Disparities in Revascularization After ST Elevation Myocardial Infarction (STEMI) Before and After the 2002 IOM Report.

OBJECTIVES: To examine nationwide trends for racial disparities in Percutaneous Coronary Intervention after ST elevated Myocardial Infarction (STEMI). BACKGROUND: The Institute of Medicine (IOM) report published in 2002 showed that African Americans were less likely to receive coronary revascularization such as CABG and stents even after controlling for socioeconomics. It recommended increased awareness of these disparities among health professionals to reduce this. We hypothesized that increased awareness of disparities since this report would have translated to reduction in racial disparities in percutaneous coronary intervention. METHODS: A retrospective analysis was conducted using data from the Agency of Healthcare Research and Quality's (AHRQ) National Inpatient Sample (NIS) 1998-2007. All patients with STEMI during this period were identified. The proportion that received Percutaneous Coronary Intervention (PCI) during the incident admission was compared by different ethnicities over the time period. Multivariable regression for each year was conducted using Poisson regression with robust variances. The analysis controlled for gender, insurance status, co-morbidities, hospital bed size, location and teaching status. RESULTS: Based on the database, about 2.04 million patients were managed for acute Myocardial Infarction from 1998 to 2007, of these 938,176 had STEMI. The primary PCI rate after STEMI among Caucasians was 29.1%, African Americans-23.3% and Hispanics-28.3% [P < 0.001] On multivariate regression, compared to Caucasians, African Americans and Hispanics respectively were 26% (IRR = 0.74) and 16% (IRR = 0.84) less likely to receive PCI (both with P < 0.001) during the entire study period. CONCLUSION: Ethnic disparities in primary PCI after STEMI persist despite the 2002 IOM report.

Transthyretin Cardiac Amyloidosis in Black Americans.

Transthyretin-related cardiac amyloidosis is a progressive infiltrative cardiomyopathy that mimics hypertensive and hypertrophic heart disease and often goes undiagnosed. In the United States, the hereditary form disproportionately afflicts black Americans, who when compared with whites with wild-type transthyretin amyloidosis, a phenotypically similar condition, present with more advanced disease despite having a noninvasive method for early identification (genetic testing). Although reasons for this are unclear, this begs to consider the inadequate access to care, societal factors, or a biological basis. In an effort to improve awareness and explore unique characteristics, we review the pathophysiology, epidemiology, and therapeutic strategies for transthyretin amyloidosis and highlight diagnostic pitfalls and clinical pearls for identifying patients with amyloid heart disease.

Correlation of Prehypertension with Left Ventricular Mass Assessed by Cardiac Magnetic Resonance Imaging.

Introduction. The purpose of this observational cross-sectional study was to assess left ventricular mass (LVM) in prehypertensive individuals in comparison to normotensives and to determine if central blood pressure (BP) correlates better with LVM index (LVMI) than brachial BP. Methods and Result. Brachial and central BP measurements were completed at first visit and at 4 weeks in 65 healthy volunteers who were at least 40 years old and not on medication. Subjects were divided into two groups of normotensives and prehypertensives based on JNC-7 criteria and LVM was obtained using cardiac magnetic resonance imaging. Prehypertensives had significantly higher LVMI compared to normotensives (P < 0.01). Brachial and central BP also both positively correlate with LVMI (r = 0.460, P < 0.01; r = 0.318, P = 0.012, resp.) in both groups and neither method was superior to the other. After multivariate regression analysis and adjusting for cardiovascular risk factors, prehypertension remained an independent determinant of LVM. Conclusion. Prehypertension is associated with cardiovascular target organ damage, and central BP was not superior to brachial BP or vice versa for association with LVMI.

Right Atrial Myxoma and Syncope.

BACKGROUND: Right atrial myxoma accounts for 15-20% of cardiac myxomas and syncope is a very rare manifestation. We present the case of an 89-year-old man with right atrial myxoma and syncope, and discuss the role of cardiac magnetic resonance imaging (MRI) in the diagnosis of myxomas. CASE REPORT: An 89-year-old man with a history of hypertension, hyperlipidemia, chronic kidney disease stage 4, mild dementia, and benign prostatic hyperplasia presented to the emergency department with an episode of syncope. Physical examination demonstrated normal and regular heart sounds, and normal respiratory rate and oxygen saturation. Echocardiogram described a well-circumscribed echo-dense mass in the right atrial cavity, which was attached to the septum but not obstructing the tricuspid annulus, measuring 1.7×2.2 cm at its widest diameter. Cardiac MRI revealed a mass with dark intensity which enhanced heterogeneously following intravenous administration of gadolinium-chelate, consistent with a myxoma. The location of this myxoma, coupled with the presence of a stalk allowing mobility, provides a clue to how this patient experienced transient obstruction of the tricuspid valve leading to syncope. CONCLUSIONS: Right heart tumors should be considered in the differential diagnosis of unexplained syncope. Cardiac MRI with gadolinium-chelate administration can help differentiate this tumor from a right-sided atrial thrombus, which can pose a diagnostic challenge.

A Rare Association of Sinus Venosus-Type Atrial Septal Defect and Persistent Left Superior Vena Cava Detected by Transthoracic Echocardiography and Cardiac Magnetic Resonance Imaging.

BACKGROUND: Association of persistent left superior vena cava (PLSVC) and sinus venosus-type atrial septal defect (SVASD) is rare. We describe a patient with dilated coronary sinus (CS) found to have PLSVC and SVASD. CASE REPORT: The patient is a 60-year-old man with history of stroke who underwent a transthoracic echocardiogram (TTE) for evaluation of shortness of breath. TTE demonstrated a markedly dilated CS. Agitated saline was injected into the left antecubital vein to further assess CS. The parasternal long axis view demonstrated immediate filling of the CS and confirmed the presence of a PLSVC. Apical 4-chamber view with injection of agitated saline into the right antecubital vein demonstrated immediate contrast opacification of both atria, consistent with a right to left cardiac shunt. Cardiac magnetic resonance (CMR) was performed, which confirmed the TTE findings of PLSVC and defined the cardiac shunt as SVASD. CONCLUSIONS: PLSVC should be suspected in a patient with an abnormally dilated CS. In this case we identified a rare association of PLSVC with a SVASD. TTE with agitated saline contrast injection and CMR are useful diagnostic tools for PLSVC and associated cardiac congenital anomalies, respectively.

Comparison among tomographic radionuclide ventriculography algorithms for computing left and right ventricular normal limits.

BACKGROUND: Various algorithms have been developed to compute right ventricular (RV) and left ventricular (LV) end-diastolic volumes, end-systolic volumes, and ejection fractions (EF) from tomographic radionuclide ventriculography (TRV). The aims of this investigation were to establish sex-specific normal limits, to determine whether different algorithms produce the same normal values, and to compare TRV normal limits vs for magnetic resonance imaging values in the literature. METHODS: Fifty-one healthy volunteers (29 men, 22 women) were studied prospectively. All subjects had normal electrocardiograms and echocardiographic examinations, and underwent both planar radionuclide ventriculography and TRV. Four algorithms were used to process TRV data. RESULTS: Normal limits for most functional parameters differed significantly from one algorithm to another. Volumes were greater in men, but no statistically significant differences were found between men and women for LV EF or RV EF values for any method. Normal LV and RV EF and volumes were largely consistent with the literature for cardiac magnetic resonance imaging. CONCLUSIONS: Ventricular measurements differ significantly among TRV algorithms. Therefore, it is important to apply sex-specific normal limits that are specific to a given TRV algorithm in interpreting LV and RV EF and volume measurements for each patient.

Model dependence of gated blood pool SPECT ventricular function measurements.

BACKGROUND: Calculation differences between various gated blood pool (GBP) single photon emission computed tomography (SPECT) (GBPS) algorithms may arise as a result of different modeling assumptions. Little information has been available thus far regarding differences for right ventricular (RV) function calculations, for which GBPS may be uniquely well suited. METHODS AND RESULTS: Measurements of QBS (Cedars-Sinai Medical Center, Los Angeles, Calif) and BP-SPECT (Columbia University, New York, NY) algorithms were evaluated. QBS and BP-SPECT left ventricular (LV) ejection fraction (EF) correlated strongly with conventional planar-GBP LVEF for 422 patients (r = 0.81 vs r = 0.83). QBS correlated significantly more strongly with BP-SPECT for LVEF than for RVEF (r = 0.80 vs r = 0.41). Both algorithms demonstrated significant gender differences for 31 normal subjects. BP-SPECT normal LVEF (67% +/- 9%) was significantly closer to values in the magnetic resonance imaging (MRI) literature (68% +/- 5%) than QBS (58% +/- 9%), but both algorithms underestimated normal RVEF (52% +/- 7% and 50% +/- 9%) compared with the MRI literature (64% +/- 9%). For 21 patients, QBS correlated similarly to MRI as BP-SPECT for LVEF (r = 0.80 vs r = 0.85) but RVEF correlation was significantly weaker (r = 0.47 vs r = 0.81). For 16 dynamic phantom simulations, QBS LVEF correlated similarly to BP-SPECT (r = 0.81 vs r = 0.91) but QBS RVEF correlation was significantly weaker (r = 0.62 vs r = 0.82). Volumes were lower by QBS than BP-SPECT for all data types. CONCLUSIONS: Both algorithms produced LV parameters that correlated strongly with all forms of image data, but all QBS RV relationships were significantly different from BP-SPECT RV relationships. Differences between the two algorithms were attributed to differences in their underlying ventricular modeling assumptions.

Myocardial blood flow and efficiency in concentric and eccentric left ventricular hypertrophy.

BACKGROUND: It is not clearly understood why concentric left ventricular hypertrophy (increased left ventricular mass and relative wall thickness) is associated with higher cardiovascular risk than eccentric hypertrophy (increased left ventricular mass but normal relative wall thickness). Possible reasons include lower myocardial efficiency or perfusion reserve in concentric than in eccentric hypertrophy. We compared myocardial perfusion reserve and efficiency in normotensive controls and in hypertensive patients with concentric and with eccentric hypertrophy. METHODS: Study subjects comprised 16 patients with hypertension-induced left ventricular hypertrophy and 10 normotensive controls. We measured myocardial perfusion reserve and oxygen consumption by positron emission tomography. We calculated myocardial efficiency by dividing left ventricular minute work by myocardial oxygen consumption. RESULTS: There was no significant difference in myocardial perfusion reserve between patients with concentric (n = 9) as compared to eccentric (n = 7) hypertrophy. However, myocardial perfusion reserve in both patient groups were lower than in controls. Although myocardial efficiency in patients with eccentric hypertrophy and in controls were not different, both values were higher than measurements in patients with concentric hypertrophy (18% +/- 6% v 16% +/- 3% v 13% +/- 4%, eccentric hypertrophy versus controls versus concentric hypertrophy, respectively, P =.04 for both eccentric versus concentric hypertrophy and for controls versus concentric hypertrophy). CONCLUSIONS: Myocardial efficiency but not perfusion reserve is lower in hearts with concentric compared with eccentric left ventricular hypertrophy. This might be an explanation for the higher cardiovascular morbidity and mortality associated with concentric left ventricular hypertrophy.

Correlates of myocardial oxygen demand measured by positron emission tomography in the hypertrophied left ventricle.

BACKGROUND: The aim of this study was to identify the best correlate of myocardial oxygen demand (MVO(2)) in patients with hypertension induced left ventricular hypertrophy (LVH), and to examine whether relationships between these surrogates and MVO(2) differed between patients with LVH and control subjects. METHODS: We measured MVO(2) by positron emission tomography using carbon-11 acetate in 20 patients and 10 normotensive control subjects, and compared the relationships between commonly used surrogates and MVO(2). RESULTS: With the exception of diastolic blood pressure, the same variables correlated with resting MVO(2) in the patients and control subjects. CONCLUSIONS: The best correlate of resting MVO(2) in the patients with hypertension induced LVH was the stress-mass-heart rate product.

Positron emission tomography, echo-doppler, and exercise studies of functional capacity in hypertensive heart disease.

BACKGROUND: This study examines the relationship between functional capacity, left ventricular diastolic function, and myocardial perfusion reserve (MPR) in patients with left ventricular hypertrophy (LVH). METHODS: We studied 16 patients with LVH and 10 controls. Functional capacity was assessed by cardiopulmonary exercise, MPR by positron emission tomography, and left ventricular diastolic function by echo-Doppler. RESULTS: Functional capacity and MPR were significantly lower in the patients. Functional capacity correlated positively with MPR and left ventricular diastolic function. CONCLUSIONS: Diminished functional capacity in patients with hypertension-induced LVH is related to the impairment in MPR and left ventricular diastolic function.

Augmentation of myocardial blood flow in hypertensive heart disease by angiotensin antagonists: a comparison of lisinopril and losartan.

OBJECTIVES: The goal of this study was to compare myocardial perfusion reserve (MPR) before and after long-term treatment with lisinopril and losartan in patients with hypertension and left ventricular hypertrophy (LVH). BACKGROUND: Studies have suggested that treatment with angiotensin-converting enzyme inhibitors (ACEIs) improves MPR in patients with hypertension by potentiating endogenous bradykinins. Because angiotensin receptor blockers (ARBs) lack a direct effect on bradykinins, we hypothesized that they may not improve MPR. METHODS: We measured pre- and post-treatment myocardial blood flow (MBF) by positron emission tomography in 17 patients (lisinopril: 9 patients, losartan: 8 patients) with hypertension and LVH at baseline and after coronary vasodilation with intravenous dipyridamole. In addition, we measured rest and hyperemic blood flow in eight normotensive controls. RESULTS: Post-treatment maximal coronary blood flow and MPR in the lisinopril group increased significantly compared with pretreatment values (3.5 +/- 1.2 vs. 2.6 +/- 1.1 ml/min/g, p = 0.02; 3.7 +/- 1.1 vs. 2.4 +/- 1 ml/min/g, respectively, p = 0.002, respectively). Post-treatment hyperemic flow in the patients treated with lisinopril was not significantly different from corresponding measurements in controls (3.5 +/- 1.2 vs. 3.9 +/- 1 ml/min/g, respectively, p = NS). In the patients treated with losartan, there was no difference between pre- and post-treatment MBF values and MPR. CONCLUSIONS: Myocardial perfusion reserve and maximal coronary flow improved in asymptomatic patients with hypertension-induced LVH after long-term treatment with lisinopril but not with losartan. Thus, ACEIs, but not ARBs, might be effective in repairing the coronary microangiopathy associated with hypertension-induced LVH.