Arterial stiffness assessment in coronary microvascular dysfunction and heart failure with preserved ejection fraction: An initial report from the WISE-CVD continuation study.

Background: Heart failure with preserved ejection fraction (HFpEF) is the most common cardiac complication in patients with coronary microvascular dysfunction (CMD), yet its underlying pathways remain unclear. Aortic pulse-wave velocity (aPWV) is an indicator of large artery stiffness and a predictor for cardiovascular disease. However, aPWV in CMD and HFpEF is not well characterized and may provide understanding of disease progression. Methods: Among participants without obstructive coronary artery disease, we evaluated 51 women with suspected CMD and 20 women and men with evidence of HFpEF. All participants underwent aPWV measurement (SphygmoCor, Atcor Medical) with higher aPWV indicating greater vascular stiffness. Cardiac magnetic resonance imaging (CMRI) assessed left ventricular (LV) ejection fraction, CMD via myocardial perfusion reserve index (MPRI), and ventricular remodeling via LV mass-volume ratio. . Statistical analysis was performed using Wilcoxon rank sum tests, Pearson correlations and linear regression analysis. Results: Compared to the suspected CMD group, the HFpEF participants were older (65 ± 12 vs 56 ± 11 yrs., p = 0.002) had higher BMI (31.0 ± 4.3 vs 27.8 ± 6.7 kg/m2, p = 0.013), higher aPWV (10.5 ± 2.0 vs 8.0 ± 1.6 m/s, p = 0.05) and lower MPRI (1.5 ± 0.3 vs1.8 ± 0.3, p = 0.02), but not remodeling. In a model adjusted for cardiovascular risk factors, the HFpEF group had a lower LVEF (estimate -4.78, p = 0.0437) than the suspected CMD group. Conclusions: HFpEF participants exhibit greater arterial stiffness and lower myocardial perfusion reserve, with lower LVEF albeit not remodeling, compared to suspected CMD participants. These findings suggest arterial stiffness may contribute to progression from CMD to HFpEF. Prospective work is needed and ongoing.

SPECT/PET myocardial perfusion imaging versus coronary CT angiography in patients with known or suspected CAD.

Stress SPECT myocardial perfusion imaging (MPI) is the most commonly utilized stress imaging technique for patients with suspected or known coronary artery disease (CAD) and has a robust evidence base including the support of numerous clinical guidelines. Gated SPECT is a well-established noninvasive imaging modalities that is a core element in evaluation of patients with both acute and stable chest pain syndromes. Over the past decade, PET has become increasingly used for the same applications. By comparison, cardiac computed tomography (CT) is a more recently developed method, providing non-invasive approaches for imaging coronary atherosclerosis and coronary artery stenosis. Non-contrast CT for imaging the extent of coronary artery calcification (CAC), in clinical use since the mid-1990's, has a very extensive evidence base supporting its use in CAD prevention. While contrast-enhanced CT for noninvasive CT coronary angiography (CCTA) is relatively new, it has already developed an extensive base of evidence regarding diagnosing obstructive CAD and more recently evidence has emerged regarding its prognostic value. It is likely that non-contrast CT or CCTA for assessment of extent of atherosclerosis will become an increasing part of mainstream cardiovascular imaging practices as a first line test. In some patients, further ischemia testing with MPI will be required. Similarly, MPI will continue to be widely used as a first-line test, and in some patients, further anatomic definition of atherosclerosis with CT will also be appropriate. This review will provide a synopsis of the available literature on imaging that integrates both CT and MPI in strategies for the assessment of asymptomatic patients for their atherosclerotic coronary disease burden and risk as well as symptomatic patients for diagnosis and guiding management. We propose possible strategies through which imaging might be used to identify asymptomatic candidates for more intensive prevention and risk factor modification strategies as well as symptomatic patients who would benefit from referral to invasive coronary angiography for consideration of revascularization.

Aortic root infection in a prosthetic valve demonstrated by gallium-67 citrate SPECT.

A 70-year-old man presented with 6 weeks of worsening low back pain, fever, sweating, and weight loss with known severe lumbosacral osteoarthritis. His history included CABG in 1992, porcine aortic valve replacement, and permanent pacemaker implantation in 2002. CT of the chest, abdomen, and pelvis did not demonstrate a cause for the symptoms. Blood cultures grew penicillin-sensitive enterococcus and he was referred for evaluation of possible osteodiskitis or epidural abscess. Gallium planar imaging demonstrated increased activity in the lumbar spine, suspicious for the presence of infection, and activity was noted in the mid mediastinum as well. SPECT clearly showed increased Ga-67 activity in the region of the aortic root, suspicious for infection. A perivalvular aortic root abscess was subsequently demonstrated by transesophageal echo. This case illustrates the value of Ga-67 chest SPECT in patients with prosthetic valves for detection of endocarditis.

Effect of dopamine receptor antagonists on cocaine subjective effects: a naturalistic case study.

Schizophrenic patients on neuroleptic medications abuse cocaine and report cocaine-induced euphoria. This study was undertaken to provide better clinical characterization of these phenomena by administering the POMS and a custom-designed questionnaire. A group of heavy cocaine users who were not mentally ill served as the control group. The results clearly suggest that schizophrenic patients report cocaine-induced euphoria and post-use craving despite being treated with therapeutic doses of haloperidol or fluphenazine. The responses of the control group were similar to that of the schizophrenic group except that the latter subjects reported a greater degree of anxiety. These results suggest that blockade of D2 receptors is not sufficient to block cocaine-induced subjective effects in humans.

Lack of evidence for context-dependent cocaine-induced sensitization in humans: preliminary studies.

Cocaine-induced behavioral sensitization is the well-documented phenomenon where repeated doses of cocaine elicit increasingly greater effects on motoric activity in rats. Some observations suggest that behavioral sensitization may provide a model for understanding the mechanisms of drug-craving elicited by environmental triggers or cues. The process of fully validating such an animal model for its ability to detect effective anticraving medicines is a difficult and long-term undertaking. As a first step in that direction, we decided to determine if cocaine can produce conditioned behavioral sensitization in humans using a paradigm fairly similar to that used for rodents. Because humans do not react to cocaine with the pronounced motor activation observed in rodents, we measured a variety of end points, including blood pressure (BP), heart rate (HR), respiratory rate, pupil diameter, hormones (prolactin and cortisol), and subjective responses using the questionnaire for drug-related feelings (QDRF) and the EEG. To mimic the home and test cages used in rodent studies, two rooms were used: a small test chamber and a regular room with a window and furnishings. On day 1 each subject received a drug infusion (either saline or 40 mg cocaine IV) in both locations. On day 2, all subjects received an infusion (saline or 25 mg cocaine IV) in the test chamber. All drug infusions were conducted double blind. The paired group received cocaine on both days in the test chamber. The unpaired group received cocaine in regular room on day 1, and cocaine in the test chamber on day 2.(ABSTRACT TRUNCATED AT 250 WORDS)