Advances in Clinical Care with Contemporary Cardiac SPECT.

State of the art of cardiac SPECT imaging continues to advance. Contemporary clinical applications of cardiac SPECT are reviewed and illustrated. Beyond traditional stress and rest myocardial perfusion imaging, the role of digital SPECT technology, ultra low dose imaging with efficient stress first / stress only if normal imaging, deep learning algorithms relative to coronary angiography and SPECT CT, sourceless emission attenuation correction, myocardial blood flow and blood flow reserve to assess ischemic jeopardy, culprit ischemic territories, and cardiac allograft vasculopathy, advanced methods of SPECT detection of amyloid cardiomyopathy, resting MPI to define pre-operative regional scar prior to operative ablation, parametric radionuclide ventriculography to quantify dyssynchrony and benefit of biventricular pacing, assessment of treatment response of RV and LV function in patients with pulmonary hypertension, dual isotope MIBG imaging to assess cardiac risk, and the value proposition of real world effectiveness of SPECT cardiac imaging are illustrated.

Buccal caffeine strips for reversal of adverse symptoms of vasodilator stress.

BACKGROUND: Due to recurrent shortages of aminophylline, intravenous caffeine has emerged as a commonly used, safe and reliable method to treat adverse effects of vasodilator stress agents. We sought to evaluate the safety and effectiveness of buccal caffeine strips which are rapidly absorbed, inexpensive, readily available, and simplify caffeine administration. METHODS: Consecutive patients undergoing regadenoson stress SPECT MPI were assessed for the occurrence of symptoms during testing over an 11-week period at a single metropolitan hospital. Adverse symptoms, including their severity and duration, were recorded at the time of testing. Patient satisfaction was rated on a scale of 1 to 5 (5 being the most satisfied). Patients received reversal with caffeine if symptoms were felt to be significant enough by the patient and physician performing the test. The treatment received alternated week to week between IV caffeine (60 mg) or 100 mg buccal caffeine strips. Caffeine was given at least 3 minutes after tracer injection. A rescue dose of IV caffeine was offered 10 minutes later if indicated. RESULTS: Of the 122 patients enrolled in the study, 70 (57%) were included during buccal caffeine weeks and 52 (43%) during IV caffeine weeks, and only 28 (24%) received reversal with a caffeine agent. Seven (6%) received IV caffeine and 21 (17%) received buccal caffeine. There was no significant difference in symptom duration between IV and buccal caffeine after treatment (152.8 vs 163.4 seconds, P = 0.87). There was no significant difference in initial and final symptom severity between groups. Only 2 patients in the buccal group required rescue IV caffeine for ongoing symptoms and emesis. None of the IV group required a rescue dose. There was no significant difference in patient satisfaction between the groups (2.8 vs 3.2, P = 0.38). CONCLUSION: Buccal caffeine strips are a safe, well tolerated, and effective initial strategy to reverse adverse effects of vasodilator stress in the minority of patients who request it. Buccal caffeine alone or with IV rescue caffeine was highly effective in reversing adverse effects and was free of major adverse clinical events.

Aminophylline shortage and current recommendations for reversal of vasodilator stress: An ASNC information statement endorsed by SCMR.

Pharmacologic reversal of serious or intolerable side effects (SISEs) from vasodilator stress is an important safety and comfort measure for patients experiencing such effects. While typically performed using intravenous aminophylline, recurrent shortages of this agent have led to a greater need to limit its use and consider alternative agents. This information statement provides background and recommendations addressing indications for vasodilator reversal, timing of a reversal agent, incidence of observed SISE with vasodilator stress, clinical and logistical considerations for aminophylline-based reversal, and alternative non-aminophylline based reversal protocols.

Aminophylline shortage and current recommendations for reversal of vasodilator stress: an ASNC information statement endorsed by SCMR.

Pharmacologic reversal of serious or intolerable side effects (SISE) from vasodilator stress is an important safety and comfort measure for patients experiencing such effects. While typically performed using intravenous aminophylline, recurrent shortages of this agent have led to a greater need to limit its use and consider alternative agents. This information statement provides background and recommendations addressing indications for vasodilator reversal, timing of a reversal agent, incidence of observed SISE with vasodilator stress, clinical and logistical considerations for aminophylline-based reversal, and alternative non-aminophylline based reversal protocols.

Risk of Coronary Events 55 Years after Thymic Irradiation in the Hempelmann Cohort.

BACKGROUND: Studies of cancer survivors treated with older radiotherapy (RT) techniques (pre-1990s) strongly suggest that ionizing radiation to the chest increases the risk of coronary heart disease (CHD). Our goal was to evaluate the impact of more modern cardiac shielding techniques of RT on the magnitude and timing of CHD risk by studying a cohort exposed to similar levels of cardiac irradiation years ago. METHODS: Between 2004 and 2008, we re-established a population-based, longitudinal cohort of 2,657 subjects exposed to irradiation for an enlarged thymus during infancy between 1926 and 1957 and 4,388 of their non-irradiated siblings. CHD events were assessed using a mailed survey and from causes of death listed in the National Death Index. We used Poisson regression methods to compare incidence rates by irradiation status and cardiac radiation dose. Results were adjusted for the CHD risk factors of attained-age, sex, diabetes, dyslipidemia hypertension and smoking. RESULTS: Median age at time of follow-up was 57.5 years (range 41.2 - 88.8 yrs) for irradiated and non-irradiated siblings. The mean estimated cardiac dose amongst the irradiated was 1.45 Gray (range 0.17 - 20.20 Gy), with 91% receiving <3.00 Gy. During a combined 339,924 person-years of follow-up, 213 myocardial infarctions (MI) and 350 CHD events (MI, bypass surgery and angioplasty) occurred. After adjustment for attained age, gender, and other CHD risk factors, the rate ratio for MI incidence in the irradiated group was 0.98 (95%CI, 0.74 - 1.30), and for any CHD event was 1.07 (95%CI, 0.86 - 1.32). Higher radiation doses were not associated with more MIs or CHD events in this dose range, in either the crude or the adjusted analyses. CONCLUSIONS: Radiation to the heart during childhood of <3 Gy, the exposure in most of our cohort, does not increase the lifelong risk of CHD. Reducing cardiac radiation to this amount without increasing other cardiotoxic therapies may eliminate the increased CHD risk associated with radiotherapy for childhood cancer. By extension there is unlikely to be increased CHD risk from relatively higher dose imaging techniques, such as CT, because such techniques use much smaller radiation doses than received by our cohort.

Correction to: Clinical Quantification of Myocardial Blood Flow Using PET: Joint Position Paper of the SNMMI Cardiovascular Council and the ASNC.

The above position statement originally published containing errors in the author metadata; specifically, the Expert Content Reviewers-Andrew Einstein, Raymond Russell and James R. Corbett-were tagged as full authors of the paper. The article metadata has now been corrected to remove Drs. Einstein, Russell and Corbett from the author line, and the PubMed record has been updated accordingly.