2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease: executive summary: a report of the American College of Cardiology Foundation/American Heart Association task force on practice guidelines, and the American College of Physicians, American Association for Thoracic Surgery, Preventive Cardiovascular Nurses Association, Society for Cardiovascular Angiography and Interventions, and Society of Thoracic Surgeons

Evaluation of suspected ischemic heart disease in symptomatic women

There is a wealth of evidence about the role of a variety of diagnostic testing modalities to define coronary artery disease (CAD) risk in women presenting for evaluation of suspected myocardial ischemia. The exercise electrocardiogram (ECG) is the core index procedure, which can define risk in women capable of performing maximal exercise. Stress imaging, using echocardiography or myocardial perfusion single-photon emission computed tomography/positron emission tomography, is useful for symptomatic women with an abnormal resting ECG or for those who are functionally disabled. For women with low-risk stress imaging findings, there is a very low risk of CAD events, usually < 1%. There is a gradient relationship between the extent and severity of inducible abnormalities and CAD event risk. Women at high risk are those defined as having moderate to severely abnormal wall motion or abnormal perfusion imaging findings. In addition to stress imaging, the evidence of the relationship between CAD extent and severity and prognosis has been clearly defined with coronary computed tomographic angiography. In women, prognosis for those with mild but nonobstructive CAD is higher when compared with those without any CAD. The current evidence base clearly supports that women presenting with chest pain can benefit from one of the commonly applied diagnostic testing modalities.

Ischemic heart disease in women

Cardiovascular disease is the leading cause of death in women. Although overall mortality from coronary heart disease (CHD) has decreased, there are subsets of patients, particularly young women, in whom the mortality rate has increased. Underlying sex differences in CHD may be an explanation. Women have more frequent symptoms, more ischemia, and higher mortality than men, but less obstructive coronary artery disease (CAD). Despite this, traditional risk factor assessment has been ineffective in risk stratifying women, prompting the emergence of novel markers and prediction scores to identify a population at risk. Sex differences in manifestations and the pathophysiology of CHD also have led to differences in the selection of diagnostic testing and treatment options for women, having profound effects on outcomes. The frequent finding of nonobstructive CAD in women with ischemia suggests microvascular dysfunction as an underlying cause; therefore, coronary reactivity and endothelial function testing may add to diagnostic accuracy in female patients. In spite of evidence that women benefit from the same therapies as men, they continue to receive less-aggressive therapy, which is reflected in higher healthcare resource utilization and adverse outcomes. More sex-specific research is needed in the area of symptomatic nonobstructive CAD to define the optimal therapeutic approach.

Association of cardiac events with coronary artery disease detected by 64-slice or greater coronary CT angiography: a systematic review and meta-analysis

BACKGROUND

The value of ≥64-slice coronary CT angiography (CCTA) to determine odds of cardiac death or non-fatal myocardial infarction (MI) needs further clarification.

METHODS

We performed a systematic review and meta-analysis using publications reporting events/severity of coronary artery disease (CAD) in patients with suspected CAD undergoing CCTA. Patients were divided into: no CAD, non-obstructive CAD (maximal stenosis <50%), and obstructive CAD (≥50% stenosis). Odds ratios with 95% confidence intervals were calculated using a fixed or random effects model. Heterogeneity was assessed using the I(2) index.

RESULTS

We included thirty-two studies comprising 41,960 patients with 363 all-cause deaths (15.0%), 114 cardiac deaths (4.7%), 342 MI (14.2%), 69 unstable angina (2.8%), and 1527 late revascularizations (63.2%) over 1.96 (SD 0.77) years of follow-up. Cardiac death or MI occurred in 0.04% without, 1.29% with non-obstructive, and 6.53% with obstructive CAD. OR for cardiac death or MI was: 14.92 (95% CI, 6.78 to 32.85) for obstructive CAD, 6.41 (95% CI, 2.44 to 16.84) for non-obstructive CAD versus no CAD, and 3.19 (95% CI, 2.29 to 4.45) for non-obstructive versus obstructive CAD and 6.56 (95% CI, 3.07 to 14.02) for no versus any CAD. Similar trends were noted for all-cause mortality and composite major adverse cardiovascular events.

CONCLUSIONS

Increasing CAD severity detected by CCTA is associated with cardiac death or MI, all-cause mortality, and composite major adverse cardiovascular events. Absence of CAD is associated with very low odds of major adverse events, but non-obstructive disease significantly increases odds of cardiac adverse events in this follow-up period.

The Big Picture: Evidence Base and Current Trials in Cardiac CT

Cardiac computed tomography angiography (CCTA) has technically matured into a robust imaging modality for various cardiac disorders. Whereas early trials focused on assessment of the efficacy of CCTA in comparison with established recommended methods, current research efforts focus on the effectiveness of the technique in specific clinical scenarios. In this article, we provide an overview of recent technology advances, describe major clinical scenarios in which CCTA has been evaluated, and detail pertinent evidence from completed or ongoing clinical trials, including its use to investigate acute chest pain, its use among patients with stable chest pain syndrome, and its prognostic value for the occurrence of cardiovascular events.

Differences in coronary blood flow in aortic regurgitation and systemic arterial hypertension have implications for diastolic blood pressure targets: a systematic review and meta-analysis

The objective was to evaluate coronary blood flow (CBF) in patients with systemic arterial hypertension (HTN) and to compare it with CBF in patients with aortic regurgitation (AR). A systematic literature search was conducted using the reference terms "coronary blood flow" and either "aortic regurgitation" or "hypertension." The selection criteria included CBF measurement in a concomitant control group, except studies evaluating CBF with aortic-valve replacement surgery. Twenty-two studies met the inclusion criteria. There were 318 persons with HTN, with 185 controls; and 102 persons with AR, with 144 controls. Despite an overall increase in CBF in HTN, CBF per gram of left ventricular mass was significantly (P < 0.0001) reduced. In contrast, CBF per gram of left ventricular mass was significantly (P = 0.004) increased in AR. Aortic regurgitation was associated with a significant (P < 0.0001) increase in CBF during systole and away from diastole, in contrast to persons with HTN. Aortic-valve replacement reversed the increase in systolic CBF. These data suggest that patients with HTN are more vulnerable than patients with AR to lower diastolic blood pressure (DBP), because resting CBF is compromised in HTN. Furthermore, patients with HTN may not compensate for DBP reductions by shifting CBF to systole, such as can occur with the low DBP in AR. Lower DBP in patients with AR cannot be used to justify treating patients with HTN to similar DBP because of the dramatic differences in CBF between the 2 conditions.

Use of the Corus® CAD Gene Expression Test for Assessment of Obstructive Coronary Artery Disease Likelihood in Symptomatic Non-Diabetic Patients

The determination of the underlying etiology of symptoms suggestive of obstructive coronary artery disease (CAD, ≥50% stenosis in a major coronary artery) is a common clinical challenge in both primary care and cardiology clinics. Usual care in low to medium risk patients often involves a family history, risk factor assessment, and then stress testing with or without non-invasive imaging. If positive, this is often followed by invasive coronary angiography (ICA). Despite extensive adoption of this usual care paradigm, more than 60% of patients referred for angiography do not have obstructive CAD. In order to robustly identify those symptomatic patients without obstructive CAD, who can avoid subsequent cardiac testing and look elsewhere for the cause of their symptoms, a recently described whole blood gene expression score (GES: Corus® CAD, CardioDx, Inc., Palo Alto, CA) has been developed and validated in two multi-center trials. This paper reviews the published literature and assessments by independent parties regarding the analytical and clinical validity as well as the clinical utility of the Corus® CAD test.

Cardiac effects in perinatally HIV-infected and HIV-exposed but uninfected children and adolescents: a view from the United States of America

Introduction

Human immunodeficiency virus (HIV) infection is a primary cause of acquired heart disease, particularly of accelerated atherosclerosis, symptomatic heart failure, and pulmonary arterial hypertension. Cardiac complications often occur in late-stage HIV infections as prolonged viral infection is becoming more relevant as longevity improves. Thus, multi-agent HIV therapies that help sustain life may also increase the risk of cardiovascular events and accelerated atherosclerosis.

Discussion

Before highly active antiretroviral therapy (HAART), the two-to-five-year incidence of symptomatic heart failure ranged from 4 to 28% in HIV patients. Patients both before and after HAART also frequently have asymptomatic abnormalities in cardiovascular structure. Echocardiographic measurements indicate left ventricular (LV) systolic dysfunction in 18%, LV hypertrophy in 6.5%, and left atrial dilation in 40% of patients followed on HAART therapy. Diastolic dysfunction is also common in long-term survivors of HIV infection. Accelerated atherosclerosis has been found in HIV-infected young adults and children without traditional coronary risk factors. Infective endocarditis, although rare in children, has high mortality in late-stage AIDS patients with poor nutritional status and severely compromised immune systems. Although lymphomas have been found in HIV-infected children, the incidence is low and cardiac malignancy is rare. Rates of congenital cardiovascular malformations range from 5.6 to 8.9% in cohorts of HIV-uninfected and HIV-infected children with HIV-infected mothers. In non-HIV-infected infants born to HIV-infected mothers, foetal exposure to ART is associated with reduced LV dimension, LV mass, and septal wall thickness and with higher LV fractional shortening and contractility during the first two years of life.

Conclusions

Routine, systematic, and comprehensive cardiac evaluation, including a thorough history and directed laboratory assays, is essential for the care of HIV-infected adults and children as cardiovascular illness has become a part of care for long-term survivors of HIV infection. The history should include traditional risk factors for atherosclerosis, prior opportunistic infections, environmental exposures, and therapeutic and illicit drug use. Laboratory tests should include a lipid profile, fasting glucose, and HIV viral load. Asymptomatic cardiac disease related to HIV can be fatal, and secondary effects of HIV infection often disguise cardiac symptoms, so systematic echocardiographic monitoring is warranted.

Value of reserve pulse pressure in improving the risk stratification of patients with normal myocardial perfusion imaging

AIMS

To evaluate the incremental prognostic value of reserve-pulse pressure (reserve-PP: exercise-PP minus rest-PP) to standard risk factors among patients with suspected coronary artery disease (CAD) but normal exercise myocardial perfusion imaging (MPI).

METHODS AND RESULTS

We studied 4269 consecutive symptomatic patients without known CAD who were referred for exercise MPI but had normal MPI results (mean age 58 ± 12 years, 56% females, 84% referred for evaluation of chest pain or dyspnoea, 95% with intermediate pretest likelihood of CAD). There were 202 deaths over 5.1 ± 1.4 years of follow-up. Reserve-PP was abnormal (<44 mmHg increase in PP from rest) in 1894 patients (44%). Patients with an abnormal reserve-PP had a higher risk of death compared with patients with normal reserve-PP [hazard ratio (HR): 2.47, 95% CI, 1.8-3.3]. In multivariable models adjusting for age, sex, ejection fraction, medications, heart rate recovery, Duke treadmill score (DTS), and rest-PP, each 10 mmHg lower reserve-PP was associated with a 20.6% increase in risk-adjusted mortality (adjusted HR 0.83, 95% CI 0.76-0.91). Models incorporating reserve-PP significantly reclassified risk compared with models without these parameters (net reclassification index 14.3%, P = 0.0007; integrated discrimination index 0.69, P = 0.01).

CONCLUSION

In patients without a history of CAD and a normal MPI, an abnormal reserve-PP identified and reclassified those at higher risk of death independent of known risk factors and DTS.

Coronary Artery Calcium Testing in Symptomatic Patients: An Issue of Diagnostic Efficiency

The detection and quantification of coronary artery calcification (CAC) significantly improves cardiovascular risk prediction in asymptomatic patients. Many have advocated for expanded CAC testing in symptomatic patients based on data demonstrating that the absence of quantifiable CAC in patients with possible angina makes obstructive coronary artery disease (CAD) and subsequent adverse events highly unlikely. However, the widespread use of CAC testing in symptomatic patients may be limited by the high background prevalence of CAC and its low specificity for obstructive CAD, necessitating additional testing ('test layering') in a large percentage of eligible patients. Further, adequately powered prospective studies validating the comparative effectiveness of a 'CAC first' approach with regards to cost, safety, accuracy and clinical outcomes are lacking. Due to marked reductions in patient radiation exposure and higher comparative accuracy and prognostic value make coronary computed tomographic angiography the preferred CT-based test for appropriately selected symptomatic patients.

Pharmacodynamic impacts of proton pump inhibitors on the efficacy of clopidogrel in vivo--a systematic review

BACKGROUND

There is considerable debate about whether concomitant use of proton pump inhibitors (PPIs) should be recommended for patients who are prescribed clopidogrel after acute coronary syndrome. Most pharmacokinetic and pharmacodynamic studies in vivo were conducted using small sample sizes and were single centered, resulting in conflicting data.

HYPOTHESIS

PPIs may attenuate the antiplatelet effect of clopidogrel in vivo and lead to an increased risk of cardiovascular events.

METHODS

PubMed, the Cochrane Library, Embase, Web of Science, and China Biology Medicine Disc were searched. Randomized controlled trials that compared pharmacodynamic impacts of a PPI on the efficacy of clopidogrel in vivo were included. Two independent reviewers evaluated study quality and extracted data for meta-analysis.

RESULTS

We identified 8 eligible studies. Compared to clopidogrel treatment alone, patients who received both a PPI and clopidogrel had less of a decrease in the platelet reactivity index (weighted mean difference [WMD]: 8.18; 95% confidence interval [CI]: 6.81-9.56; P<0.00001), less adenosine 5'-diphosphate-induced platelet aggregation inhibition (WMD: 7.28; 95% CI: 2.44-12.11; P=0.003), higher P2Y12 reaction units (WMD: 40.58; 95% CI: 19.31-61.86; P=0.0002), and higher risks of clopidogrel resistance (odds ratio [OR]: 2.49; 95% CI: 1.49-4.14; P=0.0005). There were no significant differences, however, for the incidences of major adverse cardiovascular events between the 2 groups (OR: 1.07; 95% CI: 0.44-2.59; P=0.88), and treatment with a PPI and clopidogrel significantly reduced the risk of adverse gastrointestinal events (OR: 0.16; 95% CI: 0.04-0.62; P=0.008).

CONCLUSIONS

Concomitant use of a PPI with clopidogrel attenuated the antiplatelet effect of clopidogrel, but may be clinically unimportant because there were no clinical differences in the risk for major adverse cardiovascular events.

Developmental actions of natriuretic peptides in the brain and skeleton

The concept that atrial natriuretic peptide (ANP) and the closely related peptides BNP and CNP might be involved in the ontogeny of several organ systems emerged in the late 1980s. While many of the reported in vitro actions have not been examined in the context of organ development in vivo, recent studies demonstrate that mice which lack or overexpress natriuretic peptides or receptors exhibit pronounced skeletal growth defects. This article discusses how natriuretic peptides and other factors appear to regulate bone growth as an example of how natriuretic peptides might participate in the ontogeny of other organ systems. Evidence indicating that natriuretic peptides regulate neural development is then reviewed. Natriuretic peptides and receptors exhibit complex expression patterns in the developing nervous system, where they have been shown to act on neural cells as early as at the embryonic neural tube stage. Interestingly, both bone and brain growth appear to utilize primarily CNP and the CNP-specific type B receptor, and perhaps the type C receptor. In vitro data indicate that CNP may act on developing neurons, astrocytes and Schwann cells like a classical growth factor, regulating proliferation, patterning, phenotypic specification, survival and axonal pathfinding. Natriuretic peptides might also have roles in the vascularization of the embryonic brain, establishment of the blood-brain and blood-nerve barriers, and perhaps in nerve regeneration.