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INSIDE THIS ISSUE OF JACC
Inside This Issue of JACC
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Pharmacologic Studies
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Long-Term Safety of Ranolazine.
Ranolazine, a novel anti-anginal agent, has shown good efficacy for relief of symptoms, but there is little data on long-term safety. Koren and colleagues followed almost 800 patients receiving open-label ranolazine for 2 years. No patients dropped out due to electrocardiographic abnormalities. The 2-year survival of 94.4% compares favorably with an estimated survival of 90% based on their Duke Treadmill Scores. This nonrandomized, nonblinded study helps to alleviate some concerns regarding the safety of ranolazine. See page 1027.
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Pharmacologic Studies
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Atorvastatin Improves Platelet Inhibition Compared to Ezetimibe Combination Therapy.
Whereas the clinical benefits of statins are well known, there remains debate as to the importance of low-density lipoprotien (LDL) lowering versus pleiotropic effects. Piorkowski and colleagues randomized 50 patients to either atorvastatin 40 mg daily or atorvastatin 10 mg plus ezetimibe and measured platelet reactivity at baseline and after 4 weeks. All patients recieved combination therapy with clopidogrel and aspirin. The effects on the cholesterol profile were similar, but high-dose atorvastatin resulted in significant improvements in measures of platelet reactivity compared with baseline and with combination therapy. This small study suggests that the pleiotropic, rather than the LDL-lowering, effects of high-dose atorvastatin result in improved platelet inhibition. See page 1035. See figure.
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Cardiac Imaging
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Integrated SPECT/CT Device Compared With Coronary Angiography.
Hybrid single-photon emission computed tomography (SPECT)/CT devices offer the potential to combine the prognostic value of nuclear perfusion with the anatomic information from CT angiography in one study. Furthermore, the attenuation information from the CT can be used to increase the specificity of the perfusion data. Rispler and colleagues compared SPECT/CT with conventional coronary angiography in 56 patients. Twenty-three percent of coronary segments had to be excluded, mostly because of motion artifact affecting the CT images. Compared to CT alone, the integrated SPECT/CT improved the specificity from 63% to 95% and the positive predictive value from 33% to 77%. This study demonstrates that combining SPECT with CT angiography can substantially improve specificity and positive predictive value. See page 1059.
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Heart Failure and BNP
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Clues to the BNP Paradox.
One of the paradoxes of heart failure physiology is why patients with elevated B-type natriuretic peptide (BNP) levels seem to not have the beneficial effects of BNP on reducing congestion and edema. Liang and colleagues studied plasma from 5 patients with congestive heart failure and found that most of the circulating BNP is actually the uncleaved proBNP. In cell culture assays, this proBNP is 6 to 8 times less physiologically active than BNP. They hypothesize that the increased production of proBNP may overwhelm the ability of cardiac myocytes to process it to the mature peptide, thereby resulting in the release of significant amounts of the less physiologically active proBNP. See page 1071. See figure.
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Heart Rhythm Disorders
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LQTS Risk Reduced During Pregnancy, Higher in Postpartum Period.
Little is known about the risks of pregnancy for females with long QT syndrome (LQTS). Seth and colleagues studied the risk of experiencing an adverse cardiac event, including syncope, aborted cardiac arrest, and sudden death, during and after pregnancy in almost 400 women. During pregnancy, the risk of an adverse event was only one-quarter of the pre-pregnancy risk. However, the risk was almost 3 times higher in the 9 months after delivery. The risks were higher for subjects with the LQT2 genotype and were reduced by beta-blockers. This study suggests that pregnancy is safe for women with LQTS but there is a need for increased vigilance during the postpartum period. See page 1092. See figure.
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Pharmacologic Studies
Pharmacologic Studies
