William Hiser

Inhibition of carotid artery neointimal formation with intravenous microbubbles

Because therapeutic gene products such as synthetic antisense oligodeoxynucleotides (ODN) bind to albumin-coated microbubbles, we sought to determine whether IV perfluorocarbon-exposed sonicated dextrose albumin (PESDA) microbubbles could target their delivery to the carotid artery following balloon injury. In 5 pigs, the concentration of ODN taken up within the carotid vascular wall was found to be significantly increased when the IV antisense (ODN) was administered bound to PESDA (ODN-PESDA), and while transcutaneous low-frequency (20 kHz) ultrasound was applied over the carotid artery. Based on these results, a chronic model was then developed, in which 21 pigs received either IV ODN-PESDA, ODN alone, or control, following carotid balloon injury. At 30 days following balloon injury, percent area stenosis was only 8 +/- 2% in the ODN-PESDA groups compared to 19 +/- 8% and 28 +/- 3% in the other groups (p < 0.01). IV PESDA may be a method of noninvasively targeting the delivery of therapeutic genes.

Comparison of clinical and morphologic cardiac findings in patients having cardiac transplantation for ischemic cardiomyopathy, idiopathic dilated cardiomyopathy, and dilated hypertrophic cardiomyopathy.

This article compares intergroup and intragroup clinical and morphologic findings in patients with ischemic cardiomyopathy (IC), idiopathic dilated cardiomyopathy (IDC), and dilated hypertrophic cardiomyopathy (HC) undergoing cardiac transplantation (CT). Few previous publications have described findings in native hearts explanted at the time of CT. The explanted heart in 92 patients having CT was examined in uniform manner with particular attention to the sizes of the ventricular cavities and the presence of and extent of ventricular scarring. Of the 92 hearts examined, 47 had IC, 35 had IDC, and 10 had dilated HC. Although considerable degrees of intragroup variation occurred, the mean degree of left ventricular dilatation was similar among the patients with IC, IDC, and dilated HC. All patients with IC had left ventricular free wall scarring more extensive than that involving the ventricular septum, but the intragroup variation in the amounts of scarring was considerable. Nine of the 10 patients with dilated HC also had ventricular wall scarring, but it was more extensive in the ventricular septum than in the left ventricular free wall and involvement of the right ventricular wall also was present. Eight (23%) of the 35 IDC patients also had grossly visible ventricular scars but they were small and only 1 of the 8 had coronary narrowing and that was not in the distribution of the scarring. Narrowing of 1 or more epicardial coronary arteries >75% in cross-sectional area by plaque was present in all 47 IC patients, in 8 of the 35 IDC patients (7 had no ventricular scars), and in none of the 10 dilated HC patients. Coronary angiography was the major clinical tool allowing separation of the IC, IDC, and HC patients. Coronary angiography did not detect narrowing in any of the 8 patients with IDC who were found to have coronary narrowing on anatomic study. Thus, among patients with IC, IDC, and dilated HC having CT, distinctive anatomic features allow separation of patients with IC, IDC, and dilated HC, but within each group considerable variation in left ventricular cavity size and extent of ventricular scarring occurs.

Outcomes of Patients Admitted for Observation of Chest Pain

BACKGROUND Low-risk chest pain is a common cause of hospital admission; however, to our knowledge, there are no guidelines regarding the appropriate use of stress testing in such cases. METHODS We performed a retrospective cohort study of patients 21 years and older who were admitted to our tertiary care center with chest pain in 2007 and 2008. Using electronic records and chart review, we sought (1) to identify differences in the use of stress testing based on patient demographics and comorbidities, pretest probability of coronary artery disease, and house staff coverage and (2) to describe the results of stress testing and patient outcomes, including revascularization procedures and 30-day readmissions for myocardial infarction. RESULTS Of 2107 patients, 1474 (69.9%) underwent stress tests, and the results were abnormal in 184 patients (12.5%). Within 30 days, 22 patients (11.6%) with abnormal test results underwent cardiac catheterization, 9 (4.7%) underwent revascularization, and 2 (1.1%) were readmitted for myocardial infarction. In a multivariable model, stress test ordering was positively associated with age younger than 70 years (RR [relative risk], 1.12; 95% CI, 1.02-1.23), private insurance (vs Medicare/Medicaid: RR, 1.19; 95% CI, 1.11-1.27), and no house staff coverage (RR, 1.39; 95% CI, 1.28-1.50). Of patients with low (<10%) pretest probability, 68.0% underwent stress testing, but only 4.5% of these had abnormal test results. CONCLUSIONS Most patients who are admitted with low-risk chest pain undergo stress testing, regardless of pretest probability, but abnormal test results are uncommon and rarely acted on. Ordering stress tests based on pretest probability could improve efficiency without endangering patients.

Allometric model improves scaling of left atrial size in obese population: The use of body weight containing variables is challenged

Background: Scaling left atrial (LA) size remains a challenge. An allometric model using body weight (BW) as scaling variable was recently proposed. We sought to examine the performance of this model in an obese population. Methods: A total of 266 consecutive overweight (110) and obese subjects (class I, II, and III obese 81, 47, and 28, respectively) were studied; 46 normal subjects with normal body mass index (BMI) served as controls. LA dimension (LAD) was scaled to BW, body surface area (BSA), BMI and height, respectively, using both isometric and allometric models. Results: There were no significant differences in age, gender, or height among the five groups. The prevalence of comorbid conditions, wall thickness, E/E’ and LAD measures increased significantly with increasing weight group (P < 0.01–0.001). With the isometric model, LAD corrected by BW, BSA, and BMI significantly but paradoxically decreased across the groups (P < 0.05–0.001). With the allometric model, LAD overcorrection by BM, BSA, and BMI was improved, but remained in the class III obese group. In contrast, scaling LAD to height showed significant and graded increase across the five groups in accordance with the increases of BMI, E/E’ and the prevalence of comorbid conditions. Conclusion: All isometric models that correct LAD by BW or BW containing variables underestimate LA size in overweight and obese groups. The allometric model using height provides more consistent results and should be preferred to models using BW or BW containing variables in scaling LAD in obese population. (Echocardiography 2011;28:253‐260)

Fatal pheochromocytoma crisis precipitated by dobutamine stress echocardiography

The safety of dobutamine stress echocardiography (DSE) has been demonstrated in multiple studies with a major complication rate of <1%. Specifically, ventricular tachycardia during DSE has a reported incidence of 0.3%, and has been bound to be of no prognostic significance in patients without obstructive coronary artery disease. We report a unique case of fatal pheochromocytoma crisis precipitated by DSE in a patient with heretofore unknown adrenal disease. We are once again reminded that no diagnostic modality is absolutely without risk; however, minimal they might be.

Inpatient Echocardiography Use for Common Cardiovascular Conditions

A recent analysis of the Nationwide Inpatient Sample (NIS) found that inpatient echocardiography was associated with improved survival but was used only infrequently in clinical situations where echocardiography is often indicated.1 One potential limitation of this study was highlighted by an internal validation which showed that rates of echocardiography use were much higher at the author’s hospital than reported in NIS. For example, among patients with myocardial infarction, validation rates were 75% versus 6.3% for the NIS. Given this discrepancy, we sought to determine the accuracy of claims data, such as the NIS, for quantifying echocardiography use. We hypothesized that the International Classification Disease-9 Clinical Modification ( ICD-9 CM ) code for echocardiography (88.72) would show poor sensitivity for echocardiography use, and that actual echocardiography use rates would be higher than reported in NIS. We used the Premier Healthcare Informatics (Charlotte, NC) dataset that includes data on a geographically and structurally diverse group of hospitals from 2014 to assess inpatient echocardiography across 8 broad patient conditions for which echocardiography is commonly ordered. Unlike NIS, which reports only standard demographic data and ICD-9 procedure and …