The Role of Cardiac PET in Diagnosis and Prognosis of Ischemic Heart Disease: Optimal Modality Across Different Patient Populations.

PURPOSE OF REVIEW: Despite single-photon emission computerized tomography (SPECT) being the most used nuclear imaging technique for diagnosis of coronary artery disease (CAD), many now consider positron emission tomography (PET) as a superior modality. This review will focus on the advances of cardiac PET in recent years and its advantages compared to SPECT in diagnosis and prognosis of CAD. RECENT FINDINGS: PET's higher resolution and enhanced diagnostic accuracy, as well as lower radiation exposure, all help explain the rationale for its wider spread and use. PET also allows for measurement of myocardial blood flow (MBF) and myocardial flow reserve (MFR), which aids in several different clinical scenarios, such as diagnosing multivessel disease or identifying non-responders. PET has also been shown to be useful in diagnosing CAD in various specific populations, such as patients with prior COVID-19 infection, cardiac transplant, and other comorbidities.

The effect of coronavirus disease 2019 pneumonia on myocardial ischemia detected by single-photon emission computed tomography myocardial perfusion imaging.

OBJECTIVE: We aimed to examine the effects of COVID-19 pneumonia on cardiac ischemia detected by myocardial perfusion imaging with single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) in patients presenting with chest pain and shortness of breath after recovery from COVID-19. MATERIALS AND METHOD: Patients with a history of COVID-19 confirmed by reverse transcriptase-PCR test who underwent SPECT-MPI for the evaluation of ischemia with the complaints of chest pain and shortness of breath were screened for this study. Patients who underwent thorax CT during the acute period of the COVID-19 were included. Patients with and without pneumonia were determined based on computed tomographic criteria. The patients with a summed stress score of at least 4 on SPECT-MPI were considered to have abnormal MPI in terms of ischemia. RESULTS: A total of 266 patients were included in the study. Sixty-five (24%) patients had ischemia findings on SPECT-MPI. Thorax CT showed pneumonia in 152 (57%) patients, and the patients were divided into two groups as pneumonia and nonpneumonia. Abnormal SPECT-MPI scores, which represented myocardial ischemia, were higher in the pneumonia group. Multivariate logistic regression analyses showed that the presence of hyperlipidemia and pneumonia on CT increased the risk of ischemia on SPECT-MPI (OR, 2.08; 95% CI, 1.08-3.99; P-value = 0.029; and OR, 2.90; 95% Cl, 1.52-5.54; P-value = 0.001, respectively). CONCLUSION: COVID-19 pneumonia was identified as an independent predictor of ischemia on SPECT-MPI. Symptoms including chest pain and shortness of breath in patients who have had COVID-19 pneumonia may be attributed to coronary ischemia.

SPECT myocardial perfusion imaging identifies myocardial ischemia in patients with a history of COVID-19 without coronary artery disease.

We aimed to examine the effect of a history of COVID-19 on myocardial ischemia in single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) in patients who presented with shortness of breath and/or chest pain after recovery. For this single-center retrospective study, patients who presented at cardiology outpatient clinics and had SPECT-MPI were screened. A total of 1888 patients were included in the study, 340 of whom had a history of COVID-19. 64 patients with > 50% stenosis on coronary angiography were excluded from the study. The primary outcome of the study was abnormal MPI. In the study population, the median age was 56 (49-64 IQR) years, and 1127 (65%) of the patients were female. Abnormal MPI was detected in 77 patients (23%) in the COVID-19 group and in 244 patients (16%) in the non-COVID-19 group. After adjustment was performed for clinical predictors using Bayesian logistic regression, an important association was found between the presence of a confirmed prior COVID-19 infection and abnormal MPI (posterior median odds ratio, 1.70 [95% CrI, 1.20-2.40], risk difference, 9.6% [95% CrI, 1.8%, 19.7%]). In SPECT-MPI, ischemia rates were observed to be higher in COVID-19 group and it was found that a confirmed prior COVID-19 might predict of abnormal MPI.

Quantifying and reporting cardiac findings in imaging of COVID-19 patients.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection continues to be a public health emergency and a pandemic of international concern. As of April 31st,  the reported cases of COVID-19 are three million in 186 countries. Reported case fatality has crossed 200 thousand among which more than fifty thousand has been in the USA. Most patients present with symptoms of fever, cough, and shortness of breath following exposure to other COVID-19 patients. Respiratory manifestations predominate in patients with mild, moderate, severe illness. Imaging of patients with COVID-19 consistently reports various pulmonary parenchymal involvement. In this article we wanted to reinforce and review the various reported imaging patterns of cardiac and mediastinal involvement in COVID-19 patients. Among patients with COVID 19 who underwent various imaging of chest various cardiac findings including pericardial effusion, myocarditis, cardiomegaly has been reported. Most of these findings have been consistently reported in patients with significant acute myocardial injury, and fulminant myocarditis. Acute biventricular dysfunction has also been reported with subsequent improvement of the same following clinical improvement. Details of cardiac MRI is rather limited. In a patient with clinical presentation of acute myocarditis, biventricular myocardial interstitial edema, diffuse biventricular hypokinesia, increased ventricular wall thickness, and severe LV dysfunction has been reported. Among patients with significant clinical improvement in LV structure and function has also been documented. With increasing number of clinical cases, future imaging studies will be instrumental in identifying the various cardiac manifestations, and their relation to clinical outcome.

Effects of the COVID-19 pandemic on myocardial perfusion imaging for ischemic heart disease.

PURPOSE: We assessed the effects of the COVID-19 pandemic on myocardial perfusion imaging (MPI) for ischemic heart disease during the lockdown imposed by the Italian Government. METHODS: We retrospectively reviewed the number and the findings of stress single-photon emission computed tomography (SPECT)-MPI performed between February and May 2020 during the COVID-19 pandemic at the University of Napoli Federico II. The number and the findings of stress SPECT-MPI studies acquired in the corresponding months of the years 2017, 2018, and 2019 were also evaluated for direct comparison. RESULTS: The number of stress SPECT-MPI studies performed during the COVID-19 pandemic (n = 123) was significantly lower (P < 0.0001) compared with the mean yearly number of procedures performed in the corresponding months of the years 2017, 2018, and 2019 (n = 413). Yet, the percentage of abnormal stress SPECT-MPI studies was similar (P = 0.65) during the pandemic (36%) compared with the mean percentage value of the corresponding period of the years 2017, 2018, and 2019 (34%). CONCLUSION: The number of stress SPECT-MPI studies was significantly reduced during the COVID-19 pandemic compared with the corresponding months of the previous 3 years. The lack of difference in the prevalence of abnormal SPECT-MPI studies between the two study periods strongly suggests that many patients with potentially abnormal imaging test have been missed during the pandemic.

Safety measures and clinical outcome of Nuclear Cardiology Department during Covid-19 lockdown pandemic: Northern Italy experience.

BACKGROUND: The Covid-19 pandemic led to a complete renewal of clinical activities of Italian hospitals. During the lockdown, all hospitals in Italy had to suspend non-urgent clinical activities. The prolonged suspension of elective activities could have caused a series of problems. METHODS: A new ad hoc protocol was designed. Single-day fast-imaging protocol with regadenoson-stress 99mTc-tetrofosmin imaging was preferred. Patients were contacted by phone 4 days before the test and answered to a questionnaire which will be repeated on the day of the exam. Body temperature <37.5 degrees C and no Covid-19 symptoms were necessary to enter the unit. Patients wore surgical mask and gloves. Social distancing was maintained throughout the examination. Healthcare professionals wore a personal protective equipment. RESULTS: A total of 46 patients were studied from April 7 to May 15, 2020, before the publication of the recommendations from ASNC and SNMMI. None of the patients experienced complications. Follow-up of patients discharged was carried by phone. No Covid-19 infection symptoms were reported. On May 18, 2020 all the healthcare providers of nuclear cardiology department underwent serological testing IgG and IgM and none were positive. CONCLUSION: Strict ad hoc hygiene protocol for Covid-19 pandemic avoids diagnostic-therapeutic delay and lengthening of waiting lists. Our experience confirms that pursuing WHO recommendations and recent indication of ASNC and SNMMI is safe for both health providers and patients. Moreover, the incidence of significant inducible ischemia rises when correct stratification of patients is performed.