Clinical practice. Chronic stable angina

Antianginal actions of beta-adrenoceptor antagonists

Angina pectoris is usually the first clinical sign of underlying myocardial ischemia, which results from an imbalance between oxygen supply and oxygen demand in the heart. This report describes the pharmacology of beta-adrenoceptor antagonists as it relates to the treatment of angina. The beta-adrenoceptor antagonists are widely used in long-term maintenance therapy to prevent acute ischemic episodes in patients with chronic stable angina. Beta-adrenoceptor antagonists competitively inhibit the binding of endogenous catecholamines to beta1-adrenoceptors in the heart. Their anti-ischemic effects are due primarily to a reduction in myocardial oxygen demand. By decreasing heart rate, myocardial contractility and afterload, beta-adrenoceptor antagonists reduce myocardial workload and oxygen consumption at rest as well as during periods of exertion or stress. Predictable adverse effects include bradycardia and cardiac depression, both of which are a direct result of the blockade of cardiac beta1-adrenoceptors, but adverse effects related to the central nervous system (eg, lethargy, sleep disturbances, and depression) may also be bothersome to some patients. Beta-adrenoceptor antagonists must be used cautiously in patients with diabetes mellitus, peripheral vascular disease, heart failure, and asthma or other obstructive airway diseases. Beta-adrenoceptor antagonists may be used in combination with nitrates or calcium channel blockers, which takes advantage of the diverse mechanisms of action of drugs from each pharmacologic category. Moreover, concurrent use of beta-adrenoceptor antagonists may alleviate the reflex tachycardia that sometimes occurs with other antianginal agents.

Residual high-grade angina after enhanced external counterpulsation therapy

OBJECTIVE

We evaluated the degree of residual angina on the outcomes of enhanced external counterpulsation (EECP) therapy for chronic stable angina.

BACKGROUND

Angina refractory to medical therapy is common in the pool of patients who are not completely revascularized by angioplasty or bypass surgery.

METHODS

We examined 902 patients enrolled from 1998 to 2001 in the Second International Enhanced External Counterpulsation Patient Registry. Baseline and outcome variables were stratified by the last recorded Canadian Cardiovascular Society class.

RESULTS

Residual Class 3 (12.1%) or 4 (2.3%) angina was uncommon among patients with severe coronary artery disease after treatment with EECP. Prevalence of diabetes, hypertension, dyslipidemia, and heart failure was similar among the anginal post-EECP anginal classes. Multivessel coronary disease was more common in those with higher-grade angina at completion. More frequent and severe angina at entry was more common in those with the higher anginal classes at EECP (P<.001). There were no differences in the rates of chronic medications utilized or prior revascularization. At 3-year follow-up, rates of death, myocardial infarction, percutaneous coronary intervention, and coronary artery bypass surgery tended to be higher across increasing residual angina classes. The composite cardiac event rates were 34%, 33%, and 44% for those with Class 0, Class 1/2, and Class 3/4 angina at EECP completion (P=.01), respectively. Multivariate analysis for the composite endpoint found residual Class 3/4 angina (OR=1.59, 95% CI=1.19-2.17, P=.002), diabetes (OR=1.57, 95% CI=1.23-2.01, P=.0003), age (per decile OR=1.17, 95% CI=1.04-1.31, P=.007), and greater EECP augmentation (OR=0.79, 95% CI=0.65-0.96, P=.02) as significant predictors.

CONCLUSIONS

Residual high-grade angina after EECP occurs in those with more severe angina and multivessel disease at baseline and is associated with cardiac events over the next 3 years. These data suggest that close clinical observation and intensive management of those with high-grade angina post-EECP are warranted.

Pentaerythrityl Tetranitrate and Nitroglycerin, but not Isosorbide Mononitrate, Prevent Endothelial Dysfunction Induced by Ischemia and Reperfusion

BACKGROUND

Short term exposure to nitroglycerin (GTN) has protective properties that are similar to ischemic preconditioning. Whether other organic nitrates such as pentaerithrityl tetranitrate (PETN) and isosorbide mononitrate (ISMN) have similar protective effects has not been explored.

METHODS AND RESULTS

In a randomized, parallel, double blind, controlled trial, 37 healthy young volunteers received no therapy (n=10), transdermal GTN 1.2 mg for 2 hours (n=9), PETN 80 mg (n=9), or ISMN 40 mg (n=9). Twenty-four hours later, endothelium-dependent flow-mediated vasodilation (FMD) was measured before and after local exposure to ischemia and reperfusion (IR). In the no therapy group, IR blunted FMD (FMD after IR: 1.9+/-0.6%, P<0.05), an effect that was prevented by GTN (FMD after IR: 5.3+/-1.4%, P<0.05 compared with no therapy). PETN had the same protective effect (FMD after IR: 8.1+/-1.3%, P<0.05 compared with no therapy), whereas ISMN had no significant pharmacological preconditioning effect (FMD after-IR: 3.6+/-0.8%, P=ns compared with no therapy). While it blocked the effect of GTN, Vitamin C (n=8) did not modify PETN preconditioning (FMD after IR: 6.3+/-0.9%, P=ns compared with before IR), showing that this phenomenon is not mediated by oxygen free radical production. In an effort to identify the mechanism of PETN preconditioning, isolated human endothelial cells were incubated with PETN, GTN, or ISMN. Only PETN induced expression of the genes encoding for heme oxygenase and ferritin, which have been involved in ischemic and pharmacological preconditioning.

CONCLUSIONS

We show important differences among organic nitrates in their capacity to prevent IR-induced endothelial dysfunction. GTN and PETN, but not ISMN, have this preconditioning effect. The potential clinical implications of these data warrant further investigation.

Ranolazine in patients with coronary artery disease

Traditional anti-anginal agents such as beta-blockers and nitrates improve symptoms of cardiac ischemia by affecting either blood pressure or heart rates. Despite aggressive therapy, many patients suffer persistent angina, and optimal therapy is limited by intolerance to traditional agents. Ranolazine, a novel anti-anginal agent that is approved for use in the US, is felt to improve ischemic symptoms by reducing myocardial cellular sodium and calcium overload via inhibition of the late sodium current (I(Na)) of the cardiac action potential. Several Phase-III trials in patients with chronic angina have demonstrated that ranolazine improves exercise tolerance and reduces ischemic symptoms as compared with placebo. In the largest evaluation of ranolazine, the MERLIN-TIMI 36 trial (Metabolic Efficiency with Ranolazine for Less Ischemia in non ST elevation acute coronary syndrome), ranolazine did not reduce the risk of death or recurrent myocardial infarction in patients with non-ST-elevation acute coronary syndromes, but it did improve ischemic symptoms over the subsequent year of therapy. Thus, ranolazine offers clinicians a new therapy in the long-term treatment of patients with chronic angina.

Ranolazine in patients with angina and coronary artery disease

The optimal management of coronary artery disease is based on achieving two parallel objectives: 1) prevention of major cardiovascular events, and 2) resolution of symptoms. Traditional antianginal agents improve ischemic symptoms by reducing myocardial oxygen demand through modulation of heart rate, preload, and/or afterload. Ranolazine is a novel antianginal agent believed to relieve ischemia by reducing myocardial cellular sodium and calcium overload via inhibition of the late sodium current of the cardiac action potential. In three randomized double-blind trials in selected patients with chronic angina, ranolazine prolonged exercise duration and reduced symptoms when compared with placebo when given as either monotherapy or in combination with traditional antianginal pharmacotherapy. When evaluated in patients with non-ST-elevation acute coronary syndromes, ranolazine reduced recurrent ischemia but did not significantly reduce the risk of death or myocardial infarction at 1 year. Ranolazine complements traditional antianginal agents and offers clinicians a new option in the long-term treatment of patients with angina.

A prospective, randomized, double-blind, placebo controlled trial of beta-blockade in patients who have undergone surgical correction of tetralogy of Fallot

AIMS

Our purpose was to evaluate the effect of a treatment over six months with bisoprolol on the surrogate parameters of N-Terminal-pro brain natriuretic peptide, subsequently to be described as brain natriuretic peptide, peak uptake of oxygen, and ventricular function assessed by magnetic resonance imaging in grown ups and adults who had undergone surgical correction of tetralogy of Fallot.

METHODS AND RESULTS

We designed a prospective, randomized, double-blind, placebo controlled trial. We enrolled 33 patients, aged 30.9 plus or minus 9.5 years in either class 1 or 2 of the grading of the New York Heart Association class with both levels of brain natriuretic peptide greater than 100 pg/ml and a reduced peak uptake of oxygen less than 25 ml/kg/min. During treatment with Bisoprolol, the levels of brain natriuretic peptide increased significantly from 206 plus or minus 95 to 341 plus or minus 250 pg/ml (p< 0.05), and those of atrial natriuretic peptide from 4117 plus or minus 1837 to 5340 plus or minus 2102 fmol/ml (p = 0.0005). These measures remained unchanged in the group of patients receiving the placebo. Peak uptake of oxygen did not differ significantly in either group, nor did treatment have any significant effect on right and left ventricular volumes and ejection fractions as determined by magnetic resonance imaging. The clinical state as judged within the grading system of the New York Heart Association was also unchanged by beta-blockade.

CONCLUSION

Beta blockade with Bisoprolol seems to have no beneficial effect on asymptomatic or mildly symptomatic patients with right ventricular dysfunction secondary to repaired tetralogy of Fallot with residual pulmonary regurgitation and/or stenosis.

Trimetazidine added to combined hemodynamic antianginal therapy in patients with type 2 diabetes: a randomized crossover trial

BACKGROUND

In nondiabetic patients with stable angina, combined treatment with hemodynamic agents and trimetazidine is well-tolerated and effective in controlling ischemia. This study aims to evaluate the antiischemic and metabolic effects of trimetazidine in patients with type 2 diabetes mellitus, not eligible for revascularization, who remained symptomatic despite the use of at least 2 antianginal agents.

METHODS

A randomized, double-blind, crossover clinical trial was used. Ten patients were randomized to receive trimetazidine (20 mg, 3 times a day) or placebo for 6-week periods. At baseline and at the end of each 6-week intervention period, clinical and biochemical evaluations, exercise testing, 24-hour ambulatory blood pressure, and Holter monitoring were performed.

RESULTS

During trimetazidine therapy, patients had significant improvement on angina functional class (P < .05), with decrease in the number of weekly angina episodes (1.5 +/- 0.8 vs 0.4 +/- 0.7, P < .01), and in sublingual nitrate doses (1.4 +/- 0.7 mg vs 0.1 +/- 0.3 mg, P < .001). Time to 1-mm ST-segment depression during exercise test was increased after trimetazidine use (229 +/- 126 seconds at baseline, 276 +/- 101 seconds after placebo, and 348 +/- 145 seconds after trimetazidine, P < .001). No differences were observed between treatment periods on mean 24-hour blood pressure, heart rate, and rate-pressure product evaluated concomitantly with ambulatory blood pressure and Holter monitoring. Glycemic and lipid profiles were similar after trimetazidine and placebo use.

CONCLUSIONS

In patients with diabetes who remain symptomatic, the addition of trimetazidine improves symptoms and exercise responses without hemodynamic or metabolic changes. The present data suggest that trimetazidine may be an effective adjunct therapy for these patients, but further investigation is needed to confirm these findings.

Aortic valve sclerosis: a marker of significant obstructive coronary artery disease in patients with chest pain?

BACKGROUND

Previous reports suggested a relationship between coronary artery disease (CAD) and aortic valve sclerosis (AVS). However, whether AVS can be used as a marker of obstructive CAD (obCAD) in patients with chest pain is unknown. We hypothesized that AVS is a predictive marker for obCAD in patients hospitalized for chest pain.

METHODS

We studied 93 consecutive patients with chest pain undergoing coronary angiography. All had negative cardiac enzymes and no previous diagnosis of cardiac ischemic disease. AVS was detected by transthoracic echocardiography. Resting electrocardiography, left ventricular systolic function, wall-motion abnormalities, and stress test results were considered. We calculated the diagnostic value for obCAD of AVS, stress test, and combination of the two methods.

RESULTS

ObCAD was present in 29 patients (31%). Patients with obCAD had a higher prevalence of AVS (38 vs 14%, P = .02) and positive stress test (67 vs 28%, P = .02). The odds ratio for obCAD in the presence of AVS was 3.7 (95% confidence interval 1.3-10.4, P = .01). AVS (P = .01) and a positive stress test (P = .002) were independent predictors for obCAD at the multivariate analysis. AVS had sensitivity of 38% and specificity of 86%. Stress test had sensitivity of 67% and specificity of 72%. When echocardiographic detection of AVS was combined with stress test, the sensitivity and negative predictive value improved to 93% and 96%, respectively.

CONCLUSIONS

AVS is an independent predictor for obCAD in patients with chest pain, thus, it should be considered in the risk stratification of these patients.

Diseases of aging that emerge from the metabolic syndrome

With advancing age, interpatient variability increases. Physiologic and pathologic apoptosis progress at widely different rates in each organ system in each person. The effect of any disease on an individual depends on the genetic makeup, social and environmental insults, and adequacy of and compliance with medical therapy. Time spent interviewing, examining, and preparing elderly patients preoperatively pays dividends intra- and postoperatively, with fewer "rescue requiring events," fewer "failures to rescue," lower observed-to expected morbidity and mortality ratios, better patient care, and greater patient and professional satisfaction. Elderly patients will require anesthetic services in greater numbers in the years to come. The baby boomers are coming. Are you ready for them?

Adjunctive value of CT coronary angiography in the diagnostic work-up of patients with typical angina pectoris

AIMS

To determine the adjunctive value of CT coronary angiography (CTCA) in the diagnostic work-up of patients with typical angina pectoris.

METHODS AND RESULTS

CTCA was performed in 62 consecutive patients (45 male, mean age 58.8 +/- 7.7 years) with typical angina undergoing diagnostic work-up including exercise-ECG and conventional coronary angiography. Only patients with sinus heart rhythm and ability to breath hold for 20 s were included. Patients with initial heart rates >/=70 beats/min received beta-blockers. We determined the post-test likelihood ratios, to detect or exclude patients with significant (>/=50% lumen diameter reduction) stenoses, of exercise-ECG and CTCA separately, and of CT performed after exercise-ECG testing. The prevalence of patients with significant coronary artery disease (CAD) was 74%. Positive and negative likelihood ratios for exercise-ECG were 2.3 [95% confidence interval (CI): 1.0-5.3] and 0.3 (95% CI: 0.2-0.7) and for CTCA 7.5 (95% CI: 2.1-27.1) and 0.0 (95% CI: 0.0-8), respectively. CTCA increased the post-test probability of significant CAD after a negative exercise-ECG from 58 to 91%, and after a positive exercise-ECG from 89 to 99%, while CT correctly identified patients without CAD (probability 0%).

CONCLUSION

Non-invasive CTCA is a potentially useful tool, in the diagnostic work-up of patients with typical angina pectoris, both to detect and to exclude significant CAD.

Trials and tribulations associated with angina and traditional therapeutic approaches

Ischemic heart disease is the foremost cause of death in the United States and the developed countries. Stable angina is the initial manifestation of ischemic heart disease in one half of the patients and becomes a recurrent symptom in survivors of myocardial infarction (MI) and other forms of acute coronary syndromes (ACS). There are multiple therapeutic modalities currently available for treatment of anginal symptoms in patients with stable CAD. These include anti-anginal drugs and myocardial revascularization procedures such as coronary artery bypass graft surgery (CABGS), percutaneous transluminal coronary angioplasty (PTCA) and percutaneous coronary intervention (PCI). Anti-anginal drug therapy is based on treatment with nitrates, beta blockers, and calcium channel blockers. A newly approved antianginal drug, ranolazine, is undergoing phase III evaluation. Not infrequently, combination therapy is often necessary for adequate symptom control in some patients with stable angina. However, there has not been a systematic evaluation of individual or combination antianginal drug therapy on hard clinical end points in patients with stable angina. Most revascularization trials that have evaluated treatment with CABGS, PTCA, or PCI in patients with chronic CAD and stable angina have not shown significant improvement in survival or decreased incidence of non-fatal MI compared to medical treatment. In the CABGS trials, various post-hoc analyses have identified several smaller subgroups at high-risk in whom CABGS might improve clinical outcomes. However, there are conflicting findings in different reports and these findings are further compromised due to the heterogeneous groups of patients in these trials. Moreover, no prospective randomized controlled trial (RCT) has confirmed an advantage of CABGS, compared to medical treatment, in reduction of hard clinical outcomes in any of the high-risk subgroups. Based on the available data, it appears reasonable to conclude that for most patients (except perhaps in those with presence of left main disease > 50% stenosis) there is no apparent survival benefit of CABGS compared to medical therapy in stable CAD patients with angina. Although these trial have reported better symptom control associated with the revascularization intervention in most patients, this has not been adequately compared using modern medical therapies. Available data from recent studies also suggest treatment with an angiotensin converting enzyme inhibitor (ACEI), a statin and a regular exercise regimen in patients with stable CAD and angina pectoris.

[Knowledge and implementation of cardiovascular risk clinical practice guidelines by general practitioners and specialists]

INTRODUCTION AND OBJECTIVES

Patients at a high risk of cardiovascular disease rarely achieve the preventive targets stipulated by the clinical practice guidelines published by professional bodies. The aims of the ACORISC registry were to determine the level of compliance with guidelines on prevention by general practitioners and specialists and to assess the findings in terms of risk factors.

METHODS

The study included 5849 consecutive patients (mean age 65 years) with type 2 diabetes or chronic ischemic heart disease who were seen as outpatients. In addition, 384 participating physicians were questioned on their knowledge and use of practice guidelines.

RESULTS

Overall, 91% of patients also had hypertension. Physicians tended to have better knowledge of and to implement guidelines published by the closest related professional bodies. Some 14% of treatment provided was inappropriate, half of which involved oral antidiabetics. Conversely, 48% of patients for whom guidelines recommended an angiotensin inhibitor did not receive one. The target figures for blood pressure, body mass index, and cholesterol were achieved in only 13%, 21% and 39% of patients, respectively.

CONCLUSIONS

Overall, 75% of risk factors in patients with diabetes or chronic ischemic heart disease were not appropriately treated by general practitioners or specialists in accordance with current clinical practice guidelines. The inappropriate use of oral antidiabetics was particularly common.

A comparison of two multiple-characteristic decision-making models for the comparison of antihypertensive drug classes: Simple Additive Weighting (SAW) and Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS)

BACKGROUND

Multiple-characteristics decision-making (MCDM) models can be used to calculate a score, based on a set of characteristics, for a number of alternative drugs or drug classes to allow comparison between them and thus enhance evidence-based pharmacotherapy.

OBJECTIVE

To compare two MCDM models, Simple Additive Weighting (SAW) and Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS), in determining first-line antihypertensive drug class.

METHODS

Five different classes of antihypertensive drugs were analyzed: diuretics, beta-adrenoceptor antagonists (beta-blockers), dihydropyridine calcium channel blockers (DHP-CCBs), ACE inhibitors, and angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]). Four characteristics were deemed relevant for the determination of first-line antihypertensive drug class: effectiveness, persistence with treatment as a measure of tolerability, cost, and clinical experience. Weight factors were determined by sending questionnaires to cardiologists, pharmacists, general practitioners (GPs), and internists in The Netherlands. Absolute scores for the characteristics were determined from literature (effectiveness and persistence) and health insurance data (costs and clinical experience).

RESULTS

Ninety-two cardiologists (33% of those sent the questionnaire), 90 GPs (31%), 87 internists (31%), and 123 pharmacists (43%) completed the questionnaire. Among all professions, according to both SAW and TOPSIS, ACE inhibitors were ranked as the first-line antihypertensive drug class, typically followed by beta-blockers.

CONCLUSION

Both SAW and TOPIS analyses, using weight factors assigned by cardiologists, pharmacists, GPs, and internists from The Netherlands, rank ACE inhibitors as the first choice among antihypertensive drug classes for the treatment of uncomplicated hypertension. Both methods are valuable tools in the development of evidence-based pharmacotherapy.

Ranolazine for the management of coronary artery disease

BACKGROUND

Despite coronary revascularization and standard antianginal therapy, many patients continue to experience symptoms of stable angina and progression of their disease. Ranolazine is a new class of antianginal agent. Unlike standard antianginal agents, it alters glucose and fatty acid metabolism for a different approach to the management of coronary artery disease.

OBJECTIVE

This article discusses the clinical pharmacology of ranolazine and its use in the management of chronic stable angina.

METHODS

Peer-reviewed articles and abstracts were identified from MEDLINE and the Current Contents database (both from 1966 to September 20, 2006) using the search terms ranolazine, angina, pharmacokinetics, and pharmacology. Citations from available articles were reviewed for additional references. Abstracts presented at recent professional meetings were also reviewed.

RESULTS

Ranolazine is a cell membrane inhibitor of the late sodium current. Extended-release ranolazine was recently approved in the United States for the treatment of chronic angina. Ranolazine is metabolized in the liver by the cytochrome P-450 (CYP) 3A4 system. Because of its potential to prolong corrected QT (QTc) intervals, ranolazine should not be used in patients with hepatic impairment, those with QTc prolongation, or those taking drugs known to prolong QTc intervals or drugs that are potent CYP 3A4 inhibitors. Other adverse effects of ranolazine include dizziness, headache, constipation, and nausea. Placebo-controlled clinical studies performed to date have found that sustained-release ranolazine 500 to 1500 mg PO BID was associated with significantly increased time to onset of angina (range of increase, 27.0-144.0 s; P < 0.05 [varied among studies]), exercise duration (range of increase, 23.8-99.0 s; P < 0.05 [varied among studies] ), and time to 1-mm ST depression (range of increase, 27.6-146.2 s; P < 0.05 [varied among studies]). In addition, exercise duration was found to be significantly longer with ranolazine compared with atenolol (453 vs 430 s; P = 0.006).

CONCLUSIONS

Ranolazine is a new antianginal agent that is effective in the management of chronic angina. Its unique mechanism of action warrants further study in other cardiovascular conditions such as heart failure and arrhythmias. Ongoing studies will address whether ranolazine can reduce clinical end points such as cardiovascular death and myocardial infarction.

Treatment decisions in stable coronary artery disease: Insights from the Euro Heart Survey on Coronary Revascularization

OBJECTIVE

We sought to assess determinants of clinical decision making in patients with stable coronary artery disease.

METHODS

The 2936 patients with stable angina pectoris who enrolled in the Euro Heart Survey on Coronary Revascularization were the subject of this analysis. After the diagnosis has been confirmed, physicians decided on treatment: medical management or revascularization therapy by means of percutaneous coronary intervention or coronary bypass surgery. We applied logistic regression analyses to evaluate the relation between baseline characteristics and treatment decision: medical treatment versus percutaneous coronary intervention, medical treatment versus coronary bypass surgery, and percutaneous coronary intervention versus coronary bypass surgery.

RESULTS

The median age was 64 years, 77% were men, and 20% had diabetes. Medical therapy was intended in 690 (24%) patients, percutaneous coronary intervention in 1503 (51%) patients, and coronary bypass surgery in the remaining 743 (25%) patients, respectively. Revascularization was generally preferred in patients with more severe anginal complaints, an intermediate-to-large area of myocardium at risk, and preserved left ventricular function who had not undergone prior coronary revascularization, provided lesions were suitable for treatment. Coronary bypass surgery was preferred over percutaneous coronary intervention in multivessel or left main disease, as well as in those with concomitant valvular heart disease, provided a sufficient number of lesions were suitable for coronary bypass surgery. In those with previous coronary bypass surgeries, more often percutaneous coronary intervention was preferred than redo coronary bypass surgery. Diabetes was not associated with more frequent preference for coronary bypass surgery.

CONCLUSIONS

In the hospitals that participated in the Euro Heart Survey on Coronary Revascularization, treatment decisions in stable coronary artery disease were largely in agreement with professional guidelines and determined by multiple factors. Most important deviations between guideline recommendations and clinical practice were seen in patients with extensive coronary disease, impaired left ventricular function, and diabetes.

[Therapy of chronic coronary artery disease: medical treatment vs. bypass surgery vs. coronary intervention]

The management of coronary artery disease should always include life style modification, control of cardiovascular risk factors and drugs with proven prognostic efficacy, i.e. antiplatelet drugs, statins, ss-blockers and, in most cases, ACE-inhibitors. Nitrates, sometimes also calcium antagonists, are used to control the symptoms of angina pectoris. Revascularisation by percutaneous treatment (stent implantation) or bypass surgery is indicated in patients with large areas of ischemia during stress testing or with high risk coronary anatomy during angiography, especially with reduced ventricular function, or when the angina cannot be adequately controlled by medicinal management. Single vessel and uncomplicated two vessel involvement are usually treated using a stent. Main stem stenosis, three vessel and severe two vessel involvement, particularly with reduced ventricular function, remain the domain of bypass surgery. Controlled studies show identical prognoses for patients with multiple vessel involvement for whom both treatment strategies are possible, although there is a higher reintervention rate for the stent patients. Coronary anatomy, ventricular function, as well as various patient-related factors have to be taken into account when deciding on the form of revascularisation therapy.

Multidetector CT for visualization of coronary stents

Whereas the clinical diagnosis of in-stent thrombosis is straightforward, that of in-stent restenosis remains a problem, because although many patients experience chest pain after coronary stent placement, that symptom is secondary to ischemia in only a few. The use of a noninvasive technique to identify such patients for early invasive intervention versus more conservative management is thus highly desirable. Multidetector computed tomography (CT) performed with 16-section scanners recently emerged as such a technique and has overtaken modalities such as electron-beam CT and magnetic resonance imaging as an alternative to conventional angiography for the assessment of in-stent restenosis. The improved hardware design of the current 64-section CT scanners allows even better delineation of stent struts and lumen. The more reliable criterion of direct lumen visualization thus may be substituted for the presence of distal runoff, which lacks specificity for a determination of in-stent patency because of the possibility of collateral pathways. However, the capability to accurately visualize the in-stent lumen depends partly on knowledge of the causes of artifacts and how they can be compensated for with postprocessing and proper image display settings. In addition, an understanding of the major stent placement techniques used in the treatment of lesions at arterial bifurcations is helpful.

Prognostic value of myocardial perfusion imaging in patients with known or suspected stable angina pectoris: Evaluation in a setting in which myocardial perfusion imaging did not influence the choice of treatment

OBJECTIVE

Previous investigations on the prognostic value of myocardial perfusion imaging (MPI) were performed under circumstances in which the test result was known to the patient's physician. We wanted to examine the prognostic value of MPI in patients with known or suspected stable angina in a setting in which MPI could not influence the diagnostic and therapeutic strategy.

DESIGN

A prospective series of 507 patients referred to coronary angiography for this condition were examined by MPI before angiography. Management was based on symptoms and angiographic findings, as the results of MPI were not communicated. Patients were followed for a mean of 45.3 +/- 7.7 months.

RESULTS

During follow-up, 20 patients (3.9%) suffered from myocardial infarction, 19 (3.8%) died and eight (1.6%) were revascularized >1 year after MPI resulting in a combined annual event rate of 2.5%. Patients with normal MPI had a low annual event rate of 1.6% (or 1.1% with regard to myocardial infarction or death only). In contrast, event rates in patients with reversible or mixed ischaemia were 4.0% per year. MPI added independent prognostic value to standard clinical data in a multivariate Cox model.

CONCLUSION

We could confirm that in patients with known or suspected stable angina, MPI is a valuable risk stratifying tool.

The Role of Ranolazine in the Management of Chronic Stable Angina

This continuing feature will update readers on recent developments in cardiovascular pharmacotherapy. Cardiovascular disease remains the number one killer in the United States, and more clinical outcome trials have been conducted in cardiology than in any other field of medicine. Given this rapidly expanding knowledge base, pharmacists can have a significant impact on prevention and treatment—if they keep current with developments in drug therapy.

Chronic Stable Angina: Angiotensin-Converting Enzyme Inhibitor Therapy and/or Calcium-Channel Blocker Therapy—When is it Indicated?

Objective:

To discuss outcomes data assessing the use of angiotensin-converting enzyme (ACE) inhibitors and calcium-channel blockers (CCBs) in the prevention of cardiovascular events in patients with chronic stable angina that have been published since the 2002 American College of Cardiology/American Heart Association (ACC/AHA) updated guidelines for the treatment of chronic stable angina.

Data Sources:

A MEDLINE search (2002–April 2006) identified 60 primary, review, and meta-analysis articles. The inclusion criteria were: patients with stable coronary artery disease, chronic stable angina, or coronary heart disease; evaluation of long-term therapy with either ACE inhibitor or CCB therapy; prospective, randomized, controlled clinical trials; cardiovascular events as the primary endpoint of the study; and date of publication after the 2002 ACC/AHA guidelines.

Study Selection and Data Extraction:

All articles identified from the literature search were evaluated, and all clinical trials deemed relevant were included in this review. Six randomized trials met inclusion criteria and evaluated the utility of ACE inhibitor and CCB therapy in reducing cardiovascular events in patients with coronary artery disease and/or chronic stable angina.

Data Synthesis:

Patient populations, background therapy, and the study endpoints of all 6 trials varied. However, all primary endpoints assessed cardiovascular events. Two of the 3 ACE inhibitor trials demonstrated a significant reduction in the primary endpoint and 1 of the 3 CCB trials demonstrated a significant reduction in the primary endpoint.

Conclusions:

Newer evidence cumulatively supports the addition of an ACE inhibitor to standard antianginal pharmacotherapy to reduce the risk of cardiovascular events. However, benefit is influenced by severity of illness and use of additional cardiovascular risk reduction pharmacotherapy. The level of supporting evidence for ACE inhibitor therapy in chronic stable angina is higher than that cited in the 2002 ACC/AHA guidelines. Newer evidence evaluating the use of CCBs to prevent cardiovascular events in patients with stable coronary artery disease is controversial and remains consistent with the 2002 guidelines.

Diabetes does not influence treatment decisions regarding revascularization in patients with stable coronary artery disease

OBJECTIVE

To evaluate whether in stable angina preference for coronary revascularization by either percutaneous coronary intervention (PCI) or coronary artery bypass surgery (CABG) is influenced by diabetes status and whether this has prognostic implications.

RESEARCH DESIGN AND METHODS

A total of 2,928 consecutive patients with stable angina who were enrolled in the prospective Euro Heart Survey on Coronary Revascularization were studied. Multivariable analyses were applied to evaluate the relation between diabetes, treatment decision, and 1-year outcome.

RESULTS

Diabetes was documented in 587 patients (20%) who had more extensive coronary disease. Revascularization was intended in 74% of patients with diabetes and in 77% of those without diabetes. In patients selected for revascularization, CABG was intended in 35% of diabetic and in 33% of nondiabetic patients. Multivariable analyses did not change these findings, but in some subgroups diabetes influenced treatment decisions. For example, diabetic subjects with mild heart failure had more often intended revascularization (91%) than those without diabetes (67%, P < 0.001). Treatment decisions in patients with more extensive (left main, multivessel, or proximal left anterior descending artery) disease were not influenced by diabetes status. Diabetes was not associated with an increased incidence of all-cause death, nonfatal cerebrovascular accident, or nonfatal myocardial infarction at 1 year, regardless of preferred treatment. The incidence of the combined end points was 7.3% in diabetic and 6.8% in nondiabetic patients (adjusted hazard ratio 1.0 [95% CI 0.7-1.4]).

CONCLUSIONS

In stable angina, treatment decisions regarding revascularization or the choice for CABG or PCI were not influenced by the presence of diabetes. Diabetes was not associated with a poor prognosis.

Antianginal Efficacy of Ranolazine When Added to Treatment With Amlodipine

OBJECTIVES

The purpose of this study was to determine if ranolazine improves angina in stable coronary patients with persisting symptoms despite maximum recommended dose of amlodipine.

BACKGROUND

Ranolazine is a unique antianginal agent that has been effective in stable angina, but it has not been studied in the setting of maximum recommended doses of conventional antianginal agents.

METHODS

Stable patients with coronary disease and > or =3 anginal attacks per week despite maximum recommended dosage of amlodipine (10 mg/day) were randomized to 1,000 mg ranolazine or placebo twice a day for 6 weeks. Primary end point was the frequency of angina episodes per week during the double-blind treatment phase. Efficacy was also assessed by nitroglycerin consumption per week and the Seattle Angina Questionnaire (SAQ). Adjustment for multiple testing of secondary end points used a hierarchic closed testing procedure. Efficacy was assessed in subgroups based on baseline angina frequency, concomitant long-acting nitrate use, gender, and age. Safety was assessed by adverse events and electrocardiogram evaluations.

RESULTS

A total of 565 patients were randomized: 281 patients to ranolazine and 284 patients to placebo. Baseline characteristics were similar between treatment groups. At baseline, angina frequency averaged 5.63 +/- 0.18 episodes/week, and nitroglycerin consumption averaged 4.72 +/- 0.21 tablets/week. Compared with placebo, ranolazine significantly reduced frequency of angina episodes (2.88 +/- 0.19 on ranolazine vs. 3.31 +/- 0.22 on placebo; p = 0.028) and nitroglycerin consumption (2.03 +/- 0.20 on ranolazine vs. 2.68 +/- 0.22; p = 0.014), with treatment effect that appeared consistent across subgroups. The median angina weekly episode rate at baseline was 4.5 per week. Subgroup analysis showed statistically significant reductions of angina frequency, nitroglycerin use, and SAQ angina frequency for patients with a baseline frequency >4.5 per week but only of angina frequency for those with baseline frequency < or =4.5 per week. Patients with more frequent angina appeared to have a more pronounced treatment effect. No hemodynamic changes were observed. Ranolazine was well tolerated.

CONCLUSIONS

Ranolazine significantly reduced frequency of angina and nitroglycerin consumption compared with placebo and was well tolerated. (The ERICA [Efficacy of Ranolazine In Chronic Angina] Trial; http://clinicaltrials.gov; NCT00091429).

Central arterial pressure and arterial pressure pulse: new views entering the second century after Korotkov

The ubiquitous brachial cuff method gained widespread clinical acceptance for blood pressure recording after confirmation of its prognostic value in 1917. This method displaced radial pulse waveform analysis by sphygmography, which also gave prognostic Information but was difficult to use. Since that time, brachial cuff sphygmomanometry has migrated from the physician's office to 24-hour monitoring and home use, with electronic methods replacing the Korotkov sound technique for determining systolic and diastolic pressure. Detailed instrumental studies, required by regulatory bodies, revealed inaccuracies of all cuff methods for recording true intra-arterial pressure. A major source of inaccuracy in assessing left ventricular load is the amplification of the pressure wave in its transit from the central aorta to upper limb arteries, as extensively studied by Earl H. Wood at the Mayo Clinic in Rochester, Minn, in the 1950s. This limitation can be overcome by combining newer methods using radial artery waveform analysis in conjunction with conventional cuff sphygmomanometry to noninvasively measure the central aortic pressure waveforms. Recent studies using radial tonometry have proved that this is more effective than conventional manometry in predicting cardiovascular events and gauging response to therapy. Measurement of central as well as peripheral arterial pressure and physiology is becoming increasingly used as an office practice and a laboratory procedure.

How effective are rapid access chest pain clinics? Prognosis of incident angina and non-cardiac chest pain in 8762 consecutive patients

OBJECTIVE

To determine whether rapid access chest pain clinics are clinically effective by comparison of coronary event rates in patients diagnosed with angina with rates in patients diagnosed with non-cardiac chest pain and the general population.

DESIGN

Multicentre cohort study of consecutive patients with chest pain attending the rapid access chest pain clinics (RACPCs) of six hospitals in England.

PARTICIPANTS

8762 patients diagnosed with either non-cardiac chest pain (n = 6396) or incident angina without prior myocardial infarction (n = 2366) at first cardiological assessment, followed up for a median of 2.57 (interquartile range 1.96-4.15) years.

MAIN OUTCOME MEASURES

Primary end point--death due to coronary heart disease (International Classification of Diseases (ICD)10 I20-I25) or acute coronary syndrome (non-fatal myocardial infarction (ICD10 I21-I23), hospital admission with unstable angina (I24.0, I24.8, I24.9)). Secondary end points--all-cause mortality (ICD I20), cardiovascular death (ICD10 I00-I99), or non-fatal myocardial infarction or non-fatal stroke (I60-I69).

RESULTS

The cumulative probability of the primary end point in patients diagnosed with angina was 16.52% (95% confidence interval (CI) 14.88% to 18.32%) after 3 years compared with 2.73% (95% CI 2.29% to 3.25%) in patients with non-cardiac chest pain. Coronary standardised mortality ratios for men and women with angina aged <65 years were 3.52 (95% CI 1.98 to 5.07) and 4.39 (95% CI 1.14 to 7.64). Of the 599 patients who had the primary end point, 194 (32.4%) had been diagnosed with non-cardiac chest pain. These patients were younger, less likely to have typical symptoms, more likely to be south Asian and more likely to have a normal resting electrocardiogram than patients with angina who had the primary end point.

CONCLUSION

RACPCs are successful in identifying patients with incident angina who are at high coronary risk, but there is a need to reduce misdiagnosis and improve outcomes in patients diagnosed with non-cardiac chest pain who accounted for nearly one third of cardiac events during follow-up.

Angina pectoris: evaluation in the office

Angina pectoris is a clinical manifestation of myocardial ischemia. Complete evaluation consists of a review of risk factors, a careful history, and, typically, a provocative test. Stress testing can be performed with exercise(treadmill, bicycle, or arm ergometry) or pharmacologic agents that increase cardiac work (dobutamine) or dilate the coronary vessels (adenosine or dipyridamole). Patients who have high-risk features found by clinical history or by stress testing should be referred for coronary angiography and possible revascularization. Comprehensive management of patients who have angina (with or without revascularization) includes smoking cessation,diet and weight control, vasculoprotective drugs (aspirin, statins, and possibly ACE inhibitors), and antianginal medications (nitrates, D-blockers, and calcium channel blockers). These strategies have led to an important reduction in morbidity and mortality over the past 2 decades, and the focus on implementing guidelines for patients who are currently undertreated is expected to improve outcomes further.

Role of cholesterol and lipid organization in disease

Membrane lipids are essential for biological functions ranging from membrane trafficking to signal transduction. The composition of lipid membranes influences their organization and properties, so it is not surprising that disorders in lipid metabolism and transport have a role in human disease. Significant recent progress has enhanced our understanding of the molecular and cellular basis of lipid-associated disorders such as Tangier disease, Niemann-Pick disease type C and atherosclerosis. These insights have also led to improved understanding of normal physiology.