosis (29.6% v. 18.2% in men) as did patients over the age of 70 years (28.6% v. 16.3% if below 70 years). It is concluded that the prevalence of clinically significant carotid bifurcation disease (greater than 50% stenosis in the common or internal carotid arteries) in patients with claudication is high (20.5%). The presence of an asymptomatic high-grade stenosis (D+ or E) in 11.8% of patients with claudication should alert the clinician that he is treating a patient who is at a high risk of developing cerebrovascular ischaemic complications.

Intermittent claudication as a manifestation of silent myocardial ischemia: a pilot study.

One hundred consecutive patients with intermittent claudication were screened noninvasively with electrocardiography chest wall mapping stress test and transcutaneous aortovelography during bicycle ergometry. Electrocardiographic chest wall stress testing indicated three-vessel coronary disease in 25 patients and left anterior descending plus circumflex (left main stem equivalent) disease in seven. In these 32 patients transcutaneous aortovelography demonstrated a decrease in stroke distance (an index of cardiac stroke volume) (median, -28%; 90% range, +5% to -48%), and coronary angiography confirmed the presence and severity of the disease. The claudication distance ranged between 50 and 250 meters. After myocardial revascularization or medical therapy a significant increase occurred in the stroke distance after exercise (median, +20; 90% range, +40% to -25%); also a significant increase in the postexercise pressure index and a reduction in the recovery time (p less than 0.01). No change occurred in the ankle/pressure index at rest. Twelve patients were able to walk without being limited by claudication; 15 reported improvement with a two to tenfold increase in claudication distance. No change occurred in three. The results indicate that silent myocardial ischemia is a common finding in patients with intermittent claudication. It produces left ventricular dysfunction and a decrease in stroke volume leading to a large fall in ankle pressure and early onset of claudication during exercise. Niltrates and myocardial revascularization tend to reverse this.

Noninvasive detection of coronary artery disease in patients presenting with claudication.

ECG chest wall mapping with bicycle ergometry which can detect not only myocardial ischaemia but also individual coronary artery territories involved has been used to screen 100 consecutive patients presenting with claudication. Fifty-three had a positive history and/or evidence of ischaemic heart disease on a resting ECG. The test was positive in 38, negative in 38 and inconclusive in 24, the latter because of inadequate heart rate response. In 11 out of 38 (29%) with a positive test there was no history or evidence of myocardial ischaemia on a conventional resting ECG. ECG changes suggestive of three vessel coronary disease were found in three, single vessel coronary disease in 16 and two vessel disease in 19. Of the latter, eight had changes in the LAD/circumflex distribution, indicating left main stem or equivalent disease. These together with the three with triple vessel coronary disease constituted a subset of 11 (11%) high risk patients who merited coronary angiography with a view to confirming the presence of severe coronary disease.

The effect of enalapril on leg muscle blood flow in patients with claudication.

In the percent study the authors have demonstrated that the peripheral blood flow and resistance as measured by strain-gauge venous occlusion plethysmography were favourably altered by enalapril. The peripheral blood flow increased significantly and since there was no detectable change in ankle pressure this indicated a decrease in resistance during administration of the drug.

The significance of cerebral infarction and atrophy in patients with amaurosis fugax and transient ischemic attacks in relation to internal carotid artery stenosis: a preliminary report.

There is a growing appreciation for the high incidence of silent cerebral infarction and cerebral atrophy on CT scans in patients with amaurosis fugax (AF) and hemispheric transient ischemic attacks (TIAs). Seventy patients with AF only (no TIAs), 104 patients with hemispheric TIAs (no AF), 185 patients without focal carotid territory symptoms (i.e., vertebrobasilar TIAs or asymptomatic carotid bruit only), and 129 patients with stroke and good recovery were studied with CT scan and duplex scanning to grade the degree of stenosis of the internal carotid artery (grades: A = normal, B = 0% to 15% stenosis, C = 16% to 49%, D = 50% to 99%, and E = occlusion). In patients with AF, the incidence of infarction increased from 20% in grades A, B, and C to 40% in grade D and 58% in grade E. The incidence of atrophy increased in parallel from 10% in grade A to 30% in grade E. The increased incidence of atrophy with increasing degrees of stenosis was not the result of increasing degrees of stenosis per se, but the associated increase in the incidence of infarction (patients without CT infarcts in grades D and E had 5% and 0% incidence of atrophy). In patients with hemispheric TIAs, the incidence of CT infarction increased from 25% in grades A and B to 48% in grades D and E. The incidence of atrophy did not show a parallel increase. Our findings support the hypothesis that atrophy is associated not only with cerebral infarction but may be causally related.(ABSTRACT TRUNCATED AT 250 WORDS)

How should we investigate the arteriopath for coexisting lesions.

The surgical techniques dealing with patients suffering from chronic arterial disease were developed during the first era of vascular surgery. Computerised tomography and other non-invasive screening techniques which were developed in the middle years has resulted in improved selection of patients for arteriography and surgery and has provided better means for study of the natural history of the disease. Latterly increased sophistication of these techniques has enabled us to detect and accurately assess asymptomatic arterial disease and to follow its development in the cerebrovascular, peripheral and coronary arterial circulation. This has resulted in a better understanding of risk factors involved both in the presenting lesion and in the circulation in general. From the latter point of view since the surgical management of ischaemic heart disease has improved so dramatically in the last 15 years, it is felt that a greater degree of success should be obtained in patients undergoing peripheral vascular reconstructive surgery. It is suggested therefore that adequate evaluation of the cardiac and cerebrovascular status of patients suffering from peripheral vascular disease should help to improve the overall prognosis and it is the object of this paper to set out the ways and means in which this might be achieved.

Twice-daily verapamil for hypertension: a comparison with propranolol.

Recent reports have confirmed that some slow calcium channel inhibitors have useful antihypertensive properties because they produce dilatation of the peripheral arterioles without reflex tachycardia. Verapamil is such a drug, but its clinical role in the management of hypertension is not clear. An open crossover trial was performed to compare the 24-hour profiles of blood pressure reduction after long-term therapy with a standard beta-adrenoceptor blocker, propranolol, and verapamil. Nineteen patients were studied by continuous ambulatory intraarterial recording and the order of drug administration was determined by random allocation. The drugs were administered 2 times a day and titrated according to casual clinic pressures (propranolol, 40 to 240 mg 2 times a day; verapamil, 120 to 240 mg 2 times a day). Mean hourly blood pressure and heart rate values were obtained over a 24-hour cycle and the responses to isometric and dynamic exercise were also examined. The drugs produced a uniform and comparable reduction in blood pressure throughout the day, together with a reduction in heart rate, which was greater with propranolol. Comparable effects were also seen on the pressor responses to exercise. Both drugs were equally well tolerated and caused no patient withdrawals. Thus, oral verapamil given 2 times a day shows a degree of efficacy similar to that of propranolol and provides 24-hour blood pressure control. This slow calcium channel inhibitor was well tolerated and may be used as initial therapy for hypertension.

Propranolol versus verapamil for the treatment of essential hypertension.

Recent reports have confirmed that slow calcium channel inhibitors have useful antihypertensive properties because they produce dilatation of the peripheral arterioles without reflex tachycardia. Their clinical place in the management of hypertension has yet to be clearly defined, and thus we have performed an open crossover trial to compare the 24-hour profiles of blood pressure reduction after chronic therapy with propranolol and verapamil. Nineteen patients were studied by continuous ambulatory intraarterial recording and the order of drug administration was decided by random allocation. Drug dosage was twice daily and titrated according to casual clinic pressures (propranolol, 40 to 240 mg twice a day; verapamil, 120 to 240 mg twice a day). Mean hourly blood pressure and heart rate values were obtained over a 24-hour cycle, and the responses to isometric and dynamic exercise were also examined. Both drugs were shown to produce a uniform and comparable reduction in blood pressure throughout the whole day, together with a reduction in heart rate, which was greater with propranolol. Comparable effects were also seen on the pressor responses to exercise. Both drugs were equally well tolerated and caused no patient withdrawals. We conclude that oral verapamil given twice daily showed a similar degree of efficacy to propranolol and provided 24-hour blood pressure control. This slow calcium channel inhibitor may be useful as initial therapy for hypertension, particularly for those patients in whom beta-adrenoreceptor blockers are contraindicated.

Acute and chronic effects of sustained action buccal nitroglycerin in severe congestive heart failure.

Vasodilators, such as nitroglycerin, have been widely used in the treatment of acute and chronic heart failure for therapeutic manipulation of the venous and arterial circulations to improve left ventricular function. We have tested the efficacy of a new formulation for sustained release buccal delivery of nitroglycerin (biological life 5-6 hr) in 21 patients with severe congestive heart failure due to ischaemic cardiomyopathy using maximal treadmill exercise testing and radionuclide angiography. A single-blind placebo-controlled acute and an open chronic phase (4 weeks) of treatment were employed. The mean dose was 23.4 mg daily, and clinical assessment suggested significant improvement in 15 patients. The mean ejection fraction (placebo) of 14.1% +/- 1.6 SEM increased to 19.1% +/- 1.7 (acute) and to 21.6% +/- 1.7 (chronic treatment) (P less than 0.001; n = 16). The mean exercise time increased from 3.02 +/- 0.4 min (basal) to 5.95 +/- 0.6 min (chronic) (P less than 0.001). Segmental wall motion abnormality was shown to improve after treatment for 4 weeks. There were no major side effects. Nine patients were reassessed after 24 weeks on the same regimen; exercise time and left ventricular ejection fraction were similar to the 4-week period, thus demonstrating a sustained improvement in cardiac function and functional capacity. A worthwhile functional and objective haemodynamic improvement was demonstrated in these patients with severe chronic congestive heart failure. This mode of treatment may have useful therapeutic value in the management of patients with a wide range of ischaemic heart failure.

The effect of a new calcium channel blocker nicardipine on 24-hour ambulatory blood pressure and the pressor response to isometric and dynamic exercise.

We have assessed the potential antihypertensive effect of a new slow channel blocker, nicardipine, in a group of patients with essential hypertension. Fourteen patients completed a study using the 'Oxford' system for recording blood pressure during free ambulation and physiological testing. An initial 24-h recording was performed on no treatment and repeated following chronic therapy with 40 mg b.d. of nicardipine. During each recording, the patients performed isometric and dynamic exercise according to a standardized protocol. Within-patient comparisons of consecutive mean hourly systolic and diastolic blood pressures showed a reduction throughout the 24 h during nicardipine therapy. The reduction in blood pressure was also maintained at the peaks of isometric and dynamic exercise. Side-effects were encountered frequently and led to four patient withdrawals. Nicardipine appears to be effective in reducing blood pressure although the frequency of encountered side-effects may limit its usefulness as a first-line antihypertensive agent.

Nifedipine tablets for systemic hypertension: a study using continuous ambulatory intraarterial recording.

The action of nifedipine tablets was examined in 17 patients with essential hypertension focusing particularly on the profile of blood pressure (BP) reduction over 24 hours resulting from both twice-daily and once-daily therapy (dose range 40 to 120 mg daily). This new formulation of nifedipine has a more prolonged and lower peak plasma level than an equivalent dose of nifedipine capsules. Our patients were fully ambulant and studied by continuous intraarterial recording techniques. BP responses during isometric and dynamic exercise testing were also observed. Within-patient comparisons of consecutive mean hourly systolic and diastolic BP showed a highly significant effect from twice-daily therapy (p less than 0.001) for nearly the entire day. Also, significantly lower BP was maintained during isometric and dynamic exercise. Mean hourly heart rates were not significantly altered. The profile of action of the single morning dose was initially similar, but its efficacy diminished from 6 P.M. to 8 A.M. on the following day. Side effects were not unduly troublesome and did not cause any patient withdrawals. Four patients developed mild ankle edema. Two others had facial flushing. Nifedipine given twice daily in tablet form, therefore, is an effective antihypertensive drug capable of lowering BP consistently over 24 hours in ambulant patients and during formal exercise testing. We suggest that this agent may be useful as initial therapy for systemic hypertension, although the tablets are not as yet widely available.

Initial assessment of meptazinol in the treatment of the pain of myocardial infarction/unstable angina.

Meptazinol, a new analgesic agent, was used to treat chest pain in patients admitted to a coronary care unit with suspected myocardial infarction or unstable angina. A pilot study showed that meptazinol was effective in relieving pain in 15 out of 22 subjects. There were no adverse haemodynamic effects nor respiratory depression. Nausea and/or vomiting occurred with administration of the drug but as these symptoms may occur in patients with myocardial infarction who have not received any analgesia (Ingram et al., 1980), a cause and effect relationship cannot be inferred in this respect. The incidence of other side effects ascribed to meptazinol was low.

Nifedipine tablets for hypertension: a study using continuous ambulatory intra-arterial recording.

A study using continuous ambulatory intra-arterial blood pressure recording has shown that nifedipine tablets given twice daily can provide 24 hour control of blood pressure and maintain lower absolute blood pressure levels during isometric and dynamic exercise.