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

Exploring the impact of recent COVID-19 infection on perfusion and functional parameters derived from gated myocardial perfusion imaging in patients undergoing evaluation for coronary artery disease

OBJECTIVE

This study seeks to evaluate how recent COVID-19 infection affects myocardial perfusion and functional parameters derived from gated myocardial perfusion imaging in patients undergoing evaluation for coronary artery disease. The goal is to enhance our understanding of COVID-19's influence on the cardiovascular system.

METHOD

Conducted at Farshchian Heart Hospital from 2022 to 2023, this case-control study enrolled patients suspected of coronary artery disease, stratified into two groups: those with confirmed COVID-19 infection within the past 6 months (study group) and those without prior COVID-19 infection (control group). Employing a 2-day protocol, stress testing and gated SPECT MPI were performed. Statistical analysis included descriptive statistics, Chi-square test, Student's t test, and Mann-Whitney U test.

RESULT

Among the 86 patients included, 43 were in each group. Significantly higher summed stress core and summed difference score values were observed in the study group compared to the control group (p < 0.05). In addition, the study group exhibited significantly altered global left ventricular ejection fraction, end-diastolic volume, and end-systolic volume (p < 0.05). Non-perfusion findings, including transient ischemic dilation and transient right ventricular visualization, were more prevalent in the study group.

CONCLUSION

Recent COVID-19 infection is associated with impaired myocardial perfusion and altered functional parameters as detected by MPI. These findings underscore the intricate interplay between COVID-19 and cardiovascular health, emphasizing the importance of comprehensive evaluation and management strategies to address cardiac complications in affected individuals. Further research is warranted to elucidate the underlying mechanisms and optimize patient care in the context of COVID-19-associated cardiovascular manifestations.

Novel Cardiovascular and Pulmonary Findings in the Noninvasive Ischemic Assessment of Patients With Coronavirus 2019 (COVID-19)

In the past several years, the coronavirus pandemic has introduced multiple medical disciplines to various new forms of disease previously unknown and has shown us a unique presentation of already existing diseases. We continue to understand the long-term effects of the pandemic on the population's health and continue to find new unique features previously unknown. This paper presents the unique feature of lung uptake abnormalities discovered on nuclear stress testing for cardiac perfusion defects, a consistent finding in multiple individuals with recent COVID-19 or ongoing infection.

The role of myocardial perfusion imaging in predicting myocardial ischemia in patients diagnosed with long COVID

OBJECTIVE

Incomplete recovery with long-term complications weeks beyond the acute coronavirus disease 2019 (COVID-19) infection is referred to as long COVID. Among the well-known long-term complications of COVID-19, myocardial damage is a frequently encountered side effect. Yet there is a lack of data for identifying high-risk patients who are more likely to develop long-term cardiovascular complications following COVID-19. Myocardial perfusion imaging (MPI) is the primary functional imaging modality in evaluating myocardial ischemia This study aimed to investigate the role of MPI in predicting myocardial ischemia in patients diagnosed with long COVID.

METHODS

Subjects were selected from eligible long COVID patients and control subjects without a prior history of COVID-19 who were referred to the nuclear medicine department for stress and rest single-photon emission computed tomography (SPECT) MPI. All participants' past medical records and clinical, and demographic characteristics were scanned. In addition, patients undergoing coronary angiography (CAG) following SPECT MPI were documented and patients with critical coronary stenosis were identified.

RESULTS

Our results revealed that long COVID patients had higher rates of abnormal summed stress scores compared to the control subjects (p < 0.05). Additionally, serum CRP level, SPECT lung-to-heart ratio (LHR), and the presence of long COVID were independent predictors of ischemia. The presence of long COVID was the best predictor of ischemia among the aforementioned parameters (p < 0.001).

CONCLUSION

Our data indicate that SPECT MPI provides comprehensive information on myocardial perfusion and left ventricular function in long COVID patients.

SPECT and PET myocardial perfusion imaging in Austria, Germany, and Switzerland results of the first joint survey of 2021

PURPOSE

This paper presents the results of the first joint survey on the use of SPECT and PET myocardial perfusion imaging (MPI) and cardiac amyloidosis imaging in Austria, Germany, and Switzerland of the year 2021.

METHODS

A questionnaire was sent in 2022 to centres practicing nuclear medicine.

RESULTS

Data from 14 Austrian (10,710 SPECT), 218 German (133,047 SPECT), and 16 Swiss centres (11,601 MPI (6,879 SPECT, 4722 PET)) were analysed. In Austria and Germany, the PET MPI numbers were close to zero and not considered. Official MPS numbers from 2015 to 2021 from Austria and Germany revealed a decline in Austria by about 40% in the pandemic years 2020 to 2021, but an increase in Germany by 9%. Ambulatory care cardiologists represented the major referral group (56-71%). Mostly, stress tests were performed pharmacologically (58-92%). Contrary to Germany, a 1-day protocol was predominant (58-97%) in Austria and Switzerland. The leading camera systems were SPECT-CT in Austria and Switzerland (57-79%) and multi-head systems in Germany (58%). Switzerland had the highest proportion of SPECT MPI with attenuation correction (84%), followed by Austria (43%), and Germany (33%). Electrocardiogram-gated SPECT MPI showed an overall high penetration of 87-99%. Scoring was most frequently applied in Germany (72%), followed by Austria (64%), and Switzerland (60%). Related to the population, the number of cardiac amyloidosis imaging was highest in Austria, followed by Switzerland and Germany.

CONCLUSIONS

This first joint survey of 2021 shows considerable differences among the countries. The Swiss situation is outstanding due to the wide use of PET MPI. In terms of camera equipment, Switzerland is also leading, followed by Austria and Germany. Despite the differences in procedural issues, the results reveal an overall high standard of MPI imaging.

Myocardial Perfusion SPECT and ATTR imaging 2021 in Germany: Results of the 9th Survey

AIM

This paper presents the results of the 9th survey of myocardial perfusion SPECT (MPS) from the reporting year 2021.

METHODS

218 questionnaires (131 practices (PR), 58 hospitals (HO), 29 university hospitals (UH)) were evaluated. Results of the last survey 2018 are set in squared brackets.

RESULTS

MPS data from a total of 133,057 [145,930] patients (-8.8%) with 131,868 [143,707] stress and 106,546 [121,899] rest MPS were analysed. A comparison with official data revealed that 54% all MPS were recorded. From 2018 to 2021, official data showed a every year an increase in MPS numbers. On average, 610 [502] MPS patients (+22%) were examined in each department. 74% [69%] of the responders reported an increase or no changes in their MPS patient numbers. Ambulatory care cardiologists represented as always, the mayor referral group (68% [69%]). For the first time, pharmacological stress was more frequently applied than ergometry (42% [51]). Regadenoson was mostly used. The use of the different protocols remained nearly unchanged. Two-day protocols were predominantly applied (49% [48%]). A shift from multi-headed cameras (58% [72%]) to SPECT-CT systems (24% [17%]) was found. Attenuation correction was performed in 33% [26%] of all MPS. 88% [86%] of all stress, 88% [87%] of all rest and 87% [83%] of all stress and rest MPS were acquired as gated SPECT. 72% [67%] of all departments performed scoring by default. The number of departments without scoring decreased to 13% [16%].

CONCLUSIONS

The MPS Study 2021 shows that the long-term positive development of MPS imaging in Germany is continuing. The COVID-19 pandemia did not change this trend. The procedural and technical details of MPS imaging reveal a high level of guideline conformity.

Myocardial perfusion SPECT in Germany from 2012 to 2021: insights into development and quality indicators

PURPOSE

This paper summarises the results of 4 national surveys on the numbers, utilisation and technique of myocardial perfusion SPECT (MPS) from 2012 to 2021.

METHODS

A one-page questionnaire for information on MPS in 2012, 2015, 2018 and 2021 was sent to German centres practising nuclear medicine. To check for representativeness, the numbers obtained were related to official annual data and furthermore to the numbers of invasive coronary angiography procedures (ICA).

RESULTS

MPS examinations increased by > 40% from 2012 to 2021 and showed a centralisation with increasing MPS per centre. In 2020, a mild impact of the COVID-19 pandemic could be observed in the form of only a slight MPS increase, which was compensated in the following year. Outpatient care cardiologists represent the most important referrer (70%). Mostly, 2-day protocols were used. One-day protocols and stress-only protocols showed insignificant changes. The use of exercise stress decreased steadily. In 2021, exercise stress was replaced by pharmacological stress as the most frequent stress modality. Camera systems showed a shift to more SPECT-CT systems. The use of gated SPECT increased to almost 90%. Quantitative scoring showed an increasing acceptance. The ratio of invasive coronary angiographies (ICA) to MPS was between 3.9 and 4.5. A significant proportion of ICA in the context of CCS (chronic coronary syndrome) was performed without prior testing for ischaemia.

CONCLUSION

The 2012 to 2021 MPS surveys reveal a continuously growing number of examinations with only a mild temporary effect of the COVID-19 pandemic and a centralisation with increasing numbers per centre. Performance and technical data reveal a high-grade adherence of MPS practice to the current ESC guideline. A large potential of non-invasive diagnostics remains for the future.

Myocardial perfusion imaging in the era of COVID-19: a systematic review

PURPOSE

As COVID-19 was uncovered, it became evident that specific individuals could experience multi-organ complications for quite a while after infection. Among them, there were several cardiovascular complications. Myocardial perfusion imaging single photon emission computed tomography (MPI SPECT) can be utilized to detect and evaluate cardiac problems regardless of whether COVID caused them. By examining all publications relevant to the impacts of the pandemic on SPECT MPI imaging, we aimed to understand how the COVID pandemic affected different aspects of the MPI, how intense these effects were, and what the consequences were.

METHOD

On the 6th of June, 2022, a four-domain search strategy was developed and implemented by searching the following databases: PubMed, SCOPUS, EMBASE, Web of Science, and the Cochrane Central Register of Controlled Trials. The retrieved records have been put through two levels of screening. The search for forward and backward citations provided more results.

RESULTS

This study contained 32 papers, divided into the following three categories: 1. Case reports and series; 2. A comparison of the number of MPIs conducted before and after the pandemic; and 3. SPECT MPI findings.

CONCLUSION

We observed through the article review that CT scans performed in combination with MPI are crucial and should be interpreted within the context of COVID, especially during outbreaks. Moreover, we discovered that in the initial months of the pandemic, the number of SPECT MPIs performed globally decreased, with the fall being more significant in some countries, primarily in low- to middle-income regions. Lastly, we found that individuals with a history of COVID-19 may be more prone to having MPIs that demonstrate abnormalities, such as ischemia.

Impact of the COVID-19 pandemic on the use of myocardial perfusion imaging for the assessment of coronary artery disease: a Brazilian experience

This study sought to evaluate the influence of the COVID-19 pandemic on the use of MPI for the assessment of CAD in a Nuclear Cardiology laboratory in Rio de Janeiro, Brazil. The frequency of abnormal MPI, as well as the proportion of tests with ischemia or fibrosis were not significantly different among the groups.  Abnormal MPI tests pre-lockdown was 204 and the number during lockdown - 8, the percentage of “missing” abnormal tests was of 81%. The logistic regression analysis showed that age (OR=11.4, p&lt;0.001), the presence of at least 1 cardiac risk factor (OR=4.4, p=0.036), and known CAD (OR=5.27, p=0.02) were independent. Predictors of the performance of MPI during the lockdown period, with an inverse association with age (β= -0.053). This study reinforces the perception that in current days, and possibly for a long time, there should be continued surveillance over CAD incidence and manifestations, due to potentially missed diagnoses secondary to the COVID-19 pandemic.

The collateral damage of COVID-19 to cardiovascular services: a meta-analysis

AIMS

The effect of the COVID-19 pandemic on care and outcomes across non-COVID-19 cardiovascular (CV) diseases is unknown. A systematic review and meta-analysis was performed to quantify the effect and investigate for variation by CV disease, geographic region, country income classification and the time course of the pandemic.

METHODS AND RESULTS

From January 2019 to December 2021, Medline and Embase databases were searched for observational studies comparing a pandemic and pre-pandemic period with relation to CV disease hospitalisations, diagnostic and interventional procedures, outpatient consultations, and mortality. Observational data were synthesised by incidence rate ratios (IRR) and risk ratios (RR) for binary outcomes and weighted mean differences for continuous outcomes with 95% confidence intervals. The study was registered with PROSPERO (CRD42021265930). A total of 158 studies, covering 49 countries and 6 continents, were used for quantitative synthesis. Most studies (80%) reported information for high-income countries (HICs). Across all CV disease and geographies there were fewer hospitalisations, diagnostic and interventional procedures, and outpatient consultations during the pandemic. By meta-regression, in low-middle income countries (LMICs) compared to HICs the decline in ST-segment elevation myocardial infarction (STEMI) hospitalisations (RR 0.79, 95% confidence interval [CI] 0.66-0.94) and revascularisation (RR 0.73, 95% CI 0.62-0.87) was more severe. In LMICs, but not HICs, in-hospital mortality increased for STEMI (RR 1.22, 95% CI 1.10-1.37) and heart failure (RR 1.08, 95% CI 1.04-1.12). The magnitude of decline in hospitalisations for CV diseases did not differ between the first and second wave.

CONCLUSIONS

There was substantial global collateral CV damage during the COVID-19 pandemic with disparity in severity by country income classification.

The Impact of the COVID-19 Pandemic on Hospital Services for Patients with Cardiac Diseases: A Scoping Review

This study aims to assess the impact of the COVID-19 pandemic on hospital cardiac care, as assessed by performance indicators. Scoping review methodology: performance indicators were extracted to inform on changes in care during January–June 2020. Database searches yielded 6277 articles, of which 838 met the inclusion criteria. After full-text screening, 94 articles were included and 1637 indicators were retrieved. Most of the indicators that provided information on changes in the number of admissions (n = 118, 88%) signaled a decrease in admissions; 88% (n = 15) of the indicators showed patients’ delayed presentation and 40% (n = 54) showed patients in a worse clinical condition. A reduction in diagnostic and treatment procedures was signaled by 95% (n = 18) and 81% (n = 64) of the indicators, respectively. Length of stay decreased in 58% (n = 21) of the indicators, acute coronary syndromes treatment times increased in 61% (n = 65) of the indicators, and outpatient activity decreased in 94% (n = 17) of the indicators related to outpatient care. Telehealth utilization increased in 100% (n = 6). Outcomes worsened in 40% (n = 35) of the indicators, and mortality rates increased in 52% (n = 31). All phases of the pathway were affected. This information could support the planning of care during the ongoing pandemic and in future events.

Noninvasive Imaging for Patients with COVID-19 and Acute Chest Pain

Acute chest pain is a common presentation in patients with COVID-19. Although noninvasive cardiac imaging modalities continue to be important cornerstones of management, the pandemic has brought forth difficult and unprecedented challenges in the provision of timely care while ensuring the safety of patients and providers. Clinical practice has adapted to these challenges, with several recommendations and societal guidelines emerging on the appropriate use of imaging modalities. In this review, we summarize the current evidence base on the use of noninvasive cardiac imaging modalities in COVID-19 patients with acute chest pain, with a focus on acute coronary syndromes.

Impact of COVID-19 infection on short-term outcome in patients referred to stress myocardial perfusion imaging

PURPOSE

We assessed the impact of COVID-19 infection on cardiovascular events in patients with suspected or known coronary artery disease (CAD) referred to stress single-photon emission computed tomography myocardial perfusion imaging (MPS).

METHODS

A total of 960 consecutive patients with suspected or known CAD were submitted by referring physicians to stress MPS for assessment of myocardial ischemia between January 2018 and June 2019. All patients underwent stress-optional rest MPS. Perfusion defects were quantitated as % of LV myocardium and expressed as total perfusion defect (TPD), representing the defect extent and severity. A TPD ≥ 5% was considered abnormal.

RESULTS

During a mean follow-up of 27 months (range 4-38) 31 events occurred. Moreover, 55 (6%) patients had a COVID-19 infection. The median time from index MPS to COVID-19 infection was 16 months (range 6-24). At Cox multivariable analysis, abnormal MPS and COVID-19 infection resulted as independent predictors of events. There were no significant differences in annualized event rate in COVID-19 patients with or without abnormal MPS (p = 0.56). Differently, in patients without COVID-19, the presence of abnormal MPS was associated with higher event rate (p < .001). Patients with infection compared to those without had a higher event rate in the presence of both normal and abnormal TPD.

CONCLUSION

In patients with suspected or known CAD, the presence of COVID-19 infection during a short-term follow-up was associated with a higher rate of cardiovascular events.

Myocardial perfusion SPECT findings in postCOVID period

PURPOSE

To investigate if (i) the risk of ischemia on myocardial perfusion scan (MPS), (ii) number of coronary angiographies (CAG) performed, and (iii) necessity for invasive (stent implantation or coronary artery bypass grafting (CABG)) or medical treatment increased in patients infected with COVID-19.

METHODS

Patients who were referred to MPS between August 2020 and April 2021 with a history of active symptomatic COVID-19 infection (confirmed by PCR positivity) in the last 6 months were involved in the study group. Age-and gender-matched control group was composed of randomly chosen patients who attended for MPS between January 2019 and September 2019, before pandemic. Frequency of ischemia, CAG, and invasive or medical treatments were compared between groups.

RESULTS

Ischemia was reported more frequently in the study group (p < 0.001). In clinical evaluation, regardless of the MPS results, the necessity for invasive evaluation with CAG and treatment (either medical therapy or invasive interventions) was higher in the study group (p = 0.006 and p = 0.015). It was also true for patients with abnormal MPS results (p = 0.008 and p = 0.024) but not for the patients with ischemia (p = 0.29 and p = 0.06).

CONCLUSION

There exists a significant increase in the frequency of ischemia on MPS, undergoing CAG, stent implantation or CABG, and initiation of medical therapy in patients with a history of COVID-19 infection in the last 6 months. MPS is a reliable method in patients who present with cardiovascular symptoms in the late COVID period.

A comprehensive review of imaging findings in COVID-19 - status in early 2021

Medical imaging methods are assuming a greater role in the workup of patients with COVID-19, mainly in relation to the primary manifestation of pulmonary disease and the tissue distribution of the angiotensin-converting-enzyme 2 (ACE 2) receptor. However, the field is so new that no consensus view has emerged guiding clinical decisions to employ imaging procedures such as radiography, computer tomography (CT), positron emission tomography (PET), and magnetic resonance imaging, and in what measure the risk of exposure of staff to possible infection could be justified by the knowledge gained. The insensitivity of current RT-PCR methods for positive diagnosis is part of the rationale for resorting to imaging procedures. While CT is more sensitive than genetic testing in hospitalized patients, positive findings of ground glass opacities depend on the disease stage. There is sparse reporting on PET/CT with [18F]-FDG in COVID-19, but available results are congruent with the earlier literature on viral pneumonias. There is a high incidence of cerebral findings in COVID-19, and likewise evidence of gastrointestinal involvement. Artificial intelligence, notably machine learning is emerging as an effective method for diagnostic image analysis, with performance in the discriminative diagnosis of diagnosis of COVID-19 pneumonia comparable to that of human practitioners.

Prevalence of abnormal SPECT myocardial perfusion imaging during the COVID-19 pandemic

Purpose

The aim of this study is to evaluate the rate of abnormal myocardial perfusion imaging (MPI) studies at a single medical center during the COVID-19 pandemic compared to prior to the pandemic.

Methods

We retrospectively studied stress single-photon emission computed tomography (SPECT)-MPI studies performed during the peak of COVID-19 restrictions at the University of Alabama Medical Center in comparison to the same time period in 2019.

Results

SPECT-MPI volume was reduced from 553 per month in 2019 to 105 per month in 2020. The proportion of abnormal SPECT-MPI for the 2020 cohort (61 ± 13 years, 48% men, 41% black) was not different from the 2019 cohort (62 ± 12 years, 48% men, 42% black) (31% vs. 27%, p = 0.4). Similar proportion of patients in the 2 cohorts had abnormal myocardial perfusion, moderate-large perfusion defects, myocardial ischemia, myocardial scar, and abnormal left ventricular ejection fraction. The proportion of abnormal SPECT-MPIs was not different based on whether patients were evaluated face-to-face or by telemedicine (28% vs. 27%, p > 0.9) but was higher for cardiology providers (40% vs. 20%, p < 0.001).

Conclusions

There was a significant reduction in the number of SPECT-MPI studies performed during the peak restrictions from the pandemic. Despite this restriction, the rate of abnormal studies remained stable. Our study suggests that it remains difficult to predict which patients will have abnormal SPECT-MPI even when providers and stress laboratories are forced to prioritize the performance of studies to high-yield patients.

Cardiac magnetic resonance imaging during the COVID-19 pandemic: A southern Italian single-center experience

Purpose

We aimed to assess the impact of COVID-19 pandemic on cardiac magnetic resonance (CMR) imaging studies performed during the lockdown imposed by the Italian Government from March 2020 to May 2020.

Materials and method

We reviewed the number and the findings of CMR scans performed during the COVID-19 pandemic between March and May 2020 at University of Naples Federico II. The number and the findings of CMR studies acquired in the corresponding months of 2017, 2018 and 2019 were also assessed for direct comparison.

Results

A total of 117 CMR studies was considered, including the procedures performed during the pandemic (n = 18) and those performed in the corresponding months of the prior 3 years (n = 99). The number of CMR studies performed during the COVID-19 pandemic was significantly (P < .01) lower compared to the mean number (n = 33) of the procedures performed in the corresponding months of 2017-2019. The percentage of abnormal CMR studies was similar (P = 0.73) during the pandemic (67 %) compared to that found in the corresponding months of 2017-2019 (70 %) suggesting that many abnormal tests were missed due to the lockdown.

Conclusion

The number of CMR studies was significantly reduced during the COVID-19 pandemic compared to the corresponding period of the previous three years. The lack of difference in the prevalence of abnormal CMR studies between the two study time intervals strongly suggests that many patients with potentially abnormal imaging test have been missed during the pandemic.