Guidelines for the management of patients with chronic stable angina: diagnosis and risk stratification

Current status and perspectives of nuclear cardiology

Nuclear cardiology has long been used to identify myocardial ischemia for appropriate treatment strategies for stable coronary artery disease (CAD). After the Ischemia Trial, it is time to reevaluate the significance of ischemia assessment. Functional imaging continues to play pivotal role in detecting microcirculatory disturbances. PET provides a clear image of blood flow distribution and is useful for the quantitative evaluation of myocardial flow reserve (MFR), which plays an important role in predicting treatment strategies and improving prognosis in CAD. Heart failure has become a major area of focus in cardiovascular medicine. Radionuclide imaging has been widely applied in this field. FDG PET is useful in identifying cardiac sarcoidosis and active inflammation. Clinical values of I-123 MIBG and BMIPP SPECT have been reported worldwide from Japan. Additionally, clinical experiences of Tc-99m pyrophosphate imaging have recently gained attention for assessing cardiac amyloidosis. Cardiac PET/CT and PET/MR imaging permit combined assessment of metabolic/functional/structural analyses of various cardiac diseases. While other non-invasive imaging modalities have rapidly been developed, the roles of radionuclide imaging remain to be valuable for early and accurate diagnosis and patient management in most cases of chronic CAD and various cardiovascular diseases.

The detection of viable myocardium by low-dose dobutamine stress speckle tracking echocardiography in patients with old myocardial infarction

PURPOSE

To explore the significance and value of speckle-tracking echocardiography (STE) associated with low-dose dobutamine stress echocardiography (LDDSE) for the detection of viable myocardium (VM) in patients with old myocardial infarction (OMI).

METHODS

We performed STE with LDDSE in 33 hospitalized patients with OMI and left ventricular systolic dysfunction. QLAB software was used to analyze strain (S) and strain rate (Sr). Percutaneous coronary intervention (PCI) was subsequently performed. The movement of each wall segment was observed by routine echocardiography before and after 1, 3, and 6 months of PCI, and improvement was regarded as the gold standard for diagnosing VM.

RESULTS

Compared with semi-quantitative wall-motion analysis combined with LDDSE, the sensitivity, specificity, and accuracy of c-STE (combining the three directions of S and Sr) at LDDSE were 91.6%, 79.5%, and 87.5%, respectively (p < 0.02). Among the deformation parameters, longitudinal strain (LS) and longitudinal strain rate (LSr) had the highest sensitivity, specificity, and accuracy. Upon combining LS and LSr at LDDSE to parallel tests, the sensitivity, specificity, and accuracy were 91.7%, 90%, and 90.6%, respectively. Compared with baseline, LVEF after PCI increased from 43.3% ± 2.6% to 47.3% ± 2.9% (p < 0.001).

CONCLUSIONS

Global strain at LDDSE is superior to semi-quantitative wall-motion analysis with LDDSE for the assessment of VM. When the multivariable analysis and the parallel tests are combined, LS combined with LSr can be considered an independent predictor of VM. LVEF is improved after PCI in patients with VM and OMI. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:545-554, 2016.

Exercise Modulates Oxidative Stress and Inflammation in Aging and Cardiovascular Diseases

Despite the wealth of epidemiological and experimental studies indicating the protective role of regular physical activity/exercise training against the sequels of aging and cardiovascular diseases, the molecular transducers of exercise/physical activity benefits are not fully identified but should be further investigated in more integrative and innovative approaches, as they bear the potential for transformative discoveries of novel therapeutic targets. As aging and cardiovascular diseases are associated with a chronic state of oxidative stress and inflammation mediated via complex and interconnected pathways, we will focus in this review on the antioxidant and anti-inflammatory actions of exercise, mainly exerted on adipose tissue, skeletal muscles, immune system, and cardiovascular system by modulating anti-inflammatory/proinflammatory cytokines profile, redox-sensitive transcription factors such as nuclear factor kappa B, activator protein-1, and peroxisome proliferator-activated receptor gamma coactivator 1-alpha, antioxidant and prooxidant enzymes, and repair proteins such as heat shock proteins, proteasome complex, oxoguanine DNA glycosylase, uracil DNA glycosylase, and telomerase. It is important to note that the effects of exercise vary depending on the type, intensity, frequency, and duration of exercise as well as on the individual's characteristics; therefore, the development of personalized exercise programs is essential.

C-reactive protein after stroke in arterial hypertension

OBJECTIVE

To evaluate the relationship between plasma high-sensitivity C-reactive protein level and the risk of recurrent coronary and cerebral ischemic events after ischemic stroke in patients with arterial hypertension.

METHODS

102 patients with mild-to-moderate arterial hypertension (67 male, aged 56-68 years) were enrolled in the study. Serum high-sensitivity C-reactive protein was determined on study entry only. Clinical interviews were performed every 3 months during 1 year after blood sampling. Clinical events included confirmed ischemic stroke or transient ischemic attack, coronary ischemic events, sudden death, diabetes mellitus, and all cardiovascular events including chronic heart failure and hospitalization.

RESULTS

Patients in the highest quartile of high-sensitivity C-reactive protein levels had a significantly higher adjusted odds ratio for clinical events compared to those in the first quartile (odds ratio = 7.46, 95% confidence interval: 1.55-19.6, p = 0.001). A receiver operating characteristic curve detected a plasma high-sensitivity C-reactive protein cutoff level of 5.58 mg·L(-1) (76.7% sensitivity, 80.3% specificity). A Cox regression model identified high-sensitivity C-reactive protein >5.58 mg·L(-1) as an independent predictor of further cardiovascular events (hazard ratio = 7.14, 95% confidence interval: 1.15-12.6, p = 0.009).

CONCLUSION

We suggest that high-sensitivity C-reactive protein levels >5.58 mg·L(-1) strongly predict increased risk of cumulative cardiovascular events after ischemic stroke in hypertensive patients.

Nonacute coronary syndrome anginal chest pain

Anginal chest pain is one of the most common complaints in the outpatient setting. While much of the focus has been on identifying obstructive atherosclerotic coronary artery disease (CAD) as the cause of anginal chest pain, it is clear that microvascular coronary dysfunction (MCD) can also cause anginal chest pain as a manifestation of ischemic heart disease, and carries an increased cardiovascular risk. Epicardial coronary vasospasm, aortic stenosis, left ventricular hypertrophy, congenital coronary anomalies, mitral valve prolapse, and abnormal cardiac nociception can also present as angina of cardiac origin. For nonacute coronary syndrome (ACS) stable chest pain, exercise treadmill testing (ETT) remains the primary tool for diagnosis of ischemia and cardiac risk stratification; however, in certain subsets of patients, such as women, ETT has a lower sensitivity and specificity for identifying obstructive CAD. When combined with an imaging modality, such as nuclear perfusion or echocardiography testing, the sensitivity and specificity of stress testing for detection of obstructive CAD improves significantly. Advancements in stress cardiac magnetic resonance imaging enables detection of perfusion abnormalities in a specific coronary artery territory, as well as subendocardial ischemia associated with MCD. Coronary computed tomography angiography enables visual assessment of obstructive CAD, albeit with a higher radiation dose. Invasive coronary angiography remains the gold standard for diagnosis and treatment of obstructive lesions that cause medically refractory stable angina. Furthermore, in patients with normal coronary angiograms, the addition of coronary reactivity testing can help diagnose endothelial-dependent and -independent microvascular dysfunction. Lifestyle modification and pharmacologic intervention remains the cornerstone of therapy to reduce morbidity and mortality in patients with stable angina. This review focuses on the pathophysiology, diagnosis, and treatment of stable, non-ACS anginal chest pain.

Sixty-four-slice computed tomography of the coronary arteries: cost-effectiveness analysis of patients presenting to the emergency department with low-risk chest pain

OBJECTIVES

The aim was to use a computer model to estimate the cost-effectiveness of 64-slice multidetector computed tomography (MDCT) of the coronary arteries in the emergency department (ED) compared to an observation unit (OU) stay plus stress electrocardiogram (ECG) or stress echocardiography for the evaluation of low-risk chest pain patients presenting to the ED.

METHODS

A decision analytic model was developed to compare health outcomes and costs that result from three different risk stratification strategies for low-risk chest pain patients in the ED: stress ECG testing after OU care, stress echocardiography after OU care, and MDCT with no OU care. Three patient populations were modeled with the prevalence of symptomatic coronary artery disease (CAD) being very low risk, 2%; low risk, 6% (base case); and moderate risk, 10%. Outcomes were measured as quality-adjusted life years (QALYs). Incremental cost-effectiveness ratios (ICERs), the ratio of change in costs of one test over another to the change in QALY, were calculated for comparisons between each strategy. Sensitivity analyses were conducted to test the robustness of the results to assumptions regarding the characteristics of the risk stratification strategies, costs, utility weights, and likelihood of events.

RESULTS

In the base case, the mean (+/- standard deviation [SD]) costs and QALYs for each risk stratification strategy were MDCT arm $2,684 (+/- $1,773 to $4,418) and 24.69 (+/- 24.54 to 24.76) QALYs, stress echocardiography arm $3,265 (+/- $2,383 to $4,836) and 24.63 (+/- 24.28 to 24.74) QALYs, and stress ECG arm $3,461 (+/- $2,533 to $4,996) and 24.59 (+/- 24.21 to 24.75) QALYs. The MDCT dominated (less costly and more effective) both OU plus stress echocardiography and OU plus stress ECG. This resulted in an ICER where the MDCT arm dominated the stress echocardiography arm (95% confidence interval [CI] = dominant to $29,738) and where MDCT dominated the ECG arm (95% CI = dominant to $7,332). The MDCT risk stratification arm also dominated stress echocardiography and stress ECG in the 2 and 10% prevalence scenarios, which demonstrated the same ICER trends as the 6% prevalence CAD base case. The thresholds where the MDCT arm remained a cost-saving strategy compared to the other risk stratification strategies were cost of MDCT, < $2,097; cost of OU care, > $1,092; prevalence of CAD, < 70%; MDCT specificity, > 65%; and a MDCT indeterminate rate, < 30%.

CONCLUSIONS

In this computer-based model analysis, the MDCT risk stratification strategy is less costly and more effective than both OU-based stress echocardiography and stress ECG risk stratification strategies in chest pain patients presenting to the ED with low to moderate prevalence of CAD.

Relationship between arterial distensibility and coronary atherosclerosis in angina patients

OBJECTIVE

Arterial stiffening is associated with an increased risk of cardiovascular disease. However, limited evidence exists on whether it also relates to subclinical atherosclerosis, thereby providing a non-invasive marker of the overall cardiovascular status. The aim of the present study was to provide information on arterial stiffening in angina patients in whom angiographic evaluation allowed quantification of coronary atherosclerosis.

METHODS

We studied 101 patients with angina from a large number admitted to our hospital for coronary angiography. In each patient, radial (RA), subdiaphragmatic aorta (AO) and carotid (CA) distensibility (Dist) were measured by an ultrasonic device, following ultrasonic exclusion of atherosclerotic lesions at these specific sites. Patients were classified into three groups according to the angiographic findings: (i) no significant coronary lesions (lumen obstruction < 50%, group A); (ii) one (group B); and (iii) two or three (group C) coronary vessels with hemodynamic significant plaques (lumen obstruction > 50%).

RESULTS

Age, male prevalence, previous cardiovascular disease and interventions were progressively greater or more common from group A to C, whereas several other risk factors (plasma glucose, serum cholesterol, smoking, history of hypertension, etc.) did not differ between the three groups or between the group with single vessel (B) versus the group with multivessel disease (C). CA and AO Dist decreased progressively from group A to C with a significant relationship in the group as a whole between distensibility values and the number of diseased vessels. The progressive decrease in AO Dist from group A to C remained significant after adjustment for variables that showed between-group differences (such as gender, age and systolic blood pressure) and the ROC curve showed it to be a more sensitive and specific marker of coronary atherosclerosis than CA Dist. RA Dist was similar in the three groups and showed no relationship with the number of diseased vessels in the group as a whole.

CONCLUSION

In patients with angina, AO and CA Dist are related to the severity of coronary atherosclerosis, with the relationship being better for alterations in aortic than in carotid mechanical properties. Large elastic artery (and in particular aortic) stiffening can thus be considered as a marker of the severity of coronary atherosclerosis, providing non-invasive obtainable information on the need to proceed with further clinical examinations.

Clinical study on effect of Garlicin in stabilizing the carotid artery atherosclerotic plaque in patients with primary hypertension and coronary artery disease

OBJECTIVE

To investigate the effect of garlicin in treating carotid artery atherosclerotic plaque (CAAP) in patients with primary hypertension and coronary heart disease (PHT-CHD).

METHODS

Seventy-nine patients with PHT-CHD were randomly divided into the treated group (39 patients) treated with garlicin and fosinopril and the control group (40 patients) treated with fosinopril alone. The change of CAAP was evaluated by high frequency ultrasonic examination every six months, and the changes of intercellular adhesion molecule-1 (ICAM-1) and high sensitive C-reactive protein (hs-CRP) were measured by ELISA, with the observation proceeding for 52 weeks totally.

RESULTS

By the end of the experiment, the number of complex plaques, Crouse integrals, intima-media thickness, serum ICAM-1 and hs-CRP were significantly lower in the treated group than those in the control group with significant difference (P < 0.05).

CONCLUSION

Garlicin could stabilize CAAP to a certain extent and shows a definite vascular protective effect in patients with PHT-CHD.

Drug insight: If inhibitors as specific heart-rate-reducing agents

Heart rate is determined primarily by spontaneously repeating net inward current carried by sodium ions and potassium ions through hyperpolarization-activated cyclic-nucleotide-gated channels. Within the heart, these channels are found most abundantly in sinoatrial cardiomyocytes. The channels open in response to membrane hyperpolarization, modulated by local cAMP concentrations. They permit activation of the I(f) current, which can be blocked specifically by molecules characterized by linked benzazepinone and benzocyclobutane rings, and which are devoid of effects on cardiac conduction, inotropy or peripheral vascular tone. The resulting heart-rate reduction has been effective in angina prevention in clinical trials involving 4,000 patients, using the prototype I(f) inhibitor, ivabradine. No serious adverse events have been attributed to the treatment; the most prominent side-effect is dose-related, always reversible and often transient visual symptoms that seldom result in voluntary drug discontinuation.

Exercise testing in asymptomatic adults: a statement for professionals from the American Heart Association Council on Clinical Cardiology, Subcommittee on Exercise, Cardiac Rehabilitation, and Prevention

Along with coronary artery calcium scanning, ankle-brachial index measurement, and carotid artery ultrasound, exercise electrocardiography has been proposed as a screening tool for asymptomatic subjects thought to be at intermediate risk for developing clinical coronary disease. A wealth of data indicate that exercise testing can be used to assess and refine prognosis, particularly when emphasis is placed on nonelectrocardiographic measures such as exercise capacity, chronotropic response, heart rate recovery, and ventricular ectopy. Nevertheless, randomized trial data on the clinical value of screening exercise testing are absent; that is, it is not known whether a strategy of routine screening exercise testing in selected subjects reduces the risk for premature mortality or major cardiac morbidity. The writing group believes that a large-scale randomized trial of such a strategy should be performed.

Antianginal and antiischemic effects of ivabradine, an I(f) inhibitor, in stable angina: a randomized, double-blind, multicentered, placebo-controlled trial

BACKGROUND

Heart rate reduction should benefit patients with chronic stable angina by improving myocardial perfusion and reducing myocardial oxygen demand. This study evaluated the antianginal and antiischemic effects of ivabradine, a new heart rate-lowering agent that acts specifically on the sinoatrial node.

METHODS AND RESULTS

In a double-blind, placebo-controlled trial, 360 patients with a > or =3-month history of chronic stable angina were randomly assigned to receive ivabradine (2.5, 5, or 10 mg BID) or placebo for 2 weeks, followed by an open-label 2- or 3-month extension on ivabradine (10 mg BID) and a 1-week randomized withdrawal to ivabradine (10 mg BID) or placebo. Primary efficacy criteria were changes in time to 1-mm ST-segment depression and time to limiting angina during bicycle exercise (exercise tolerance tests), performed at trough of drug activity. In the per-protocol population (n=257), time to 1-mm ST-segment depression increased in the 5 and 10 mg BID groups (P<0.005); time to limiting angina increased in the 10 mg BID group (P<0.05). Deterioration in all exercise tolerance test parameters occurred in patients who received placebo during randomized withdrawal (all P<0.02) but not in those still receiving ivabradine. No rebound phenomena were observed on treatment cessation.

CONCLUSIONS

Ivabradine produces dose-dependent improvements in exercise tolerance and time to development of ischemia during exercise. These results suggest that ivabradine, representing a novel class of antianginal drugs, is effective and safe during 3 months of use; longer-term safety requires additional assessment.