About MyoStrain® Accuracy

Daniel Lenihan, MD
“It’s one thing to detect the problem; it’s another to manage it better. So, that’s the real frontier that we want to tackle. We don’t just want to identify a problem; you want to manage it better so that these patient scan still get the best cancer therapy that they may be eligible for, [and] at the same time, protect their heart over the course of this treatment.” 

[Reference] How cardiovascular magnetic resonance may help cancer patients. ESC Council Webinar. 2020.

"MyoStrain is the first test that provides physicians with the inherent visibility to monitor the effects of cardiotoxicity from cancer therapy and promote the use of cardio-protective drugs on the heart. This is a game-changing technology that could revolutionize how we carefully monitor patients undergoing cancer treatment.”

[Reference] New PROACT Study to Evaluate MyoStrain in the Detection & Management of Cardiotoxicity in Cancer Patients

“MyoStrain provides a way to follow chemotherapy patients, identifying those that are beginning to develop toxicity and…give them medication that will hopefully improve their cardiac reserve and you see a responsive change on the MRI measurements.”

[Reference] Global Cardio-Oncology Summit 2018.

Sebastian Kelle, MD, PhD
“The Congress has been very successful in creating awareness for MyoStrain, which could become the new standard in cardiac function testing in patients with risks of heart failure. Its speed, ease and accuracy makes the test very patient-centric. Patients want to have an accurate functional assessment of their heart."

[Reference] Hauptstadt Congress 2019.

“This new sensitive cardiac function test (MyoStrain) potentially opens numerous unmet markets because the test could be used not only to quantify early cardiac dysfunction but also in aiding physicians to manage drug therapies. Over time, recurring testing enables physicians to understand the effects of therapies to individualize care.”

[Reference] Myocardial Solutions Receives FDA 510(k) Clearance for MyoStrain

“MyoStrain provides a quantitative, single-heartbeat MRI test that allows us to detect patient heart risk without radiation or contrast injections, and may therefore offer a proactive, patient-centric tool to effectively detect and manage patients at risk of heart failure.”

[Reference] Korosoglou G, et al. J Am Coll Cardiol Cardiovasc Imaging. Jan 13, 2021. DOI: 10.1016/j.jcmg.2020.10.024

Grigorios Korosoglou, MD
"Through its progressive curve, MyoStrain helps clinicians to not only determine a patient’s risk of developing heart failure, but to individualize care as well by monitoring the effectiveness of treatment on the patient overtime. This may allow clinicians to focus on preventing the progression of heart dysfunction early on for improved clinical outcomes and quality of life for patients.”

[Reference] Steen H, et al. J Cardiovasc Magn Reson23, 45(2021). https://doi.org/10.1186/s12968-021-00711-w

“MyoStrain was able to both identify and classify cardiac risk in patients who did not exhibit any cardiovascular symptoms and where traditional metrics could not. These are substantial findings that could profoundly impact the standard of care in cardiology and cardio-oncology.”

[Reference] Korosoglou G, et al. J Am Coll Cardiol Cardiovasc Imaging. Jan 13, 2021. DOI: 10.1016/j.jcmg.2020.10.024

Susan Dent, MD
“MyoStrain bridges a crucial gap in oncology and cardiology care. Thanks to the advances in oncology care, cancer is more treatable now than ever before. While clinical outcomes for cancer patients have improved, there is increasing concern about the potential short- and long-term side effects of these treatments, including the potentially detrimental impact they may have on the heart."

[Reference] Guisca S, et al. Circulation. 2021;14:e012459

“The cases I have shown you today, I think, clearly show that MyoStrain certainly may help oncologists in clinical decision making…hopefully, as further information comes into practice, we will be able to use this technology to help us make decisions around the delivery of cancer care safely to our patients”

[Reference] Virtual Cardio-Oncology Summit 2020.

Teresa López-Fernández, MD
“With MyoHealth, we are able to minimize the scan time and minimize the analysis time…This new cardiac MRI technique allows us to better implement cardiac MRI in our daily practice”

[Reference] Virtual Cardio-Oncology Summit 2020.

Henning Steen, MD, PhD
"Utilizing [MyoStrain] measurements in clinical practice could aid physicians in identifying individual patients who potentially benefit from proactive cardioprotective therapy even before the onset of cardiotoxicity."

[Reference] Geršak B, et al. Predicting the severity of subclinical chemotherapy-induced cardiotoxicity using Fast-SENC segmental myocardial strain— An interim report (NCT03543228). (SCMR 2019).

“[MyoStrain] could be a paradigm shift in imaging for MRI, so that we have the tools to risk stratify asymptomatic patients and also the progression of [dysfunction] measurements.”

[Reference] MyoStrain Detects Early Subclinical Pathological Intramyocardial Dysfunction ahead of Current Imaging Modalities (Hamburg Registry)

“MyoStrain offers the visibility needed to help clinicians assess early asymptomatic dysfunction in our patients. It uses a unique and highly sensitive technique to acquire segmental strain, which provides us both the ability to detect and subsequently categorize these patients into risk groups based on the individual patterns and severity of their dysfunction.”

[Reference] Steen H, et al. J Cardiovasc Magn Reson 23, 45(2021). https://doi.org/10.1186/s12968-021-00711-w

“MyoStrain can divide patients into healthy patients, at-risk patients, pre-heart failure and heart failure patients based on the percentage of normal myocardium segments.”

[Reference] Global Cardio-Oncology Summit 2018.

“[MyoStrain has] good reproducibility, excellent applicability, segmental circumferential data that is not captured by echocardiograms, very fast, simple CMR protocols, you can do four patients per hour, very sensitive to myocardial deformation and changes, no contrast agents, arrhythmia independent and vendor independent.”

[Reference] Global Cardio-Oncology Summit 2018.

“Door to door, from when the patient enters the facility to when he/she leaves, it takes 22 minutes. So with less than 15 minutes of scan time, you can do four patients per hour."

[Reference] Global Cardio-Oncology Summit 2018.

“MyoStrain [detects] the reduction of circumferential and longitudinal strain when feature tracking does not.”

[Reference] Global Cardio-Oncology Summit 2018.

Deborah Kwon, MD
"[MyoStrain] holds promise for identifying patients early in their myocardial disease trajectory who are at risk for declining contractility over time and may benefit from early therapeutic intervention."

[Reference] Cardiac MRI: 7 New and Emerging Developments to Be Aware Of. Cleveland Clinic. 2021.

Marco Ochs, MD
"The hyperventilation/breath-hold maneuver combined with MyoStrain/MyoStress provides a fast and safe scan procedure for clinicians to assess their patients without needing contrast agents or pharma stressors. The result is a 15-minute, needle-free MyoStress test designed to help advance ischemia detection, improve workflow efficiency and enhance the overall patient experience.”

[Reference] Ochs M, et al. J Am Coll Cardiol Cardiovasc Imaging. Apr 14, 2021. DOI: 10.1016/j.jcmg.2021.02.022

Valentina Püntmann, MD
“Prior to cancer-related treatment, Cardiac MRI is helping us in recognizing pre-existing conditions, risk assessment of patients, and also guiding prevention of patients at risk of heart failure during or post-CR-treatment.  For this we need standardized, accurate and validated tools, allowing us to detect small differences on the individual basis. MyoStrain is an excellent candidate to deliver this."

[Reference] How cardiovascular magnetic resonance may help cancer patients. ESC Council Webinar. 2020.

Matthias Friedrich, MD
“There are numerous limitations concerning the safety, feasibility, logistical effort, and speed with today’s stress testing techniques. We adapted the hyperventilation/breath-hold maneuver with MyoStrain to help overcome these limitations, providing a fast, safe and non-invasive approach to improve the cardiovascular assessment of patients suspected of coronary artery disease. This is a huge step.”

[Reference] Ochs M, et al. J Am Coll Cardiol Cardiovasc Imaging. Apr 14, 2021. DOI: 10.1016/j.jcmg.2021.02.022

Lauren Baldassarre, MD
"MyoStrain is a promising technology to help ensure cardiac health in patients receiving potentially cardio-toxic cancer therapies.”

[Reference] New PROACT Study to Evaluate MyoStrain in the Detection & Management of Cardiotoxicity in Cancer Patients

“MyoStrain has the potential to overcome the barriers of cardiac MRI availability and complexity."

[Reference] Global Cardio-Oncology Summit 2018.

Amit Patel, MD
“Changes in circumferential and longitudinal strain during intermediate-dose dobutamine infusion by [MyoStrain] can unmask CAD prior to the development of any quantifiable alteration in wall thickening by cine-CMR”

[Reference] Kawaji K, et al.  Detection of regional wall motion changes that precedes wall thickening using Strain-Encoded (SENC) CMR with intermediate-dose Dobutamine stress. SCMR 2019. (n=29)

Ronald Mikolich, MD
“The ability to evaluate progression of LV strain abnormalities with [MyoStrain] may help identify changes in LV function before the onset of a reduction in LVEF and development of heart failure”

[Reference] Kulifay S, et al. Detection of Sub-clinical Left Ventricular Dysfunction in Obese Patients. AHA Scientific Sessions 2018.

“The ability to identify and quantify abnormal left ventricular GLS and GCS with [MyoStrain] also opens the door to assess any benefit of therapy, including diet, exercise and bariatric surgery”

[Reference] Kulifay S, et al. Detection of Sub-clinical Left Ventricular Dysfunction in Obese Patients. AHA Scientific Sessions 2018.

What is Strain?

“Strain” in everyday language can mean “stretching” and it is used to describe “deformation” (D’Hooge 2000). The MyoStrain report will show the amount of strain (deformation) for 37 segments of the left ventricle and 11 segments of the right ventricle. The value of each segment is calculated by taking the average of “peak strain” of each of the pixels within that segment.

In a heathy heart, the wall will deform well as it goes through cardiac cycle; however, in an unhealthy heart, the heart wall might be stiffer and not move or “deform” as much. Or even worse, the muscle can be so weak that the wall bulges out instead of compressing as the heart goes into systolic phase. The strain numbers are negative because we are measuring compression of the myocardium. A lower strain number indicates more compression of the given region of the myocardium.

MyoStrain Strain Scale

More information regarding the strain legend used in the MyoStrain program can be found from the following papers:

Neizel M, et al. “Strain-encoded MRI for evaluation of left ventricular function and transmurality in acute myocardial infarction.” Circ Cardiovasc Imaging. 2009;2(2):116-122 View Publication >>

Wong DT, et al. “Magnetic resonance-derived circumferential strain provides a superior and incremental assessment of improvement in contractile function in patients early after ST-segment elevation myocardial infarction.” European Radiology. 2014;24:1219-1228. View Publication >>

Oyama-Manabe N, et al. “Identification and further differentiation of subendocardial and transmural myocardial infarction by fast strain-encoded (SENC) magnetic resonance imaging at 3.0 Tesla” European Radiology. 2011;21(11):2362-2368. View Publication >>

Neizel M, et al. “Impact of Systolic and Diastolic Deformation Indexes Assessed by Strain-Encoded Imaging to Predict Persistent Severe Myocardial Dysfunction in Patients After Acute Myocardial Infarction at Follow-Up.” Journal of the American College of Cardiology. 2010;56:1056-1062. View Publication >>

Choi E-Y, et al. “Prognostic value of myocardial circumferential strain for incident heart failure and cardiovascular events in asymptomatic individuals: the Multi-Ethnic Study of Atherosclerosis.” European Heart Journal. 2013;34:2354-2361. View Publication >>

Koos R, et al. “Layer-specific strain-encoded MRI for the evaluation of left ventricular function and infarct transmurality in patients with chronic coronary artery disease.” Int J Cardiol. 2013;166:85-89. View Publication >>

American Heart Association (AHA) MODEL

The AHA models used in MyoStrain are derived from the following publication:

Cerqueira et al., “Standardize Myocardial Segmentation and Nomenclature for Tomographic Imaging of the Heart,” Circulation, 2002;105:539-542 View Publication >>

Traditional Global Measurements

Normal Ranges of MyoStrain Measurements

The output of the SENC images post-processing is a report that shows various measurements.  One set of measurements is the traditional global measurements (ejection fraction, chamber volumes and masses).

These measurements are presented with the normal ranges published by Zhan et al.¹ The other set is the strain measurements (circumferential and longitudinal) presented with the normal ranges of strains as published by Neizel et al.²

Traditional Global measurements (LVEF and indexed LVEDV, LVESV, LVSV and LV Mass):

1. Y. Zhan et al., “Derivation of consolidated normal reference values for right and left ventricular quantification by cardiac magnetic resonance using a novel meta-analytic approach,” Journal of Cardiovascular Magnetic Resonance, vol. 18, no. 1, p. O75, 2016/01/27 2016 View Publication >>

Strain (circumferential and longitudinal):

2. M Neizel  et al. “Strain-encoded MRI for evaluation of left ventricular function and transmurality in acute myocardial infarction.” Circ Cardiovasc Imaging. 2009;2(2):116-122. View Publication >>

Accuracy of MyoStrain Traditional Global Measurements

The accuracy of MyoStrain measurements are determined by the Limit of Agreement (LOA).  The LOA is the range that covers the 95% of differences between the measurement of the two devices.  For example, if MyoStrain measures LVEF of 67%, the LOA of (-13,+10) means that 95% for a large number LVEF values of the same subject measured using the gold standard Cine MRI will lie between 54% and 77%.  The LOA depends on many factors, including images quality and inter-operator and inter-observer variabilities.  This LOA was originally based on two predicate devices (Diagnosoft HARP for Strain, Diagnosoft VIRTUE for traditional measurements), however these ranges have been reduced to reflect measured accuracy in MyoStrain.

To demonstrate the accuracy of MyoStrain measurements, we calculated the correlation coefficients using Diagnosoft VIRTUE 5.51 measurements of the LV EF, End-Diastolic Volume (EDV), End-Systolic Volume (ESV), Mass, and Stroke Volume (SV).  We considered the measurements accurate by requiring that the variations in global measurements due to workstation and user variability to be within the accepted cutoffs of published guidelines and clinical results.  We specified that targeted correlation coefficients of the global measures generated by MyoStrain, in comparison to the gold standard cardiac MRI, must be equal or better than the following:  EF:  R=0.79, p

Since the LV Mass is similar to LV volumes, we decided that the R and p values follow the same criteria for EDV.  Our acceptance criteria required the following bounds for the 95% range of measurements differences between MyoStrain and Diagnosoft VIRTUE:

  • LVEF: (-20,+20)
  • LVEDV: (-45,+45)
  • LVESV: (-25,+25)
  • LVSV: (-40, +40)
  • LVMass: (-35, +35)

Based on a sample size N=23 of healthy subjects and patients, MyoStrain demonstrated the following acceptable LOA:

  • LVEF: (-13,+10)
  • LVEDV: (-40,+35)
  • LVESV: (-19,+21)
  • LVSV: (-36,+29)
  • LVMass: (-19,+30)

The Bland-Altman Graphs of these calculations can be seen below:

Bland-Altman Graph of LVEF
Bland-Altman Graph of LV Mass
Bland-Altman Graph of LVEDV
Bland-Altman Graph of LVESV
Bland-Altman Graph of SV

The LOA and accuracy of Strain calculations were based on tests using a mechanical phantom with known actual strain values.  Phantom analysis demonstrated that MyoStrain has the acceptable LOA of (-5,+5). Note that LOA of MyoStrain of Strain measured in vivo in humans is unknown and could be different.