Society for Cardiovascular Magnetic Resonance (SCMR) guidance for re-activation of cardiovascular magnetic resonance practice after peak phase of the COVID-19 pandemic

In this context, the overarching goal of this document is to provide a COVID-19 re-activation strategy specifically for CMR practices with the goal of offering CMR services in an environment which is as safe as possible for patients, technologists, physicians, and other frontline staff (Fig. 2).

Many national and local governments continue to provide guidance and regulations related to physical distancing protocols, stay-at-home and shelter-in-place orders, PPE precautions, and other regulatory matters. Moreover, local healthcare systems and hospitals are providing updated guidelines for patients, staff, and physicians who are transitioning back to more normalized healthcare delivery. The guidelines for CMR practice re-activation provided in this document are intended only as a supplement to these local governmental and health system guidelines which should be adhered to at all times.

When evaluating the appropriate timing to scale up semi-urgent and elective procedures, CMR units should consider coordinating with local and state public health and hospital system officials to review the availability of PPE for staff and patients, testing capacity, CMR facility readiness including physical distancing preparedness in reception areas, and workforce availability (including technologists, nurses, and interpreting physicians). Moreover, the needs of specific clinical services which are also re-activating should also be considered including other MRI specialties, electrophysiology, other imaging, interventional cardiology, heart failure, cardiac surgery, thoracic surgery, and vascular surgery [11]. Re-activation should proceed at a rate that appropriately balances the availability of resources with the clinical demand for CMR examinations and patient readiness.

In the recent initial COVID-19 guideline document, the SCMR classified cardiovascular imaging examinations as urgent, semi-urgent, and elective, and advised that most non-urgent exams be delayed [9]. As the first peak phase passes, semi-urgent and elective CMR examinations can begin to be scheduled. The American College of Radiology (ACR) has provided guidance on the safe resumption of non-urgent diagnostic imaging, while a consensus document from multiple North American cardiovascular societies has outlined procedures for safe re-introduction of cardiovascular services [11, 12]. According to the ESCR, cardiac imaging programs should be firstly reopened to patients with “subacute” indications that were rescheduled during the pandemic, whereas pre-operative scans may be scheduled close to the surgical procedures [7]. In general, identifying appropriate examinations and scheduling time frames should be based on shared decision making between referring providers, CMR unit physicians and staff, and patients. While this approach is always recommended, the COVID-19 specific risks associated with imaging patients, including risks to frontline healthcare workers, must be weighed against the benefit of the examination. Thus, if a patient’s risk of illness or death from delaying CMR is greater than the risk of nosocomial transmission to healthcare workers and patients, then the CMR examination should be performed in a timely fashion.

A tiered plan for re-activation based on study indication and urgency will be useful for prioritizing patients for scheduling purposes. However, in order to limit potential exposures, other considerations should also influence scheduling of CMR examinations including additional patient appointments at the same facility, the potential impact of CMR findings on timing and availability of surgical procedures, and the availability of the CMR unit team including technologists and nursing. Patients whose CMR procedures were delayed as a result of the pandemic should also be prioritized as much as possible, but it is reasonable to re-assess the appropriateness of the exam and consider the availability or recent performance of alternative diagnostic modalities given the potentially long interval since the original imaging order was placed.

Once a particular patient and indication is deemed appropriate, the optimal CMR protocol must be carefully considered to ensure successful diagnosis and minimize the likelihood of patient callbacks or other delays in interpretation. Generally, CMR studies should be tailored to answer a particular clinical question(s) with the goal of creating time-efficient protocols [13]. However, in the context of COVID19, reducing redundancy in diagnostic testing can help limit exposure, and opportunities to expand CMR protocols should be considered in a multidisciplinary fashion. A representative example is the resumption of electrophysiology ablation procedures which require pulmonary vein mapping. If CMR pulmonary vein mapping is performed, the CMR protocol may be optimized to evaluate for left atrial appendage (LAA) thrombus by including long inversion time late gadolinium enhanced (LGE) images through the LAA, or targeted, post-gadolinium balanced steady state free precession (bSSFP) cine imaging [14, 15]. These modifications could reduce the need for dedicated transesophageal echocardiography for LAA thrombus evaluation and be particularly useful at high volume institutions. Other similar protocol modifications can be considered and may include the addition of stress perfusion CMR, dedicated valvular imaging, or CMR angiography as may be appropriate in a given patient with the goal of decreasing potential overall patient and healthcare worker COVID-19 exposure.

Additional strategies to consider include the implementation of rapid imaging protocols to reduce imaging times and improve throughput. Both the Impact of Non-invasive CMR Assessment (INCA) Peru study and the Rapid Cardiovascular Magnetic Resonance for Ischemic Heart Disease Investigation (RAPID-IHD) study have demonstrated the feasibility of acquiring localizer images, short and long axis segmented bSSFP cine images, and LGE with scan times averaging less than 20 min [16, 17]. Additional sequences such as native T1 or T2 mapping could then be easily added to this protocol in appropriately selected patients.

Remote CMR image interpretation should provide the highest level of protection to CMR interpreting physicians. When this is not feasible, limiting the number of staff on site is recommended. When on site, physical distancing measures are necessary including isolated reading rooms and phone or text interactions with technologists, nurses, and other physicians is preferred.

While urgent studies may require some compromise in ideal image interpretation protocols, semi-urgent and elective imaging should only be pursued when a comprehensive interpretation is feasible. The interpreting physician should have access to necessary high-resolution screen, post-processing, 3D visualization, and cardiac functional analysis and tissue characterization software.

In patients with findings which are suspicious for COVID-19 infection including typical lung parenchymal findings [26], myocarditis [27], or pulmonary embolism [26], the ordering physician should immediately be made aware. Notification is especially important in patients who have not been diagnosed as COVID-19 positive and are likely at increased risk of spreading the disease. For cardiologist readers, suspicious extra-cardiac findings should be discussed with a cardiothoracic radiologist.

The resumption of CMR research should likely be performed using a phased approach with the overall goal for the safe and effective return to in-person research activities while adhering to local and institutional guidelines. The strategies in many cases should mirror those described above for clinical re-activation including comprehensive screening of research participants and staff, appropriate physical distancing practices and PPE utilization. Limiting the number of research staff in a specific area, such as a CMR reading room, control rooms, research offices, or laboratories at any given time is also recommended. In general, research activities should continue to be performed remotely as much as possible with in-person activities performed only as needed, making sure that equipment-cleaning measures have been defined, and the number of individuals involved in a given research visit minimized. Potential phases for return to research activities may include the initial resumption of phantom testing activities or pre-clinical animal research while adequate screening, physical distancing, and PPE protocols are being developed. Resuming human subjects research should likely focus initially on time-sensitive research studies such as clinical trials with pre-specified protocols, followed by less restrictive human subject research. Obviously, the risk of COVID-19 infection to subjects and staff should be considered when recruiting research subjects, and ideally subjects would undergo COVID-19 testing prior to imaging whenever possible. Subjects should be made aware of the safety protocols utilized by the research facility. Also, research team members should receive specific training on COVID-19 safety procedures.