Impact of Gd-153 scanning line source attenuation correction on downstream invasive testing.

BACKGROUND: Attenuation correction (AC) using hardware and software solutions has been shown to increase the specificity of SPECT MPI by decreasing false positive results and improving prognostic ability. Theoretically this should reduce downstream testing and unnecessary costs. We sought to assess the consequences of the use of Gd-153 scanning line source attenuation correction during SPECT myocardial perfusion imaging (MPI) on downstream invasive testing. METHODS: All patients who underwent a clinically indicated Tc-99m stress SPECT MPI study from 2013 to 2015 at five hospitals (2 with AC and 3 without) were retrospectively reviewed. Patient demographics, results of testing, subsequent coronary angiography within 3 months, and revascularization were recorded. The results of the MPI studies, downstream angiogram utilization, and results of angiography were compared and a propensity matched subgroup analysis was performed. RESULTS: A total of 9968 patients underwent SPECT MPI during the study time period (6106 performed with AC and 3862 without). Out of 3928 patients included in the propensity matched cohort, there was no difference in the proportion of abnormal MPI results between the two groups (31.5% vs 30.4%, P = 0.47), however, more patients underwent coronary angiography within 90 days in the AC group (10.6% vs 8.7%, P = 0.05). There was no significant difference in the proportion of patients with angiographically significant obstructive disease (53.4% vs 56.1%, P = 0.19), however, fewer patients in the AC group with obstructive coronary disease were revascularized (36.1% vs 46.8%, P = 0.04). The findings remained consistent after sub-group analysis in patients without known coronary disease. CONCLUSION: The use of scanning line source AC did not meaningfully influence the rate of abnormal MPI results or downstream invasive testing in this cohort. The clinical utility of scanning line source AC may be limited to facilitating stress-first imaging protocols.

SPECT myocardial perfusion imaging in liver transplantation candidates.

BACKGROUND: The optimal cardiovascular evaluation prior to liver transplantation remains controversial and includes stress echocardiography, stress MPI, cardiac CTA, and coronary angiography. This study summarizes our experience of the past decade using SPECT MPI in patients with end-stage liver disease, including patient characteristics, stress testing protocols, test results, the need for repeat testing, and downstream testing. METHODS: All patients who underwent a clinically indicated stress SPECT MPI study as part of their pre-liver transplant evaluation from 2004 to 2014 were reviewed from the Nuclear Cardiology database. Results of perfusion imaging, repeat testing, subsequent angiography, and need for revascularization were reviewed. RESULTS: A total of 2500 patients were referred for SPECT MPI, of those 111 had known CAD and 271 underwent more than one MPI study. Compared to other patients undergoing stress MPI, pre-liver transplant patients were younger, had fewer cardiac risk factors and lower prevalence of prior cardiac history, and used pharmacologic stress more often. During the study decade, patient age increased, prevalence of hypertension increased and smoking decreased, prevalence of known CAD increased, and the number of abnormal studies decreased. Abnormal perfusion results were present in 7.8% of pre-liver transplant patients compared to 34.3% of all other patients. In a multivariate model, age and lower ejection fraction were associated with an abnormal MPI result. Of the 64 patients who underwent subsequent invasive or non-invasive coronary angiography after an abnormal MPI, obstructive CAD was diagnosed in 25 patients (1.0%), non-obstructive CAD was diagnosed in 23 patients (0.9%), and normal coronaries found in 16 patients (0.6%); a total of 18 (0.7%) of these underwent coronary revascularization. The average time to repeat testing was 27.2 ± 17.9 months. In a multivariate model, younger age and exercise stress were associated with repeat testing. In only 17 patients out of 271 with a normal initial perfusion, the repeat study became abnormal. The use of stress-first imaging was successful in 80% of patients with a reduction in Tc-99m dose from 39.1 to 18.3 mCi. CONCLUSION: Abnormal SPECT MPI results in candidates for liver transplantation are infrequent compared to non-liver transplant patients and the incidence of obstructive CAD on subsequent angiography even less. Repeat testing in those on the transplant waiting list after initial normal test results appears to be of limited value. Stress-first protocols may be considered for the majority of these patients to reduce testing time and radiation exposure.

Do ICD diagnostics predict failure of ventricular tachycardia response to antitachycardia pacing and need for shock?

BACKGROUND: Among heart failure patients with implantable cardioverter defibrillators (ICDs), monomorphic ventricular tachycardia (MMVT) failing antitachycardia pacing (ATP) and terminated by shock renders higher mortality as compared to MMVT terminated by ATP only. It is unknown if the higher mortality in ATP failure reflects decompensated heart failure. OBJECTIVE: It was the purpose of the present study to determine if ICD heart failure diagnostics can predict the failure of ATP and the need to shock to terminate MMVT. METHODS: This was a single-center retrospective review of 103 consecutive patients with Medtronic ICDs who had MMVT and received ICD therapy. Heart failure diagnostics preceding each MMVT event were reviewed including atrial fibrillation burden, patient activity, night heart rate, heart rate variability, Optivol® fluid index, and MMVT heart rate. RESULTS: A total of 452 MMVT events were analyzed, of which 23% required shock. Compared to MMVT that responded to ATP, MMVT that failed ATP and required shock had significantly faster heart rates and higher atrial fibrillation burden. Patient activity, night heart rate, heart rate variability, and OptiVol® fluid index were similar between ATP responsive MMVT events and those that failed ATP. In a multivariate analysis adjusting for baseline characteristics, higher atrial fibrillation burden and lower patient activity were associated with ATP failure and shock termination. CONCLUSION: Device diagnostics associated with decompensated heart failure identified MMVT events that failed ATP and necessitated shock.

Selexipag, an Oral Prostacyclin-Receptor Agonist for Pulmonary Arterial Hypertension.

OBJECTIVE: To evaluate the data supporting the approval of selexipag and discuss its potential place in therapy for managing pulmonary arterial hypertension (PAH). DATA SOURCES: A systematic review of the literature for all relevant articles was performed through January 16, 2017, using MEDLINE and SCOPUS. A manual search of references from reports of clinical trials, review articles, and recent conference abstracts was performed to identify additional relevant studies. STUDY SELECTION AND DATA EXTRACTION: Eligible citations included in vitro or in vivo evaluations of selexipag, with no restrictions on patient population or indication. Data related to the patient populations and outcomes of interest were extracted from each citation. DATA SYNTHESIS: Single phase II and phase III trials have been published evaluating selexipag in patients with PAH. In 43 patients, the phase II trial showed that selexipag significantly reduced pulmonary vascular resistance by 30% versus placebo ( P = 0.0045) and improved 6-minute walk distance by 24 m ( P < 0.05). The larger phase III trial enrolled 1156 patients with PAH, showing that selexipag lowered the incidence of death or PAH-related complications by 40% versus placebo ( P < 0.001). Selexipag also improved 6-minute walk distance and lowered hospitalization risk. Common adverse events included headache, diarrhea, nausea, and jaw pain. CONCLUSIONS: The specific role of selexipag for managing PAH patients is unclear because of its modest efficacy, lack of mortality reduction, and cost similar to intravenous prostacyclins. Additional clinical trials exploring combination therapy as well as its role in other types of pulmonary hypertension are needed.

Acute mechanical circulatory support for cardiogenic shock in India.

Cardiogenic shock continues to have high morbidity and mortality, despite advances in the field. Temporary mechanical circulatory support (TMCS) devices, if instituted in a timely fashion, can help stabilize critically ill patients with cardiogenic shock from various aetiologies and cardiac arrest, and provide time for organ recovery or till durable support or transplantation can be achieved. Currently, several options for TMCS devices exist. In this review, we discuss indications, contraindications, characteristics of the various available devices, and important issues pertaining to their management.

The Imperfect Cytokine Storm: Severe COVID-19 With ARDS in a Patient on Durable LVAD Support.

As health systems worldwide grapple with the coronavirus disease-2019 (COVID-19) pandemic, patients with durable LVAD support represent a unique population at risk for the disease. This paper outlines the case of such a patient who developed COVID-19 complicated by a "cytokine storm" with severe acute respiratory distress syndrome and myocardial injury and describes the challenges that arose during management.

Predisposition or Protection?: COVID-19 in a Patient on LVAD Support With HIV/AIDS.

There is a desperate search to discover effective therapies against coronavirus disease-2019 (COVID-19). Patients with human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) comprise a unique population whose clinical course may provide insights into the effects of antiretroviral therapy on COVID-19. We describe the case of a patient with HIV/AIDS on left ventricular assist device support who was hospitalized and recovered from COVID-19. (Level of Difficulty: Intermediate.).

Challenges in heart transplantation during COVID-19: A single-center experience.

BACKGROUND: Orthotopic heart transplantation (OHT) recipients may be particularly vulnerable to coronavirus disease 2019 (COVID-19). OHT during the pandemic presents unique challenges in terms of feasibility and safety. METHODS: Chart review was performed for consecutive OHT recipients with COVID-19 and waitlisted patients who underwent OHT from March 1, 2020 to May 15, 2020. RESULTS: Of the approximately 400 OHT recipients followed at our institution, 22 acquired COVID-19. Clinical characteristics included median age 59 (range, 49-71) years, 14 (63.6%) were male, and median time from OHT to infection was 4.6 (2.5-20.6) years. Symptoms included fever (68.2%), gastrointestinal complaints (55%), and cough (46%). COVID-19 was severe or critical in 5 (23%). All patients had elevated inflammatory biomarkers. Immunosuppression was modified in 85% of patients. Most (n = 16, 86.4%) were hospitalized, 18% required intubation, and 14% required vasopressor support. Five patients (23%) expired. None of the patients requiring intubation survived. Five patients underwent OHT during the pandemic. They were all males, ranging from 30 to 59 years of age. Two were transplanted at United Network of Organ Sharing Status 1 or 2, 1 at Status 3, and 2 at Status 4. All were successfully discharged and are alive without allograft dysfunction or rejection. One contracted mild COVID-19 after the index hospitalization. CONCLUSION: OHT recipients with COVID-19 appear to have outcomes similar to the general population hospitalized with COVID-19. OHT during the pandemic is feasible when appropriate precautions are taken. Further study is needed to guide immunosuppression management in OHT recipients affected by COVID-19.

Left Ventricular Assist Devices 101: Shared Care for General Cardiologists and Primary Care.

Ambulatory patients with a left ventricular assist device (LVAD) are increasing in number, and so is their life expectancy. Thus, there is an increasing need for care of these patients by non-LVAD specialists, such as providers in the emergency department, urgent care centers, community-based hospitals, outpatient clinics, etc. Non-LVAD specialists will increasingly come across LVAD patients and should be equipped with the knowledge and skills to provide initial assessment and management for these complex patients. These encounters may be for LVAD-related or unrelated issues. However, there are limited data and guidelines to assist non-LVAD specialists in caring for these complex patients. The aim of our review, targeting primary care providers (both inpatient and outpatient), general cardiologists, and other providers is to describe the current status of durable LVAD therapy in adults, patient selection, management strategies, complications and to summarize current outcome data.