Efficiency of tetrofosmin versus sestamibi achieved through shorter injection-to-imaging times: A systematic review of the literature.

Based on superior image quality, more accurate gated images, and lower radiation exposure to patients, Technetium-99m (Tc-99m) based tracers are preferred over Thallium-201 for SPECT myocardial perfusion imaging. The two Tc-99m tracers, sestamibi and tetrofosmin, have many similar characteristics but there are differences in blood and liver clearance rates, as well as the recommended time after injection for imaging to achieve optimal image quality. Because published peer-reviewed studies examining optimal times between injection and imaging are limited, it can be difficult to identify evidence-based opportunities to optimize imaging protocols. Using systematic literature review methods, this study was designed to identify and consolidate the available evidence on the use of sestamibi compared to tetrofosmin for variable injection to imaging times in regard to test efficiency, including test length and re-scan rates, and image quality, including overall quality and cardiac to extra-cardiac ratios. The composite of this data shows that earlier imaging with tetrofosmin is equivalent to later imaging with sestamibi when assessing subjective image quality or when quantifying heart-to-extra-cardiac ratios. Image quality and heart-to-extra-cardiac ratios comparing early versus later imaging with tetrofosmin were comparable if not equivalent to each other. The equivalency of the imaging quality occurs with 15 minutes (on average) earlier imaging compared to sestamibi and 30 minutes compared to standard time tetrofosmin. The subjective findings of equivalent image quality are also shown with objective measurements of heart-to-extra-cardiac ratios. In this review, the significantly shorter injection-to-acquisition times with tetrofosmin compared to sestamibi resulted in better efficiency and less waiting times for patients; in addition, significantly higher re-scan rates with sestamibi compared to tetrofosmin due to hepatic activity contributed to better throughput with tetrofosmin.

Proceedings of the ASNC cardiac PET summit meeting, May 12 2014, Baltimore MD : 4. Novel applications of cardiovascular PET.

While it is well recognized that cardiac PET has the ability to accurately detect myocardial ischemia and coronary blood flow, there are multiple other novel and clinically important cardiac applications of PET which are now available for the evaluation of various disease processes of the cardiovascular system. Many of these applications utilize F18-fluorodeoxyglucose (FDG), a glucose analog which is retained within cells with a high metabolic activity and which has been used extensively in nuclear medicine to evaluate oncology patients and has recently also been used to evaluate infections. This review provides an overview of some of the clinically available novel applications, Figure 1, in cardiac PET which were discussed at the American Society of Nuclear Cardiology Cardiac PET Summit, May 12, 2014. Figure 1 Novel applications of cardiac PET.

Managing the Complications of Mild Therapeutic Hypothermia in the Cardiac Arrest Patient.

Mild therapeutic hypothermia (MTH) is used to lower the core body temperature of cardiac arrest (CA) patients to 32°C from 34°C to provide improved survival and neurologic outcomes after resuscitation from in-hospital or out-of-hospital CA. Despite the improved benefits of MTH, there are potentially unforeseen complications associated during management. Although the adverse effects are transient, the clinician should be aware of the associated complications when managing the patient receiving MTH. We aim to provide the medical community comprehensive information related to the potential complications of survivors of CA receiving MTH, as it is imperative for the clinician to understand the physiologic changes that take place in the patient receiving MTH and how to prepare for them and manage them if they do occur. We hope to provide information of how to manage these potential complications through both a review of the current literature and a reflection of our own experience.

Relationship between quantitative cardiac neuronal imaging with ¹²³I-meta-iodobenzylguanidine and hospitalization in patients with heart failure.

PURPOSE: Hospitalization in patients with systolic heart failure is associated with morbidity, mortality, and cost. Myocardial sympathetic innervation, imaged by (123)I-meta-iodobenzylguanidine ((123)I-mIBG), has been associated with cardiac events in a recent multicenter study. The present analysis explored the relationship between (123)I-mIBG imaging findings and hospitalization. METHODS: Source documents from the ADMIRE-HF trial were reviewed to identify hospitalization events in patients with systolic heart failure following cardiac neuronal imaging using (123)I-mIBG. Time to hospitalization was analyzed with the Kaplan-Meier method and compared to the mIBG heart-to-mediastinum (H/M) ratio using multiple-failure Cox regression. RESULTS: During 1.4 years of median follow-up, 362 end-point hospitalizations occurred in 207 of 961 subjects, 79 % of whom had H/M ratio <1.6. Among subjects hospitalized for any cause, 88 % had H/M ratio <1.6 and subjects with H/M ratio <1.6 experienced hospitalization earlier than subjects with higher H/M ratios (log-rank p = 0.003). After adjusting for elevated brain natriuretic peptide (BNP) and time since heart failure diagnosis, a low mIBG H/M ratio was associated with cardiac-related hospitalization (HR 1.48, 95 % CI 1.05 - 2.0; p = 0.02). CONCLUSION: The mIBG H/M ratio may risk-stratify patients with heart failure for cardiac-related hospitalization, especially when used in conjunction with BNP. Further studies are warranted to examine these relationships.

Central line associated blood stream infection related to cooling catheter in cardiac arrest survivors undergoing therapeutic hypothermia by endovascular cooling.

INTRODUCTION: The risk of central line associated blood stream infections (CLABSI) related to cooling catheters used for therapeutic hypothermia (TH) is unclear. METHODS: We performed a retrospective analysis on 131 cardiac arrest survivors between 2007 and 2010, who underwent TH by femorally placed endovascular cooling catheter. All patients received prophylactic intravenous ampicillin-sulbactam for 72 hours to reduce the risk of aspiration pneumonia. Cooling catheter related CLABSI and other infections over a period of seven days from initiation of TH were estimated. RESULTS: Of a total 131 patients, 16 (12%) patients had bacteremia or infection prior to initiation of TH and were excluded. Of the remaining 115 (88%) patients, zero (0%) patients had cooling catheter related CLABSI and 23 (20%) patients had other infections during the study period. CONCLUSION: In cardiac arrest survivors undergoing TH, femorally placed endovascular cooling catheter is not associated with an increased incidence of CLABSI.

Risk stratification of CAD with SPECT-MPI in women with known estrogen status.

OBJECTIVE: To compare exercise tolerance testing (ETT) with gated single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) risk stratification in women with an intermediate to high CAD pretest risk and known estrogen status (ES). BACKGROUND: SPECT-MPI is an effective test for risk stratifying patients with stable angina. However in women, the current guidelines recommend the exercise tolerance testing (ETT) as first line test. Further, the relationship of stress imaging to ES, an independent risk indicator for CAD, is unknown. METHODS: 2,194 women with an intermediate to high CAD pre-test risk were referred for a clinically indicated ETT with gated SPECT-MPI. Duke treadmill scores (DTS) and summed stress score (SSS) were calculated. SSS were classified as normal (SSS < 3), mildly abnormal (SSS 4-8), or moderate-severely abnormal (SSS > 8). The ES was assessed as premenopausal, postmenopausal on hormone replacement therapy (HRT) as ES+ while postmenopausal not on HRT were ES-. An annualized cardiac event rate of a composite of cardiac death, unstable angina (UA) leading to hospitalization, non-fatal myocardial infarction, or late coronary revascularization was calculated for all the groups. RESULTS: The annualized cardiac event rate was 1.3% PPY, 2.1% PPY, and 3.2% PPY for low, intermediate, and high risk DTS (P = .2). Patients with intermediate DTS and mildly abnormal or moderate-severely abnormal gated SPECT-MPI had a significantly higher cardiac event rates (5.3% PPY and 10.8% PPY, respectively) than those with a normal gated SPECT-MPI (1.2%, PPY, P = .01). This was also demonstrated on further Cox-regression analysis. Risk stratification of SPECT-MPI over DTS was independent of ES. CONCLUSION: Gated SPECT-MPI provides risk stratification beyond standard exercise stress testing for women with suspected coronary artery disease, especially in patients with intermediate DTS and is independent of ES.

The impact of pulmonary hypertension on outcomes of patients with low left ventricular ejection fraction: a propensity analysis.

BACKGROUND AND AIM OF THE STUDY: Pulmonary hypertension (PH) is commonly described as a risk factor in cardiac surgery; however, the effect of a low left ventricular ejection fraction (LVEF) on PH has not been assessed. Hence, the study aim was to determine whether PH increases operative mortality and survival outcome in patients with a low LVEF. METHODS: Between January 2001 and September 2009, a total of 845 consecutive patients with LVEF < 40% was enrolled into the study. Among these patients, 444 had a pulmonary pressure < 40 mmHg (NPH group), while in 401 patients the pulmonary pressure was > or = 40 mmHg. RESULTS: Preoperatively, the PH patients were older (p < 0.001), had a lower LVEF (p = 0.001), and had a higher logistic EuroSCORE (p < 0.001) and serum creatinine level (p < 0.026) when compared to NPH patients. The PH patients showed a greater tendency to develop postoperative complications (p < 0.001). After adjusting by propensity score, the in-hospital mortality was significantly higher among PH patients (p < 0.001), while multivariate logistic regressions revealed PH as an independent predictor for in-hospital mortality (p = 0.036). The 12-, 36-, and 60-month follow up mortality rates were significantly higher in the PH group. By using a Cox logistic regression model, PH was shown to be an independent predictor for follow up mortality (p = 0.035). CONCLUSION: Pulmonary hypertension increased the morbidity and mortality in patients with a low LVEF who were undergoing cardiac surgery. Future studies may identify subgroups that may benefit from a preoperative optimization of PH and/or intra- and postoperative therapies directed at minimizing the effects of the condition.

Major adverse cardiac events among postpercutaneous coronary intervention patients on clopidogrel and proton pump inhibitors.

OBJECTIVE: To determine if concomitant use of proton pump inhibitors (PPIs) and clopidogrel is associated with adverse events among postpercutaneous coronary intervention (PCI) patients. METHODS: This is a single-center, retrospective case-control study of 3,287 consecutive patients on clopidogrel who underwent PCI. Univariate and multivariate analyses determined if concomitant PPI and clopidogrel use was associated with major adverse cardiac events (MACE). RESULTS: There were significantly more deaths (3.0% vs 1.1%; P < 0.001), repeat revascularizations (3.8% vs 2.1%; P = 0.005) and MACE (7.1% vs 3.5%; P < 0.001) in the clopidogrel and PPI group. Cox regression revealed that PPI is an independent predictor of MACE (HR 1.70, 95% CI of 1.20-2.41; P = 0.003), mortality (HR 1.79; 95% CI 1.03-3.12, P = 0.038), and target-vessel revascularization (HR 1.75; 95% CI 1.12-2.72, P = 0.014). CONCLUSIONS: Concomitant use of PPIs and clopidogrel among post PCI patients was associated with increased rates of all-cause mortality, target vessel revascularization, and combined MACE at nine months follow-up.

Medical subspecialty hospitalist programs.

Hospital medicine is the fastest growing medical specialtyin the United States. Time pressures on primary-care physicians in the office and cost pressures on hospitals are the main driving forces behind this movement. Despite initial criticism and skepticism, hospitalist programs have proven cost effective in clinical and academic departments of internal medicine. These programs have recently been used in medical subspecialty departments as well. Hartford Hospital adopted a new specialty hospitalist program in its cardiovascular department. This program grew to become one of the most successful hospitalist programs in the hospital. Since better quality of care at a lower cost is the ultimate goal for any proposed health-care innovation, we predict that similar subspecialty hospitalist programs will become an accepted part of future hospital care. This article discusses specialty hospitalist care and describes our development of such a program at Hartford Hospital.

Use of prehospital electrocardiograms for the treatment of patients with ST-segment elevation myocardial infarction.

Use of prehospital electrocardiograms (ECG) by emergency medical personnel may reduce door-to-balloon (DTB) time in patients with ST-segment elevation myocardial infarction (STEMI) referred for urgent percutaneous coronary intervention (PCI). A 79-year-old female awoke from sleep with severe substernal chest pain and called 911 for assistance. The patient was initially evaluated by advanced life support paramedics who performed a 12-lead ECG at the patient's home. The ECG, which demonstrated an acute inferior STEMI, was transferred using a novel, web-based system to Hartford Hospital's Emergency Department. As a result of prehospital communication, the on-call catheterization team was mobilized prior to the patient's arrival. The patient underwent successful PCI of an occluded right coronary artery with a DTB time of 67 minutes and was subsequently discharged four days later. Use of prehospital electrocardiography combined with early catheterization laboratory mobilization allowed for timely STEMI reperfusion according to national guidelines, despite "off-hour" presentation.

COOL-ARREST: Results from a Pilot Multicenter, Prospective, Single-Arm Observational Trial to Assess Intravascular Temperature Management in the Treatment of Cardiac Arrest.

Targeted temperature management (TTM) is recommended postcardiac arrest. The cooling method with the highest safety and efficacy is unknown. The COOL-ARREST pilot trial aimed to evaluate the safety and efficacy of the most contemporary ZOLL Thermogard XP Intravascular Temperature Management (IVTM) system for providing mild TTM postcardiac arrest. This multicenter, prospective, single-arm, observational pilot trial enrolled patients at eight U.S. hospitals between July 28, 2014, and July 24, 2015. Adult (≥18 years old), out-of-hospital cardiac arrest subjects of presumed cardiac etiology who achieved return of spontaneous circulation (ROSC) were considered for inclusion. Patients were excluded if (1) awake or consistently following commands after ROSC, (2) significant prearrest neurological dysfunction, (3) terminal illness or advanced directives precluding aggressive care, and (4) severe hemodynamic instability or shock. Patient temperature was maintained at 33.0°C ± 0.3°C for a total of 24 hours followed by controlled rewarming (0.1-0.2°C/h). Logistic regressions were used to assess association of good functional outcome (modified Rankin Scale ≤3) measured at the time of hospital discharge with shockable rhythm (yes/no), age, gender, race/ethnicity, lay-rescuer cardiopulmonary resuscitation, time to basic life support (minutes), time to ROSC (minutes), lactate (mg/dL), and pH on admission. The ZOLL IVTM system was effective at inducing TTM (median time to target temperature from initiation, 89 minutes [interquartile range 42-155]). Adverse events most often included electrolyte abnormalities and dysrhythmias. Of patients surviving to hospital discharge, 16/20 patients had a good functional outcome. A total of 18 patients survived through 90-day follow-up, at which time 94% (17/18) of patients had good functional outcome. The COOL-ARREST pilot trial demonstrates high safety and efficacy of the ZOLL Thermogard XP IVTM system in the application of mild TTM postcardiac arrest. This observational trial also revealed noteworthy variability in the management of postcardiac arrest patients, particularly with the use of early withdrawal of life-sustaining therapy.

Current Status of Patient Radiation Exposure of Cardiac Positron Emission Tomography and Single-Photon Emission Computed Tomographic Myocardial Perfusion Imaging.

BACKGROUND: Radiation exposure during nuclear cardiology procedures has received much attention and has prompted citations for radiation reduction. In 2010, the American Society of Nuclear Cardiology recommended reducing the average patient study radiation exposure to <9 mSv in 50% of studies by 2014. Cardiac positron emission tomography (PET) for myocardial perfusion imaging (MPI) has emerged within recent years, but current radiation exposure in cardiac nuclear PET laboratories is unknown. This study evaluated current reported patient radiation exposure from nuclear laboratories in the United States applying for Intersocietal Accreditation Commission accreditation for MPI using single photon emission computed tomography (SPECT) or PET. METHODS AND RESULTS: This was an analysis of nuclear cardiology studies submitted to the Intersocietal Accreditation Commission for either or both cardiac PET and SPECT accreditation. Cardiac SPECT data represented year 2015 while PET data combined years 2013 to 2015. Data was analyzed with χ2 and Mann-Whitney U tests (reported as median, 25th percentile, and 75th percentile). Reported PET MPI radiation exposure for 111 laboratories (532 patient cases) was 3.7 (3.2-4.1) mSv per study with no geographic variation. Reported SPECT MPI radiation exposure for 665 laboratories (3067 patient studies) was 12.8 (12.2-14.3) mSv. Highest radiation exposure was found in the South region. Technetium-only studies resulted in a median of 12.2 mSv per study. CONCLUSIONS: Radiation exposure from cardiac PET MPI in US laboratories applying for Intersocietal Accreditation Commission accreditation is low (111 laboratories, 3.7 mSv) and substantially lower than cardiac SPECT (665 laboratories, 12.8 mSv).

The Effects of In-Hospital Intravenous Cold Saline in Postcardiac Arrest Patients Treated with Targeted Temperature Management.

BACKGROUND: Recent data suggest that rapid infusion of intravenous (IV) cold saline for Targeted Temperature Management (TTM) after cardiac arrest is associated with higher rates of rearrest, pulmonary edema, and hypoxia, with no difference in neurologic outcomes or survival when administered by Emergency Medical Services. We sought to determine the effects of IV cold saline administration in the hospital setting in postcardiac arrest patients to achieve TTM and its effect on clinical parameters and neurologic outcomes. METHODS AND RESULTS: A cohort of 132 patients who completed TTM after cardiac arrest in a single institution was retrospectively studied. Patients who did not receive cold saline were matched by age, gender, Glasgow coma scale, downtime, and presenting rhythm to patients who received cold saline. Demographics, cardiac rearrest, diuretic use, time to target temperature, and Cerebral Performance Category (CPC) scores were recorded among other variables. Patients who received cold saline achieved target temperature sooner (280 vs. 345 minutes, p = 0.05), had lower lactate levels on day 1 (4.2 ± 3.5 mM vs. 6.0 ± 4.9 mM, p = 0.019) and day 2 (1.3 ± 2.2 mM vs. 2.2 ± 3.2 mM, p = 0.046), increased incidence of pulmonary edema (51.5% vs. 31.8%, p = 0.006), and increased diuretic utilization (63.6% vs. 42.4%, p = 0.014). There was no significant difference in cardiac rearrest, arterial oxygenation, and CPC scores (ps > 0.05). CONCLUSIONS: Infusion of IV cold saline is associated with shorter time to target temperature, increased incidence of pulmonary edema, and diuretic use, with no difference in cardiac rearrest, survival, and neurologic outcomes.

Use of bivalirudin to treat heparin-induced thrombocytopenia in a patient with idiopathic giant-cell myocarditis.

Giant-cell myocarditis (GCM) is a rare, idiopathic disorder of young adults with high rates of morbidity and mortality. We describe a unique case of giant cell myocarditis associated with heparin-induced thrombocytopenia and thrombosis syndrome (HITTS). Our patient responded to therapy with bivalirudin, but later succumbed to complications from multiorgan failure. To our knowledge, this is the first reported case of GCM associated with HITTS, which was treated with bivalirudin (Angiomax; The Medicines Company; Parsippany, NJ).

The Future of Cardiac Imaging: Report of a Think Tank Convened by the American College of Cardiology.

The American College of Cardiology's Executive Committee and Cardiovascular Imaging Section Leadership Council convened a discussion regarding the future of cardiac imaging among thought leaders in the field during a 2 day Think Tank. Participants were charged with thinking broadly about the future of imaging and developing a roadmap to address critical challenges. Key areas of discussion included: 1) how can cardiac imaging services thrive in our new world of value-based health care? 2) Who is the cardiac imager of the future and what is the role of the multimodality imager? 3) How can we nurture innovation and research in imaging? And 4) how can we maximize imaging information and optimize outcomes? This document describes the proceedings of this Think Tank.

Acid-base optimization during hypothermia.

Cardiac arrest (CA) often results in hemodynamic and metabolic compromise with associated poor prognosis. Therapeutic hypothermia (TH) has become the standard of care for CA survivors, decreasing reperfusion injury and intercellular acid-base disturbances, with improved neurologic outcomes. These benefits are realized despite a mild acidosis that can potentially occur during TH. By contrast, the severity of acidosis after return of spontaneous circulation (ROSC) must be monitored carefully and managed appropriately. Bicarbonate should be used only in case of severe acidosis and as a continuous infusion. The blood gas samples are usually warmed to 37 °C before analysis; hence, it is worth noting that the blood gas values are temperature dependent. Therefore, a calculated correction for values may be necessary.