ACC/AHA 2002 guideline update for the management of patients with chronic stable angina--summary article: a report of the American College of Cardiology/American Heart Association Task Force on practice guidelines (Committee on the Management of Patients With Chronic Stable Angina)

Exercise echocardiography

Exercise echocardiography has been used for 30 years. It is now considered a consolidated technique for the diagnosis and risk stratification of patients with known or suspected coronary artery disease (CAD). Of the stress echocardiography techniques, it represents the first choice for patients who are able to exercise. Given that the cost-effectiveness and safety of stress echocardiography are higher than those of other imaging techniques, its use is likely to be expanded further. Recent research has also proposed this technique for the evaluation of cardiac pathology beyond CAD. Although the role of new technology is promising, the assessment of cardiac function relies on good quality black and white harmonic images.

Recent advances in the management of chronic stable angina I: approach to the patient, diagnosis, pathophysiology, risk stratification, and gender disparities

The potential importance of both prevention and personal responsibility in controlling heart disease, the leading cause of death in the USA and elsewhere, has attracted renewed attention. Coronary artery disease is preventable, using relatively simple and inexpensive lifestyle changes. The inexorable rise in the prevalence of obesity, diabetes, dyslipidemia, and hypertension, often in the risk cluster known as the metabolic syndrome, drives the ever-increasing incidence of heart disease. Population-wide improvements in personal health habits appear to be a fundamental, evidence based public health measure, yet numerous barriers prevent implementation. A common symptom in patients with coronary artery disease, classical angina refers to the typical chest pressure or discomfort that results when myocardial oxygen demand rises and coronary blood flow is reduced by fixed, atherosclerotic, obstructive lesions. Different forms of angina and diagnosis, with a short description of the significance of pain and silent ischemia, are discussed in this review. The well accepted concept of myocardial oxygen imbalance in the genesis of angina is presented with new data about clinical pathology of stable angina and acute coronary syndromes. The roles of stress electrocardiography and stress myocardial perfusion scintigraphic imaging are reviewed, along with the information these tests provide about risk and prognosis. Finally, the current status of gender disparities in heart disease is summarized. Enhanced risk stratification and identification of patients in whom procedures will meaningfully change management is an ongoing quest. Current guidelines emphasize efficient triage of patients with suspected coronary artery disease. Many experts believe the predictive value of current decision protocols for coronary artery disease still needs improvement in order to optimize outcomes, yet avoid unnecessary coronary angiograms and radiation exposure. Coronary angiography remains the gold standard in the diagnosis of coronary artery obstructive disease. Part II of this two part series will address anti-ischemic therapies, new agents, cardiovascular risk reduction, options to treat refractory angina, and revascularization.

Side Differences of Carotid Intima-Media Thickness in Predicting Cardiovascular Events Among Patients With Coronary Artery Disease

Population-based studies have demonstrated differences in intima—media thickness (IMT) measured from the left and right common carotid arteries (CCAs). However, its prognostic implications among patients with established coronary artery disease (CAD) remain unknown. Correlations between the left and right CCAs and the composite end point of cardiac death or nonfatal acute coronary syndrome among 149 patients with angiographically confirmed stable CAD were studied. A total of 22 patients had cardiovascular events during the 32.1 ± 10.9 months follow-up. Multivariate analysis revealed that prior ischemic stroke (hazard ratio [HR]: 15.36, 95% confidence interval [CI]: 4.49-52.59, P < .001), extent of CAD (HR: 1.56, 95%CI: 1.01-2.42, P = .046), and right CCA IMT (HR: 17.07, 95%CI: 2.16-134.69, P = .007) but not the left CCA IMT, independently predicted cardiovascular events. The right CCA IMT independently predicted event-free survival among patients with established CAD, suggesting that the left and right CCA may exhibit different prognostic values in our population.

Race differences in cardiac catheterization: the role of social contextual variables

BACKGROUND

Race differences in the receipt of invasive cardiac procedures are well-documented but the etiology remains poorly understood.

OBJECTIVE

We examined how social contextual variables were related to race differences in the likelihood of receiving cardiac catheterization in a sample of veterans who were recommended to undergo the procedure by a physician.

DESIGN

Prospective observational cohort study.

PARTICIPANTS

A subsample from a study examining race disparities in cardiac catheterization of 48 Black/African American and 189 White veterans who were recommended by a physician to undergo cardiac catheterization.

MEASURES

We assessed social contextual variables (e.g., knowing somebody who had the procedure, being encouraged by family or friends), clinical variables (e.g., hypertension, maximal medical therapy), and if participants received cardiac catheterization at any point during the study.

KEY RESULTS

Blacks/African Americans were less likely to undergo cardiac catheterization compared to Whites even after controlling for age, education, and clinical variables (OR = 0.31; 95% CI, 0.13, 0.75). After controlling for demographic and clinical variables, three social contextual variables were significantly related to increased likelihood of receiving catheterization: knowing someone who had undergone the procedure (OR = 3.14; 95% CI, 1.70, 8.74), social support (OR = 2.05; 95% CI, 1.17, 2.78), and being encouraged by family to have procedure (OR = 1.45; 95% CI, 1.08, 1.90). After adding the social contextual variables, race was no longer significantly related to the likelihood of receiving catheterization, thus suggesting that social context plays an important role in the relationship between race and cardiac catheterization.

CONCLUSIONS

Our results suggest that social contextual factors are related to the likelihood of receiving recommended care. In addition, accounting for these relationships attenuated the observed race disparities between Whites and Blacks/African Americans who were recommended to undergo cardiac catheterization by their physicians.

[Laws of syndrome element combination in stable angina pectoris: a study based on cluster analysis and corresponding-correlation analysis]

OBJECTIVE

To study the classification of common symptoms and the laws of syndrome element combination in 251 cases of stable angina pectoris (SAP) by using cluster analysis and corresponding-correlation analysis.

METHODS

A total of 251 SAP cases were selected and their information from four diagnosis in traditional Chinese medicine was recorded. The classification of common symptom and the laws of syndrome element combination were investigated by cluster analysis and corresponding-correlation analysis.

RESULTS

Twenty-five symptoms found in 251 SAP cases were divided into four types by cluster analysis: deficiency of heart qi, deficiency of spleen qi, deficiency of qi and yin, and phlegm accumulation and blood stasis. The deficiency of heart qi had the closest relation to phlegm accumulation and blood stasis. By corresponding-correlation analysis, the deficiency of qi had the closest relation to blood stasis, next was turbid phlegm and heat stagnation, and then deficiency of qi and deficiency of yin.

CONCLUSION

Blood stasis due to deficient qi is the key factor in pathogenesis of SAP. Deficiency of qi plus blood stasis, deficiency of qi plus deficiency of yin, blood stasis plus turbid phlegm, deficiency of heart qi plus blood stasis plus turbid phlegm are common syndrome element combinations of SAP. It is proved that cluster analysis and corresponding-correlation analysis are the proper methods for studying laws of syndrome element combination.

Results of interventional treatment of stress positive coronary artery disease

The aim of this study was to define the impact of percutaneous coronary intervention (PCI) including stenting in patients with stress-positive stable coronary artery disease on long-term prognosis and symptoms. A group of 1,018 patients were identified from the angiographic and single-photon emission computed tomographic (SPECT) databases (technetium-99m sestamibi or tetrofosmin at rest and during stress) January 1, 2000, to December 31, 2003, to have significant coronary artery disease (>50% diameter stenosis on quantitative coronary angiography) and positive SPECT findings. Two hundred sixty-six patients were medically treated. Seven hundred fifty-two patients with positive SPECT findings who underwent PCI were matched to 266 patients of similar age, gender, number and location of stenotic arteries, left ventricular function, and size of SPECT perfusion defect who underwent medical treatment. Clinical events (death, nonfatal myocardial infarction, and revascularization) as well as clinical symptoms (angina or dyspnea, Canadian Cardiovascular Society class II to IV) were determined after a follow-up period of 6.4 +/- 1.2 years. In 524 of the 532 patients (98%), clinical follow-up was obtained. There were no differences between the PCI and medical groups in the frequencies of death (13.5% vs 10.9%) and myocardial infarction (5.3% vs 5.6%) during follow-up. PCI patients had more revascularization procedures <1 year after choice of treatment modality (14.7% vs 6.0%, p <0.002). During the subsequent follow-up period (>1 year), the 2 groups did not differ in the frequency of revascularization procedures. At the end of follow-up, patients in the PCI group complained less frequently of angina pectoris (38% vs 49%, p = 0.014). In conclusion, in patients with stress-positive stable coronary artery disease, PCI including stenting did not reduce mortality or rate of nonfatal myocardial infarction. The PCI group complained less frequently of angina pectoris at long-term follow-up.

Evaluation of contrast wash-in and peak enhancement in adenosine first pass perfusion CMR in patients post bypass surgery

BACKGROUND

Adenosine first pass perfusion cardiovascular magnetic resonance (CMR) yields excellent results for the detection of significant coronary artery disease (CAD). In patients with coronary artery bypass grafts (CABG) the kinetics of a contrast bolus may by altered only due to different distances through the bypass grafts compared to native vessels, thereby possibly imitating a perfusion defect. The aim of the study was to evaluate semiquantitative perfusion parameters in order to assess possible differences in epicardial contrast kinetics in areas supplied by native coronaries and CABG, both without significant stenosis.

METHODS

Twenty patients with invasive exclusion of significant CAD (control group) and 38 patients with CABG without angiographically significant (>or=50%) stenosis in unbypassed coronaries or grafts were retrospectively included in the study. They underwent adenosine first pass (0.05 mmol/kg Gd-DTPA) perfusion (3 short axis views/heart beat) and late gadolinium enhancement (LGE) imaging 1 day before invasive coronary angiography. Areas perfused by native coronaries and/or the different bypasses were identified in X-ray angiography using the 16 segment model. In each of these areas upslope and maximal signal intensity (SImax) relative to the left ventricular parameters, time to 50% maximal signal intensity (TSI50%max) and time to maximal signal intensity (TSImax) were calculated.

RESULTS

In areas perfused by coronary arteries with bypasses compared to native coronaries relative upslope and relative SImax did not show a significant difference. TSI50%max and TSImax in native coronaries and bypasses were 7.2s +/- 1.9s vs. 7.5s +/- 1.9s (p < 0.05) and 12.6s +/- 3.0s vs. 13.1s +/- 3.0s (p < 0.05), respectively. The delay in Tmax resulted in a significant (p < 0.05) delay of 0.5 +/- 1.1 heart beats (=images) when adjusted to the heart rate. Differences in time were most pronounced in areas perfused by left internal mammary artery grafts rather than by venous CABG, but were also present between native vessel territories in patients without CAD, albeit with smaller variability.

CONCLUSION

Adenosine perfusion CMR in patients post CABG may be associated with a short delay in contrast arrival. However, once the contrast is in the myocardium there is similar wash-in kinetics and peak enhancement. Therefore, since the delay is only short, the possibly differing contrast kinetics through grafts and native vessels does not seem to be a limiting factor for the accuracy of first pass adenosine perfusion in patients post CABG.

Therapeutic goals in patients with refractory chronic angina

Refractory angina presents a major clinical challenge for everyday medical practice. Despite the widespread use of statins and improvements in revascularization techniques, a substantial proportion of patients with preserved left ventricular function and no life-threatening arrhythmias remain symptomatic, with severe debilitating angina. Because the rate of major cardiac events in this population is relatively low, the major aim of therapy should be not only to prolong survival but also to improve quality of life. The cornerstone of therapy for all these patients should be the aggressive modification of risk factors using evidence-based treatment, with the aim of stabilizing the disease process and improving overall survival. No opportunity for revascularization should be overlooked. Complementary approaches should be implemented to raise the angina threshold by either reducing oxygen demand or improving hemodynamics to increase myocardial oxygen supply. This review provides an update on therapeutic techniques and goals, and reinforces the need for a multidisciplinary approach to the management of patients with refractory angina.

Combined cardiac CT and MRI for the comprehensive workup of hemodynamically relevant coronary stenoses

OBJECTIVE

The purpose of our study was to prospectively evaluate the accuracy of a comprehensive assessment of coronary artery disease (CAD) with prospectively ECG-gated coronary CT angiography (CTA) and perfusion-cardiac MRI for the detection of hemodynamically relevant coronary stenoses.

SUBJECTS AND METHODS

Forty-seven consecutive patients underwent k-space and time broad-use linear acquisition speed-up technique accelerated perfusion-cardiac MRI at 1.5 T and dual-source coronary CTA. Catheter coronary angiography (CA), coronary CTA, and perfusion-cardiac MRI were all performed within a median time interval of 7.5 days. Detection of hemodynamically relevant stenoses by the combination of coronary CTA plus perfusion-cardiac MRI was compared with the combination of CA plus perfusion-cardiac MRI, the latter serving as the standard of reference.

RESULTS

CA identified stenoses in 75 of 141 coronary arteries (53.2%) in 33 of 47 patients (70.2%). Cardiac MRI revealed perfusion defects in 30 of 47 patients (63.8%). Image quality of coronary CTA was diagnostic in 635 of 638 segments (99.5%). Coronary CTA revealed stenoses greater than 50% in 76 of 141 coronary arteries (53.9%) of 33 of 47 patients (70.2%). Sensitivity, specificity, negative and positive predictive value, and accuracy of coronary CTA and perfusion-cardiac MRI versus CA and perfusion-cardiac MRI for the detection of hemodynamically relevant stenoses were 96.7%, 100%, 94.4%, 100%, and 97.9%, respectively.

CONCLUSION

The combination of coronary CTA and perfusion-cardiac MRI shows diagnostic performance comparable to that of CA and perfusion-cardiac MRI. Preliminary data suggest that coronary CTA may replace CA in the diagnosis of hemodynamically relevant CAD.

Intensive multifactorial intervention for stable coronary artery disease: optimal medical therapy in the COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial

OBJECTIVES

This paper describes the medical therapy used in the COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial and its effect on risk factors.

BACKGROUND

Most cardiovascular clinical trials test a single intervention. The COURAGE trial tested multiple lifestyle and pharmacologic interventions (optimal medical therapy) with or without percutaneous coronary intervention in patients with stable coronary disease.

METHODS

All patients, regardless of treatment assignment, received equivalent lifestyle and pharmacologic interventions for secondary prevention. Most medications were provided at no cost. Therapy was administered by nurse case managers according to protocols designed to achieve predefined lifestyle and risk factor goals.

RESULTS

The patients (n = 2,287) were followed for 4.6 years. There were no significant differences between treatment groups in proportion of patients achieving therapeutic goals. The proportion of smokers decreased from 23% to 19% (p = 0.025), those who reported <7% of calories from saturated fat increased from 46% to 80% (p < 0.001), and those who walked >or=150 min/week increased from 58% to 66% (p < 0.001). Body mass index increased from 28.8 +/- 0.13 kg/m(2) to 29.3 +/- 0.23 kg/m(2) (p < 0.001). Appropriate medication use increased from pre-randomization to 5 years as follows: antiplatelets 87% to 96%; beta-blockers 69% to 85%; renin-angiotensin-aldosterone system inhibitors 46% to 72%; and statins 64% to 93%. Systolic blood pressure decreased from a median of 131 +/- 0.49 mm Hg to 123 +/- 0.88 mm Hg. Low-density lipoprotein cholesterol decreased from a median of 101 +/- 0.83 mg/dl to 72 +/- 0.88 mg/dl.

CONCLUSIONS

Secondary prevention was applied equally and intensively to both treatment groups in the COURAGE trial by nurse case managers with treatment protocols and resulted in significant improvement in risk factors. Optimal medical therapy in the COURAGE trial provides an effective model for secondary prevention among patients with chronic coronary disease. (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation; NCT00007657).

Single-photon emission computed tomography myocardial perfusion imaging in the diagnosis of left main disease

BACKGROUND

Left main disease (LMD), defined as > or = 50% lesion stenosis, occurs in 3% to 5% of patients undergoing catheterization. Limited data on the value of single-photon emission computed tomography (SPECT) imaging for diagnosis of LMD exists.

HYPOTHESIS

This study sought to evaluate the diagnostic accuracy of SPECT imaging in the diagnosis of LMD.

METHODS

A total of 74 consecutive patients with LMD, identified from our catheterization lab database (January 2003-December 2007) with gated exercise (15 patients) or adenosine (59 patients), thallium 201, or Tc-99m SPECT imaging within 6 months of index angiography were included. Group 1 (Gp 1) included 33 patients with isolated LMD. Group 2 (Gp 2) consisted of 41 patients with LMD and 1-vessel disease (6); LMD and 2-vessel disease (24); and LMD and 3-vessel disease (11).

RESULTS

Reversible perfusion defects (PD) were absent in 6 (18%) of Gp 1 and 8 (20%) of Gp 2 patients. Among Gp 1 patients, PD in 1-vessel, 2-vessel, 3-vessel distribution were seen in 20 (61%), 5 (15%), and 2 (6%) patients respectively. In comparison, PD in 1-vessel, 2-vessel, 3-vessel distribution were observed in 20 (49%), 12 (29%), and 1 (2%) of Gp 2 patients respectively. Left main (LM) pattern was noted in 6 patients (Gp 1: 2, Gp 2: 4). Transient ischemic dilatation (TID) was encountered in 34 patients (Gp 1: 17, Gp 2: 17) and in 4 patients with normal perfusion scans.

CONCLUSIONS

These data represent the largest analysis of patients with "isolated" LMD. Approximately 19% of patients with LMD have no reversible PD on SPECT. While LM pattern is rare, 1-vessel distribution PD and TID represent the most frequent SPECT abnormalities.

Ranolazine's Role in the Treatment of Chronic Stable Angina

Objective:

To evaluate the role of ranolazine as an effective and safe first-line treatment option for the management of chronic stable angina (CSA).

Data Sources:

A literature search was conducted using MEDLINE (1966-August 2009), International Pharmaceutical Abstracts (1970-August 2009), and Cochrane database (publications archived until August 2009) using the terms chronic stable angina and ranolazine. In addition, reference citations from publications identified were reviewed.

Study Selection and Data Extraction:

English-language, randomized, controlled trials evaluating ranolazine extended release (ER) for the treatment of CSA in humans were selected for review. Four randomized controlled trials were identified. Findings pertaining to efficacy and safety were extracted.

Data Synthesis:

Three randomized, placebo-controlled CSA studies (N = 191, N = 823, N = 565) and 1 non-ST-segment elevation acute coronary syndrome (ACS) study (N = 6560) were identified that evaluated ranolazine ER. The 3 CSA studies showed that ranolazine ER treatment resulted in statistically significant improvements in exercise tolerance, time to angina onset, and time to 1-mm ST-segment depression. Two of the 3 CSA studies showed statistically significant reductions in angina episodes per week and nitroglycerin use per week compared to placebo. No significant reduction in cardiovascular events was seen in the non-ST-segment elevation ACS study following 1 year of treatment with ranolazine ER. Evidence has demonstrated that monotherapy with ranolazine ER is effective in increasing exercise tolerance in patients with CSA. Ranolazine ER therapy added to traditional antianginal therapy has shown efficacy in increasing exercise tolerance and minimally decreasing angina frequency in clinical trials.

Conclusions:

Ranolazine ER should be used judiciously in the management of CSA and should not be used as a first-line agent routinely unless traditional therapy is contraindicated.

Management of stable coronary artery disease

Results of two randomised controlled trials for the management of mild-to-moderate chronic stable coronary artery disease (Clinical Outcomes Utilizing Revascularization and Aggressive drug Evaluation [COURAGE] and Bypass Angioplasty Revascularization Investigation type-2 Diabetes [BARI-2D]) have stimulated a vigorous debate about whether an initial strategy of revascularisation or a conservative approach with drugs is most effective. The conclusions of these two trials were clear: for some patients randomly assigned after angiography to revascularisation or pharmacological therapy, rates of death and myocardial infarction did not differ between the two strategies. What remains unresolved is how to generalise these data to patients without angiography, the role of stress testing, and the preferred approach to patients with relevant ischaemia on stress testing. This Review draws attention to the controversial issues in both management approaches, analyses the strengths and limitations of recent trials, and proposes a treatment algorithm that is applicable to daily clinical practice. Findings suggest that the severity of anginal symptoms and the extent of ischaemia in stress testing could help to identify patients who are at increased risk and who might benefit from an early invasive strategy. On the basis of the data and considerations presented, a strategy of initial optimum pharmacological therapy or direct invasive management can be tailored to an individual's circumstances and preferences.

Cardiac syndrome X: current concepts

Cardiac syndrome X is a heterogeneous entity, both clinically and pathophysiologically, encompassing a variety of pathogenic mechanisms. Management of this syndrome represents a major challenge to the treating physician. They often seek medical care because of recurring and disabling chest pain, which may imply repetitive and costly invasive and non-invasive investigations. A careful patient evaluation for underlying pathophysiologic mechanism and exclusion of other causes of chest pain along with attention to various psychological aspects is helpful in reducing the stress and suffering of these patients. This article reviews the available literature on the pathophysiology and current controversies surrounding the management of this difficult to treat condition.

The emerging role of exercise testing and stress echocardiography in valvular heart disease

Exercise testing has an established role in the evaluation of patients with valvular heart disease and can aid clinical decision making. Because symptoms may develop slowly and indolently in chronic valve diseases and are often not recognized by patients and their physicians, the symptomatic, blood pressure, and electrocardiographic responses to exercise can help identify patients who would benefit from early valve repair or replacement. In addition, stress echocardiography has emerged as an important component of stress testing in patients with valvular heart disease, with relevant established and potential applications. Stress echocardiography has the advantages of its wide availability, low cost, and versatility for the assessment of disease severity. The versatile applications of stress echocardiography can be tailored to the individual patient with aortic or mitral valve disease, both before and after valve replacement or repair. Hence, exercise-induced changes in valve hemodynamics, ventricular function, and pulmonary artery pressure, together with exercise capacity and symptomatic responses to exercise, provide the clinician with diagnostic and prognostic information that can contribute to subsequent clinical decisions. Nevertheless, there is a lack of convincing evidence that the results of stress echocardiography lead to clinical decisions that result in better outcomes, and therefore large-scale prospective randomized studies focusing on patient outcomes are needed in the future.

Current analysis of the results of the COURAGE trial: has an optimal treatment been reached in clinical practice?

The COURAGE (Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation) trial was designed to evaluate the benefits of percutaneous coronary intervention in reducing the risk of cardiovascular events in patients with chronic stable coronary artery disease. The results reinforce the prior evidence regarding the importance of medical treatment which should be a universal goal. The study population enrolled was quite average for a routine cardiology clinic. However, the results of cardiac intervention are center-dependent and therefore need to be analyzed as such. Patients should initially receive the optimal medical treatment. Patients with symptom persistence, intolerance to medical treatment, and moderate to severe ischemia should be considered candidates for combined treatment. Treatment needs to be individualized and discussed with the patient. New studies, without the limitations of the COURAGE trial, enrolling high-risk patients treated with new interventional technologies, are needed to assess the impact of ischemia in long-term prognosis.

Long-term morbidity and mortality among medically managed patients with angina and multivessel coronary artery disease

BACKGROUND

There are little data regarding outcomes in patients with angina and severe coronary artery disease (CAD) treated with medical management. Using the Duke Databank of Cardiovascular Disease, we describe the prevalence and long-term outcomes of patients with angina and multivessel CAD treated medically after catheterization.

METHODS

Patients undergoing catheterization for angina (chest pain without recent revascularization or myocardial infarction) with severe CAD (>or=75% stenosis in >or=2 epicardial vessels) were identified (n = 8,555). One and five year outcomes in the 32% (n = 2,776) of patients who did not receive revascularization in the 30 days after catheterization were described. Predictors of 1-year death, cardiac rehospitalization, and late revascularization in this population were identified.

RESULTS

The population had a median age of 66, were mostly male, had significant comorbidities, and most had prior revascularization. Outcomes were poor at 1 and 5 years: death (11% and 37%), cardiac rehospitalization (29% and 61%), and late revascularization (10% and 27%). The cumulative rate of death, myocardial infarction, late revascularization, or cardiac rehospitalization occurred in 38% at 1 year and 76% at 5 years. Prior coronary artery bypass grafting was the only variable independently associated with protection from death, cardiac rehospitalization, and late revascularization.

CONCLUSIONS

Medical management after catheterization is a common in patients with severe CAD and angina. Of patients treated with medical management, one third will have a recurrent cardiac event within the first year highlighting the poor outcomes and high utilization of resources by this patient population.

Coronary computed tomography angiography with a consistent dose below 1 mSv using prospectively electrocardiogram-triggered high-pitch spiral acquisition

AIMS

We evaluated the feasibility and image quality of a new scan mode for coronary computed tomography angiography (CTA) with an effective dose of less than 1 mSv.

METHODS AND RESULTS

In 50 consecutive patients (body weight <or= 100 kg, sinus rhythm <or=60 b.p.m. after pre-medication, coronary CTA was performed using a dual-source CT system with 2 x 128 x 0.6 mm collimation, 0.28 s rotation time, a pitch of 3.2 or 3.4, 100 kV tube voltage and current of 320 mA s. Data acquisition was prospectively triggered at 60% of the R-R interval and completed within one cardiac cycle. Image quality was evaluated using a four-point scale (1 = absence of any artefacts to 4 = uninterpretable). In all 50 patients, imaging was successful. Mean duration of data acquisition was 258 +/- 20 ms. Mean dose-length product was 62 +/- 5 mGy cm, the effective dose was 0.87 +/- 0.07 mSv (0.78-0.99 mSv). Of the 742 coronary artery segments, 94% had an image quality score of 1, 5.0% a score of 2, 0.9% a score of 3, and 4 segments (0.5%) were 'uninterpretable'.

CONCLUSION

In non-obese patients with a low and stable heart rate, prospectively ECG-triggered high-pitch spiral coronary CTA provides excellent image quality at a consistent dose below 1.0 mSv.

The study of myocardial perfusion and coronary anatomy imaging roles in CAD (SPARC): design, rationale, and baseline patient characteristics of a prospective, multicenter observational registry comparing PET, SPECT, and CTA for resource utilization and clinical outcomes

OBJECTIVES

To design a multicenter study comparing the prognostic value and post-test resource utilization of PET, CT Coronary Angiography (CTA), and SPECT in clinical practice.

BACKGROUND

Although PET, CTA, and SPECT are widely used, their relative clinical- and cost-effectiveness are undefined.

METHODS

The Study of Myocardial Perfusion and Coronary Anatomy Imaging Roles in CAD (SPARC) is a prospective, multicenter, observational registry that has enrolled 3019 patients undergoing clinically referred SPECT, PET, and CTA with the goal of comparing posttest resource utilization and comparative prognostic value. Resource utilization assessment will enroll intermediate-high likelihood patients without prior CAD, while prognostic assessment will include both these patients and patients with prior CAD. Secondary analyses include assessments of diagnostic accuracy, cost, and referral to revascularization. Sites recruited into at least two of the three imaging arms. Except for semi-quantitative interpretation, site protocols will be used for all imaging studies and images forwarded to an image repository. Follow-up for catheterization, revascularization, cardiac death, myocardial infarction, all-cause death and medication use changes will be performed at 90-day, 1, and 2 years. Standard statistical methods will be used to risk-adjust results within and between study arms. SPARC will have >85% power (two-sided test, alpha = 0.01) to detect a 5% catheterization rate difference at 90 days between the three arms and >90% power to detect a 2% difference in cardiac death, or nonfatal MI within 2 years of the index test.

Women and ischemic heart disease: evolving knowledge

Evolving knowledge regarding sex differences in coronary heart disease is emerging. Given the lower burden of obstructive coronary artery disease (CAD) and preserved systolic function in women, which contrasts with greater rates of myocardial ischemia and near-term mortality compared with men, we propose the term "ischemic heart disease" as appropriate for this discussion specific to women rather than CAD or coronary heart disease (CHD). This paradoxical difference, where women have lower rates of anatomical CAD but more symptoms, ischemia, and adverse outcomes, appears linked to abnormal coronary reactivity that includes microvascular dysfunction. Novel risk factors can improve the Framingham risk score, including inflammatory markers and reproductive hormones, as well as noninvasive imaging and functional capacity measurements. Risk for women with obstructive CAD is increased compared with men, yet women are less likely to receive guideline-indicated therapies. In the setting of non-ST-segment elevation acute myocardial infarction, interventional strategies are equally effective in biomarker-positive women and men, whereas conservative management is indicated for biomarker-negative women. For women with evidence of ischemia but no obstructive CAD, antianginal and anti-ischemic therapies can improve symptoms, endothelial function, and quality of life; however, trials evaluating impact on adverse outcomes are needed. We hypothesize that women experience more adverse outcomes compared with men because obstructive CAD remains the current focus of therapeutic strategies. Continued research is indicated to devise therapeutic regimens to improve symptom burden and reduce risk in women with ischemic heart disease.

Impact of an initial strategy of medical therapy without percutaneous coronary intervention in high-risk patients from the Clinical Outcomes Utilizing Revascularization and Aggressive DruG Evaluation (COURAGE) trial

We explored the safety and quality-of-life consequences of treating patients with stable coronary disease and high-risk features initially with optimal medical therapy (OMT) alone compared to OMT plus percutaneous coronary intervention. This was a post hoc analysis of Clinical Outcomes Utilizing Revascularization and Aggressive DruG Evaluation (COURAGE) trial patients. We defined high risk as the onset of Canadian Cardiovascular Society class III angina within 2 months or stabilized acute coronary syndrome within 2 weeks of enrollment. The primary end point was death or myocardial infarction after 4.6 years. Of the 2,287 patients enrolled in the COURAGE trial, 264 (12%) were high risk and had a relative risk of 1.56 for death or myocardial infarction (p = 0.0008) compared to those with non-high-risk features. A total of 35 primary events occurred in the OMT group and 32 in the percutaneous coronary intervention plus OMT group (hazard ratio 1.11, 95% confidence interval 0.69 to 1.79; p = 0.68). No significant difference was found in the prevalence of angina between the 2 groups at 1 year. During the first year of follow-up, 30% of the OMT patients crossed over to the revascularization group. In conclusion, an initial strategy of OMT alone for high-risk patients in the COURAGE trial did not result in increased death or myocardial infarction at 4.6 years or worse angina at 1 year, but it was associated with a high rate of crossover to revascularization.

Role of angiotensin II type 1 receptor antagonists in the treatment of hypertension in patients aged >or=65 years

Systolic blood pressure (SBP) increases with age, and hypertension affects approximately two-thirds of adults in the US aged >60 years. Blood pressure (BP) increases as a consequence of age-related structural changes in large arteries, which lead to loss of elasticity and reduced vascular compliance. Increased pulse wave velocity augments SBP, resulting in a high prevalence of isolated systolic hypertension. Because age itself elevates cardiovascular risk, effective treatment of hypertension in an older (aged >or=65 years) patient population prevents many more events per 1000 patients treated than treatment of younger hypertensive patients. Recommendations for treating hypertension are similar in older patients compared with the general population. The Seventh Report of the Joint National Committee on Detection, Prevention, Evaluation, and Treatment of High Blood Pressure recommends target BP goals of <140/90 mmHg for patients with uncomplicated hypertension, and <130/80 mmHg for those with diabetes mellitus or renal disease. Recent guidelines and position papers have extended these aggressive treatment goals to include patients with coronary artery disease, other types of vascular disease and heart failure. Randomized clinical trials have demonstrated the efficacy of calcium channel antagonists (calcium channel blockers [CCBs]), low-dose diuretics, ACE inhibitors and angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) in reducing the risk of stroke and other adverse cardiovascular outcomes in older patients; beta-adrenoceptor antagonists are less effective in terms of endpoint reduction. The majority of older patients require two or more drugs to achieve BP goals. Despite active treatment, half of these patients do not achieve target BP, in part because of the reluctance of physicians to intensify treatment, a phenomenon referred to as 'clinical inertia'. ARBs are effective antihypertensive agents in older patients and have been shown to reduce cardiovascular endpoints in patients with hypertension, diabetic nephropathy, cerebrovascular disease and heart failure. ARBs produce additive BP reduction when combined with diuretics or CCBs. They also have the advantage of placebo-like tolerability, and this contributes favourably to patient compliance with long-term treatment, which is a prerequisite for reducing morbidity and mortality.

Improvement of fractional flow reserve and collateral flow by treatment with external counterpulsation (Art.Net.-2 Trial)

BACKGROUND

Arteriogenesis (collateral artery growth) is nature's most efficient rescue mechanism to overcome the fatal consequences of arterial occlusion or stenosis. The goal of this trial was to investigate the effect of external counterpulsation (ECP) on coronary collateral artery growth.

MATERIALS AND METHODS

A total of 23 patients (age 61 +/- 2.5 years) with stable coronary artery disease and at least one haemodynamic significant stenosis eligible for percutaneous coronary intervention were prospectively recruited into the two study groups in a 2 : 1 manner (ECP : control). One group (ECP group, n = 16) underwent 35 1-h sessions of ECP in 7 weeks. In the control group (n = 7), the natural course of collateral circulation over 7 weeks was evaluated. All patients underwent a cardiac catheterization at baseline and after 7 weeks, with invasive measurements of the pressure-derived collateral flow index (CFIp, primary endpoint) and fractional flow reserve (FFR).

RESULTS

In the ECP group, the CFIp (from 0.08 +/- 0.01 to 0.15 +/- 0.02; P < 0.001) and FFR (from 0.68 +/- 0.03 to 0.79 +/- 0.03; P = 0.001) improved significantly, while in the control group no change was observed. Only the ECP group showed a reduction of the Canadian Cardiovascular Society (CCS, P = 0.008) and New York Heart Association (NYHA, P < 0.001) classification.

CONCLUSION

In this study, we provide direct functional evidence for the stimulation of coronary arteriogenesis via ECP in patients with stable coronary artery disease. These data might open a novel noninvasive and preventive treatment avenue for patients with non-acute vascular stenotic disease.

Complementary prognostic values of stress myocardial perfusion and late gadolinium enhancement imaging by cardiac magnetic resonance in patients with known or suspected coronary artery disease

BACKGROUND

Recent studies have demonstrated the significant prognostic value of stress cardiac magnetic resonance (CMR) myocardial perfusion imaging. Apart from characterizing reversible perfusion defect (RevPD) from flow-limiting coronary stenosis, CMR late gadolinium enhancement (LGE) imaging is currently the most sensitive method for detecting subendocardial infarction (MI). We therefore tested the hypothesis that characterization of these 2 processes from coronary artery disease by CMR can provide complementary prognostic values.

METHODS AND RESULTS

We performed CMR myocardial perfusion imaging followed by LGE imaging on 254 patients referred with symptoms of myocardial ischemia. At a median follow-up of 17 months, 49 cardiac events occurred, including 12 cardiac deaths, 16 acute MIs, and 21 cardiac hospitalizations. RevPD and LGE both maintained a >3-fold association with cardiac death or acute MI (death/MI) when adjusted for each other and for the effects of patient age and gender (adjusted hazard ratio, 3.31; P=0.02; and hazard ratio, 3.43; P=0.01, respectively). In patients without a history of MI who had negative RevPD, LGE presence was associated with a >11-fold hazards increase in death/MI. Patients with neither RevPD nor LGE had a 98.1% negative annual event rate for death/MI. For association with major adverse cardiac events, RevPD was the strongest multivariable variable in the best overall model (hazard ratio, 10.92; P<0.0001).

CONCLUSIONS

CMR imaging provides robust risk stratification for patients who present with symptoms of ischemia. Characterization of RevPD and LGE by CMR provides strong and complementary prognostic implication for cardiac death or acute MI.

Magnetic resonance adenosine perfusion imaging in patients after coronary artery bypass graft surgery

OBJECTIVES

The aim of the study was to evaluate the feasibility and diagnostic performance of the combination of adenosine stress perfusion and late gadolinium enhancement (LGE) in patients after coronary artery bypass graft surgery (CABG).

BACKGROUND

Cardiac magnetic resonance (CMR) imaging allows the detection of significant coronary artery disease by adenosine stress perfusion and infarct imaging. Myocardial contrast kinetics may be altered in patients after CABG owing to more complex myocardial perfusion and different distances of the contrast bolus through different bypasses and native coronary vessels. Additionally, all studies have excluded patients after CABG.

METHODS

In all, 78 patients (age 66 +/- 8 years; 71 men) underwent CMR imaging including left ventricular function, first-pass adenosine stress perfusion (adenosine 140 microg/min/kg) using 0.05 mmol/kg body weight gadolinium-diethylenetriaminepenta-acetic acid and an additional 0.15 mmol/kg for LGE 1 day before invasive coronary angiography. Images were analyzed visually using the speed of contrast wash-in and maximal signal intensity. Transmural LGE defects of the size of a vessel or graft territory defined by angiography were considered true negatives, even when supplied by a stenosed/occluded vessel/graft. Stenoses >50% in grafts and grafted or ungrafted native vessels (diameter > or =2 mm) in invasive angiography were considered significant.

RESULTS

The prevalence of patients with significant stenosis was 63% (69% functionally 1-vessel, 28% 2-vessel, and 3% 3-vessel disease). Sensitivity and specificity were 77% and 90%, respectively, on a patient basis, and 71% and 89% on a vessel territory basis. Sensitivity, if only areas supplied by grafts (n = 196) were evaluated, was 78% and specificity was 94%, compared with territories supplied by ungrafted native vessels (n = 51) with sensitivity and specificity of 63% and 91%, respectively. Sensitivity and specificity for the 53 areas with prior infarction were 88% and 79%, respectively.

CONCLUSIONS

For patients after surgical revascularization, the combination of stress perfusion and LGE yields good diagnostic accuracy for the detection and localization of significant stenoses. However, sensitivity is reduced compared with published data in patients without CABG. Prior myocardial infarction can be examined without loss of accuracy.

Clinical effectiveness of coronary computed tomographic angiography in the triage of patients to cardiac catheterization and revascularization after inconclusive stress testing: results of a 2-year prospective trial

BACKGROUND

Management of patients with suspected coronary artery disease (CAD) and inconclusive stress imaging test findings may result in invasive coronary angiography (ICA). Coronary computed tomographic angiography (CCTA) may be useful in defining the risk of CAD and adverse outcomes in this patient population, as well as in reducing the need for ICA.

METHODS

We prospectively enrolled 199 sequential patients referred by cardiologists for CCTA after either inconclusive or nondiagnostic stress imaging tests. Before CCTA, physicians identified a "planned catheterization" group of patients who would undergo invasive angiography if CCTA were not available. After CCTA testing, patients were followed for >or=2 years. We established the added diagnostic value of the CCTA and its prognostic power in prediction of intermediate-term follow-up events in this patient population as compared to available historical and clinical predictors of CAD, stress ECG, and stress imaging test results using a multivariable Cox proportional hazards survival analysis.

RESULTS

Both observed data and results of the multivariable model for the prediction of obstructive CAD (>50% stenosis), or major cardiac events (death MI or revascularization), demonstrated that clinical, stress ECG, and imaging results were weakly predictive, whereas CCTA was found to be a strong independent and incremental predictor of the absence of either significant CAD or MACE in this population. None of the 93 patients with normal CCTA scans had MACE events, whereas 18 patients with evidence of CAD on the CCTA results underwent revascularization. Overall, physicians planned ICA in 125 patients (63.0%); after CCTA, ICA was performed in only 32 (16.0%) cases over 2 years. In this population with no other highly effective noninvasive clinical tools for diagnostic and prognostic estimation, the overall negative predictive value of CCTA for either CAD > 50% or MACE for 2 years was 99%.

CONCLUSION

Observations from this prospective study demonstrate the significant added diagnostic value and prognostic potential of CCTA in patients with suspected CAD and either inconclusive or nondiagnostic stress test results in real-world settings. Normal CCTA results are associated with excellent intermediate-term prognosis in this clinical subset, and invasive angiography can be safely avoided in the majority of these patients when the results of CCTA are available.

Coronary CT angiography and myocardial perfusion imaging to detect flow-limiting stenoses: a potential gatekeeper for coronary revascularization?

AIMS

To evaluate the diagnostic accuracy of a combined non-invasive assessment of coronary artery disease with coronary CT angiography (CTA) and myocardial perfusion imaging (MPI) for the detection of flow-limiting coronary stenoses and its potential as a gatekeeper for invasive examination and treatment.

METHODS AND RESULTS

In 78 patients (mean age 65 +/- 9 years) referred for coronary angiography (CA), additional CTA and MPI (using single-photon emission-computed tomography) were performed and the findings not communicated. Detection of flow-limiting stenoses (justifying revascularization) by the combination of CTA and MPI (CTA/MPI) was compared with the combination of quantitative coronary angiography (QCA) plus MPI (QCA/MPI), which served as standard of reference. The findings of both combinations were related to the treatment strategy (revascularization vs. medical treatment) chosen in the catheterization laboratory based on the CA findings. Sensitivity, specificity, positive and negative predictive value, and accuracy of CTA/MPI for the detection of flow-limiting coronary stenoses were 100% each. More than half of revascularization procedures (21/40, 53%) was performed in patients without flow-limiting stenoses and 76% (47/62) of revascularized vessels were not associated with ischaemia on MPI.

CONCLUSION

The combined non-invasive approach CTA/MPI has an excellent accuracy to detect flow-limiting coronary stenoses compared with QCA/MPI and its use as a gatekeeper appears to make a substantial part of revascularization procedures redundant.