Prognostic value of coronary risk factors, exercise capacity and single photon emission computed tomography in liver transplantation candidates: A 5-year follow-up study

BACKGROUND

Although consensus-based guidelines support noninvasive stress testing prior to orthotopic liver transplantation (OLT), the optimal screening strategy for assessment of coronary artery disease in patients with end-stage liver disease (ESLD) is unclear. This study sought to determine the relative predictive value of coronary risk factors, functional capacity, and single photon emission computed tomography (SPECT) on major adverse cardiovascular events and all-cause mortality in liver transplantation candidates.

METHODS

Prior to listing for transplantation, 404 consecutive ESLD patients were referred to a University hospital for cardiovascular (CV) risk stratification. All subjects met at least one of the following criteria: inability to perform > 4 METs by history (62%), insulin-treated diabetes mellitus (53%), serum creatinine > 1.72 mg/dL (8%), history of MI, PCI or CABG (5%), stable angina (3%), cerebrovascular disease (1%), peripheral vascular disease (1%). Subjects underwent Technetium-99m SPECT with multislice coronary artery calcium scoring (CACS) using exercise treadmill or standard adenosine stress in those unable to achieve 85% maximal heart rate (Siemens Symbia T16). Abnormal perfusion was defined as a summed stress score (SSS) ≥ 4.

RESULTS

Of the 404 patients, 158 (age 59 ± 9 years; male 68%) subsequently underwent transplantation and were included in the primary analysis. Of those, 50 (32%) died after a mean duration follow-up of 5.4 years (maximal 10.9 years). Most deaths (78%) were attributed to noncardiovascular causes (malignancy, sepsis, renal failure). Of the 32 subjects with abnormal perfusion (20%), nine (6%) had a high-risk perfusion abnormality defined as a total perfusion defect size (PDS) ≥ 15% and/or an ischemic PDS ≥ 10%. Kaplan-Meier survival curves demonstrated abnormal perfusion was associated with increased CV mortality (generalized Wilcoxon, P = 0.014) but not all-cause death. Subjects with both abnormal perfusion and an inability to exercise > 4 METs had the lowest survival from all-cause death (P = 0.038). Abnormal perfusion was a strong independent predictor of CV death (adjusted HR 4.2; 95% CI 1.4 to 12.3; P = 0.019) and MACE (adjusted HR 7.7; 95% CI 1.4 to 42.4; P = 0.018) in a multivariate Cox regression model that included age, sex, diabetes, smoking and the ability to exercise > 4 METs. There was no association between CACS and the extent of perfusion abnormality, nor with outcomes.

CONCLUSIONS

Most deaths following OLT are noncardiovascular. Nonetheless, abnormal perfusion is prevalent in this high-risk population and a stronger predictor of cardiovascular morbidity and mortality than functional status. A combined assessment of functional status and myocardial perfusion identifies those at highest risk of all-cause death. (Exercise Capacity and Single Photon Emission Computed Tomography in Liver Transplantation Candidates [ExSPECT]; ClinicalTrials.gov Identifier: NCT03864497).

Myocardial Infarction and Persistent Angina With No Obstructive Coronary Artery Disease

Women with myocardial infarction with no obstructive coronary artery disease (MINOCA) are increasingly recognized. Women with MINOCA are at high risk for major adverse cardiovascular events. In this case, we focus on the importance of early identification and management of MINOCA to improve patients’ angina and related quality of life. (Level of Difficulty: Beginner.)

Workplace Violence in Chinese Hospitals: The Effects of Healthcare Disturbance on the Psychological Well-Being of Chinese Healthcare Workers

Healthcare disturbance is a form of workplace violence against healthcare workers perpetrated by patients, their relatives, and gangs hired by them. It is a prevalent phenomenon in China, where evidence suggests that it impacts on the job satisfaction of healthcare workers. This study aims to examine the relationship between healthcare disturbance, surface acting as a response to emotional labour, and depressive symptoms in Chinese healthcare workers. The study adopted a cross-sectional design and used an online survey methodology. Data were collected from 418 doctors and nurses from one hospital in China. The results showed that frequency of healthcare disturbance was positively related to surface acting and depressive symptoms, respectively; surface acting was also positively related to depression, while deep acting showed no effect on symptoms of depression. Furthermore, surface acting in response to emotional labour mediated the relationship between healthcare disturbance and depressive symptoms. The results highlight the importance of preventing healthcare disturbance and of training healthcare staff in strategies for managing emotional demands in reducing depressive symptoms in Chinese healthcare staff.

Adenosine vs Regadenoson Pharmacologic Stress Differs in Women with Suspected Coronary Microvascular Dysfunction: A Report from the Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD) Study

Background

Stress cardiac magnetic resonance (CMR) imaging with myocardial perfusion reserve index (MPRI) measurement has emerged as a noninvasive method for assessing coronary microvascular dysfunction (CMD) in the absence of obstructive coronary artery disease (CAD). Pharmacologic stress with adenosine or regadenoson is typically used with comparable coronary vasodilation, but higher unadjusted MPRI has been reported with regadenoson in healthy men. This difference has not been assessed in symptomatic or healthy women.

Methods

In a prospective cohort study, 139 symptomatic women with suspected CMD and no obstructive CAD underwent stress CMR and invasive coronary flow reserve (CFR) testing. Adenosine was the default vasodilator (n=99), while regadenoson was used if history of asthma or prior adenosine intolerance (n=40). Stress CMR was also performed in 40 age-matched healthy controls using adenosine (n=20) and regadenoson (n=20). Unpaired t-tests and analysis of covariance were performed to compare MPRI with adenosine and regadenoson in the symptomatic women and healthy controls.

Results

Compared to regadenoson cases, adenosine cases had lower invasive CFR (2.64±0.62 vs 2.94±0.68, p=0.01) and pharmacologic heart rate change (28±16 vs 38±15 bpm, p=0.0008). Unadjusted MPRI was lower in the adenosine compared to regadenoson cases (1.73±0.38 vs 2.27±0.59, p<0.0001). When adjusted for heart rate, rate-pressure-product, and invasive CFR, MPRI remained lower in the adenosine cases (p<0.0001). Invasive CFR to adenosine correlated with adenosine MPRI (r 0.17, p=0.02) but not regadenoson MPRI (r -0.14, p=0.19). There was no significant difference in MPRI in the controls who received adenosine vs regadenoson (2.27±0.33 vs 2.38±0.44, p=0.36).

Conclusion

In women undergoing stress CMR for suspected CMD, those who received adenosine had lower MPRI than those who received regadenoson. However, there were no differences in MPRI in the healthy controls. These findings suggest there may be physiologic differences in adenosine and regadenoson response in the coronary microcirculation of symptomatic women.

Results of Serial Myocardial Perfusion Imaging in End-Stage Renal Disease

For patients awaiting renal transplantation, there is guideline consensus on the need for ischemia testing but no agreement on the frequency of repeat testing. Moreover, there are no data in this population evaluating changes in ischemia assessed with serial myocardial perfusion imaging. Consecutive patients (n = 649) with end-stage renal disease (ESRD) were referred for cardiovascular risk stratification before renal transplantation between 2007 and 2013. Of these, 151 patients (54 ± 9 years) underwent 2 stress-rest technetium-99^m single-photon emission computed tomographic (SPECT) studies with CT attenuation correction in accordance with regional guidelines, which recommend repeat imaging in high-risk subjects who have not undergone renal transplantation within 3 years. An abnormal perfusion result was defined as a summed stress score ≥4. The median interval between imaging was 39 months. At baseline, 28% of patients (42/151) had abnormal SPECT perfusion, half with a fixed defect. Nine subjects (6%) underwent revascularization between SPECT studies after the baseline imaging demonstrated an ischemic perfusion defect size affecting ≥10% of the myocardium. On repeat imaging, 60% (25/42) had abnormal perfusion. In the 72% (109 of 151) with normal baseline SPECT perfusion, 19% (21/109) demonstrated new ischemia at follow-up and 3% (3/109) had an ischemic perfusion defect size ≥10%. The development of new-onset ischemia was associated with systolic hypertension (p = 0.015), serum phosphate (p = 0.043), and Agatston score (p = 0.002), but not diabetes (p = 0.12). In conclusion, there is a high frequency of new-onset ischemia in patients with ESRD awaiting renal transplantation. Further study is needed to define the optimal timing for repeat stress testing.

Comparison of the Coronary Artery Calcium Score and Number of Calcified Coronary Plaques for Predicting Patient Mortality Risk

Multiple coronary artery calcium (CAC) parameters have recently been proposed to improve risk prediction in patients with intermediate clinical risk based on CAC scoring, but outcome data that assess these variables are relatively sparse. We analyzed data from 11,633 consecutive asymptomatic patients undergoing CAC scanning that were followed for 8.8 ± 3.5 years for all-cause mortality (ACM). The patients who had coronary artery calcification were grouped by the number of calcified coronary plaques: 0, 1 to 5, 6 to 20, and >20 plaques. We examined the independent prognostic value of plaque number and its synergistic prognostic value when added to the CAC score. We observed a stepwise increase in ACM with increasing plaque number. In patients with a CAC score of 1 to 99, 6 plaques or more were associated with increased mortality. In patients with CAC scores of 100 to 399, there was a stepwise increase in ACM with increasing plaque number. For CAC >400, the risk of ACM was high regardless of plaque number. After risk adjustment, the number of plaques was a significant predictor of risk for ACM in the patients with an intermediate CAC score. In these patients, additional consideration of plaque number improved net reclassification improvement for predicting ACM by 29%. In conclusion, the number of calcified plaques adds to risk stratification beyond the CAC score in patients with intermediate CAC scores.

Typical angina is associated with greater coronary endothelial dysfunction but not abnormal vasodilatory reserve

Background

Typical angina (TA) is defined as substernal chest pain precipitated by physical exertion or emotional stress and relieved with rest or nitroglycerin. Women and elderly patients are usually have atypical symptoms both at rest and during stress, often in the setting of nonobstructive coronary artery disease (CAD).

Hypothesis

To further understand this, we performed subgroup analysis comparing subjects who presented with TA vs nontypical angina (NTA) using baseline data of patients with nonobstructive CAD and coronary microvascular dysfunction (CMD) enrolled in a clinical trial.

Methods

155 subjects from the RWISE study were divided into 2 groups based on angina characteristics: TA (defined as above) and NTA (angina that does not meet criteria for TA). Coronary reactivity testing (responses to adenosine, acetylcholine, and nitroglycerin), cardiac magnetic resonance–determined myocardial perfusion reserve index (MPRI), baseline Seattle Angina Questionnaire (SAQ), and Duke Activity Status Index (DASI) scores were evaluated.

Results

The mean age was 55 ± 10 years; Overall, 30% of subjects had TA. Baseline shortness of breath, invasively assessed acetylcholine‐mediated coronary endothelial function, and SAQ score were worse in the TA group (all P < 0.05), whereas adenosine‐mediated coronary flow reserve, MPRI, and DASI score were similar to the NTA group.

Conclusions

Among subjects with CMD and no obstructive CAD, those with TA had more angina pectoris, shortness of breath, and worse quality of life, as well as more severe coronary endothelial dysfunction. Typical angina in the setting of CMD is associated with worse symptom burden and coronary endothelial dysfunction. These results indicate that TA CMD subjects represent a relatively new CAD phenotype for future study and treatment trials.

Abstract 108: Impact of a Wireless "Wearable" Device to Measure Daily Activity in Patients With Coronary Microvascular Disease Treated With Late Na Channel Inhibition (ranolazine): a Substudy of the RWISE Clinical Trial

Background: Since late Na channel inhibition (ranolazine) improves exercise duration in the stress laboratory among angina patients, we questioned if this benefit would translate to impact step-count during daily life assessed by a "wearable" device.

Methods: We conducted a pilot substudy within a randomized, double-blinded, placebo-controlled, cross-over trial of subjects with angina, non-obstructive coronary artery disease and coronary microvascular dysfunction. Ranolazine was administered (500-1000mg BID for 2 weeks). The outcome of interest was difference in Fitbit Flex daily step-count during weeks 2 of ranolazine or placebo treatment. Other outcomes included angina, quality of life, ischemia, diastolic function.

Results: 30 subjects were analyzed. Overall, late Na channel inhibition reduced daily step-count vs. placebo (5757 +/- 3076 vs. 6593 +/- 3393, p=0.01) and did not improve angina. However, among those with improved angina (SAQ-7 improvement), a direct correlation with increased step-count (0.42, p=0.02) was observed, most due to typical angina (0.57, p=0.05) (Fig).

Conclusions: We report the "first" data set from a wearable monitor to measure step-count in a controlled late Na channel inhibition trial. Our results suggest short-term late Na channel inhibition (ranolazine) does not increase step-count during daily life.

Cold Pressor Stress Cardiac Magnetic Resonance Myocardial Flow Reserve Is Not Useful for Detection of Coronary Endothelial Dysfunction in Women with Signs and Symptoms of Ischemia and No Obstructive CAD

Background

Coronary endothelial function testing using acetylcholine is not routinely available, while non-pharmacological cold pressor testing (CPT) is considered an endothelial stressor. Noninvasive cardiac magnetic resonance imaging (CMRI) myocardial perfusion reserve index (MPRI) can detect coronary microvascular dysfunction (CMD). We evaluated if CPT stress CMRI MPRI could detect invasive coronary endothelial dysfunction.

Methods

Coronary reactivity testing was performed in 189 women with symptoms and signs of ischemic but no obstructive coronary artery disease as previously described plus CPT stress. Subjects also underwent pharmacologic and CPT stress during CMRI (1.5 T). Statistical analysis comparing CPT MPRI between groups was performed by Welch`s t-test and Mann-Whitney where appropriate. Anderson-Darling test and Levene test were considered to verify the normality and homogeneity of variances assumptions. Correlation analyses between CPT MPRI and both invasive and noninvasive measures of CMD were performed using Spearman correlation.

Results

While CPT MPRI correlated with pharmacological stress MPRI, it did not correlate with invasive measures of CMD including invasively measured responses to intracoronary (IC) adenosine, IC acetylcholine, CPT, or IC nitroglycerin. Additionally CPT MPRI was not significantly different between subjects with normal compared to abnormal pharm stress MPRI or normal compared to abnormal invasive CMD parameters.

Conclusion

Despite correlation with pharmacological stress MPRI, non-invasive CPT MPRI does not appear to be useful for detecting CMD in symptomatic women.

Prognostic Utility of Calcium Scoring as an Adjunct to Stress Myocardial Perfusion Scintigraphy in End-Stage Renal Disease

Coronary artery calcium score (CACS) is a strong predictor of adverse cardiovascular events in the general population. Recent data confirm the prognostic utility of single-photon emission computed tomographic (SPECT) imaging in end-stage renal disease, but whether performing CACS as part of hybrid imaging improves risk prediction in this population is unclear. Consecutive patients (n = 284) were identified after referral to a university hospital for cardiovascular risk stratification in assessment for renal transplantation. Participants underwent technetium-99m SPECT imaging after exercise or standard adenosine stress in those unable to achieve 85% maximal heart rate; multislice CACS was also performed (Siemens Symbia T16, Siemens, Erlangen, Germany). Subjects with known coronary artery disease (n = 88) and those who underwent early revascularization (n = 2) were excluded. The primary outcome was a composite of death or first myocardial infarction. An abnormal SPECT perfusion result was seen in 22% (43 of 194) of subjects, whereas 45% (87 of 194) had at least moderate CACS (>100 U). The frequency of abnormal perfusion (summed stress score ≥4) increased with increasing CACS severity (p = 0.049). There were a total of 15 events (8 deaths, and 7 myocardial infarctions) after a median duration of 18 months (maximum follow-up 3.4 years). Univariate analysis showed diabetes mellitus (Hazard ratio [HR] 3.30, 95% CI 1.14 to 9.54; p = 0.028), abnormal perfusion on SPECT (HR 5.32, 95% CI 1.84 to 15.35; p = 0.002), and moderate-to-severe CACS (HR 3.55, 95% CI 1.11 to 11.35; p = 0.032) were all associated with the primary outcome. In a multivariate model, abnormal perfusion on SPECT (HR 4.18, 95% CI 1.43 to 12.27; p = 0.009), but not moderate-to-severe CACS (HR 2.50, 95% CI 0.76 to 8.20; p = 0.130), independently predicted all-cause death or myocardial infarction. The prognostic value of CACS was not incremental to clinical and SPECT perfusion data (global chi-square change = 2.52, p = 0.112). In conclusion, a perfusion defect on SPECT is an independent predictor of adverse outcome in potential renal transplant candidates regardless of the CACS. The use of CACS as an adjunct to SPECT perfusion data does not provide incremental prognostic utility for the prediction of mortality and nonfatal myocardial infarction in end-stage renal disease.

Demons versus Level-Set motion registration for coronary 18F-sodium fluoride PET

Ruptured coronary atherosclerotic plaques commonly cause acute myocardial infarction. It has been recently shown that active microcalcification in the coronary arteries, one of the features that characterizes vulnerable plaques at risk of rupture, can be imaged using cardiac gated ¹⁸F-sodium fluoride (¹⁸F-NaF) PET. We have shown in previous work that a motion correction technique applied to cardiac-gated ¹⁸F-NaF PET images can enhance image quality and improve uptake estimates. In this study, we further investigated the applicability of different algorithms for registration of the coronary artery PET images. In particular, we aimed to compare demons vs. level-set nonlinear registration techniques applied for the correction of cardiac motion in coronary ¹⁸F-NaF PET. To this end, fifteen patients underwent ¹⁸F-NaF PET and prospective coronary CT angiography (CCTA). PET data were reconstructed in 10 ECG gated bins; subsequently these gated bins were registered using demons and level-set methods guided by the extracted coronary arteries from CCTA, to eliminate the effect of cardiac motion on PET images. Noise levels, target-to-background ratios (TBR) and global motion were compared to assess image quality. Compared to the reference standard of using only diastolic PET image (25% of the counts from PET acquisition), cardiac motion registration using either level-set or demons techniques almost halved image noise due to the use of counts from the full PET acquisition and increased TBR difference between ¹⁸F-NaF positive and negative lesions. The demons method produces smoother deformation fields, exhibiting no singularities (which reflects how physically plausible the registration deformation is), as compared to the level-set method, which presents between 4 and 8% of singularities, depending on the coronary artery considered. In conclusion, the demons method produces smoother motion fields as compared to the level-set method, with a motion that is physiologically plausible. Therefore, level-set technique will likely require additional post-processing steps. On the other hand, the observed TBR increases were the highest for the level-set technique. Further investigations of the optimal registration technique of this novel coronary PET imaging technique are warranted.

Motion Correction of 18F-NaF PET for Imaging Coronary Atherosclerotic Plaques

Ruptured coronary atherosclerotic plaques commonly cause acute myocardial infarction. It has recently been shown that active microcalcification in the coronary arteries, one of the features that characterizes vulnerable plaques at risk of rupture, can be imaged using (18)F-NaF PET. We aimed to determine whether a motion correction technique applied to gated (18)F-NaF PET images could enhance image quality and improve uptake estimates.

METHODS

Seventeen patients with myocardial infarction (n = 7) or stable angina (n = 10) underwent (18)F-NaF PET and prospective coronary CT angiography. PET data were reconstructed in 4 different ways: the first was 1 gated bin (end-diastolic phase with 25% of the counts), the second was 4 gated bins (consecutive 25% segments), the third was 10 gated bins (consecutive 10% segments), and the fourth was ungated. Subsequently, with data from either 4 or 10 bins, gated PET images were registered using a local, nonlinear motion correction method guided by the extracted coronary arteries from CT angiography. Global noise levels and target-to-background ratios (TBR) defined on manually delineated coronary plaque lesions were compared to assess image quality and uptake estimates.

RESULTS

Compared with the reference standard of using only 1 bin of PET data, motion correction using 10 bins of PET data reduced image noise by 46% (P < 0.0001). TBR in positive lesions for 10-bin motion-corrected data was 11% higher than for 1-bin data (1.98 [interquartile range, 1.70-2.37] vs. 1.78 [1.58-2.16], P = 0.0027) and 33% higher than for ungated data (1.98 [1.70-2.37] vs. 1.49 [1.39-1.88], P < 0.0001).

CONCLUSION

Motion correction of gated (18)F-NaF PET/coronary CT angiography is feasible, reduces image noise, and increases TBR. This improvement may allow more reliable identification of vulnerable coronary artery plaques using (18)F-NaF PET.

Diastolic dysfunction in women with signs and symptoms of ischemia in the absence of obstructive coronary artery disease: a hypothesis-generating study

BACKGROUND

Angina, in the absence of obstructive coronary artery disease, is more common in women, is associated with adverse cardiovascular morbidity and mortality, and is a major burden to the healthcare system. Although advancements have been made to understand the mechanistic underpinning of this disease, the functional consequence remains unclear.

METHODS AND RESULTS

Cardiac magnetic resonance imaging was performed to assess left ventricular function in 20 women with signs and symptoms of ischemia, but no obstructive coronary artery disease (cases), and 15 age- and body mass index-matched reference controls. Functional imaging included standard cinematic imaging to assess left ventricular morphology and global function, along with tissue tagging to assess left ventricular tissue deformation. Systolic function was preserved in both cases and controls, with no differences in ejection fraction (mean±SE: 63.1±8% versus 65±2%), circumferential strain (-20.7±0.6% versus -21.9±0.5%), or systolic circumferential strain rate (-105.9±6.1% versus -109.0±3.8% per second). In contrast, we observed significant differences between cases and controls in diastolic function, as demonstrated by reductions in both diastolic circumferential strain rate (153.8±8.9% versus 191.4±8.9% per second; P<0.05) and peak rate of left ventricular untwisting (-99.4±8.0° versus -129.4±12.8° per second; P<0.05).

CONCLUSIONS

Diastolic function is impaired in women with signs and symptoms of ischemia in the absence of coronary artery disease, as assessed by cardiac magnetic resonance tissue tagging. These results are hypothesis-generating. Larger studies are needed to define the exact mechanism(s) responsible and to establish viable treatment strategies.

Fluorodeoxyglucose positron emission tomography-computed tomography: a novel approach for the diagnosis of cholecystitis for equivocal diagnoses after ultrasound imaging

Although hepatobiliary iminodiacetic acid (HIDA) scan is often used when the diagnosis of cholecystitis remains questionable after ultrasound, it carries a high false-positive rate and has other limitations. Fluorodeoxyglucose positron emission tomography-computed tomography (18FDG PET-CT) has recently gained enthusiasm for its ability to detect infection and inflammation. In this study, we evaluate the accuracy of 18FDG PET-CT in diagnosing cholecystitis. Nineteen patients with suspected cholecystitis (Group S) underwent PET-CT and 10 had positive PET-CT findings. Of these 10, nine underwent cholecystectomies, and pathology confirmed cholecystitis in all nine. One patient was managed nonoperatively as a result of multiple comorbidities. Of the nine patients with negative PET-CT, six were managed nonoperatively, safely discharged, and had no readmissions at 3-month follow-up. The other three patients with negative PET-CT underwent cholecystectomies, and two showed no cholecystitis on pathology. The third had mild to moderate cholecystitis with focal mucosal erosion/ulceration without gallbladder wall thickening on pathology. 18FDG PET-CT detected gallbladder inflammation in all but one patient with pathology-proven cholecystitis with a sensitivity and specificity of 0.90 and 1.00, respectively. 18FDG-PET-CT appears to be a promising, rapid, direct, and accurate test in diagnosing cholecystitis and could replace HIDA scan in cases that remain equivocal after ultrasound.

Fluorodeoxyglucose Positron Emission Tomography–Computed Tomography: A Novel Approach for the Diagnosis of Cholecystitis for Equivocal Diagnoses after Ultrasound Imaging

Although hepatobiliary iminodiacetic acid (HIDA) scan is often used when the diagnosis of cholecystitis remains questionable after ultrasound, it carries a high false-positive rate and has other limitations. Fluorodeoxyglucose positron emission tomography–computed tomography (18FDG PET-CT) has recently gained enthusiasm for its ability to detect infection and inflammation. In this study, we evaluate the accuracy of 18FDG PET-CT in diagnosing cholecystitis. Nineteen patients with suspected cholecystitis (Group S) underwent PET-CT and 10 had positive PET-CT findings. Of these 10, nine underwent cholecystectomies, and pathology confirmed cholecystitis in all nine. One patient was managed nonoperatively as a result of multiple comorbidities. Of the nine patients with negative PET-CT, six were managed nonoperatively, safely discharged, and had no readmissions at 3-month follow-up. The other three patients with negative PET-CT underwent cholecystectomies, and two showed no cholecystitis on pathology. The third had mild to moderate cholecystitis with focal mucosal erosion/ulceration without gallbladder wall thickening on pathology. 18FDG PET-CT detected gallbladder inflammation in all but one patient with pathology-proven cholecystitis with a sensitivity and specificity of 0.90 and 1.00, respectively. 18FDG-PET-CT appears to be a promising, rapid, direct, and accurate test in diagnosing cholecystitis and could replace HIDA scan in cases that remain equivocal after ultrasound.

Comparative value of coronary artery calcium and multiple blood biomarkers for prognostication of cardiovascular events

The value of coronary artery calcium (CAC) scoring versus multiple biomarkers in increasing risk prediction for cardiovascular disease (CVD) remains unknown. The study group consisted of 1,286 asymptomatic participants (mean ± SD 59 ± 8 years old) with no known coronary heart disease. Mean follow-up time was 4.1 ± 0.4 years with the primary outcome of combined CVD (cardiac death, myocardial infarction, stroke, and late target vessel revascularization). CAC was calculated by the method of Agatston. Biomarkers measured were C-reactive protein, interleukin-6, myeloperoxidase, B-type natriuretic peptide, and plasminogen activator-1. During follow-up 35 participants developed CVD events including cardiac deaths (6%), myocardial infarction (23%), strokes (17%), and late revascularizations (54%). In Cox proportional-hazards models adjusted for Framingham Risk Score (FRS), presence of log CAC beyond FRS was associated with increased hazards for CVD events (hazard ratio 1.7, 95% confidence interval [CI] 1.4 to 2.0, p <0.001). Multiple biomarkers score was also associated with increased risk beyond FRS (hazard ratio 2.1, p = 0.02) per 1-U increase in score; however, the c-statistic did not increase significantly (0.75, 95% CI 0.68 to 0.84, p = 0.32). The c-statistic increased when log CAC was incorporated into FRS without or with multiple biomarkers score (c-statistic 0.84, p = 0.003 and p = 0.008 respectively). Addition of CAC to risk factors showed significant reclassification (net reclassification improvement 0.35 (95% CI 0.11 to 0.58, p = 0.007; integrated discrimination index 0.076, p = 0.0001), whereas addition of multiple biomarkers score did not show significant reclassification. In conclusion, in this study of asymptomatic subjects without known CVD, addition of CAC but not biomarkers substantially improved risk reclassification for future CVD events beyond traditional risk factors.

Entrapment of mitral chordal apparatus causing early postoperative dysfunction of a St. Jude mitral prosthesis

Preservation of subvalvular apparatus is increasingly performed during mitral valve replacement. We describe a case of early postoperative St. Jude mitral valve dysfunction as a result of chordal entrapment.

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)