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)

Assessment of myocardial scarring improves risk stratification in patients evaluated for cardiac defibrillator implantation

OBJECTIVES

We tested whether an assessment of myocardial scarring by cardiac magnetic resonance imaging (MRI) would improve risk stratification in patients evaluated for implantable cardioverter-defibrillator (ICD) implantation.

BACKGROUND

Current sudden cardiac death risk stratification emphasizes left ventricular ejection fraction (LVEF); however, most patients suffering sudden cardiac death have a preserved LVEF, and many with poor LVEF do not benefit from ICD prophylaxis.

METHODS

One hundred thirty-seven patients undergoing evaluation for possible ICD placement were prospectively enrolled and underwent cardiac MRI assessment of LVEF and scar. The pre-specified primary endpoint was death or appropriate ICD discharge for sustained ventricular tachyarrhythmia.

RESULTS

During a median follow-up of 24 months the primary endpoint occurred in 39 patients. Whereas the rate of adverse events steadily increased with decreasing LVEF, a sharp step-up was observed for scar size >5% of left ventricular mass (hazard ratio [HR]: 5.2; 95% confidence interval [CI]: 2.0 to 13.3). On multivariable Cox proportional hazards analysis, including LVEF and electrophysiological-study results, scar size (as a continuous variable or dichotomized at 5%) was an independent predictor of adverse outcome. Among patients with LVEF >30%, those with significant scarring (>5%) had higher risk than those with minimal or no (≤5%) scarring (HR: 6.3; 95% CI: 1.4 to 28.0). Those with LVEF >30% and significant scarring had risk similar to patients with LVEF ≤30% (p = 0.56). Among patients with LVEF ≤30%, those with significant scarring again had higher risk than those with minimal or no scarring (HR: 3.9; 95% CI: 1.2 to 13.1). Those with LVEF ≤30% and minimal scarring had risk similar to patients with LVEF >30% (p = 0.71).

CONCLUSIONS

Myocardial scarring detected by cardiac MRI is an independent predictor of adverse outcome in patients being considered for ICD placement. In patients with LVEF >30%, significant scarring (>5% LV) identifies a high-risk cohort similar in risk to those with LVEF ≤30%. Conversely, in patients with LVEF ≤30%, minimal or no scarring identifies a low-risk cohort similar to those with LVEF >30%.

Effect of obesity on B-type natriuretic peptide levels in patients with pulmonary arterial hypertension

Brain natriuretic peptide (BNP) levels are lower in obese patients with left ventricular failure than in their comparably ill, leaner counterparts. The effect of obesity on BNP in patients with pulmonary arterial hypertension (PAH) is unknown. We reviewed our prospective PAH registry data collected from November 2001 to December 2007 for patients undergoing right heart catheterization who met the criteria for PAH and had the BNP level and body mass index determined at baseline. The median BNP level for the lean, overweight, and obese patients was 285 pg/ml (interquartile range 131 to 548), 315 pg/ml (interquartile range 88 to 531), and 117 pg/ml (interquartile range 58 to 270), respectively (p = 0.029). A greater body mass index was associated with a lower BNP level, adjusted for age, gender, New York Heart Association functional class, hypertension, coronary artery disease, and mean right atrial and pulmonary arterial pressures (p <0.001). No statistically significant differences were found among the groups in age, race, medical co-morbidities, underlying etiology of PAH, use of vasoactive medications, New York Heart Association functional class, echocardiographic parameters, or pulmonary function. Obese patients had greater right atrial and pulmonary artery pressures. Increased BNP was associated with worse survival in the lean and overweight patients only. In conclusion, the BNP levels are attenuated in obese patients with PAH despite similar or worse hemodynamics or functional class compared to lean or overweight patients and should therefore be interpreted with caution.

Prognostic impact of baseline low blood pressure in hypertensive patients with stable coronary artery disease of daily clinical practice

The authors' aim was to investigate the prognostic value of first-visit systolic and diastolic blood pressure (SBP/DBP) in hypertensive patients with stable coronary artery disease (sCAD) in conditions of contemporary daily clinical practice. From February 1, 2000, to January 31, 2004, 690 consecutive hypertensive patients with sCAD (mean age 68 ± 10 years, 65% male) were prospectively followed in the outpatient cardiology clinic for major events (acute coronary syndrome, revascularization, stroke, heart failure, or death) and associations with baseline SBP/DBP were investigated. At first visit, median SBP/SDP were 130/75 mm Hg (interquartile range, 25-75; 120-140/70-80 mm Hg). After 25 months of follow-up (median), 19 patients died (2.8%); 10 from cardiovascular causes (1.5%), 87 patients experienced a coronary event (13%), and 130 patients (19%) a major event. After adjusting for baseline variables, DBP <75 mm Hg or SBP <130 mm Hg resulted in independent predictors of major events (hazard ratio [HR], 1.52; 95% confidence interval [CI], 1.07-2.16, P=.02; HR, 1.68; 95% CI, 1.18-2.40, P=.004, respectively), coronary events (HR, 1.78; 95% CI, 1.15-2.75, P=.009; HR, 1.84; 95% CI, 1.20-2.83, P=.005, respectively), and cardiovascular mortality (HR, 7.02; 95% CI, 1.26-39.04, P=.03; HR, 9.26; 95% CI, 1.33-64.32, P=.02, respectively). In this study, a low first-visit SBP or DBP was associated with an adverse prognosis in hypertensive patients with sCAD of contemporary daily clinical practice.

Combination of myocardial perfusion imaging and coronary artery calcium scanning: potential synergies for improving risk assessment in subjects with suspected coronary artery disease

For many years, the mainstay of noninvasive evaluation of patients suspected of ischemic cardiovascular disease (CVD) centered on the use of myocardial perfusion imaging (MPI). In recent years, the advent of newer modalities such as coronary artery calcium (CAC) scanning, coronary CT angiography, and MRI have broadened the means of assessing cardiac patients for this purpose. Moreover, the advent of these newer modalities has created potential synergies whereby combinations of tests may be clinically useful. In this review, we assess the potential synergies between MPI, whether assessed by single photon emission computed tomography (SPECT) or positron emission tomography (PET), and CAC scanning. Whereas MPI has long been used for diagnostic assessment and for risk stratification purposes, the emerging uses of CAC scanning now appear multifold: screening for CVD, triaging patients for diagnostic stress testing, improving risk stratification in patients following stress testing, and enhancing the direct management of patients' CVD risk following CAC scanning. Recent work suggests that CAC scanning may be emerging as the initial test of choice for most asymptomatic patients. The advent of hybrid SPECT-CT and PET-CT scanners may signify an important new opportunity for the combined use of these modalities in the higher-risk asymptomatic patient population.

Reduced peripheral vascular reactivity in refractory angina pectoris: Effect of enhanced external counterpulsation

AIMS

To examine if the skin microvascular bed is altered and can be modified by enhanced external counterpulsation (EECP) in patients with chronic refractory angina.

METHODS

Twenty patients diagnosed with refractory angina were divided into EECP (n = 10) or no EECP (n = 10) groups. The data were compared to matched healthy subjects (n = 20). The cutaneous forearm microvascular blood flow was measured by Laser-Doppler flowmetry. The vascular responsiveness to iontophoretic administration of acetylcholine (ACh), sodium nitroprusside (SNP) and local skin warming were studied. Measurements of Canadian Cardiovascular Society (CCS)-class, blood pressure and plasma samples were registered.

RESULTS

EECP patients showed reduced CCS-class compared to no EECP (P < 0.05). Both EECP and no EECP (P < 0.05) groups had decreased systolic blood pressure (SBP) as compared to SBP at baseline (P < 0.05). There was no difference in resting blood flow between the two refractory groups at baseline as well as after EECP and seven weeks of follow-up. Responses to heating, the responses to ACh and SNP in the cutaneous microcirculation were lower in both groups of refractory angina patients as compared to healthy subjects (P < 0.05). EECP patients corresponded positively to the treatment shown by reduced plasma level of soluble interleukin-2 receptor and CCS-class.

CONCLUSIONS

Refractory angina patients have reduced responsiveness in their cutaneous microcirculation to ACh, SNP and heat compared to healthy subjects. Although EECP reduced the CCS-class, this effect was not associated with improvements in responsiveness of the cutaneous microcirculation.

High-intensity interval training in cardiac rehabilitation

High-intensity interval training (HIIT) is frequently used in sports training. The effects on cardiorespiratory and muscle systems have led scientists to consider its application in the field of cardiovascular diseases. The objective of this review is to report the effects and interest of HIIT in patients with coronary artery disease (CAD) and heart failure (HF), as well as in persons with high cardiovascular risk. A non-systematic review of the literature in the MEDLINE database using keywords 'exercise', 'high-intensity interval training', 'interval training', 'coronary artery disease', 'coronary heart disease', 'chronic heart failure' and 'metabolic syndrome' was performed. We selected articles concerning basic science research, physiological research, and randomized or non-randomized interventional clinical trials published in English. To summarize, HIIT appears safe and better tolerated by patients than moderate-intensity continuous exercise (MICE). HIIT gives rise to many short- and long-term central and peripheral adaptations in these populations. In stable and selected patients, it induces substantial clinical improvements, superior to those achieved by MICE, including beneficial effects on several important prognostic factors (peak oxygen uptake, ventricular function, endothelial function), as well as improving quality of life. HIIT appears to be a safe and effective alternative for the rehabilitation of patients with CAD and HF. It may also assist in improving adherence to exercise training. Larger randomized interventional studies are now necessary to improve the indications for this therapy in different populations.

High On-Aspirin Platelet Reactivity and Clinical Outcome in Patients With Stable Coronary Artery Disease: Results From ASCET (Aspirin Nonresponsiveness and Clopidogrel Endpoint Trial)

Background

Patients with stable coronary artery disease on single-antiplatelet therapy with aspirin are still at risk for atherothrombotic events, and high on-aspirin residual platelet reactivity (RPR) has been suggested as a risk factor.

Methods and Results

In this randomized trial, the association between platelet function determined by the PFA100 platelet function analyzer system (Siemens Healthcare Diagnostics, Germany) and clinical outcome in 1001 patients, all on single-antiplatelet therapy with aspirin (160 mg/d) was studied. Patients were randomized to continue with aspirin 160 mg/d or change to clopidogrel 75 mg/d. A composite end point of death, myocardial infarction, ischemic stroke, and unstable angina was used. At 2-year follow-up, 106 primary end points were registered. The prevalence of high RPR was 25.9%. High on-aspirin RPR did not significantly influence the primary end point in the aspirin group (13.3% versus 9.9%, P=0.31). However, in post hoc analysis, patients with von Willebrand factor levels or platelet count below median values and high on-aspirin RPR had a statistically significant higher end point rate than that of patients with low RPR (20% versus 7.5%, P=0.014, and 18.2% versus 10.8%, P=0.039, respectively). The composite end point rate in patients with high on-aspirin RPR treated with clopidogrel was not different from that of patients treated with aspirin (7.6% versus 13.3%, P=0.16).

Conclusions

In stable, aspirin-treated patients with coronary artery disease, high on-aspirin RPR did not relate to clinical outcome and did not identify a group responsive to clopidogrel. Post hoc subgroup analysis raised the possibility that high on-aspirin RPR might be predictive in patients with low von Willebrand factor or platelet count, but these findings will require confirmation in future studies.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov Unique identifier: NCT00222261. (J Am Heart Assoc. 2012;1:e000703 doi: 10.1161/JAHA.112.000703.)

Shadow of diabetes over cardiovascular disease: comparative quantification of population-attributable all-cause and cardiovascular mortality

BACKGROUND

We contrasted impacts on all-cause and cardiovascular disease (CVD) mortality of diabetes vs. CVD.

METHODS

Among participants the Tehran lipid and glucose study aged ≥ 30 years (n = 9752), we selected those who participated in the follow-up study until 20 March 2009 (n = 8795). Complete data on covariate were available for 8, 469 participants, contributing to a 67935 person-year follow up. In the analysis of outcomes (all-cause and CVD mortality), diabetes and CVD were assessed using Cox proportional hazard regression model adjusting for established CVD risk factors. We used population attributable hazard fraction (PAHF) and rate advancement period (RAP) that expresses how much sooner a given mortality rate is reached among exposed than among unexposed individuals.

RESULTS

Ten percent of the participants self-reported to have pervious CVD, and diabetes was ascertained in 17% of participants at baseline examination. During a median follow-up of 9 years 386 participants died of which 184 were due to CVD. All-cause and CVD mortality rate (95% CIs) were 5.5 (5.0-6.1) and 2.6 (2.3-3.0) per 1000 person-year, respectively. The PAHF of all-cause mortality for diabetes 9.2 (7.3-11.1) was greater than the one for CVD 3.5 (1.1-5.5). RAP estimates for all-cause mortality associated with diabetes ranged from 7.4 to 8.6 years whereas the RAP estimates for all-cause mortality associated with CVD ranged from 3.1 to 4.3 years. The PAHF of CVD mortality for diabetes 9.4 (6.8-12.0) was greater than the one for CVD 4.5 (1.8-7.0). RAP estimates for CVD mortality associated with diabetes ranged from 8.2 to 9.8 years whereas the RAP estimates for CVD mortality associated with CVD ranged from 4.7 to 6.7 years.

CONCLUSIONS

We demonstrated that diabetes, which was shown to be keeping pace with prevalent CVD in terms of conferring excess risk of incident CVD, is currently causing more deaths in the population than does CVD.

Comparison of exercise electrocardiography and stress perfusion CMR for the detection of coronary artery disease in women

BACKGROUND

Exercise electrocardiography (ECG) is frequently used in the work-up of patients with suspected coronary artery disease (CAD), however the accuracy is reduced in women. Cardiovascular magnetic resonance (CMR) stress testing can accurately diagnose CAD in women. To date, a direct comparison of CMR to ECG has not been performed.

METHODS AND RESULTS

We prospectively enrolled 88 consecutive women with chest pain or other symptoms suggestive of CAD. Patients underwent a comprehensive clinical evaluation, exercise ECG, a CMR stress test including perfusion and infarct imaging, and x-ray coronary angiography (CA) within 24 hours. CAD was defined as stenosis ≥70% on quantitative analysis of CA.Exercise ECG, CMR and CA was completed in 68 females (age 66.4 ± 8.8 years, number of CAD risk factors 3.5±1.4). The prevalence of CAD on CA was 29%. The Duke treadmill score (DTS) in the entire group was -3.0±5.4 and was similar in those with and without CAD (-4.5±5.8 and -2.4±5.1; P=0.12). Sensitivity, specificity and accuracy for CAD diagnosis was higher for CMR compared with exercise ECG (sensitivities 85% and 50%, P=0.02, specificities 94% and 73%, P=0.01, and accuracies 91% and 66%, P=0.0007, respectively). Even after applying the DTS the accuracy of CMR was higher compared to exercise ECG (area under ROC curve 0.94±0.03 vs 0.56±0.07; P=0.0001).

CONCLUSIONS

In women with intermediate-to-high risk for CAD who are able to exercise and have interpretable resting ECG, CMR stress perfusion imaging has higher accuracy for the detection of relevant obstruction of the epicardial coronaries when directly compared to exercise ECG.

Analysis on outcome of 5284 patients with coronary artery disease: the role of integrative medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Traditional Chinese Medicine (TCM) has a history of thousands of years and has made great contributions to the health and well-being of the people. Integrative medicine (IM) treatment, combing TCM and conventional medicine, has been the most representative characteristic for coronary artery disease (CAD) patients in China, especially those in IM hospitals. However, the secondary prevention status of CAD and the potential benefit of IM therapy in improving CAD prognosis remains unclear.

MATERIALS AND METHODS

By means of a unified clinical and research information platform, we collected clinical information of hospitalized patients with CAD in cardiovascular department of 9 IM hospitals in Beijing and Tianjin from January 2003 to September 2006. The primary endpoints were major adverse cardiac events (MACEs) which include all-cause death in hospital and during one-year follow-up, acute myocardial infarction (AMI), percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG). The diagnostic and therapeutic status of CAD patients was evaluated based on the latest available clinical guidelines. Meanwhile, a logistic stepwise regression analysis was also used to identify independent prognostic factors.

RESULTS

5284 hospitalized patients with CAD were registered. The top five TCM patterns were in turn blood stasis 79.3%, Qi deficiency 56.5%, phlegm-turbidness 41.1%, Yin deficiency 24.8%, Yang deficiency 11.3%. The standard-reaching rate of CAD patients with hyperlipidemia was 85.6% for total cholesterol, 31.2% for triglyceride, 21.4% for low-density lipoprotein cholesterol, 52.5% for high-density lipoprotein cholesterol, while it was 61.9% and 80.9% in systolic and diastolic blood pressure of CAD with hypertension respectively. The top five commonly used herbs by functions were Qi-tonifying agents 89.25%, blood-activating agents 86.04%, Qi-regulating agents 77.60%, heat-clearing agents 67.50%, dampness-draining agents 65.95%. The herbs commonly used were Salvia miltiorrhiza Bunge 63.10%, Poria 59.99%, Raidx Astragali 49.67%, Radix Paeoniae Rubra 48.71%, peach seed 47.32%, angelica 46.82%, Radix Ligustici Chuanxiong 46.36%, safflower 45.40%, Pinellia 45.30%, glycyrrhiza 41.36%. 90 patients (1.7%) died in hospital, and the overall incidence of endpoints was 6.1% (322/5284). The logistic stepwise regress analysis showed that AMI (OR, 5.62, 95% CI=2.56-12.33), heart failure (OR, 2.68, 95% CI=1.67-4.29), age≥60 years (OR, 2.01, 95% CI=1.22-3.30), and medication of phosphodiesterase inhibitors (OR, 1.67, 95% CI=1.15-2.42) were independent risk factors for in-hospital mortality and one-year follow-up MACEs, while statins (OR, 0.23, 95% CI=0.06-0.91) and IM therapy (OR, 0.69, 95% CI=0.49-0.97) were protective factors.

CONCLUSION

There was still certain gap between the usage of conventional medicine and clinical guideline in IM hospitals of China. Integrative Medicine might have potential benefit for CAD patients in reducing MACEs. However, the scheme of IM intervention and the mechanism of action are still needed to be further determined.

Non-linear contribution of glucose measures to cardiovascular diseases and mortality: reclassifying the Framingham's risk categories: a decade follow-up from the Tehran lipid and glucose study

BACKGROUND

We investigated non-linear contribution of fasting plasma glucose (FPG) and 2-hour post-challenge plasma glucose (2h-PCPG) to the risk of CVD and mortality. We hypothesized that glucose measures improve risk-stratification made by the Framingham's general CVD risk algorithm.

METHODS

Among participants aged ≥ 30 (n=8071), not taking glucose-lowering agents, 6169 (3477 women) remained eligible. Non-linear contribution of FPG and 2h-PCPG to incident CVD and mortality were assessed using Cox models incorporating restricted cubic splines functions. Risk reclassification improvement conferred by FPG and 2h-PCPG was examined using an extended version of net reclassification index (NRI) that takes into account the censoring nature of survival data.

RESULTS

We documented 465 incident CVD events (402 CHD), 212 deaths from any cause (94 CVD deaths). Excluding the contribution of the 2h-PCGP to mortality (that was linear) dose-response relationships between glucose measures and CVD and mortality were curvilinear with nadirs below which decreasing levels of glucose were unlikely to offer any benefit. These nadirs were assigned to FPG of 4.9-5.3 and 2h-PCPG of 6.0 mmol.l(-1). Glucose measures added to the predictive ability of the Framingham's general CVD risk algorithm with cutpoint-free NRIs ranging from 19 to 54%.

CONCLUSION

Glucose measures contributed to the risk of CVD and mortality in a curvilinear fashion, we observed increased risk below glucose thresholds currently used to define diabetes, supporting criteria for the diagnosis of impaired fasting glycemia and impaired glucose tolerance. Glucose measures were observed to add to predictive ability of the predictive model which included established cardiovascular risk factors.

Stable angina pectoris: the medical management of symptomatic myocardial ischemia

Coronary artery disease (CAD) remains an important cause of morbidity and mortality and is a serious public health problem. Over the last 4 decades there have been dramatic advances in the both the prevention and treatment of CAD. The management of CAD was revolutionized by the development of effective surgical and percutaneous revascularization techniques. In this review we discuss the importance of the medical management of symptomatic, stable angina. Medical management approaches to both the treatment and prevention of symptomatic myocardial ischemia are summarized. In Canada, organic nitrates, β-adrenergic blocking agents, and calcium channel antagonists have been available for the therapy of angina for more than 25 years. All 3 classes are of proven benefit in the improvement of symptoms and exercise capacity in patients with stable angina. Although there is no clear first choice within these classes of anti-anginal agents, the presence of prior or concurrent conditions (for example, prior myocardial infarction and/or hypertension) plays an important role in the choice of anti-anginal class in individual patients. For some patients, combinations of different anti-anginal agents can be effective; however it is recommended that this approach be individualized. Although not currently available in Canada, other classes of anti-anginal agents have been developed; their mechanism of action and clinical efficacy is discussed. Patients with stable angina have an excellent prognosis. Patients in this category who obtain relief from symptomatic myocardial ischemia may do well without invasive intervention.

Vasculoprotective properties of enhanced external counterpulsation for coronary artery disease: beyond the hemodynamics

A growing pool of evidence has shown that enhanced external counterpulsation (EECP) is a non-invasive, safe, low-cost, and highly beneficial therapy for patients with coronary artery disease. However, the exact mechanisms of benefit exerted by EECP therapy remain only partially understood. The favorable hemodynamic effects of EECP were previously considered as the primary mechanism of action. Nevertheless, recent advances have shed light on the shear stress-increasing effects of EECP which are vasculoprotective and anti-atherosclerotic. EECP-induced endothelial shear stress increase may lead to improvement in endothelial function and morphology, attenuation of oxidative stress and inflammation, and promotion of angiogenesis and vasculogenesis. This review summarizes evidence of the potential mechanisms contributing to the immediate and long-term benefits of EECP, from the perspective of its shear stress-increasing effects.