Cardiac imaging for the assessment of patients being evaluated for kidney transplantation.

Cardiac risk assessment before kidney transplantation has become widely accepted. However, the optimal patient selection and screening tool for cardiac assessment remain controversial. Clinicians face several challenges in this process, including the ever-growing pre-transplant population, aging transplant candidates, increasing prevalence of coronary artery disease, and scarcity of donor organs. Optimizing the cardiovascular risk profile in kidney transplant candidates is necessary to better appropriate limited donor organs and improve patient outcomes. Increasing waiting times from the initial evaluation for transplant candidacy to the actual transplant raises questions regarding re-testing and re-stratification of risk. In this review, we summarize and discuss the current literature on cardiac evaluation prior to kidney transplantation. We also propose simple evidence-based evaluation algorithms for initial and follow-up CAD surveillance in patients being wait-listed for kidney transplantation.

Cardiac imaging for the assessment of patients being evaluated for liver transplantation.

Cardiac risk assessment prior to liver transplantation has become widely accepted. With the emergence of nonalcoholic steatohepatitis among the leading causes of end-stage liver disease and the steady rise of the age of liver transplant recipients, the burden of cardiovascular diseases has markedly increased in this population. Selecting appropriate liver transplant candidates is crucial due to the increasing demand for scarce donor organs. The use of noninvasive cardiac imaging for pre-operative assessment of the cardiovascular status of liver transplant recipients has been on the rise, yet the optimal assessment strategy remains an area of active debate. In this review, we examine the relevant literature pertaining to the diagnostic and prognostic applications of noninvasive cardiac imaging in this population. We also propose a simple literature-based evaluation algorithm for CAD surveillance in liver transplant candidates.

Right ventricle assessment in patients with pulmonary embolism at low risk for death based on clinical models: an individual patient data meta-analysis.

AIMS: Patients with acute pulmonary embolism (PE) at low risk for short-term death are candidates for home treatment or short-hospital stay. We aimed at determining whether the assessment of right ventricle dysfunction (RVD) or elevated troponin improves identification of low-risk patients over clinical models alone. METHODS AND RESULTS: Individual patient data meta-analysis of studies assessing the relationship between RVD or elevated troponin and short-term mortality in patients with acute PE at low risk for death based on clinical models (Pulmonary Embolism Severity Index, simplified Pulmonary Embolism Severity Index or Hestia). The primary study outcome was short-term death defined as death occurring in hospital or within 30 days. Individual data of 5010 low-risk patients from 18 studies were pooled. Short-term mortality was 0.7% [95% confidence interval (CI) 0.4-1.3]. RVD at echocardiography, computed tomography or B-type natriuretic peptide (BNP)/N-terminal pro BNP (NT-proBNP) was associated with increased risk for short-term death (1.5 vs. 0.3%; OR 4.81, 95% CI 1.98-11.68), death within 3 months (1.6 vs. 0.4%; OR 4.03, 95% CI 2.01-8.08), and PE-related death (1.1 vs. 0.04%; OR 22.9, 95% CI 2.89-181). Elevated troponin was associated with short-term death (OR 2.78, 95% CI 1.06-7.26) and death within 3 months (OR 3.68, 95% CI 1.75-7.74). CONCLUSION: RVD assessed by echocardiography, computed tomography, or elevated BNP/NT-proBNP levels and increased troponin are associated with short-term death in patients with acute PE at low risk based on clinical models. RVD assessment, mainly by BNP/NT-proBNP or echocardiography, should be considered to improve identification of low-risk patients that may be candidates for outpatient management or short hospital stay.

How well do we represent ourselves: an analysis of cardiology fellowships website content.

Background: The Internet is the primary source of information for prospective cardiology fellowship aspirants. The objective of this study was to evaluate cardiology fellowship programs' online profile. Materials & methods: Two independent reviewers accessed 221 US based cardiology fellowship program websites obtained through Fellowship and Residency Electronic Interactive Database for pre-selected 20 criteria. The update status of websites was assessed using 6-point criteria. Results: Only 25 (11.3%) websites were fully up-to-date; 23 (10.4%) fulfilled 80% of the 20-point criteria and 85 (38.5%) program websites had fewer than 50% of the criteria listed. Conclusion: Most cardiology fellowship program websites lack crucial details. In this technology driven age, efforts should be made to ensure updated websites.

Impact of chronic thrombocytopenia on in-hospital outcomes and healthcare resource utilization after transcatheter aortic valve replacement.

BACKGROUND: There is little data on the impact of chronic thrombocytopenia (CTP) on outcomes after transcatheter aortic valve repair (TAVR). Most studies are from single centers and mostly focused on postprocedure thrombocytopenia. OBJECTIVES: This study sought to report on the impact of CTP (>1 year) on in-hospital outcomes and healthcare resource utilization after TAVR. METHODS: From the National Inpatient Sample (NIS) between 2012 and 2015, we identified patients with CTP who underwent TAVR. A 1:1 propensity-matched cohort was created to examine in-hospital outcomes in patients with and without CTP. The primary outcome was in-hospital mortality. Secondary outcomes included postprocedure complications, length of stay, total cost, and discharge disposition. RESULTS: A matched pair of 4,300 patients with and without CTP were identified. Patients with CTP had higher in-hospital mortality as compared to no CTP patients (6.0 vs. 3.3%, p-value .007), increased postprocedure hemorrhage, platelet and blood transfusion, vascular complications, postop sepsis, and acute kidney injury. With regards to resource utilization, CTP patients had a longer length of stay, higher total cost and were more likely to be discharged to a facility (34.1 vs. 27.6%) other than home (All, p-value <.001). Subanalysis, however, revealed this difference in resource utilization was seen when patients developed postprocedure complications. CONCLUSION: This study demonstrated higher risk of in-hospital mortality, perioperative complications, and healthcare resource utilization in patients with baseline CTP undergoing TAVR. Further studies are required to investigate ways to improve the management of these patients.

Assessment of myocardial viability using single-photon emission computed tomography myocardial perfusion imaging.

PURPOSE OF REVIEW: The assessment of myocardial viability continues to be a pressing and sometimes challenging clinical question. Among other imaging modalities proven to be useful in the assessment of myocardial viability, single-photon emission computed tomography (SPECT) instrumentation and expertise continue to be the most widely available to the practicing physicians. Understanding the utility of SPECT myocardial perfusion imaging in this domain is an enduring need. RECENT FINDINGS: A wealth of basic science and clinical data established the value of a variety of Tl-201 and Tc-99m SPECT protocols in the assessment of myocardial viability. The diagnostic performance for Tl-201 and Tc-99m imaging protocols for identifying viable myocardium is very good and is comparable for both agents. Quantitative assessment of radiotracer uptake can predict, in an objective manner, the probability of recovery of myocardial function following revascularization. SUMMARY: SPECT myocardial perfusion imaging with Tl-201 and Tc-99m tracers can provide an objective and quantifiable assessment of myocardial viability, which can help predict the likelihood of myocardial function recovery following coronary revascularization. Effective application of this imaging technique can guide clinical decision-making for coronary revascularization.

The long-term prognostic value of highly sensitive cardiac troponin I in patients with acute pulmonary embolism.

BACKGROUND: In patients with acute pulmonary embolism (PE), detectable levels of cardiac troponin I (cTnI) using a highly sensitive assay have been associated with increased in-hospital mortality. We sought to investigate the impact of detectable cTnI on long-term survival following acute PE. HYPOTHESIS: Detectable cTnI levels in patients presenting with acute PE predict increased long-term mortality following hospital discharge. METHODS: In a retrospective cohort study, we analyzed consecutive patients with confirmed acute PE and cTnI assay available from the index hospitalization. The detectable cTnI level was ≥0.012 ng/mL. Patients were classified into low and high clinical risk groups according to the Pulmonary Embolism Severity Index (PESI) at presentation. Subjects were followed for all-cause mortality subsequent to hospital discharge using chart review and Social Security Death Index. RESULTS: A cohort of 289 acute PE patients (mean age 56 years, 51% men), of whom 152 (53%) had a detectable cTnI, was followed for a mean of 3.1 ± 1.8 years after hospital discharge. A total of 71 deaths were observed; 44 (29%) and 27 (20%) in the detectable and undetectable cTnI groups, respectively (P = 0.05). Detectable cTnI was predictive of long-term survival among low-risk (P = 0.009) but not high-risk patients (P = 0.78) who had high mortality rates irrespective of cTnI status. CONCLUSIONS: In patients with acute PE, detectable cTnI is predictive of long-term mortality, particularly among patients who were identified as low risk according to PESI score.

Impact of insurance carrier, prior authorization, and socioeconomic status on appropriate use of SPECT myocardial perfusion imaging in private community-based office practice.

BACKGROUND: The impact of health insurance carrier and socioeconomic status (SES) on the adherence to appropriate use criteria (AUC) for radionuclide myocardial perfusion imaging (MPI) is unknown. HYPOTHESIS: Health insurance carrier's prior authorization and patient's SES impact adherence to AUC for MPI in a fee-for-service setting. METHODS: We conducted a prospective cohort study of 1511 consecutive patients who underwent outpatient MPI in a multi-site, office-based, fee-for-service setting. The patients were stratified according to the 2009 AUC into appropriate/uncertain appropriateness and inappropriate use groups. Insurance status was categorized as Medicare (does not require prior authorization) vs commercial (requires prior authorization). Socioeconomic status was determined by the median household income in the ZIP code of residence. RESULTS: The proportion of patients with Medicare was 33% vs 67% with commercial insurance. The rate of inappropriate use was higher among patients with commercial insurance vs Medicare (55% vs 24%; P < 0.001); this difference was not significant after adjusting for confounders known to impact AUC determination (odds ratio: 1.06, 95% confidence interval: 0.62-1.82, P = 0.82). The mean annual household income in the residential areas of patients with inappropriate use as compared to those with appropriate/uncertain use was $72 000 ± 21 000 vs $68 000 ± 20 000, respectively (P < 0.001). After adjusting for covariates known to impact AUC determination, SES (top vs bottom quartile income area) was not independently predictive of inappropriate MPI use (odds ratio: 0.9, 95% confidence interval: 0.53-1.52, P = 0.69). CONCLUSIONS: Insurance carriers prior authorization and SES do not seem to play a significant role in determining physicians adherence to AUC for MPI.

Effective risk stratification of patients on the basis of myocardial perfusion SPECT is dependent on appropriate patient selection.

Myocardial perfusion imaging (MPI) with single-photon emission computed tomography (SPECT) is commonly used in risk assessment, as an abnormal scan predicts a multifold increase in cardiac risk. Recent studies have showed that application of the appropriate use criteria (AUC) sharpens the prognostic value of SPECT-MPI, while inappropriate use is clinically ineffective and may lead to unnecessary downstream invasive testing and revascularization procedures. In this review, we will discuss recent literature examining the impact of appropriate use on the prognostic value of SPECT-MPI and downstream decision-making. We will also discuss the implications of appropriate use on cost-effectiveness of MPI.

Cardiac imaging for the assessment of patients being evaluated for kidney or liver transplantation.

Cardiac risk assessment prior to kidney and liver transplantation is controversial. Given the paucity of available organs, selecting appropriate recipients with favorable short- and long-term cardiovascular risk profile is crucial. Using noninvasive cardiac imaging tools to guide cardiovascular risk assessment and management can also be challenging and controversial. In this article, we address the burden of coronary artery disease among kidney and liver transplant candidates and review the literature pertaining to the diagnostic accuracy and the prognostic value of noninvasive cardiac imaging techniques in this population.

Feasibility of intercity and trans-Atlantic telerobotic remote ultrasound: assessment facilitated by a nondedicated bandwidth connection.

We discuss the concept of ultrasound imaging at a distance by presenting the evaluation of a customized, lightweight, human-safe robotic arm for low-force, long-distance, telerobotic ultrasonography. We undertook intercity and trans-Atlantic telerobotic ultrasound simulation from master stations located in New York, New York and Munich, Germany, and imaged a phantom and a human volunteer located at a slave station in Burlington, Massachusetts, using standard Internet bandwidth <100 Mbps and <50 Mbps, respectively. The data from the robotic arm were tracked for understanding the time efficiency of the human interactions at the master stations. Comparison of a beginner in ultrasound operation with a professional sonographer revealed that although proficiency in using ultrasound was not a prerequisite for operating the robotic arm, previous experience in using clinical ultrasound was associated with progressively lower probe maneuvering time and speed due to an enhanced ability of the veteran operator in adjusting the finer angular motions of the probe. These results suggest that long-distance telerobotic echocardiography over a local nondedicated Internet bandwidth is feasible and can be rapidly learned by sonographers for cost-effective resource utilization.

The prognostic value of cardiac SPECT performed at the primary care physician's office.

BACKGROUND: The prognostic value of single-photon emission computed-tomography (SPECT)-myocardial perfusion imaging (MPI) is well documented. However, the utility of SPECT-MPI when performed at a low-volume primary care physician's (PCP's) office is unknown. METHODS: We conducted a prospective cohort study of consecutive patients referred by their PCP to undergo a stress-MPI at the PCP's office using a mobile laboratory. Major adverse cardiovascular events (MACE) of death, myocardial infarction (MI), and coronary revascularization were prospectively tabulated using mail and telephone interviews, chart review, and social security death index. RESULTS: One thousand three hundred ninety subjects [mean age 58 ± 13 years; 44% women] were followed for 27 ± 9 months, with a 99% complete follow-up rate. Subjects with abnormal MPI [174 (12.5%)] had significantly higher rates of all-cause mortality [5.2% vs 1.0%, P < .001], death, or MI [5.7% vs 1.5%, P = .001], and the composite of death, MI, or late revascularization (>60 days post-MPI) [12.6 vs 2.7%, P < .001]. Overall MACE risk was associated with the total perfusion abnormality burden, while the revascularization rate was related to the reversible perfusion abnormality burden. CONCLUSION: Contemporary SPECT-MPI performed in the setting of a PCP's office carries a robust prognostic value, similar to that reported in tertiary or large-volume practice settings.